CN117766556A

CN117766556A - Photosensitive device, preparation method thereof and sensor pixel unit

Info

Publication number: CN117766556A
Application number: CN202311801083.XA
Authority: CN
Inventors: 郭同辉; 周新萍; 宋磊
Original assignee: Pulse Vision Beijing Technology Co ltd
Current assignee: Pulse Vision Beijing Technology Co ltd
Priority date: 2023-12-25
Filing date: 2023-12-25
Publication date: 2024-03-26

Abstract

The embodiment of the disclosure discloses a photosensitive device, a preparation method thereof and a sensor pixel unit, wherein the photosensitive device comprises: a first impurity ion region, a second impurity ion region, a third impurity ion region, and a contact hole; the first impurity ion region is used for collecting photoelectric charges; the second impurity ion region is arranged above the first impurity ion region and is used for isolating the first impurity ion region from the insulating layer; the third impurity ion region is embedded above one side of the first impurity ion region; the contact hole is communicated with the upper part of the third impurity ion region and is used for being connected with an external component; in this embodiment, by disposing the contact hole in the third impurity ion region, the area of the second impurity ion region covering the top of the first impurity ion region is maximized, and the portion not covered by the second impurity ion region is shielded by the third impurity ion region, so that the leakage current of the first impurity ion region due to contact with the oxide insulator is reduced to the greatest extent.

Description

Photosensitive device, preparation method thereof and sensor pixel unit

Technical Field

The disclosure relates to the technical field of image sensors, in particular to a photosensitive device, a preparation method thereof and a sensor pixel unit.

Background

Image sensors have been widely used in the fields of digital cameras, mobile phones, medical treatment, automobiles, unmanned aerial vehicles, machine recognition, etc., and particularly, the rapid development of the technology for manufacturing complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) image sensors has led to higher demands on the quality of the output images of the image sensors. The main functional device of the image sensor is a photosensitive device, and the existing photosensitive device may have a leakage problem due to the production technical problem, so that the quality of a dim light image collected by the image sensor in the prior art is lower.

Disclosure of Invention

According to an aspect of an embodiment of the present disclosure, there is provided a photosensitive device including: a first impurity ion region, a second impurity ion region, a third impurity ion region, and a contact hole;

the first impurity ion region is used for collecting photoelectric charges;

the second impurity ion region is arranged above the first impurity ion region and is used for isolating the first impurity ion region from the insulating layer;

the third impurity ion region is embedded above one side of the first impurity ion region and the second impurity ion region;

The contact hole is communicated with the upper part of the third impurity ion region and is used for being connected with an external component.

Optionally, the contact hole is a metal conductor.

Optionally, the first impurity ion region is provided with the third impurity ion region at a side close to the external component.

Optionally, the first impurity ion region and the second impurity ion region are different in ion type and different in impurity ion concentration; the first impurity ion region and the third impurity ion region are the same in ion type but different in impurity ion concentration.

Optionally, the photosensitive device further includes: a semiconductor substrate;

the first impurity ion region is disposed in the semiconductor body.

According to another aspect of the embodiments of the present disclosure, there is provided a sensor pixel unit including: the photosensitive device, the reset transistor, and the auxiliary circuit described in any of the above embodiments;

the photosensitive device is used for collecting photoelectric charges and determining potential change of the photosensitive device according to the collected photoelectric charges;

the reset transistor is used for controlling the reset of the photosensitive device according to an external reset control signal;

the auxiliary circuit is used for outputting a target signal according to the potential change of the photosensitive device.

Optionally, the side of the first impurity ion region close to the reset transistor in the photosensitive device is provided with the third impurity ion region.

According to still another aspect of the embodiments of the present disclosure, there is provided a method for manufacturing a photosensitive device, including:

manufacturing a first impurity ion region on a semiconductor substrate;

manufacturing a second impurity ion region, and enabling the second impurity ion region to cover the first impurity ion region in whole;

a third impurity ion region is formed on one side of the first impurity ion region and one side of the second impurity ion region;

and manufacturing a contact hole above the third impurity ion region.

Optionally, said fabricating a third impurity ion region on one side of said first impurity ion region and said second impurity ion region, comprising:

depositing an oxide insulating material on the surface of the second impurity ion region to generate an insulating layer;

determining an injection hole on one side of the insulating layer by using a photoresist and a contact hole mask plate corresponding to the contact hole;

and implanting impurity ions into the injection hole, and generating a third impurity ion region with different impurity ion concentrations on one side of the first impurity ion region and one side of the second impurity ion region.

Optionally, the implanting impurity ions into the injection hole to generate a third impurity ion region with different impurity ion concentrations on one side of the first impurity ion region and one side of the second impurity ion region, including:

implanting impurity ions into the injection hole; the impurity ion type is the ion type of the third impurity ion region;

performing thermal annealing treatment, and activating the injected impurity ions to generate a third impurity ion region; wherein the thermal annealing temperature range is 700-1200 ℃, and the thermal annealing time range is 0.1 seconds-10 minutes.

Optionally, determining an injection hole on one side of the second impurity ion region by using the photoresist and a contact hole mask corresponding to the contact hole, including:

spin-coating photoresist on the surface of the insulating layer;

exposing the photoresist by using the contact hole mask plate, developing, determining the injection hole, and removing the photoresist in the injection hole;

and performing chemical ion etching to remove the insulating layer in the injection hole.

Optionally, after the chemical ion etching etches the insulating layer in the injection hole, the method further includes:

The unexposed photoresist is removed by cleaning.

Optionally, the fabricating a contact hole above the third impurity ion region includes:

depositing a metal conductor material into an injection hole on one side of the insulating layer, and filling the injection hole;

and removing unnecessary metal conductor materials to form the contact hole.

According to still another aspect of the embodiments of the present disclosure, there is provided an electronic device including: the processor, and the memory communicatively connected with the processor, further including the photosensitive device or the sensor pixel unit according to any one of the above embodiments;

the memory stores computer-executable instructions;

the processor executes computer-executable instructions stored by the memory to control the photosensitive device or the sensor pixel unit.

Optionally, the electronic device is incorporated into any one of: pulse cameras, high-speed cameras, audio/video players, navigation devices, fixed location terminals, entertainment units, smartphones, communication devices, devices in motor vehicles, cameras, motion or wearable cameras, detection devices, flight devices, medical devices, security devices.

The embodiment of the disclosure provides a photosensitive device, a preparation method thereof and a sensor pixel unit, which comprises the following steps: a first impurity ion region, a second impurity ion region, a third impurity ion region, and a contact hole; the first impurity ion region is used for collecting photoelectric charges; the second impurity ion region is arranged above the first impurity ion region and is used for isolating the first impurity ion region from the insulating layer; the third impurity ion region is embedded above one side of the first impurity ion region; the contact hole is communicated with the upper part of the third impurity ion region and is used for being connected with an external component; in this embodiment, by disposing the contact hole in the third impurity ion region, the area of the second impurity ion region covering the top of the first impurity ion region is maximized, and the portion not covered by the second impurity ion region is shielded by the third impurity ion region, so that the leakage current of the first impurity ion region due to contact with the oxide insulator is reduced to the greatest extent.

The technical scheme of the present disclosure is described in further detail below through the accompanying drawings and examples.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The disclosure may be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

fig. 1 shows a schematic structure of a pixel cell of a prior art three transistor structure;

FIG. 2 is a schematic cross-sectional view of a photosensitive device group in the pixel unit of the sensor shown in FIG. 1;

FIG. 3 is a schematic diagram of a photosensitive device according to an exemplary embodiment of the present disclosure;

FIG. 4 is a schematic view of the structure of the photosensitive device shown in FIG. 3 corresponding to an AB vertical section;

fig. 5 is a schematic circuit diagram of a sensor pixel unit according to an exemplary embodiment of the present disclosure;

FIG. 6 is a flow chart of a method for fabricating a photosensitive device according to an exemplary embodiment of the present disclosure;

FIG. 7-1 is a schematic vertical cross-sectional view of a photosensitive device provided in an exemplary embodiment of the present disclosure;

FIG. 7-2 is a schematic vertical cross-sectional view of a photosensitive device having an insulating layer formed on the basis of FIG. 7-1;

FIG. 7-3 is a schematic vertical cross-sectional view of the photosensitive device after spin-coating the photoresist on the basis of FIG. 7-2;

FIG. 7-4 is a schematic vertical cross-sectional view of the photosensitive device after the injection hole is made on the basis of FIG. 7-3;

fig. 7-5 are schematic vertical cross-sectional views of photosensitive devices subjected to chemical ion etching on the basis of fig. 7-4;

fig. 7-6 are schematic vertical cross-sectional views of a photosensitive device from which photoresist has been removed based on fig. 7-5;

fig. 7-7 are schematic vertical cross-sectional views of the photosensitive device after implantation of impurity ions on the basis of fig. 7-6;

fig. 7-8 are schematic vertical cross-sectional views of a photosensitive device having a third impurity ion region fabricated on the basis of fig. 7-7;

FIGS. 7-9 are schematic vertical cross-sectional views of the photosensitive device after deposition of a metallic conductor material on the basis of FIGS. 7-8;

FIGS. 7-10 are schematic vertical cross-sectional views of the completed photosensitive device prepared on the basis of FIGS. 7-9;

FIG. 8 is a schematic flow chart of step 606 in the embodiment of FIG. 6 of the present disclosure;

FIG. 9 is a flow chart of step 608 in the embodiment of FIG. 6 of the present disclosure;

fig. 10 illustrates a block diagram of an electronic device according to an embodiment of the disclosure.

Detailed Description

Hereinafter, example embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present disclosure and not all of the embodiments of the present disclosure, and that the present disclosure is not limited by the example embodiments described herein.

It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless it is specifically stated otherwise.

It will be appreciated by those of skill in the art that the terms "first," "second," etc. in embodiments of the present disclosure are used merely to distinguish between different steps, devices or modules, etc., and do not represent any particular technical meaning nor necessarily logical order between them.

It should also be understood that in embodiments of the present disclosure, "plurality" may refer to two or more, and "at least one" may refer to one, two or more.

It should also be appreciated that any component, data, or structure referred to in the presently disclosed embodiments may be generally understood as one or more without explicit limitation or the contrary in the context.

In addition, the term "and/or" in this disclosure is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" in the present disclosure generally indicates that the front and rear association objects are an or relationship. The data referred to in this disclosure may include unstructured data, such as text, images, video, and the like, as well as structured data.

It should also be understood that the description of the various embodiments of the present disclosure emphasizes the differences between the various embodiments, and that the same or similar features may be referred to each other, and for brevity, will not be described in detail.

Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

The sensor pixel unit adopts two schemes of a four-transistor structure and a three-transistor structure to collect image photoelectric signals, and the pulse sequence type image sensor pixel adopts a three-transistor structure as a pixel collecting optical signal scheme. Fig. 1 shows a schematic structure of a pixel cell of a prior art three transistor structure. As shown in fig. 1, the pixel unit includes a photosensitive device 101, a reset transistor 102, a source follower transistor 103, and a pixel selection transistor 104. The charge collection terminal of the photosensitive device 101 is labeled CT and is connected to the gate terminal of the source follower transistor 103; the gate terminal of the reset transistor 102 is labeled Vrst and the gate terminal of the pixel select transistor 104 is labeled v_sel; the source terminal of the reset transistor 102 is connected to the power supply signal Vdd, the other terminal of the photosensitive device 101 is grounded GND, and the drain terminal of the pixel selection transistor 104 is the pixel signal output terminal Vpix. The device group of the photosensitive device 101 and the reset transistor 102 within the dashed line box shown in fig. 1 may be denoted as the light device group 11. Fig. 2 is a schematic sectional view of a photosensitive device group in the pixel unit of the sensor shown in fig. 1. As shown in fig. 2, a photosensitive device 101 and a reset transistor 102 are shown, the photosensitive device 101 includes a first impurity ion region 201, a second impurity ion region 202, and a semiconductor body 203, and the photosensitive device 101 further includes a contact hole CT connected to the first impurity ion region 201; the width of the contact hole CT is denoted as a, and the distance between the second impurity ion region 202 and the edge of the reset transistor 102 is denoted as b. In the prior art, the device manufacturing process flow sequence of the optical device group 11 is to manufacture the first impurity ion region 201- > to manufacture the reset transistor 102- > to manufacture the second impurity ion region 202- > to manufacture the contact hole CT. In the existing sensor production technology, the second impurity ion region 202 and the contact hole CT are manufactured in two processes, and the second impurity ion region 202 and the contact hole CT are manufactured by using the illumination mask plate to perform alignment operation respectively, wherein the alignment accuracy is usually about tens of nanometers, so b in fig. 2 needs to be greater than a, which results in that the first impurity ion region 201 has a larger area and is not covered by the second impurity ion region 202 (the second impurity ion region 202 acts as an insulating material for isolating the first impurity ion region 201 from the outside), so that a more obvious leakage problem is caused, and the quality of a dim light image collected by the sensor in the prior art is lower; and because process fluctuation can be generated in the chip production of different batches by the process production equipment, b value change is caused, and the photosensitive response of the photosensitive device 101 is not stable. For example, the photosensitivity of different batches of image sensor chips is not equal. The obvious electric leakage problem of the photosensitive device and the unstable photosensitive response of pixels between chips can cause image noise, and especially the effect of dark light images is not ideal. In order to solve the above problems, the present disclosure provides a structure of a photosensitive device and a method for manufacturing the same, so as to solve the above technical problems.

Fig. 3 is a schematic structural view of a photosensitive device provided in an exemplary embodiment of the present disclosure. As shown in fig. 3, the photosensitive device provided in this embodiment includes: a first impurity ion region 301, a second impurity ion region 302, a third impurity ion region 303, and a contact hole 304.

A first impurity ion region 301 for collecting photoelectric charges.

The second impurity ion region 302 is disposed above the first impurity ion region 301 for isolating the first impurity ion region 301 from the insulating layer. The insulating layer is made of an insulating material, and the insulating layer is arranged above the photosensitive device, and the insulating material can be an insulating material commonly used in the prior art.

In this embodiment, in order to better understand the relationship between the structures in the photosensitive device, the AB shown in fig. 3 is taken as the position of the vertical section, and fig. 4 is a schematic structural diagram of the photosensitive device shown in fig. 3 corresponding to the AB vertical section. As shown in fig. 4, it can be more intuitively understood that the second impurity ion region 302 is covered over the first impurity ion region 301; optionally, the area of the second impurity ion region 302 is larger than that of the first impurity ion region 301, so as to achieve more comprehensive coverage of the first impurity ion region 301, and avoid the occurrence of leakage.

The third impurity ion region 303 is embedded above one side of the first impurity ion region 301 and the second impurity ion region 302.

In this embodiment, as shown in fig. 4, the third impurity ion region 303 and the first impurity ion region 301 and the second impurity ion region 302 belong to an integrated structure, the third impurity ion region 303 belongs to a region obtained by changing materials by a preparation method above one side of the first impurity ion region 301 and one side of the second impurity ion region 302, the size of the region can be determined according to the required width of the contact hole 304, and since the third impurity ion region 303 extends into the portion of the first impurity ion region 301, the second impurity ion region 302 does not completely cover the first impurity ion region 301 even if the width of the third impurity ion region 303 is larger than the required width of the contact hole 304, and due to the third impurity ion region 303, the first impurity ion region 301 is not contacted with the insulating layer, so that occurrence of electric leakage is avoided, the photosensitive response stability of a pixel unit applying a photosensitive device is improved, noise is reduced, and the effect of a sensor applying the photosensitive device in image acquisition in a dark environment is improved.

The contact hole 304 communicates with the upper side of the third impurity ion region 303 for connection with an external component.

The contact hole 304 in the present embodiment is disposed above the third impurity ion region 303, so as to realize a function of communicating the third impurity ion region 303 with external components; when the photosensitive device is applied to a pixel unit (e.g., a pixel unit structure as shown in fig. 1), the contact hole 304 may be connected to the drain terminal of the reset transistor 102 and the gate terminal of the source follower transistor 103.

The photosensitive device provided based on the above embodiment of the present disclosure includes: a first impurity ion region, a second impurity ion region, a third impurity ion region, and a contact hole; the first impurity ion region is used for collecting photoelectric charges; the second impurity ion region is arranged above the first impurity ion region and is used for isolating the first impurity ion region from the insulating layer; the third impurity ion region is embedded above one side of the first impurity ion region; the contact hole is communicated with the upper part of the third impurity ion region and is used for being connected with an external component; in this embodiment, by disposing the contact hole in the third impurity ion region, the area of the second impurity ion region covering the top of the first impurity ion region is maximized, and the portion not covered by the second impurity ion region is shielded by the third impurity ion region, so that the leakage current of the first impurity ion region due to contact with the oxide insulator is reduced to the greatest extent.

Optionally, the contact hole 304 is a metal conductor. The contact holes 304 may be made using any prior art metal conductor.

In some alternative embodiments, the first impurity ion region 301 is provided with a third impurity ion region 303 at a side close to the external component.

In this embodiment, since the contact hole 304 is disposed above the third impurity ion region 303, the contact hole 304 is used to connect with an external component (for example, a reset transistor, etc.), so that when the photosensitive device is applied to a pixel unit or the like, the third impurity ion region 303 is located at a side of the first impurity ion region close to the external component, so that the contact hole 304 is connected with the external component. The surface area of the third impurity ion region 303 is slightly larger than the surface area of the contact hole 304, and the dimension c is slightly larger than the dimension a as shown in fig. 4, alternatively, the difference is only in the order of nm.

In some alternative embodiments, the first impurity ion region 301 and the second impurity ion region 302 are different in ion type and different in impurity ion concentration; the first impurity ion region 301 and the third impurity ion region 303 are the same in ion type but different in impurity ion concentration.

Optionally, the first impurity ion region 301, the ion types including but not limited to N-type ions, the impurity ions being arsenic ions and phosphorus ions, the impurity ion concentration being 1e15 to 5e 17/cm 3, the depth being greater than 1.0um; wherein 1e15 is scientific count, 1 times 10 to the power of 15, 5e17 to the power of 5 times 10; cm 3 represents cubic centimeters.

The second impurity ion region 302, the ion type includes but is not limited to P-type ion, the impurity ion is boron ion, the concentration of the impurity ion is 1e 17/cm 3-1 e 20/cm 3, and the depth is 50 nm-150 nm; wherein the first impurity ion region 301 and the second impurity ion region 302 are different in ion type.

The third impurity ion region 303, the ion type includes but is not limited to N-type ion, the impurity ion is arsenic ion and phosphorus ion, the impurity ion concentration is 1e 18/cm 3-1 e 22/cm 3, the depth is 100 nm-500 nm; the ion type of the third impurity ion region 303 is the same as that of the first impurity ion region 301, but the impurity ion concentration and depth are different.

Optionally, as shown in fig. 4, the photosensitive device further includes: a semiconductor substrate 305.

The first impurity ion region 301 is provided in the semiconductor body 305.

Alternatively, the semiconductor body 305 may be a silicon epitaxial layer or the like.

Fig. 5 is a schematic circuit diagram of a sensor pixel unit according to an exemplary embodiment of the present disclosure. As shown in fig. 5, the pixel unit of the image sensor (hereinafter referred to as a pixel unit) provided in this embodiment includes: the photosensitive device 501, the reset transistor 502, and the auxiliary circuit 503 provided as in any of the embodiments described above;

The photosensitive device 501 is configured to collect photoelectric charges and determine a potential change of the photosensitive device 501 according to the collected photoelectric charges.

One end of the photosensitive device 501 in this embodiment is grounded, and the other end is connected to the drain end of the reset transistor 502 as a charge collection end, and the charge collection end is connected to the auxiliary circuit 503.

A reset transistor 502 for controlling reset of the photosensitive device 501 according to an external reset control signal.

Optionally, the source terminal of the reset transistor 502 receives the power signal Vdd, the gate terminal of the reset transistor 502 receives the external reset control signal Vrst, and when the reset transistor 502 is turned on, the charge collecting terminal of the photosensitive device 501 is connected to the power signal Vdd according to the control of the external reset control signal Vrst, so as to reset the photosensitive device 501.

An auxiliary circuit 503 for outputting a target signal according to the potential change of the photosensitive device.

In this embodiment, the photosensitive device 501 provided in the above embodiment is applied to the sensor pixel unit, and photoelectric conversion is implemented by using the photosensitive device 501, and since the photosensitive device 501 overcomes the problem of current leakage in the prior art, the quality of the image collected by the sensor pixel unit under the condition of dark light is improved.

Alternatively, the third impurity ion region 303 is provided on a side of the first impurity ion region 301 close to the reset transistor 502 in the photosensitive device 501.

When the photosensitive device 501 is applied to the sensor pixel unit, the reset transistor 502 is the component closest to the photosensitive device 501, and the third impurity ion region 303 is disposed on the side close to the reset transistor 502, so that the contact hole 304 can be more conveniently connected with other components.

In some alternative embodiments, the auxiliary circuit 503 may include a source follower transistor 103 and a pixel select transistor 104 as shown in the embodiment of fig. 1.

The gate of the source follower transistor 103 is connected to the photosensitive device 501, the source is connected to the power supply signal Vdd, and the drain is connected to the pixel selection transistor 104; for detecting and following the potential change of the photosensitive device 501, determining a target signal;

the source of the pixel selection transistor 104 is connected to the drain of the source follower transistor 103, the drain is a signal output terminal of the sensor pixel unit, the gate is connected to an external control signal, and whether to output a target signal is determined according to control of the external control signal.

In this embodiment, the gate terminal of the source follower transistor 103 is connected to the photosensitive device 501, and follows the potential change of the first impurity region 301 in the photosensitive device 501 to obtain a potential signal, and the pixel selection transistor 104 selects whether to output a target signal according to the control of the external control signal v_sel, where the external control signal v_sel may be an external clock signal or an external pulse signal, etc.; the pixel selection transistor 104 is controlled to output a target signal based on a timing transmission signal of an external clock circuit, and the target signal may be any one or more of a pulse signal, a potential signal, a value with a limit, and the like.

The above embodiment of the present disclosure provides a photosensitive device having a structure different from that of the prior art, and a manufacturing method thereof is also different from that of the prior art, and therefore, the present disclosure also provides a manufacturing method of the photosensitive device, based on which the photosensitive device having the above structure can be obtained.

Fig. 6 is a flowchart illustrating a method for manufacturing a photosensitive device according to an exemplary embodiment of the present disclosure. As shown in fig. 6, the method for manufacturing the photosensitive device provided in this embodiment includes:

in step 602, the first impurity ion region 301 is formed on the semiconductor substrate 305.

The semiconductor substrate is a semiconductor substrate commonly used in the art, such as a silicon epitaxial layer. The manufacturing process of the first impurity ion region is the same as that of the first impurity ion region in the photosensitive device in the prior art, and will not be described herein.

In step 604, the second impurity ion region 302 is formed so that the second impurity ion region 302 entirely covers the first impurity ion region 301.

The manufacturing process of the second impurity ion region is the same as that of the second impurity ion region in the photosensitive device in the prior art, and will not be described herein. Alternatively, after the second impurity ion region is fabricated, a schematic vertical cross-sectional view of the photosensitive device as shown in fig. 7-1 may be obtained.

In step 606, a third impurity ion region 303 is formed on the first impurity ion region 301 and the second impurity ion region 302.

In step 608, a contact hole 304 is formed over the third impurity ion region 303.

In this embodiment, the third impurity ion region 303 is prepared by being above one side of the first impurity ion region 301 and the second impurity ion region 302, and the contact hole 304 is made above the third impurity ion region 303; since the third impurity ion region 303 is prepared, the portion of the first impurity ion region 301 which cannot be covered by the second impurity ion region 302 is covered by the third impurity ion region 303, and thus the problem of leakage of the first impurity ion region 301 due to contact with the insulating layer without being completely covered is overcome.

As shown in fig. 8, step 606 may include the following steps, based on the embodiment shown in fig. 6, described above:

in step 6062, an oxide insulating material is deposited on the surface of the second impurity ion region 302 to form an insulating layer.

Optionally, an oxide insulating material is deposited on the surface of the second impurity ion region 302, and a common oxide insulating material is silicon dioxide, silicon-phosphorus glass, or the like. By deposition of the peroxide insulating material, a vertical cross-sectional schematic of the photosensitive device can be obtained, which generates an insulating layer as shown in fig. 7-2.

In step 6064, the injection hole is defined on the insulating layer side by using the photoresist and the contact hole mask corresponding to the contact hole 304. Wherein, the contact hole mask plate shape completely corresponds to the contact hole 304.

Optionally, step 6064 may further comprise the steps of:

a1, spin coating photoresist on the surface of the insulating layer.

After spin coating the photoresist, a vertical cross-sectional schematic of the photosensitive device after spin coating the photoresist as shown in fig. 7-3 can be obtained.

and a2, exposing the photoresist by using a contact hole mask plate, developing, determining an injection hole, and removing the photoresist in the injection hole.

In this embodiment, in order to more accurately manufacture the contact hole, the characteristic that the photoresist can be exposed and developed is utilized, the contact hole mask is used to expose and develop the photoresist, so as to determine an injection hole with the area identical to that of the contact hole in the photoresist, and the photoresist in the injection hole is removed to obtain a schematic vertical cross-section of the photosensitive device after the injection hole is manufactured as shown in fig. 7-4.

and a3, performing chemical ion etching to remove the insulating layer in the injection hole.

On the basis that the injection hole is manufactured, the injection hole can be deeply penetrated into the insulating layer by chemical ion etching, the insulating layer in the injection hole is etched and removed, the area and the shape of the injection hole part in the insulating layer are identical with those of the injection hole part of the photoresist part, and the vertical cross-section schematic diagram of the photosensitive device subjected to the chemical ion etching is obtained as shown in fig. 7-5.

In addition, after the photosensitive device shown in 7-5 is obtained, for facilitating the subsequent operation, and the function of the photoresist has been completed, therefore, it may further include: a4, cleaning and removing the unexposed photoresist. At this time, a vertical cross-sectional schematic of the photoresist-removed photosensitive device as shown in fig. 7-6 can be obtained.

In step 6066, the impurity ions are implanted into the injection holes, and the third impurity ion region 303 having a different impurity ion concentration is formed on one side of the first impurity ion region 301 and the second impurity ion region 302.

Optionally, step 6066 may further include:

b1, carrying out impurity ion implantation on the injection hole.

Alternatively, the impurity ions may be arsenic ions and phosphorus ions. The present embodiment expects that the impurity ion type is the ion type of the third impurity ion region 303 after the impurity ion implantation; for example, ion types include, but are not limited to, N-type ions having impurity ion concentrations of 1e 18/cm 3 to 1e 22/cm 3 and depths of 100nm to 500nm.

In this embodiment, the depth of the impurity ion implantation is deep into the second impurity ion region 302 and the first impurity ion region 301, as shown in fig. 7 to 7, and the impurity ions are implanted into the upper side of one side of the second impurity ion region 302 and the first impurity ion region 301 based on the injection holes, so as to obtain a schematic vertical cross-sectional view of the photosensitive device after the impurity ions are implanted, as shown in fig. 7 to 7.

b2, performing thermal annealing treatment, and activating the implanted impurity ions to generate a third impurity ion region.

Wherein the thermal annealing temperature range is 700-1200 ℃, and the thermal annealing time range is 0.1 second-10 minutes. In this embodiment, the thermal annealing treatment is performed to activate the implanted impurity ions and to expand the region of the impurity implantation region, and after the thermal annealing treatment, a vertical cross-sectional schematic diagram of the photosensitive device in which the third impurity ion region is fabricated as shown in fig. 7-8 is obtained. Wherein the impurity ion region is generated as a third impurity ion region 303.

In this embodiment, the third impurity ion region 303 which does not exist in the prior art is first proposed, and the third impurity ion region 303 is fabricated above one side of the first impurity ion region 301 and the second impurity ion region 302 by distinguishing from the fabrication method in the prior art, and since the injection hole is generated based on the contact hole mask corresponding to the contact hole, the difference between the area of the third impurity ion region 303 fabricated based on the injection hole and the contact hole is small, and the second impurity ion region 302 can be seen to cover the first impurity ion region 301 as much as possible.

As shown in fig. 9, on the basis of the embodiment shown in fig. 6, step 608 may include the following steps:

in step 6082, a metal conductor material is deposited into the injection hole on the insulating layer side, and the injection hole is filled.

Alternatively, a vertical cross-sectional schematic of the photosensitive device after deposition of the metal conductor material as shown in fig. 7-9 may be obtained by deposition of the metal conductor material through the injection hole. Alternatively, the metallic conductor material may be any metallic material that can perform a conductor function.

In step 6084, the unnecessary metal conductor material is removed to form a contact hole.

Optionally, the unwanted metal conductor material is removed by chemical mechanical polishing. After depositing the metal conductor material, as shown in fig. 7-9, there is an excessive metal conductor material on the surface of the insulating layer, in order to generate a photosensitive device with smooth surface and only the metal conductor material in the contact hole, in this embodiment, the excessive metal conductor material on the surface of the insulating layer is removed by chemical mechanical polishing, and at this time, only the metal conductor material is deposited in the injection hole to form the contact hole; the other parts of the surface of the photosensitive device are insulating layers, and a vertical cross-sectional schematic diagram of the photosensitive device which is manufactured as shown in fig. 7-10 is obtained.

In the embodiment of the disclosure, the preparation process of the third impurity ion region 303 and the contact hole 304 is referred to as a self-aligned process, and the area of the third impurity ion region 303 on the semiconductor surface is slightly larger than the surface area of the contact hole 304, so that the area of the second impurity ion region 302 covering the top of the first impurity ion region 301 is maximized, and the leakage current of the first impurity ion region 301 due to contact with the oxide insulator is reduced to the greatest extent; furthermore, because the process of the contact hole 304 is relatively stable, that is, the process of the size and the position of the contact hole has relatively high manufacturing precision and small process fluctuation, the photosensitive devices of chips in different batches have consistent photosensitive response and low noise.

The preparation method of the photosensitive device effectively reduces the leakage current of the photosensitive device, improves the light response of the pixel photosensitive device, and further effectively improves the image quality of a sensor applying the photosensitive device, especially the image quality collected in a dark light environment.

The embodiment of the disclosure also provides an electronic device, including: the processor, and the memory communicatively connected with the processor, further including the photosensitive device or the sensor pixel unit provided in any one of the above embodiments;

The memory stores computer-executable instructions;

the processor executes computer-executable instructions stored by the memory to control the photosensitive device or sensor pixel unit.

The electronic device provided by the present disclosure may be incorporated as any one of the following: pulse cameras, high-speed cameras, audio/video players, navigation devices, fixed location terminals, entertainment units, smartphones, communication devices, devices in motor vehicles, cameras, motion or wearable cameras, detection devices, flight devices, medical devices, security devices, and the like.

The electronic device provided by the present disclosure may be applied to any one of the following: pulse cameras, high-speed cameras, audio/video players, navigation devices, fixed location terminals, entertainment units, smartphones, communication devices, devices in motor vehicles, cameras, motion or wearable cameras, detection devices, flight devices, medical devices, security devices, and the like.

Next, an electronic device according to an embodiment of the present disclosure is described with reference to fig. 10. The electronic device may be either or both of the first device and the second device, or a stand-alone device independent thereof, which may communicate with the first device and the second device to receive the acquired input signals therefrom.

As shown in fig. 10, the electronic device includes one or more processors and memory.

The processor may be a Central Processing Unit (CPU) or other form of processing unit having data processing and/or instruction execution capabilities, and may control other components in the electronic device to perform the desired functions.

In one example, the electronic device may further include: input devices and output devices, which are interconnected by a bus system and/or other forms of connection mechanisms (not shown).

In addition, the input device may include, for example, a keyboard, a mouse, and the like.

The output device may output various information including the determined distance information, direction information, etc., to the outside. The output device may include, for example, a display, speakers, a printer, and a communication network and remote output devices connected thereto, etc.

Of course, only some of the components of the electronic device relevant to the present disclosure are shown in fig. 10 for simplicity, components such as buses, input/output interfaces, and the like being omitted. In addition, the electronic device may include any other suitable components depending on the particular application.

Furthermore, embodiments of the present disclosure may also be a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, cause the processor to perform the method of manufacturing a photosensitive device according to the various embodiments of the present disclosure described in the above section of the present disclosure.

The computer readable storage medium may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may include, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium would include the following: an electrical connection having one or more wires, a portable disk, a hard disk, random Access Memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

The basic principles of the present disclosure have been described above in connection with specific embodiments, however, it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are merely examples and not limiting, and these advantages, benefits, effects, etc. are not to be considered as necessarily possessed by the various embodiments of the present disclosure. Furthermore, the specific details disclosed herein are for purposes of illustration and understanding only, and are not intended to be limiting, since the disclosure is not necessarily limited to practice with the specific details described.

In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, so that the same or similar parts between the embodiments are mutually referred to. For system embodiments, the description is relatively simple as it essentially corresponds to method embodiments, and reference should be made to the description of method embodiments for relevant points.

The block diagrams of the devices, apparatuses, devices, systems referred to in this disclosure are merely illustrative examples and are not intended to require or imply that the connections, arrangements, configurations must be made in the manner shown in the block diagrams. As will be appreciated by one of skill in the art, the devices, apparatuses, devices, systems may be connected, arranged, configured in any manner. Words such as "including," "comprising," "having," and the like are words of openness and mean "including but not limited to," and are used interchangeably therewith. The terms "or" and "as used herein refer to and are used interchangeably with the term" and/or "unless the context clearly indicates otherwise. The term "such as" as used herein refers to, and is used interchangeably with, the phrase "such as, but not limited to.

The methods and apparatus of the present disclosure may be implemented in a number of ways. For example, the methods and apparatus of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, firmware. The above-described sequence of steps for the method is for illustration only, and the steps of the method of the present disclosure are not limited to the sequence specifically described above unless specifically stated otherwise. Furthermore, in some embodiments, the present disclosure may also be implemented as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present disclosure. Thus, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

It is also noted that in the apparatus, devices and methods of the present disclosure, components or steps may be disassembled and/or assembled. Such decomposition and/or recombination should be considered equivalent to the present disclosure.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the disclosure to the form disclosed herein. Although a number of example aspects and embodiments have been discussed above, a person of ordinary skill in the art will recognize certain variations, modifications, alterations, additions, and subcombinations thereof.

Claims

1. A photosensitive device, characterized by comprising: a first impurity ion region, a second impurity ion region, a third impurity ion region, and a contact hole;

the first impurity ion region is used for collecting photoelectric charges;

2. The photosensitive device of claim 1, wherein the contact hole is a metal conductor.

3. The photosensitive device according to claim 1 or 2, wherein the first impurity ion region is provided with the third impurity ion region on a side close to the external component.

4. A photosensitive device according to any of claims 1-3, wherein said first impurity ion region and said second impurity ion region are different in ion type and different in impurity ion concentration; the first impurity ion region and the third impurity ion region are the same in ion type but different in impurity ion concentration.

5. The photosensitive device of any of claims 1-4, wherein said photosensitive device further comprises: a semiconductor substrate;

the first impurity ion region is disposed in the semiconductor body.

6. A sensor pixel cell, comprising: a photosensitive device, a reset transistor, and an auxiliary circuit according to any one of claims 1 to 5;

7. The pixel cell according to claim 6, wherein the third impurity ion region is disposed on a side of the first impurity ion region in the photosensitive device, which is adjacent to the reset transistor.

8. A method of manufacturing a photosensitive device, comprising:

manufacturing a first impurity ion region on a semiconductor substrate;

and manufacturing a contact hole above the third impurity ion region.

9. The method of claim 8, wherein fabricating a third impurity ion region on one side of the first impurity ion region and the second impurity ion region, comprises:

10. The method of claim 9, wherein the implanting the impurity ions into the injection hole creates a third impurity ion region having a different impurity ion concentration on one side of the first impurity ion region and the second impurity ion region, comprising:

11. The method according to claim 9 or 10, wherein determining an injection hole at the second impurity ion region side by using a contact hole mask corresponding to the photoresist and the contact hole, comprises:

spin-coating photoresist on the surface of the insulating layer;

12. The method of claim 11, wherein the chemical ion etching, after etching the insulating layer in the injection hole, further comprises:

the unexposed photoresist is removed by cleaning.

13. The method of any of claims 9-12, wherein forming a contact hole over the third impurity ion region comprises:

and removing unnecessary metal conductor materials to form the contact hole.

14. An electronic device, comprising: a processor, and a memory communicatively coupled to the processor, further comprising the photosensitive device of any one of claims 1-5 or the sensor pixel unit of claim 6 or 7;

the memory stores computer-executable instructions;

15. The electronic device of claim 14, wherein the electronic device is incorporated as any one of: pulse cameras, high-speed cameras, audio/video players, navigation devices, fixed location terminals, entertainment units, smartphones, communication devices, devices in motor vehicles, cameras, motion or wearable cameras, detection devices, flight devices, medical devices, security devices.