KR20010095837A - Phase shift mask having controlled transmittance with respect to a predetermined wavelength of light by using energy trap and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A phase shift mask for controlling transmissivity of a wavelength using an energy trap and a method for manufacturing the same are provided to form a phase shifter material of high transmissivity with a wavelength longer than an exposure light with a short wavelength. CONSTITUTION: An energy trap is formed around the energy level of a test light having a wavelength longer than the wavelength of an exposure light by using a semitransparent phase shift material for an exposure light with a predetermined wavelength as a main material on a transparent substrate. A phase shift layer is formed by adding a material for reducing transmissivity of the test light. A shielding layer is formed on the phase shift layer in order to shield the exposure light. The main of the phase shift material includes Cr, Al, and O. Er is used as the material for forming the energy trap around wavelength of the test light.

Description

Phase shift mask having controlled transmittance with respect to a predetermined wavelength of light by using energy trap and manufacturing method

The present invention relates to a phase shift mask and a method of manufacturing the same.

The manufacturing process of a semiconductor device is performed by repeatedly forming a pattern of various materials on a substrate (wafer) and patterning (etching) the same into a predetermined shape. In this case, in order to etch a predetermined layer of material into a desired pattern, a photolithography process, commonly referred to as photolithography, is performed. That is, a photomask is formed on the predetermined material layer, and a photomask (12) having a light shielding film pattern (12) defining a region for blocking light on the transparent substrate (10) as shown in FIG. A photomask, strictly speaking, refers to a mask having the same size as a pattern formed on a mask and a photoresist film pattern formed by actual exposure, and in which a pattern enlarged several times larger than the pattern actually formed in a reduced projection exposure method is formed. The mask is particularly called a reticle (hereinafter referred to as a mask without distinction), and when light of a predetermined wavelength is irradiated to the mask (14), the portion of the photoresist film irradiated with light is irradiated with the pattern of the mask. That is not formed. Subsequently, when the photoresist film is developed to remove a portion to which light is irradiated or a portion not to be irradiated, a photoresist film pattern is formed along the pattern of the mask. The material layer of the desired pattern is obtained by actually etching the material layer using the thus obtained photoresist film pattern as an etching mask.

By the way, as the degree of integration of semiconductor devices increases, the line width of the material layer pattern becomes narrower. As a result, it is difficult to obtain a desired line width pattern with a conventional mask as shown in the upper portion of FIG. That is, when the line width of the pattern engraved on the mask is reduced, the light reaching the surface of the photoresist film due to the diffraction of the irradiated light has a noticeable difference in intensity at the boundary between the light blocking region 18 and the light transmitting region 16 as shown in the graph of FIG. 1. Invisible

In order to solve this problem, light having a short wavelength of less diffraction, for example, a wavelength of 248 nm or 193 nm may be used as an exposure source. However, as the line width becomes thinner, the shortening of the exposure source does not solve this problem. Accordingly, a phase shift mask has appeared to cause the destructive interference at the boundary between the light transmitting region 16 and the light blocking region 18 by using the interference of light.

The phase shift mask shown in the upper part of FIG. 2 is an attenuated, or half-tone, phase shift mask. The phase shift mask 22 is formed of a transparent substrate 20 and a phase shifter material. Equipped. As the phase shifter material, CrO, CrF, MoSiON, SiN, spin on glass (SOG), etc. are generally used. Although not shown, the phase shift mask includes a mask having a shifter pattern formed of SOG on or under a light shielding film pattern, and a transparent substrate itself is etched to a predetermined depth without using a separate phase shifter material to provide a transmission length of light. There are also substrate etching masks that shift phases by different phases (particularly, when the phase shift region and the simple light transmitting region are alternately formed, they are called Levenson type phase shift masks).

Referring to FIG. 2, the principle of a general phase shift mask will be described. Light passing through the light-transmitting region 26 has a phase and amplitude as shown by the dotted line 30 in the central part graph of FIG. Light passing through the phase shift region 28 is inverted in phase by 180 degrees and has the same phase and amplitude as the dotted line 32. Therefore, the final phase and amplitude of the light on the surface of the photoresist film become like the solid line 34. The light intensity on the surface of the photoresist film is as shown in the lower graph of FIG. 2. Finally, comparing the lower graphs of FIGS. 1 and 2, the intensity of the phase shift mask of FIG. 2 at the boundary between the light transmitting regions 16 and 26 and the light blocking region 18 or the phase shift region 28 is more robust. You can see the difference.

However, in the intensity graph of FIG. 2, it can be seen that a secondary peak called side-lobe 36 is formed in the phase shift region 28. The side lobe 36 is inevitably generated as long as the phase shifter pattern 22 does not completely block light. If the size of the side lobe is larger than a predetermined reference value, the side lobe is exposed to a photoresist film to remove unwanted patterns from the actual material layer. cause. Therefore, a light shielding film may be formed on the center portion of the phase shifter pattern 22 to prevent the side lobe 36, but this method cannot be used when the width of the phase shifter pattern 22 is small. There is also a method of using a phase shifter material having a low transmittance (typically 5-10) to reduce the side lobe 36. However, this reduces the efficiency of the phase shift mask by that much. That is, as can be seen in the phase graph of FIG. 2, the higher the transmittance of the phase shifter material is, the larger the amplitude 32 of light passing through the phase shift region 28 is, and the transmissive region 26 and the phase shift region 28 are separated. The effect of the destructive interference at the boundary is greater, and the boundary between the light transmissive area 26 and the phase shift area 28 is assured.

On the other hand, the problem of this side lobe is deeply related to the performance of the photoresist film. That is, when the photoresist film is exposed to a certain intensity (energy), the portion is dissolved and removed by a developer to form a photoresist film pattern. If the photoresist film itself is good, the strength of the side lobe is somewhat high. Even if the photoresist film is not dissolved by the developer (if the contrast of the photoresist film is high), a phase shifter material having a high transmittance (for example, about 40) can be used to increase the efficiency of the phase shift mask. In recent years, in order to meet these demands, a photoresist having a high contrast has been developed. Accordingly, a phase shift mask using a high transmittance phase shifter material is required.

It is an object of the present invention to provide a phase shifter material having a relatively high transmittance with respect to relatively short exposure light.

It is an object of the present invention to provide a method of controlling the transmittance of a phase shifter material to have a transmittance that can be inspected with respect to inspection light having a high transmittance and a wavelength longer than the wavelength of the exposure light.

It is an object of the present invention to provide a phase shift mask using the phase shifter material described above.

It is an object of the present invention to provide a method of manufacturing the phase shift mask described above.

1 is a schematic cross-sectional view of a conventional photomask and a graph showing the phase and intensity of light on the surface of a photoresist film when exposed using this photomask.

2 is a schematic cross-sectional view of a general attenuated phase shift mask and a graph showing the phase and intensity of light on the surface of a photoresist film when exposed using this phase shift mask.

3 to 5 are graphs showing transmittances of CrAlO films according to Al / Cr ratios for light having wavelengths of 193 nm, 248 nm, and 365 nm, respectively.

6 is a graph showing the transmittance of a phase shifter material whose transmittance is reduced near a predetermined wavelength by an energy trap.

FIG. 7 is a graph showing the transmittances of CrAlO films and CrAlON films, and films in which a small amount of erbium is added thereto according to an embodiment of the present invention.

8 and 9 are cross-sectional views illustrating a process of manufacturing a phase shift mask according to the present invention.

10 is a schematic diagram of an apparatus for sputtering equipment used to manufacture a phase shift mask according to the present invention.

In order to achieve the above technical problem, the present invention uses a phase shifter material which is translucent with respect to exposure light of a predetermined wavelength as a phase shifter material, and has an energy trap (i.e., near the wavelength of inspection light having a wavelength longer than the exposure light). Provided are a method of reducing transmittance to inspection light by adding a small amount of a material forming an energy trap, and a phase shift mask using the same.

In an embodiment of the present invention provides a material comprising Cr, Al and O as the phase shifter material to be the base material.

In addition, the phase shifter material serving as the base material may further include N in Cr, Al, and O.

In an embodiment of the present invention, Er is provided as an example of a material forming an energy trap near the wavelength of the inspection light.

A phase shift mask in which a small amount of Er is added as a material for forming an energy trap near the wavelength of the inspection light may be manufactured as follows. First, a transparent substrate is prepared, and a small amount of Er is added to form a phase shift layer using a phase shifter material translucent to exposure light of a predetermined wavelength on the transparent substrate as a base material, and then opaque to exposure light on the phase shift layer. One light shielding film is formed.

Here, when using a material containing Cr, Al and O as the base material and a small amount of Er is added, the phase shift layer is an alloy target containing Er in a predetermined ratio in Cr and Al, an alloy target of Cr and Al And Er may be formed by sputtering by using a multi-target formed with a separate target, or a multi-target formed by Cr, Al and Er, respectively, as a separate target, wherein the source of O is inside the sputtering chamber. As a result, O ₂ gas is supplied at a predetermined flow rate.

In addition, when a material containing Cr, Al, O, and N is used as the base material and a small amount of Er is added, this phase shift layer is formed by further supplying N ₂ gas at a predetermined flow rate as a source of N during sputtering. can do.

Hereinafter, a phase shifter material, a phase shift mask using the same, and a method of manufacturing the same will be described with reference to the accompanying drawings.

First, the mechanism by which the transmittance of the phase shifter material is determined will be described as follows.

The transmittance of the phase shifter material is closely related to the composition of the material and the wavelength of the exposure light. That is, the energy band gap Eg of the phase shifter material, that is, when the energy of the exposure light is very small or large compared to the energy required when the electrons of the phase shifter material are excited to another orbit, the energy of the exposure light is determined by the phase shifter material. Since most of the exposure light passes through the phase shifter material as it does not excite electrons, when the exposure light energy is similar to or slightly larger than the energy band gap of the phase shifter material, the exposure light energy is used to excite the electrons in the phase shifter material. As a result, the exposure light is absorbed by the phase shifter material. In particular, in the short wavelength ranges of interest such as 193 nm, 248 nm, and 365 nm, the shorter the wavelength, the greater the energy of the exposure light and the closer the energy band gap of the phase shifter material. Therefore, the shorter the wavelength of the exposure light in this range, the lower the transmittance of the exposure light to the phase shifter material. As a result, the conventional shifter material is a material having a transmittance of 1 to 30 with respect to exposure light having a wavelength of 248 nm or 365 nm, and becomes substantially opaque to light having a shorter wavelength (for example, 193 nm wavelength) and becomes a simple light shielding film. . Accordingly, the present applicant developed a phase shifter material having an appropriate transmittance even for light having a short wavelength and applied for a patent application on October 16, 1996 (Application No. 1996-46357). This patent discloses a material having a composition of CrAlO obtained using chromium oxide (Cr ₂ O ₃ ) and alumina (Al ₂ O ₃ ) as phase shifter materials satisfying the above conditions.

However, high transmittance phase shifter materials including CrAlO films have the following problems. In general, after the mask is manufactured in a desired pattern, the defect is inspected for defects. The inspection is usually performed by irradiating light having a constant wavelength on one side of the mask and detecting the intensity of light detected by a photodetector located on the opposite side of the mask. It is measured to see if the mask is manufactured in the desired pattern. By the way, the wavelength of the inspection light used in the inspection equipment is generally longer than the wavelength of the exposure light used in the actual photo process using the mask. This is because the inspection light is gradually becoming shorter in accordance with the shortening of the exposure light. However, in general, the shortening of the exposure light proceeds first and the inspection equipment is subsequently developed. In addition, the high cost of the inspection equipment makes it difficult to purchase a short wavelength inspection equipment in accordance with the wavelength of the exposure light.

Therefore, the transmittance of the phase shifter pattern determined according to the wavelength of the exposure light used in the actual exposure shows a much larger transmittance for the inspection light having a wavelength longer than the wavelength of the exposure light, and with the transmissive region where the phase shifter material is not formed. The difference in transmittance is not so large that it is impossible to check whether the pattern is properly formed. This will be described in detail with reference to FIGS. 3 to 5 as follows.

3 to 5 are graphs showing transmittances of CrAlO films, which are phase shifter materials, to light having wavelengths of 193 nm, 248 nm, and 365 nm, respectively. In each graph, the horizontal axis represents the composition ratio of Al / Cr, the vertical axis represents the thickness of the CrAlO film, and the lines 40 and 45 represent the thickness of the CrAlO film when the phase is reversed to 180 °. In each graph, it can be seen that as the Al / Cr ratio increases, the transmittance increases, and as the wavelength increases (that is, from FIG. 3 to FIG. 5), the transmittance increases. For example, when the wavelength of the exposure light is 193 nm and the transmittance at this time is 20, the film thickness at this time is approximately 124 nm and the composition ratio of Al / Cr is approximately 4.5. If the wavelength of the inspection light is 365 nm, when the transmittance is read at the point where the phase inversion line 40 and the line 50 having the Al / Cr composition ratio of 4.5 on the horizontal axis meet in FIG. .

Therefore, the phase shifter material should not only have a high transmittance for short wavelength exposure light but also have a rapid increase in transmittance even for inspection light having a wavelength longer than the exposure light. Thus, the specific conditions required for the phase shifter material according to the embodiment of the present invention described below are as follows. That is, it should have a transmittance of 5-50 with respect to exposure light, invert the phase of exposure light to 180 degrees, and have a transmittance below 50 with respect to inspection light.

Accordingly, the present applicant has developed a CrAlON film as a phase shifter material that satisfies the above conditions by further adding an N component to the CrAlO film and filed a patent application on September 18, 1999 (Application No. 1999-40288).

In the present invention, a phase shifter material having a relatively high transmittance for exposure light having a relatively short wavelength, such as the CrAlO film or CrAlON film, is further added to the phase shifter material having an energy trap for reducing the transmittance in the wavelength band of the inspection light. We propose a phase shifter material that satisfies the condition of.

First, the energy trap will be described as follows.

The decrease in the transmittance of a material to light of a certain wavelength is when the energy of the light is close to the energy needed to excite the electrons that make up the material into another orbit, as described above. Energy traps are also described on this principle, but energy traps are a phenomenon that occurs when a small amount of a certain substance is added to the base material. For example, in the case of a material in which 0.05 Cr ³⁺ ions are added using Al ₂ O ₃ as a base material, the transmittance with respect to the wavelength of light is shown in FIG. 6. 6, small amounts of added Cr ³⁺ ions have only a transmittance near a predetermined wavelength (about 380 nm and 520 nm) with little effect on the basic transmittance 60 characteristics of Al ₂ O ₃ shown in dashed lines. It is greatly dropped (62). That is, light having a wavelength near the predetermined wavelength can be almost used for excitation of electrons forming Cr ³⁺ ions. Therefore, for example, when the wavelength of inspection light is 365 nm, the transmittance can be reduced to an appropriate level as compared with the case where Cr ³⁺ ions are not added. By the way, when a large amount of Cr ³⁺ ions is added rather than a small amount compared to the base material (that is, the above-mentioned CrAlO film), such an energy trap is not formed. This is because a large amount of added Cr does not have an independent energy level but is absorbed in the energy band of the entire material. As a result, by adjusting the addition ratio of Cr ³⁺ ions, it is possible to adjust the effect of the energy trap so as to have an appropriate transmittance at the wavelength of the desired inspection light.

However, a substance in which Cr ³⁺ ions are added to Al ₂ O ₃ in a small amount is not suitable as the phase shifter material to which the present invention is directed. This is because, as shown in FIG. 6, the transmittance is almost zero at a short wavelength, that is, 193 nm, and there is no condition that satisfies an appropriate refractive index (n) and an extinction coefficient (k). Therefore, in this embodiment, Er is proposed as a material for forming such an energy trap.

Er ³⁺ ions form energy traps at about 380 nm and 520 nm similarly to Cr ³⁺ ions. Therefore, when a small amount of Er ³⁺ ions is added to a material having a relatively high transmittance in the exposure wavelength of short wavelength but high transmittance such that inspection is not possible in the inspection light of longer wavelength, it has little influence on the basic transmittance tendency and As a result, it is possible to reduce transmittance for inspection light having a long wavelength, for example, 365 nm. As such a base material, CrAlO or CrAlON described above may be used.

7 is a graph showing the transmittance with respect to the wavelength of light when a small amount of Er ³⁺ ions is added to CrAlO and CrAlON. In the drawings, reference numerals 70 and 72 are the transmittance graphs of the CrAlO film and the CrAlON film, respectively, and 74 and 76 are the transmittance graphs when small amounts of Er ³⁺ ions are added thereto, respectively. Here, the composition ratio and thickness of the CrAlO film 70 and the CrAlON film 72 are as follows.

Cr (atomic) Al (atomic) O (atomic) N (atomic) Film thickness CrAlO Film (70) 15.6 20.1 64.3 0 738 CrAlON Films (72) 32.0 27.7 16.0 24.3 329

In FIG. 7, the degree of decrease in transmittance with respect to inspection light (365 nm wavelength) may be controlled by adjusting the addition rate of Er ³⁺ ions.

Next, a phase shift mask and a method of manufacturing the same according to an embodiment of the present invention will be described in detail.

First, the phase shift mask of this embodiment will be described in detail with reference to FIGS. 8 and 9. 8 is a cross-sectional view of a blank phase shift mask made in accordance with an embodiment of the present invention. Here, the blank mask refers to a mask in which no pattern is formed as shown. In actual exposure, a mask as shown in FIG. 9 is formed by etching the light shielding film 84 and the phase shift layer 82 in the exposed region 86, which is the central portion of the blank mask, to form a desired pattern. Meanwhile, in FIGS. 8 and 9, unlike the FIGS. 1 and 2, the transparent substrate 80 faces downward, but for convenience of description, when the exposure is performed using the mask according to the present invention, the transparent substrate 80 is usually used. ) Is directed toward the exposure source. In addition, an antireflection film made of a material having a low reflectance such as chromium oxide is usually formed on the light shielding film 84 made of chromium. In FIG. 8 and FIG. 9, the illustration is omitted.

Referring back to FIG. 8, the phase shift mask of this embodiment is made of a material such as chromium and phase shift layer 82 formed by adding a small amount of Er ³⁺ ions to CrAlO or CrAlON on a transparent substrate 80 such as glass. The light shielding film 84 which was formed is formed. Here, the transmittance and phase shift amount with respect to the wavelength of light used for exposure vary depending on the thickness of the phase shift layer 82, and the transmittance and phase shift amount are also determined by the composition ratio of CrAlO or CrAlON and the added Er ³⁺ ions. Depends on the quantity Therefore, the film thickness and composition ratio which show the transmittance | permeability of 5-50 and 180 degree phase shift in the wavelength of exposure light to be used are adjusted suitably according to a desired application.

Referring to FIG. 9, the mask used in the actual exposure process is mounted on the exposure area 86 where the light shielding film 84 is removed and the desired phase shifter pattern 82 'is formed, and the identification number of the mask, exposure equipment or inspection equipment. Is composed of a peripheral region 88 in which an alignment key or the like for alignment is formed. In general, the attenuated phase shift mask removes all of the light blocking film from the exposure area 86 and forms the exposure area 86 using only the phase shifter pattern 82 ', but the phase shifter pattern 82' is used to prevent the side lobe described above. Where the width is wide, the light shielding film pattern 84 'may be left in the center of the phase shifter pattern 82'.

Hereinafter, a method of manufacturing a phase shift mask according to an embodiment of the present invention as described above will be described in detail. In particular, since the features of the present invention reside in the phase shift layer, the description will be given mainly on the process of forming the phase shift layer.

First, a manufacturing process of the blank phase shift mask shown in FIG. 8 will be described.

Although the blank phase shift mask according to the present embodiment can be formed by another method, for example, chemical vapor deposition or the like, the case where the blank phase shift mask is formed by the sputtering method will be described.

The blank phase shift mask is manufactured using sputtering equipment as shown in FIG. 10. The sputtering equipment shown in FIG. 10 includes a chamber 100, a gas inlet 112 through which reaction gases are supplied, and a chamber 100. A pump 120 and an exhaust port 118 for adjusting the pressure are provided. Each gas inlet is equipped with a mass flow controller 114 and a control valve 116 to adjust the flow rate or control the supply / discharge of the gas. The control valve 122 is also attached to the exhaust port 118. In the chamber 100, a support 102 on which the mask substrate 104 is placed is provided, and a positive pole of a DC power supply is connected to the support 102. On the opposite side of the substrate 104 a target 108 made of the material to be deposited is connected to the negative electrode 106. Here, the target 108 was used as one target made of an alloy in which a small amount of erbium (Er) was added to aluminum and chromium, but a multi-target consisting of an alloy target of aluminum and chromium and an erbium target, or each of aluminum, It is also possible to use multi-targets made of chromium and erbium. Below the target 108, a shutter 110 is provided to block the target material separated from the target from reaching the substrate 104. Although not shown, a magnet may be provided on the target 108 to apply a magnetic field to sputter gas ions or target material ions. In addition, although only one pump 120 is illustrated in FIG. 10, the pump 120 may further include a turbo pump for forming a high vacuum at a high speed.

The process of manufacturing the blank phase shift mask according to the present invention using the sputtering apparatus shown in FIG. 10 is as follows.

First, a transparent substrate 104, such as glass or quartz, is placed on the support 102, and the pump 120 is operated to remove impurities in the chamber 100. Exhaust to a pressure of about Torr. When impurities in the chamber 100 are sufficiently removed, a direct current power source having a power of approximately 60 to 100 W is applied to the support 102 and the electrode 106. When the flow control system 114 and the valve 116 of the gas inlet 112 are controlled to supply Cr ₂ O as a base gas, O ₂ gas is supplied as a reaction gas, and when CrAlON is used as a base gas, O ₂ and N ₂ are used as the reaction gas. Supply gas. In addition, argon ions (Ar +) are supplied as the sputter gas. At this time, the shutter 110 is closed. Afterwards, the pressure inside the chamber 100 is maintained at about 5-8E-3 Torr. In addition, the substrate temperature is maintained at room temperature.

When a predetermined time elapses with the shutter 110 closed, argon ions collide with the target 108 to remove impurities on the surface of the target 108, and the sputter yield reaches an equilibrium state. , Al and Er are separated by alloy ratio. After the shutter 110 is opened, the separated target material and oxygen or oxygen and nitrogen are deposited on the transparent substrate 104 to form a CrAlO film or a CrAlON film to which a small amount of Er is added.

At this time, the composition of the CrAlO film or CrAlON film to which a small amount of Er deposited on the transparent substrate 104 is added is determined by the alloy ratio of chromium, aluminum and erbium of the target 108 and the flow rate ratio of O ₂ or O ₂ and N ₂ . Is determined. Thus, the flow rate of the alloy is used for the target, and O ₂ and N ₂ as determined according to a desired composition ratio is adjusted appropriately in less than 20 sccm, respectively. In addition, the flow volume of argon gas as a sputter gas is adjusted suitably in the range of 7-30 sccm. On the other hand, in the case of using a multi-target, the area of each target may be changed while considering the sputter yield of chromium, aluminum and erbium so that chromium, aluminum and erbium are separated at a desired ratio.

CrAlO film with a small amount of Er, which is a phase shift layer, or a CrAlO film with a thickness of Er, such that the phase of the exposure light passing through the CrAlON film (82 in FIG. 8) is shifted by 180 ° according to the wavelength of the exposure light to be used during exposure. Alternatively, the above sputtering is continued until a CrAlON film is obtained, and then stopped when the desired thickness is obtained.

Subsequently, the target 108 is changed (or in a sputtering apparatus equipped with another target) to sputter for a predetermined time to form a light shielding film (84 of FIG. 8) and an antireflection film.

Next, the manufacturing method of the patterned phase shift mask used at the time of actual exposure shown in FIG. 9 is demonstrated.

The phase shift mask shown in FIG. 9 is obtained by etching the exposure area 86 of the blank phase shift mask manufactured as described above in a predetermined pattern.

First, both the antireflection film and the light shielding film 84 of the exposure area 86 are removed with respect to the blank mask of FIG. 8. In this case, the light shielding film may be partially left to prevent side lobes as described above.

Subsequently, etching is performed to actually form a phase shifter pattern. Here, the case where the CrAlO film or the CrAlON film to which a small amount of Er is added is added by plasma etching will be described.

To etch the phase shift layer, an electron beam resist is usually applied to the entire surface of the mask from which the light shielding film has been removed or partially left, and the electron beam is irradiated in a desired pattern. Subsequently, an electron beam resist pattern is formed through a developing step of removing the portion irradiated by the electron beam. Using the electron beam resist pattern as a mask, a transparent substrate is exposed by reactive ion etching using a small amount of Er-added CrAlO film or CrAlON film using, for example, Cl ₂ and O ₂ gases, thereby exposing the electron beam resist pattern. Removing all of them gives a phase shift mask for actual exposure, in which a phase shifter pattern is formed in a desired pattern.

As described above, the phase shift layer according to the present invention, that is, a film having a small amount of a substance that forms an energy trap near a predetermined wavelength of inspection light based on a material having a desired transmittance with respect to exposure light of a predetermined wavelength, The transmittance is reduced near the wavelength of the inspection light while maintaining the overall transmittance characteristics of the base material. Accordingly, the phase of the exposure light is inverted to 180 ° at a predetermined thickness with a transmittance of 5 to 50 with respect to the exposure light, and transmittance of 50 or less can be obtained for the inspection light having a longer wavelength than the exposure light. Therefore, the CrAlO film or the CrAlON film to which a small amount of Er is added according to the present invention can be used as a relatively high transmittance phase shift layer that ensures high resolution for exposure light having wavelengths of, for example, 193 nm and 248 nm. Branches can also be inspected by showing relatively low transmittance with respect to the inspection light.

Claims (6)

Transparent substrates; And A phase shifter material semitransparent to exposure light of a predetermined wavelength is formed on the transparent substrate, and an energy trap is formed near a wavelength of inspection light having a wavelength longer than that of the exposure light, thereby reducing the transmittance of the inspection light. A phase shift mask comprising a phase shift layer to which a small amount of a substance to be shaken is added. The phase shift mask of claim 1, wherein the base material of the phase shifter material comprises Cr, Al, and O. 3. A phase shift mask according to claim 1 or 2, wherein the material forming the energy trap near the wavelength of the inspection light is Er. Preparing a transparent substrate; A phase shifter material semitransparent to exposure light of a predetermined wavelength is formed on the transparent substrate, and an energy trap is formed near a wavelength of inspection light having a wavelength longer than that of the exposure light, thereby reducing the transmittance of the inspection light. Forming a phase shift layer containing a small amount of the falling material; And And forming a light shielding film that is opaque to the exposure light on the phase shift layer. The method of claim 4, wherein the forming of the phase shift layer comprises using a material including Cr, Al, and O as a base material of the phase shifter material, and forming an energy trap near a wavelength of the inspection light. Phase shift mask, characterized in that using. The method of claim 5, wherein the forming of the phase shift layer is performed by depositing by sputtering using an alloy target of Cr, Al and Er or a multi-target formed of Cr, Al and Er as separate targets, respectively. At this time, the phase shift mask manufacturing method characterized in that the supply of O ₂ gas into the sputtering chamber.