CN100573870C

CN100573870C - Semiconductor device having dual-STI and manufacture method thereof

Info

Publication number: CN100573870C
Application number: CNB2005100914776A
Authority: CN
Inventors: 光平规之; 中原武彦; 铃木康介; 角野润
Original assignee: Renesas Technology Corp
Current assignee: Renesas Electronics Corp
Priority date: 2004-08-12
Filing date: 2005-08-12
Publication date: 2009-12-23
Anticipated expiration: 2025-08-12
Also published as: CN1741273A; JP2012028805A

Abstract

Semiconductor device of the present invention is the semiconductor device with memory cell area and peripheral circuit area, comprising: silicon substrate (1) and by the lip-deep component isolation structure (6a, 6b) that is made of silicon oxide film (6) that is formed on silicon substrate (1).The degree of depth (d1) of the component isolation structure of memory cell area (6a) is more shallow than the degree of depth (d2) of the component isolation structure (6b) of peripheral circuit area, and the isolation height (h2) of the isolation height (h1) of the component isolation structure of memory cell area (6a) and the component isolation structure (6b) of peripheral circuit area is roughly the same.Thus, can improve the reliability of semiconductor device.

Description

Semiconductor device having dual-STI and manufacture method thereof

Technical field

The present invention relates to semiconductor device and manufacture method thereof, particularly the semiconductor device and the manufacture method thereof of dual-STI [Dual-STI (Shallow Trench Isolation)].

Background technology

For granular and the high speed of realizing semiconductor element, must reduce the interval of isolated component.In the past, as the method that forms the element separation zone, (localoxidation of silicon: the silicon selective oxidation) method, still, this method does not also satisfy the requirement of granular generally to adopt LOCOS.Therefore, as the alternative method of this LOCOS method, used ST1 recently.

In existing STI manufacture method, at first, lamination silicon oxide film, polysilicon and silicon nitride film on Semiconductor substrate such as silicon substrate.Secondly, utilize photoetching process to form the resist that the element separation zone is carried out opening, and with it as mask, silicon oxide film, polysilicon, silicon nitride film and Semiconductor substrate are carried out anisotropic etching, thereby form ditch (trench).Secondly, after removing resist, chemical vapour deposition technique) etc. utilize HDP (high-density plasma)-CVD (ChemicalVapor Deposition: comprehensively pile up silicon oxide film, and utilize CMP (Chemical Mechanical Polishing: chemico-mechanical polishing), silicon nitride film as stoping thing to remove unnecessary silicon oxide film, is formed the STI that has imbedded silicon oxide film in the ditch.

Dynamic random access memory) etc. here, for example, (Dynamic Random Access Memory: in the semiconductor device, the isolation of memory cell area and peripheral circuit area is withstand voltage different at DRAM.That is, because that the voltage ratio that imposes on memory cell area imposes on the voltage of peripheral circuit area is little, so withstand voltage low to the isolation of the STI requirement of memory cell area.Therefore, the depth as shallow of the STI of the depth ratio peripheral circuit area of the STI by making memory cell area can reduce the occupied area of memory cell area.Like this, with the degree of depth of STI with form the difference in zone and different structure is referred to as two STI.

In the past, two STI form as following usually.At first, utilize the manufacture method of existing STI to form shallow ridges portion in memory cell area and peripheral circuit area.Secondly, memory cell area is covered, this resist and silicon nitride film as mask, are carried out anisotropic etching to Semiconductor substrate, in the shallow ridges portion of peripheral circuit area, form zanjon portion with resist.Secondly, after removing resist, pile up silicon oxide film comprehensively, and utilize CMP that silicon nitride film is removed unnecessary silicon oxide film as the prevention thing, be formed on two STI that shallow ridges portion and zanjon portion have imbedded silicon oxide film respectively.Have again, after having formed two STI, remove the silicon oxide film, polysilicon and the silicon nitride film that on silicon substrate, form.

Have again, open in the flat 5-121537 communique, disclose at the collector electrode area of isolation and formed shallow ridges portion, form the technology of zanjon portion in the element separation zone the spy.In patent documentation 1, form the width mask pattern narrower of collector electrode area of isolation than the width in element separation zone, semiconductor device is carried out etching, slow in the partially-etched speed that width is narrow.

In addition, open in the 2001-44273 communique, disclose use TEOS (TetraEthyl Ortho Silicate: the formation method of the STI of film tetraethyl orthosilicate) the spy.In patent documentation 2, lamination pad oxide-film, silicon nitride film and TEOS film on silicon substrate, the resist that will form on the TEOS film carries out etching as mask to pad oxide-film, silicon nitride film and TEOS film, remove after the resist, with the TEOS film as mask, silicon substrate is carried out etching, thereby form ditch.

In addition, at Stephen N, Keeney ' A 130nm Generation High DensityE _Tox ^TMFlash Memory Technology ', page 11.[online];＜URL:ftp: //download.intel.com/research/silicon/0.13micronflashpres. pdf〉in, record the example of the flash memory that has used two STI.

As mentioned above, the formation method of existing couple of STI adopts resist overlaying memory unit area, and this resist and silicon nitride film as mask, are carried out anisotropic etching to Semiconductor substrate, forms zanjon portion at peripheral circuit area.When forming zanjon portion, the silicon nitride film that forms on the memory cell area is covered by resist, but the silicon nitride film that is formed on peripheral circuit area is because of becoming mask when the etching, so cover without resist.Therefore, a part of silicon nitride film that is formed at peripheral circuit area is removed by anisotropic etching, and the thickness of the silicon nitride film of the Film Thickness Ratio memory cell area of the silicon nitride film of peripheral circuit area is thin.

Because the thickness of the silicon nitride film of the Film Thickness Ratio memory cell area of the silicon nitride film of peripheral circuit area is thin, so exist the problem of the reliability decrease of semiconductor device.Below, this point is described.

If the thickness of the silicon nitride film of the Film Thickness Ratio memory cell area of the silicon nitride film of peripheral circuit area is thin, then when utilizing CMP to remove silicon oxide film unnecessary on the silicon nitride film, meeting is at the residual unnecessary silicon oxide film of step part of memory cell area and peripheral circuit area boundary.Then, when removing silicon nitride film of being formed on the silicon substrate etc., residual silicon oxide film becomes mask, and silicon nitride film below the silicon oxide film or polysilicon film etc. can not be removed.As a result, cause the bad generations of element such as foreign matter, short circuit, shape defect occur, cause the reliability of semiconductor device to reduce.

In addition, because of the isolation height of STI during by CMP as the silicon nitride film decision of block film, so the isolation height of the STI of peripheral circuit area is lower than the isolation height of the STI of memory cell area.If the isolation height of the STI of peripheral circuit area is lower than the isolation height of the STI of memory cell area, when then forming the conducting film as electrode thereafter in order to form element such as transistor, the thickness difference of the etched film on the STI step.Therefore, when this film is carried out sputter, may perhaps the film of lower floor also have been removed at the residual conducting film of STI stage portion.As a result, the problem that has the reliability reduction that makes semiconductor device.

Here, open in the disclosed technology of flat 5-121537 communique, owing to come to determine uniquely the degree of depth of ditch, make the problem that zanjon portion and shallow ridges portion can be restricted in design respectively so exist according to the width of ditch the spy.In addition, owing to do not relate to isolation height, so can not address the above problem.

In addition, open in the disclosed technology of 2001-44273 communique,, can not address the above problem about the manufacturing technology of two STI of forming zanjon portion that the degree of depth has nothing in common with each other and shallow ridges portion the spy.

And then, at Stephen N, Keeney ' A 130nm Generation High DensityE _Tox ^TMFlash Memory Technology ', page 11.[online];＜URL:ftp: //download.intel.com/research/silicon/0.13microflashpres.p df〉in the disclosed technology, the element separation aspect ratio shallow ridges portion of zanjon portion is low, can not address the above problem.In addition, about solving the problem of the residual unnecessary silicon oxide film of the step part that has a common boundary at memory cell area and peripheral circuit area, any technology is not disclosed.

Summary of the invention

The object of the present invention is to provide a kind of semiconductor device and manufacture method thereof that can improve reliability.

Semiconductor device of the present invention is to have the 1st zone and the semiconductor device in the 2nd zone, comprising: silicon substrate and the component isolation structure that is made of silicon insulating film that forms on surface of silicon substrate.The component isolation structure in depth ratio the 2nd zone of the component isolation structure in the 1st zone is shallow, and the isolation height of the component isolation structure in the isolation height of the component isolation structure in the 1st zone and the 2nd zone is roughly the same.

The manufacture method of semiconductor device of the present invention is the manufacture method with the semiconductor device in the 1st zone and the 2nd zone, comprising: the operation that forms the 1st silicon insulating film on silicon substrate; The operation of formation the 1st ditch on the 1st zone and the 1st silicon insulating film in the 2nd zone and silicon substrate; The operation of formation masking layer in being formed at the 1st ditch in the 1st zone and on the 1st silicon insulating film in the 1st zone; By masking layer and silicon insulating film are carried out etching as mask to silicon substrate, thereby in the 1st ditch in the 2nd zone, form the operation of the 2nd ditch; Remove the operation of masking layer; On the 1st silicon insulating film, form the 2nd silicon insulating film to bury the operation of the 1st ditch and the 2nd ditch; Remove the 1st on silicon substrate and the 2nd silicon insulating film and in the 1st and the 2nd ditch, form the operation of component isolation structure.

Have, in this manual, ' isolation height of component isolation structure ' is meant the height of the component isolation structure of the extreme higher position from the surface of silicon substrate to the component isolation structure again.Have, when forming common grid etc. on component isolation structure, on this position, in the operation of back was handled, the height of element separation scarcely reduced again.In addition, ' degree of depth of component isolation structure ' is meant the degree of depth of the component isolation structure that the deep-seated from the surface of silicon substrate to the component isolation structure is put.

According to semiconductor device of the present invention and manufacture method thereof, because of the isolation height of the component isolation structure in the isolation height of the component isolation structure in the 1st zone and the 2nd zone roughly the same, so can improve the reliability of semiconductor device.

Below, the present invention will be described in detail with reference to the accompanying drawings, thus, and following and other purpose, feature, form and advantage that the present invention may be better understood.

Description of drawings

Fig. 1 is the profile of the semiconductor device structure of expression the invention process form 1.

Fig. 2～Fig. 8 is the profile of the manufacture method of the semiconductor device that the invention process form 1 is shown of the order according to operation.

Fig. 9～Figure 11 is the profile that the order according to operation illustrates the manufacture method of the semiconductor device when not forming silicon oxide film on silicon nitride film.

Figure 12 be illustrated in the end of component isolation structure of memory cell area residual the oblique view of state of polysilicon.

Figure 13 is the profile of the semiconductor device structure of expression the invention process form 2.

Figure 14 is the profile of manufacture method of the semiconductor device of expression the invention process form 2.

Figure 15 is the plane graph of structure of the boundary vicinity of the memory cell area of flash memory of expression the invention process form 3 and peripheral circuit area.

Figure 16 is the profile along the XVI-XVI line of Figure 15.Figure 17 is the profile along the XVII-XVII line of Figure 15.

Figure 18 is the profile along the XVIII-XVIII line of Figure 15.

Figure 19 is the profile along the XIX-XIX line of Figure 15.

Figure 20 is the profile along the XX-XX line of Figure 15.

Figure 21 is the profile along the XXI-XXI line of Figure 15.

Figure 22～Figure 28 is the profile of the manufacture method of the semiconductor device that the invention process form 3 is shown of the order according to operation.

Figure 29 is the profile of the semiconductor device when representing not to form silicon oxide film on silicon nitride film.

Figure 30 is the oblique view of the semiconductor device when representing not to form silicon oxide film on silicon nitride film.

Figure 31 is the amplification profile that has formed the state of silicide layer on the semiconductor device that is illustrated in when not forming silicon oxide film on silicon nitride film.

Figure 32 is the amplification profile that forms the state of silicide layer in semiconductor device of the invention process form 3.

Embodiment

Below, example of the present invention is described with reference to the accompanying drawings.

(example 1)

As shown in Figure 1, the semiconductor device of this example has as the memory cell area in the 1st zone with as the peripheral circuit area in the 2nd zone.The semiconductor device of this example comprises: silicon substrate 1 and a plurality of component isolation structure 6a, the 6b that form on the surface of silicon substrate 1.Surface at the silicon substrate 1 of memory cell area forms a plurality of component isolation structure 6a, forms a plurality of component isolation structure 6b on the surface of the silicon substrate 1 of peripheral circuit area.

Component isolation structure

6a, 6b are formed by silicon oxide film.The depth d 1 of component isolation structure 6a is more shallow than the depth d 2 of component isolation structure 6b.That is, the semiconductor device of this example has the structure of two STI.In the semiconductor device of this example, the isolation height h2 of the isolation height h1 of component isolation structure 6a and component isolation structure 6b is roughly the same.In addition, when when look in the plane, the furrow width of component isolation structure 6a is than the ditch width of component isolation structure 6b.

On silicon substrate 1, gate insulating film 7 is clipped in the middle and has formed for example grid 8 of transistor 9a～9g.Transistor 9a～9g is respectively by a plurality of

component isolation structure

6a, 6b electrically insulated from one another.The source region of not shown transistor 9a～9g and drain region are clipped in the middle each grid 8 of transistor 9a～9g respectively and are formed on the surface of silicon substrate 1 of both sides.Like this, the semiconductor element as transistor 9a～9g is for example isolated by a plurality of component isolation structure 6a, 6b.Have again, form the interlayer dielectric 9 that grid 8 is covered.In addition, the border of memory cell area and peripheral circuit area forms on the active region, forms as virtual pattern: in the plane memory cell area is surrounded.

Next, use Fig. 2～Fig. 8 that the manufacture method of the semiconductor device of this example is described.

At first, as shown in Figure 2, on silicon substrate 1, for example utilizing thermal oxidation to form thickness is the substrate oxide-film 2 that is made of silicon oxide film about 5～30nm.Then, on substrate oxide-film 2, for example utilizing CVD to form thickness is polysilicon film 3 about 100～300nm.Then, on polysilicon film 3, for example utilize CVD to form silicon nitride film 4.And then, on silicon nitride film 4, for example form the silicon oxide film 5 (the 1st silicon oxide film) that constitutes by the TEOS film.

Have again, in this example, show the situation that forms polysilicon film 3, but can replace polysilicon film 3 and the formation amorphous silicon film, also can not form polysilicon film 3.In addition, in this example, show the situation that forms silicon oxide film 5 by TEOS, still, if the grinding rate of CMP then also can be the silicon insulating film outside the TEOS near the isolation insulating films of imbedding in the ditch such as silicon oxide film described later.

Secondly, as shown in Figure 3, on silicon oxide film 5, form resist 20a with regulation shape.Then, resist 20a as mask, is carried out anisotropic etching to silicon oxide film 5, silicon nitride film 4, polysilicon film 3 and substrate oxide-film 2, and then, silicon substrate 1 is carried out the anisotropic etching that the degree of depth is d1, depth d 1 for example is about 100～500nm.Thus, form a plurality of

ditch

15a, 15b (the 1st ditch) on the surface of silicon substrate 1.On the surface of the silicon substrate 1 of memory cell area, form a plurality of ditch 15a, on the surface of the silicon substrate 1 of peripheral circuit area, form a plurality of ditch 15b.In addition, on silicon oxide film 5, silicon nitride film 4, polysilicon film 3 and substrate oxide-film 2, form side wall portion 17a, the 17b that is connected with each wall portion of

ditch

15a, 15b respectively.Then, remove resist 20a.

Secondly, as shown in Figure 4, form resist 20b in being formed at the ditch 15a of memory cell area and on the silicon oxide film 5 of memory cell area.Resist 20b and silicon oxide film 5 as mask, are carried out anisotropic etching to silicon substrate 1.Thus, forming the degree of depth in the ditch 15b of peripheral circuit area is the ditch 15c of d2.When silicon substrate 1 is carried out anisotropic etching, though be the etching of under only condition, carrying out silicon substrate 1,, also etched more or less as the silicon oxide film 5 of mask.As a result, the thickness t 2 of the silicon oxide film 5b of peripheral circuit area is thinner than the thickness t 1 of the silicon oxide film 5a of memory cell area.Remove resist 20b then.

Secondly, as shown in Figure 5, each inwall of

ditch

15a, 15b is carried out oxidation, utilize the plasma CVD method of HDP etc. on

silicon oxide film

5a, 5b, to form the 2nd silicon oxide film 6.Here, because be polysilicon film 3 to be carried out oxidation when the inwall to ditch 15a, 15c carries out oxidation from transverse direction, thus can increase the beak (bird ' s beak) of component isolation structure, and can improve the characteristic of component isolation structure.

Have again, in this example, show the situation that forms the 2nd silicon oxide film 6 of HDP as isolation insulating film, but also can replace the silicon oxide film of HDP and utilize silicon oxide film such as formation such as NSG (the not mixing silicide glass) coating process of etc.ing.Key is to form silicon oxide film.

Secondly, as shown in Figure 6, utilize CMP to remove silicon oxide film 5 on the silicon nitride film 4 and the 2nd unnecessary silicon oxide film 6.Thus, in

ditch

15a, 15c, form

component isolation structure

6a, 6b respectively.Form a plurality of component isolation structure 6a in memory cell area, form a plurality of component isolation structure 6b at peripheral circuit area.

Here, because the grinding rate of

silicon oxide film

5a, 5b and the grinding rate of the 2nd silicon oxide film 6 are about equally, even so the thickness t 2 of silicon oxide film 5b is thinner than the thickness t 1 of the silicon oxide film 5a of memory cell area, it is also roughly the same with the grinding rate of peripheral circuit area that memory cell forms regional grinding rate.In addition, compare with the grinding rate of the 2nd silicon oxide film 6 with

silicon oxide film

5a, 5b, the grinding rate of silicon nitride film be its about 1/300th, so silicon nitride film 4 becomes the etching block film of CMP.Thus, can remove

silicon oxide film

5a, 5b on the silicon nitride film 4 and the 2nd unnecessary silicon oxide film 6 fully.In addition, the surface of component isolation structure 6a, the 6b that exposes from the surface of silicon nitride film 4 all has roughly the same height, and identical with the apparent height of silicon nitride film 4.That is, the upper surface of the upper surface of

component isolation structure

6a, 6b and silicon nitride film 4 is in same plane basically.

Secondly, as shown in Figure 7, for example, utilize fluoric acid that wet corrosion is carried out on each surface of

component isolation structure

6a, 6b, make

component isolation structure

6a, 6b have isolation height h1, the h2 of regulation respectively.Here, because in the operation in front, the surface of

component isolation structure

6a, 6b all has roughly the same height, so behind the wet corrosion, the isolation height h2 of the isolation height h1 of component isolation structure 6a and component isolation structure 6b is roughly the same.That is, the upper surface of the upper surface of component isolation structure 6a and component isolation structure 6b is in same plane basically.Then, remove silicon nitride film 4, polysilicon film 3 and substrate oxide-film 2, silicon substrate 1 is exposed by etching.Thus, form from the surface of silicon substrate 1 outstanding upward a plurality of

component isolation structure

6a, 6b.

Secondly, as shown in Figure 8, utilize thermal oxidation to form gate insulating film 7 on the surface of silicon substrate 1.Then, for example utilize CVD to form polysilicon film 8, gate insulating film 7 and a plurality of

component isolation structure

6a, 6b are covered.Here, when utilizing CVD on component isolation structure, to form film, if the isolation height of component isolation structure is higher, near also thickening of the film the component isolation structure then.In this example, because of the isolation height h2 of the isolation height h1 of component isolation structure 6a and component isolation structure 6b roughly the same, so near the thickness a1 of the polysilicon film 8 the component isolation structure 6a also and near the thickness b1 of the polysilicon film the component isolation structure 6b roughly the same.

Secondly, as shown in Figure 1,, can form each grid 8 of transistor 9a～9g by polysilicon film 8 being etched into the figure of regulation.As previously mentioned, since near the thickness a1 of the polysilicon film 8 the component isolation structure 6a also and near the thickness b1 of the polysilicon film the component isolation structure 6b 8 roughly the same, make silicon substrate etched so when etching, can not penetrate the gate insulating film 7 of peripheral circuit area, perhaps at the residual polysilicon film 8 of memory cell area.Then, forming interlayer dielectric 9 covers grid 8.By above operation, thereby finish the semiconductor device of this example.

The semiconductor device of this example is the semiconductor device with memory cell area and peripheral circuit area, comprising: silicon substrate 1 and by being formed at component isolation structure 6a, the 6b that silicon substrate 1 lip-deep the 2nd silicon oxide film 6 constitutes.The depth d 1 of the component isolation structure 6a of memory cell area is more shallow than the depth d 2 of the component isolation structure 6b of peripheral circuit area, and the isolation height h2 of the isolation height h1 of the component isolation structure 6a of memory cell area and the component isolation structure 6b of peripheral circuit area is roughly the same.That is, the upper surface of the upper surface of component isolation structure 6a and component isolation structure 6b is in same plane basically.

The manufacture method of semiconductor device of the present invention is the manufacture method with semiconductor device of memory cell area and peripheral circuit area, comprises following operation: form silicon oxide film 5 on silicon substrate 1; On the silicon oxide film 5 of memory cell area and peripheral circuit area and silicon substrate 1,

form ditch

15a, 15b; Form resist 20b in being formed at the ditch 15a of memory cell area and on the silicon oxide film 5 of memory cell area; By resist 20b and silicon oxide film 5 are carried out etching as mask to silicon substrate 1, thereby in the ditch 15b of peripheral circuit area, form ditch 15c; Remove resist 20b.Forming the 2nd silicon oxide film 6 on

silicon oxide film

5a, 5b buries ditch 15a, 15c.Remove

silicon oxide film

5a, 5b and the 2nd silicon oxide film 6 on the silicon substrate 1, and in each

ditch

15a, 15c, form each

component isolation structure

6a, 6b.

If according to the semiconductor device of this example, the isolation height h2 of the isolation height h1 of the component isolation structure 6a of memory cell area and the component isolation structure 6b of peripheral circuit area is roughly the same.Specifically, when the depth d 1 of component isolation structure 6a more than the 100nm and less than the depth d 2 of 200nm, component isolation structure 6b when the above 400nm of 200nm is following, the difference of isolation height h2 that can make the isolation height h1 of component isolation structure 6a and component isolation structure 6b is below 20nm.And then if use virtual pattern or the plane figure of semiconductor device is designed to suitable shape, the difference of isolation height h2 that then can make the isolation height h1 of component isolation structure 6a and component isolation structure 6b is below 5nm.The thickness of the polysilicon film 8 that forms on

component isolation structure

6a, 6b thus, becomes very even.Therefore, the nargin in the time of can improving the figure of drawing polysilicon film 8.As a result, can improve the reliability of semiconductor device.

In the manufacture method of the semiconductor device of this example, when forming ditch 15c, not with silicon nitride film 4 and with silicon oxide film 5b as mask.Because of the grinding rate of the grinding rate of

silicon oxide film

5a, 5b and the 2nd silicon oxide film 6 about equally, so, also can remove

silicon oxide film

5a, 5b on the silicon nitride film 4 and the 2nd unnecessary silicon oxide film 6 fully even

silicon oxide film

5a and 5b have step difference.In addition, because of the thickness of silicon nitride film 4 even, so can make the isolation height h2 of the isolation height h1 of component isolation structure 6a and component isolation structure 6b roughly the same.Thus, can improve the reliability of semiconductor device.

The problem that is produced when using Fig. 9～Figure 11 to describe over not on silicon nitride film 4 formation silicon oxide film 5 in detail here.

As shown in Figure 9, when not forming silicon oxide film 5, resist 20b and silicon nitride film 204b as mask, are carried out anisotropic etching to silicon substrate 1.At this moment, the silicon oxide film 204b of peripheral circuit area is etched more or less, and the thickness t 4 of silicon nitride film 204b is thinner than the thickness t 3 of the silicon nitride film 204a of memory cell area.That is, produce stage portion on the border of memory cell area and peripheral circuit area.Specifically, when the depth d 3 of component isolation structure 206a more than the 100nm and less than the depth d 4 of 200nm, component isolation structure 206b when the above 400nm of 200nm is following, can produce the poor of 30nm～80nm between the thickness t 3 of silicon nitride film 204a and the thickness t 4 of silicon nitride film 204b.

As shown in figure 10, when the border at memory cell area and peripheral circuit area produced stage portion, the 2nd silicon oxide film 6 that is present in stage portion was not removed by CMP, and left behind as the 2nd unnecessary silicon oxide film 206.In addition, the component isolation structure 206a's of the surface ratio memory cell area of the component isolation structure 206b of peripheral circuit area is surperficial low.

With reference to Figure 11, when residual the 2nd unnecessary silicon oxide film 206 on stage portion, the 2nd silicon oxide film 206 becomes mask, can not remove the silicon nitride film 4 of sub-cloud and polysilicon film 3 etc., stays unnecessary silicon nitride film 204 and polysilicon film 203.As a result, it is bad elements such as foreign matter, short circuit or shape defect to occur, causes the reliability of semiconductor device to reduce.

In addition, when the surface of the surface ratio component isolation structure 206a of component isolation structure 206b was low, the isolation height h4 of component isolation structure 206b was lower than the isolation height h3 of component isolation structure 206a.Specifically, when the depth d 3 of component isolation structure 206a more than the 100nm and less than the depth d 4 of 200nm, component isolation structure 206b when the above 400nm of 200nm is following, can produce the poor of 30nm～80nm between the isolation height h4 of the isolation height h3 of component isolation structure 206a and component isolation structure 206b.In addition, when laying the grid oxidation film of peripheral circuit area again, this difference is further strengthened.

When the isolation height h4 of component isolation structure 206b forms polysilicon film 8 under than the low state of the isolation height h3 of component isolation structure 206a, near the thickness b2 of the polysilicon film 8 the component isolation structure 206b is thinner than near the thickness a2 of the polysilicon film the component isolation structure 206a 8.Therefore, the etching polysilicon film 8 equably, or penetrate the gate insulating film 7 of peripheral circuit area and etched silicon substrate, or as shown in figure 12, at the residual polysilicon film 208 in end of the component isolation structure 206a of memory cell area.As a result, the problem that the reliability decrease of semiconductor device occurs.In addition, for avoiding this problem, when the isolation height h3 with the component isolation structure 206a of memory cell area set lowly, the component isolation structure 206b of peripheral circuit area was lower than substrate surface.As a result, produce contrary narrow channel (reverse narrow channel) effect, threshold voltage is reduced because of grid surrounds the end, active region.Thus, produce problems such as transistorized leakage current.

If the manufacture method according to the state device of this example can prevent the problems referred to above, and can form highly suitable component isolation structure, so, reliability and other performances of semiconductor device can be improved.

If state device according to this example, from the plane, the furrow width of the component isolation structure 6a of memory cell area is than the ditch width of the component isolation structure 6b of peripheral circuit area, so, when in order to make the element granular with the furrow width design of the component isolation structure 6a of memory cell area narrower the time, can alleviate composed component isolation structure 6a dielectric film imbed bad.

In the manufacture method of the semiconductor device of this example, on silicon substrate 1, formed after the silicon nitride film 4, form silicon oxide film 5.Thus, can be when removing silicon oxide film 5 with smooth silicon nitride film 4 as the etching block film.In addition, can decide isolation height h1, the h2 of

component isolation structure

6a, 6b with silicon nitride film 4.

Have again, in this example, formed the gate insulating film of memory cell area and peripheral circuit area simultaneously, but, when for example when peripheral circuit area forms the gate insulating film of different thickness, in order temporarily to remove gate insulating film and laying again, and the height of element separation is reduced only be equivalent to thickness (10～30nm) the height of the gate insulating film of removing.Just, also use the element area of the dielectric film that the gate insulating film with memory cell area forms simultaneously for capacity cell etc. at peripheral circuit area, the height of element separation is roughly the same.

In addition, the height of the element separation in this example is preferably about 0～60nm.And then preferably about 20～40nm.

(example 2)

With reference to Figure 13, the semiconductor device of this example, the border of its memory cell area and peripheral circuit area is positioned on the component isolation structure 6c.Component isolation structure 6c has the part of the depth d 1 that is positioned at memory cell area and is positioned at the part of the depth d 2 of peripheral circuit area, and the portion boundary of the part of depth d 1 and depth d 2 becomes step.

With reference to Figure 14, in this example, when forming resist 20b, also form resist 20b on the part in the ditch 15b on the border that is formed at memory cell area and peripheral circuit area.20b carries out anisotropic etching as mask with this resist.As a result, in the ditch 15b on the border that is formed at memory cell area and peripheral circuit area, the degree of depth that has formed the part of resist 20b keeps original depth d 1 constant, and in the part that does not form resist 20b, forming the degree of depth is the ditch 15c of d2.By ditch 15b and the ditch 15c landfill that uses the 2nd silicon oxide film 6 to form like this, thereby can obtain semiconductor device shown in Figure 13.

Have again, semiconductor device in addition and manufacture method thereof because and the semiconductor device and the manufacture method thereof of the example 1 of Fig. 1～shown in Figure 8 roughly the same, so to the identical symbol of same parts interpolation and omit its explanation.

The memory cell area of the semiconductor device of this example and the border of peripheral circuit area are positioned on the component isolation structure 6c.

In the manufacture method of the semiconductor device of this example, when forming resist 20b, the part in ditch 15b forms resist 20b.

Semiconductor device of this example and manufacture method thereof also can obtain the effect same with example 1.In addition, in the semiconductor device of example 1, with the active region on the border of memory cell area and peripheral circuit area as virtual pattern, but in this example, owing to can not need this virtual pattern or make it very little, so can further reduce the element area.

Have again, in example 1 and 2, show the situation of component isolation structure of 2 kinds of degree of depth of the component isolation structure 6b of the component isolation structure 6a that forms depth d 1 and depth d 2, but the invention is not restricted to such situation, also can form the component isolation structure of the multiple degree of depth.Therefore, can form the component isolation structure of 3 kinds or the 4 kinds degree of depth.

(example 3)

In this example, illustrate that an example has the semiconductor device of memory cell (flash memory).

At first, use Figure 15～Figure 21 that the structure of the semiconductor device of this example is described.

Particularly, with reference to Figure 16 and Figure 17, form the P type trap 107 of regulation and the N type trap of imbedding on the surface of silicon substrate 101.Then, utilize component isolation structure 105 that the surface of silicon substrate 101 is divided into memory cell area and peripheral circuit area, from the plane, in component isolation structure 105, have the border of memory cell area and peripheral circuit area.

Component isolation structure 105 has the part 105a of the depth d 1 that is positioned at memory cell area and is positioned at the part 105b of the depth d 2 of peripheral circuit area, and the border of the part 105b of the part 105a of depth d 1 and depth d 2 becomes step.In addition, the isolation height h of the component isolation structure 105a of memory cell area ₁₀₁(Figure 18) and the isolation height h of the component isolation structure 105b of peripheral circuit area ₁₀₂(Figure 21) roughly the same.

In memory cell area, in the element-forming region S1 that determines by component isolation structure 105a, form the grid structure 132,133 (the 1st grid structure) of memory cell transistor.In the grid structure 132,133 of memory cell transistor, on silicon substrate 101, form the floating grid (lower electrode) that constitutes by polysilicon film 108 (the 1st conducting film) via silicon oxide film 102 (the 1st gate insulating film).

On this floating grid,, form control grid (upper electrode) by silicide film 112 (the 2nd conducting film) formation of polysilicon film 111 and tungsten through ONO film 109 (dielectric film).On the silicide film 112 of tungsten, form silicon oxide film 113.Have, ONO film 109 is the laminated films that formed silicon oxide film on silicon oxide film via silicon nitride film again.In addition, on the surface of silicon substrate 101, form low concentration impurity zone 114a and high concentration impurity 114b and source region 115 as the drain region of memory cell transistor.

On the other hand, in the element-forming region S2 that the component isolation structure 105b by peripheral circuit area determines, form the transistorized grid structure 134,135 (the 2nd grid structure) that peripheral circuit is used.In transistorized grid structure 134,135, on silicon substrate 101, form the grid of silicide film 112 formations of polysilicon film 111 and tungsten through silicon oxide film 110 (the 2nd gate insulating film).On the silicide film 112 of tungsten, form silicon oxide film 113.In addition, on the surface of silicon substrate 101, form this transistorized source electrode, drain region 116,117.

Then, on component isolation structure 105, form the dummy gate structure 131 (the 3rd grid structure) that has the position relation of regulation with the end of component isolation structure 105.Dummy gate structure 131 strides across memory cell area and peripheral circuit area and forms.In dummy gate structure 131, on the silicon substrate 101 of memory cell area, form polysilicon film 108, and form ONO film 109, the top and the sidepiece covering of polysilicon film 108.In addition, form the silicide film 112 of polysilicon film 111 and tungsten, ONO film 109 is covered.The silicide film 112 of polysilicon film 111 and tungsten strides across memory cell area and peripheral circuit area and forms.On the silicide film 112 of tungsten, formed silicon oxide film 113.

On the grid structure 132,133 of memory cell transistor, transistorized grid structure 134,135 and dummy gate structure 131 side separately, form side wall oxide film 118.In addition, on silicon substrate 101, form interlayer dielectric 119, the grid structure 132,133 of memory cell transistor, transistorized grid structure 134,135 and dummy gate structure 131 are covered.

Have again, as shown in figure 17, on interlayer dielectric 119, the contact 151 that forms contact 150 that low concentration impurity zone 114a, high concentration impurity 114b and top lead-in wire (not shown) with memory cell area be electrically connected and source electrode, drain region 116,117 and the top lead-in wire (not shown) of peripheral circuit area is electrically connected.

In the semiconductor device of this example, particularly as shown in figure 15, the furrow width W1 of the component isolation structure 105a of memory cell area is narrower than the furrow width W2 of the component isolation structure 105b of peripheral circuit area.

In addition,, form dummy gate structure 131 and component isolation structure 105, make the position of the position of dummy gate structure 131 each end and corresponding elements isolation structure 105 each end inconsistent particularly as Figure 16 and shown in Figure 17.

And then, the thickness of the thickness of the polysilicon film 108 of memory cell area and the polysilicon film 108 of dummy gate structure 131 is roughly the same, each thickness of each thickness of the polysilicon film 111 in memory cell area, peripheral circuit area and the dummy gate structure 131 and the silicide film 112 of tungsten and the silicide film 112 of polysilicon film 111 in the peripheral circuit area and tungsten is roughly the same, and the thickness of silicon oxide film 102 is different with the thickness of silicon oxide film 110.

Next, use Figure 22～Figure 28 that the manufacture method of the semiconductor device of this example is described.Have, Figure 22～Figure 28 is the profile corresponding with Figure 17 again.

At first, as shown in figure 22, use and method that example 1 is same formation component isolation structure 105 in the regulation zone on silicon substrate 101 surfaces.Here, the detailed formation method of repeat element isolation structure 105 not.

Then, on the first type surface of silicon substrate 101, for example utilize thermal oxidation method etc. to form sacrificial oxidation film 102.Secondly, cross sacrificial oxidation film 102, implanting impurity ion in the territory, regulation zone on silicon substrate 101 surfaces, and heat-treat, thereby the N type trap 106 that forms P type trap 107 and imbed.Then, remove sacrificial oxidation film 102, carry out oxidation processes, form silicon oxide film 102 again by surface to silicon substrate 101.

Secondly, on silicon oxide film 102, for example utilize the CVD method to form polysilicon film 108.Then, after etching is removed polysilicon film 108 and remained in the active region of memory cell (not shown), by polysilicon film 108 is carried out oxidation processes, thereby form silicon oxide film on the surface of polysilicon film 108.Then, on silicon oxide film, via nitride silicon fiml and form silicon oxide film thus, forms ONO film 109.

Next, as shown in figure 23, on the ONO of memory cell area film 109, form photoresist figure 104c.Then, photoresist figure 104c as mask, is carried out anisotropic etching to ONO film 109 and polysilicon film 108.Thus, only form ONO film 109 and polysilicon film 108 in memory cell area.And then, remove the silicon oxide film 102 that exposes.Thus, the surface of silicon substrate 101 is exposed, only form gate insulating film 102 in memory cell area at peripheral circuit area.Then, remove photoresist figure 104c.

Next, as shown in figure 24, carry out oxidation processes, thereby form silicon oxide film 110 on the surface of the silicon substrate 101 of peripheral circuit area by surface to silicon substrate 101.Secondly, stride across memory cell area and peripheral circuit area, on ONO film 109 and polysilicon film 110, for example use the CVD method to form polysilicon film 111.Then, on polysilicon film 111, form the silicide film 112 of tungsten, and on the silicide film 112 of tungsten, form silicon oxide film 113.

Next, as shown in figure 25, on silicon oxide film 113, form photoresist figure (not shown), this photoresist figure as mask, is carried out anisotropic etching to silicon oxide film 113, thus, form the pattern of silicon oxide film 113.Then, remove this photoresist figure.Secondly, will form silicon oxide film 113 behind the pattern, the silicide film 112 and the polysilicon film 111 of tungsten carried out anisotropic etching as mask.

Utilize this anisotropic etching, on the ONO of memory cell area film 109, form the control grid that the silicide film 112 by polysilicon film 111 and tungsten constitutes.In addition, on the silicon oxide film 110 of peripheral circuit area, form the grid that the silicide film 112 by polysilicon film 111 and tungsten constitutes.And then, on the border of memory cell area and peripheral circuit area, form the polysilicon film 111 of formation dummy gate structure 131 and the silicide film 112 of tungsten.Then, inject processing, in the neighboring area, form the N type source drain region 116 (with reference to Figure 26) of low concentration by the ion of stipulating.

Secondly, as shown in figure 26, form photoresist figure 104d.With this photoresist figure 104d and graphical after silicon oxide film 113 as mask, ONO film 109 and polysilicon film 108 are carried out anisotropic etching.

By this anisotropic etching, on the silicon oxide film 102 of memory cell area, form the floating grid that constitutes by polysilicon film 108.In addition, the memory cell area at the boundary vicinity that has a common boundary with peripheral circuit area forms ONO film 109 and the polysilicon film 108 that constitutes dummy gate structure 131.Then, inject by the ion of stipulating, the element-forming region in memory cell area forms the low concentration impurity zone 114a as the drain region.Then, remove photoresist figure 104d.

Next, as shown in figure 27, form photoresist figure 104e.Then, photoresist 104e as mask, is carried out etching to the silicon substrate 101 that exposes.Secondly, inject processing, form source region 115 in memory cell area by the ion that the surface of silicon substrate 101 is stipulated.Then, remove photoresist figure 104e.

Thus, the grid structure 132,133 at memory cell area formation memory cell transistor forms the transistorized grid structure 134,135 that peripheral circuit is used at peripheral circuit area.In addition, stride across memory cell area and peripheral circuit area, on component isolation structure 105, form dummy gate structure 131.

Next, as shown in figure 28, form TEOS film (not shown), and grid structure 132,133, transistorized grid structure 134,135 and the dummy gate structure 131 of difference overlaying memory cell transistor.Handle by this TEOS film being carried out dry corrosion, thereby form each side wall oxide film 118.Secondly, form photoresist figure 104f.Then, as mask, the ion that the surface of silicon substrate 101 is stipulated injects to be handled with photoresist figure 104f and side wall oxide film 118.Thus, form the N type source drain region 117 of high concentration at peripheral circuit area.Then, remove photoresist figure 104f.And then as mask, in memory cell area, the ion that the surface of silicon substrate 101 is stipulated injects processing with side wall oxide film 118.Thus, form high concentration impurity 114b (Figure 17) in memory cell area.

Next, with reference to Figure 17, form the interlayer dielectric 119 that comprises TEOS film and BPTEOS (Boro PhosphoTetra Ethyl Ortho Silicate glass) film.Then, form the contact 150 of regional 114a of the low concentration impurity that is connected memory cell area and high concentration impurity 114b and be connected the source electrode of peripheral circuit area, the contact 151 of drain region 116,117, finish semiconductor device shown in Figure 17.

If according to the semiconductor device and the manufacture method thereof of this example, except the effect of narration in example 1 and 2, can also obtain following effect.

Promptly, as shown in figure 25, dummy gate structure 131 is set on the border of memory cell area and peripheral circuit area, and memory cell area one side of dummy gate structure 131 becomes and will constitute the structure of polysilicon film 108 with silicide film 112 laminations of the polysilicon film 111 that constitutes the control grid, tungsten of floating grid.Form the silicide film 112 of polysilicon film 111 and tungsten, with the end covering of polysilicon film 108.

By such structure, do not need the control grid part that forms in the mode that covers floating grid (polysilicon film 108) end is carried out etching.That is, do not need part shown in the a3 of Figure 25, that thickness is thicker is carried out etching.Therefore, during as the silicide film 112 of the polysilicon film 111 of the grid of the control grid of memory cell area and peripheral circuit area and tungsten, can prevent that the silicide film 112 of polysilicon film 111 and tungsten from becoming residue in the end of floating grid in etching.

In addition, when adopting photoresist figure 104d only peripheral circuit area to be covered as shown in figure 26 like that, be configured on the dummy gate structure 131 by border, thereby can prevent the shape anomaly that silicon substrate 101 or component isolation structure 105 occur because of unnecessary over etching memory cell area and peripheral circuit area.

And then the border of the zanjon of the shallow ridges of component isolation structure 105a and component isolation structure 105b has because of resulting from the crystal defect of step of bottom of trench and causes the anxiety of element function variation such as electric current leakage, so be not suitable for the formation of element.Therefore, be configured to dummy gate structure 131 by border shallow ridges and zanjon overlapping, will be unsuitable for the region overlapping that forms of element, thereby can make the element granular.

In addition, can be as example 1, (active region that does not form transistor 9a～9g among Fig. 1) goes up configuration memory units zone and peripheral circuit area and border thereof in virtual active region, thus, can the end of floating grid (polysilicon film 108) be positioned on the component isolation structure 105 as shown in Figure 23.Therefore, can prevent that when the etching floating grid silicon substrate 101 that causes because of over etching from being scraped off.That is,, like this, just increased the area of element when when overlapping,, being necessary to make the end of border and floating grid to leave configuration border and virtual active region in order to prevent that silicon substrate 101 from being scraped off.Therefore, the granular for element preferably is configured in the border on the component isolation structure.

In addition, the grid structure 133,132 of memory cell transistor is opposed through gate insulating film 102 and silicon substrate 101.Therefore, the stress that grid has imposes on memory cell area etc. easily, and crystal defect takes place memory cell area etc. easily.

Therefore, in this example, the end of memory cell area one side of dummy gate structure 131 is than more close memory cell area one side in the end of the correspondence of component isolation structure 105a (on the element-forming region of memory cell area), and the end of peripheral circuit area one side of dummy gate structure 131 is than more close memory cell area one side in the corresponding end of component isolation structure 105a (on the component isolation structure 105).

Particularly,, compare, can reduce near the part generation crystal defect component isolation structure 105 of being positioned at of silicon substrate 101 significantly with the semiconductor device in past by forming dummy gate structure 131 as described above.

Have again, in this example, all stagger with memory cell area one side in the end of dummy gate structure 131, but also can stagger with peripheral circuit area one side, still stagger with the end in element separation zone with the end of dummy gate structure, can obtain same effect.

In addition, in this example, owing to make the depth as shallow of the element separation depth ratio peripheral circuit area of memory cell area, so except being difficult to cause that imbedding of component isolation structure is bad, can also be as shown in Figure 20, form the source region 115 of removing component isolation structure and forming more shallow, thereby the influence that can avoid covering when injecting because of ion can not carry out desired injection, and reduce the resistance of source region 115.

Here, the same with example 1, the problem that is produced when using Figure 29～Figure 32 to describe over not on silicon nitride film formation silicon oxide film in detail.

In existing method, the height of the height of the component isolation structure of memory cell area and the component isolation structure of peripheral circuit area has very big difference.Therefore, if must be low unlike silicon substrate with the height setting of the component isolation structure of peripheral circuit area, then as Figure 29 and shown in Figure 30, the height of the component isolation structure 305a of memory cell area be very high.If the height of component isolation structure 305a is very high, then when forming side wall oxide film 118, also form side wall oxide film 301 in the side of the component isolation structure 305a that gives prominence to from silicon substrate 101.As a result, reduce, cause the contact resistance of contact 150 and silicon substrate 101 to uprise because of the existence of side wall oxide film 301 makes the contact 150 and the contact area of silicon substrate 101.

In the semiconductor device of this example, because of the height of the component isolation structure of the height of the component isolation structure of memory cell area and peripheral circuit area roughly the same, so can not produce problem as described above.So, can improve reliability and other performances of semiconductor device.

In addition, when forming high speed logic circuit etc. at peripheral circuit area, make the substrate surface suicided sometimes and make it to realize low resistanceization.At this moment, as shown in figure 31, with side wall oxide film 301 as mask, in the 114a of low concentration impurity zone, form high concentration impurity 114b after, make side wall oxide film 301 retreat the interior silicon substrate face suicided in zone that any exposes, formation silicide layer 30 a little by clean processing etc.At this moment, contact, thereby cause the generation of leakage by making silicide layer 30 and low concentration impurity zone 114a.In this example, shown in figure 32,,, can not cause the problems referred to above even form silicide layer 30 owing to do not form side wall oxide film in the side of component isolation structure 105 yet.

Though understand the present invention in detail by example, above-mentioned example only is some examples, the present invention is not subjected to the restriction of these examples, and the spirit and scope of the present invention only are subjected to the restriction of following claim book.

Claims

1. one kind has the 1st zone and the semiconductor device in the 2nd zone, it is characterized in that:

Comprise:

Silicon substrate and the component isolation structure that constitutes by silicon insulating film that on described surface of silicon substrate, forms,

The depth as shallow of the described component isolation structure in described the 2nd zone of the depth ratio of the described component isolation structure in described the 1st zone,

The isolation height of the described component isolation structure in the isolation height of the described component isolation structure in described the 1st zone and described the 2nd zone is roughly the same,

Also comprise:

Be formed at the 1st grid structure of the element area of determining by the described component isolation structure in described the 1st zone;

Be formed at the 2nd grid structure of the element area of determining by the described component isolation structure in described the 2nd zone;

Stride across the 3rd grid structure that described the 1st zone and described the 2nd zone form.

2. the semiconductor device of claim 1 record is characterized in that:

The furrow width of the described component isolation structure in described the 1st zone is than the ditch width of the described component isolation structure in described the 2nd zone.

3. the semiconductor device of claim 1 record is characterized in that:

Described the 1st grid structure has the lower electrode that forms and comprise the 1st conducting film at the 1st gate insulating film that forms on the described silicon substrate, on described the 1st gate insulating film, at the dielectric film that forms on the described lower electrode with on described dielectric film, form and comprise the upper electrode of the 2nd conducting film

Described the 2nd grid structure has the 2nd gate insulating film that is formed on the described silicon substrate and the grid that forms and comprise described the 2nd conducting film on described the 2nd gate insulating film,

Described the 3rd grid structure has described the 1st conducting film and the described dielectric film that forms in described the 1st zone and strides across described the 1st zone and described the 2nd conducting film that described the 2nd zone forms to cover described the 1st conducting film and described dielectric film.

4. the semiconductor device of claim 3 record is characterized in that:

The thickness of described the 1st gate insulating film is different with the thickness of described the 2nd gate insulating film.

5. the semiconductor device of claim 1 record is characterized in that:

The border in described the 1st zone and described the 2nd zone is positioned on the described component isolation structure.

6. the manufacture method with the semiconductor device in the 1st zone and the 2nd zone is characterized in that, comprising:

On silicon substrate, form the operation of the 1st silicon insulating film;

The operation of formation the 1st ditch on described the 1st zone and described the 1st silicon insulating film in described the 2nd zone and described silicon substrate;

The operation of formation masking layer in being formed at described the 1st ditch in described the 1st zone and on described the 1st silicon insulating film in described the 1st zone;

By described masking layer and described the 1st silicon insulating film are carried out etching as mask to described silicon substrate, thereby in described the 1st ditch in described the 2nd zone, form the operation of the 2nd ditch;

Remove the operation of described masking layer;

On described the 1st silicon insulating film, form the 2nd silicon insulating film, so that the operation that described the 1st ditch and described the 2nd ditch are buried;

Remove described the 1st silicon insulating film and described the 2nd silicon insulating film on the described silicon substrate, and in described the 1st ditch and described the 2nd ditch, form the operation of component isolation structure.

7. the manufacture method of the semiconductor device of claim 6 record is characterized in that, and then comprises:

On the described silicon substrate in described the 1st zone, form the operation of the 1st gate insulating film;

On described the 1st gate insulating film, form the operation of the 1st conducting film;

On described the 1st conducting film, form the operation of dielectric film;

On the described silicon substrate in described the 2nd zone, form the operation of the 2nd gate insulating film;

On the described dielectric film and form the operation of the 2nd conducting film on described the 2nd gate insulating film;

By described the 2nd conducting film of etching so that keep borderline described the 2nd conducting film be present in described the 1st zone and described the 2nd zone at least, thereby on the described dielectric film in described the 1st zone, form upper electrode, on described the 2nd gate insulating film in described the 2nd zone, form grid, and on the border in described the 1st zone and described the 2nd zone, form the operation of described the 2nd conducting film that constitutes grid structure;

By described dielectric film of etching and described the 1st conducting film, thereby on described the 1st gate insulating film, form lower electrode, and in described the 1st zone of described boundary vicinity, form the described dielectric film of formation grid structure and the operation of described the 1st conducting film.

8. the manufacture method of the semiconductor device of claim 6 record is characterized in that:

The operation that forms described masking layer comprises: the operation that forms described masking layer on the part in described the 1st ditch.

9. the manufacture method of the semiconductor device of claim 6 record is characterized in that:

And then comprise: before the operation that forms described the 1st silicon insulating film, on described silicon substrate, form the operation of silicon nitride film.

10. one kind has the 1st zone and the semiconductor device in the 2nd zone, it is characterized in that:

Comprise: silicon substrate and the component isolation structure that constitutes by silicon insulating film that on described surface of silicon substrate, forms,

The furrow width of the described component isolation structure in described the 1st zone is littler than the furrow width of the described component isolation structure in described the 2nd zone,

Also comprise: