JPH0934099A - Phase shift mask and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain a phase shift mask having an exact phase shift quantity in a relatively simple stage. SOLUTION: Light shielding film patterns 2a constituting transfer patterns of light shielding parts 21 and light transparent parts 22 are formed within the transfer region E1 on a transparent substrate 1. At least a part of these light shielding film patterns 2a are provided with patterns having the light transparent parts 22 arranged on both sides of the light shielding parts 21. The light shielding patterns 2a of the phase shift mask having phase shift parts 23 formed by removing the transparent substrate 1 in the thickness direction by as much as a prescribed depth in one of the transparent parts 22 disposed on both sides of the light shielding parts 21 are composed of a material removable by an etching method common to an etching method used at the time of removing part of the transparent substrate 1 in order to form the phase shift parts 23, thereby, the common use of the pattern exposure for forming the phase shift parts 23 with the pattern exposure common to the exposed patterns of approximately half parts of the light shielding film patterns 2a is made possible without separately executing the pattern exposure for forming the phase shift parts 23. The time for plotting by exposure is shortened and the control of the phase shift quantity is made extremely easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to improve the resolution of a transfer pattern by providing a phase shift portion which gives a phase difference between exposure lights passing through light transmitting portions on both sides of a light shielding portion of the transfer pattern. A phase shift mask, which forms a transfer pattern on a light-shielding layer formed on a transparent substrate with or without a transparent layer interposed therebetween, and at least one of light-transmitting portions existing on both sides of the light-shielding portion of the transfer pattern. The present invention relates to a phase shift mask in which a phase shift portion is formed by removing a light-shielding layer on the side of and then further removing a part of a transparent layer or a transparent substrate to a predetermined depth by an etching method, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A transfer pattern is formed on a light-shielding layer formed on a transparent substrate with or without a transparent layer in between.
By removing the light-shielding layer on at least one side of the light-transmitting portions existing on both sides of the light-shielding portion of this transfer pattern, and further removing a part of the transparent layer or the transparent substrate to a predetermined depth by an etching method, the phase shift A phase shift mask configured to form a portion is conventionally known.

As an example of a method of manufacturing this type of phase shift mask, for example, reference [(SPIE Vol. 1604, 1991, 2
36]. FIG. 7 is an explanatory diagram of this conventional method. Hereinafter, this method will be described with reference to FIG.

First, a chrome light-shielding film 2 is formed on a quartz substrate 1 and a resist film 3 is formed thereon to obtain a mask blank (see FIG. 7 (a)).

Next, the resist film 3 is exposed to a transfer pattern by electron beam drawing and developed to form a resist pattern 3a (see FIG. 7 (b)).

Next, the chrome light-shielding film 2 is etched by using the resist pattern 3a as a mask to form the light-shielding film pattern 2a.
After forming and peeling and cleaning the used resist,
Check and correct (see Fig. 7 (c)).

Next, a resist film 4 for forming a phase shift portion is formed on the substrate on which the light shielding film pattern 3a is formed (see FIG. 7D).

Next, the resist film 4 is subjected to pattern exposure of the phase shift portion by electron beam drawing and developed to form a resist pattern 4a (see FIG. 7 (e)). in this case,
The resist pattern 4a is formed such that every other light-transmitting portion of a pattern in which light-transmitting portions and light-shielding portions are alternately present is covered with a resist, and the upper surfaces of two adjacent light-shielding portions are partially covered. It is a pattern that seems to have been crossed over.

Next, the phase shift portion 23 is formed by etching the substrate 1 to a predetermined depth using the resist pattern 4a and the light shielding film pattern 2a as a mask (see FIG. 7 (f)). After removing and cleaning the resist, the inspection and correction are performed to obtain a phase shift mask (see FIG. 7).
(g)).

In this manufacturing method, it is known that the light-shielding film may be damaged when the quartz substrate 1 is etched, and an improvement plan thereof is described in, for example, Japanese Patent Application Laid-Open No. 6-51490. The method of is proposed. FIG. 8 is an explanatory diagram of this method. Hereinafter, this method will be described with reference to FIG.

First, a chrome light-shielding film 2 is formed on a quartz substrate 1 and a resist film 3 is formed thereon to obtain a mask blank (see FIG. 8 (a)).

Next, the resist film 3 is exposed to a transfer pattern by electron beam drawing and developed to form a resist pattern 3a (see FIG. 8B).

Next, the chrome light-shielding film 2 is etched by using the resist pattern 3a as a mask to form the light-shielding film pattern 2a.
After forming and peeling and cleaning the used resist,
Check and correct (see Fig. 8 (c)). The process up to this step is the same as that of the above-described manufacturing method.

Next, a resist film 4 for forming a phase shift portion is formed on the substrate on which the light shielding film pattern 3a is formed. However, the resist film 4 formed here is a positive type or negative type, but it is an image reversal-compatible resist that can be converted to the other type by applying a predetermined process. Next, the resist film 4 is exposed to the pattern of the phase shift portion by electron beam drawing and baked, and then back exposed from the back surface of the substrate 1 using the light shielding film pattern 2a as a mask (FIG. 8 (d). )).

Next, the antistatic agent applied to the resist film 4 is removed and the resist film 4 is developed to form a resist pattern 4a (see FIG. 8 (e)). In this case, the resist pattern 4a covers every other light-transmitting portion of the pattern in which light-transmitting portions and light-shielding portions are alternately present, and covers the entire upper surfaces of two adjacent light-shielding portions. It is the formed pattern.

Next, the substrate 1 is etched to a predetermined depth using the resist pattern 4a and the light shielding film pattern 2a as a mask to form a phase shift portion 23 (FIG. 8 (f)).
After removing and cleaning the used resist, the inspection and correction are performed to obtain a phase shift mask (see FIG. 8 (g)).

According to this method, since the Cr light shielding film is covered with the resist and is not exposed in the etching atmosphere, the light shielding film is not damaged.

[0018]

In any of the conventional manufacturing methods described above, in the case of exposure by electron beam drawing, first, the transfer exposure of the entire transfer pattern is performed, and then the phase shift is performed separately. It is necessary to perform drawing exposure of a partial pattern. Therefore, the drawing amount is almost 1.5 times the drawing amount of the entire transfer pattern. For this reason, exposure takes time and makes rapid manufacture difficult.

Further, since the exposure of the phase shift portion is performed on the resist film formed on the quartz substrate (non-conductive member), when electron beam drawing is selected as the exposure method, the manufacturing process is performed. Unless increased and some charge-up prevention processing is performed, pattern shape defects and position accuracy defects due to charge-up occur.

Further, in the step of forming the pattern of the phase shift portion, if the shifter portion is not formed due to an abnormal drawing such as data loss during drawing, the current defect inspecting machine will detect a defect. Detection may not be possible. That is, in the current defect inspection machine, FIG.
It may not be possible to distinguish between the case shown in Fig. 9 and the case shown in Fig. 9 (b), and it should be something like that shown in Fig. 9 (b). Even if the pattern is as shown, it is difficult to detect it with the current defect inspection machine.

Further, in the above-mentioned conventional method, as a method of forming the phase shift portion, a part of the quartz substrate of the light transmitting portion where the light shielding film is removed by forming the entire transfer pattern is further formed in the thickness direction. A method of removing only the amount necessary to obtain a desired amount of phase shift is adopted. In order to obtain an accurate phase shift amount by this method, it is necessary to make the removal amount of the quartz substrate accurate, but it is not always easy to make the removal amount accurate by one etching. Moreover, in the case of the quartz substrate, it is not always easy to correct the depth (removal amount) of the phase shift portion once formed, and if it is removed too much, the correction itself becomes very difficult.

Further, as a defect which may occur on the surface of the removed portion of the quartz substrate when forming the phase shift part, in the case of the defect as shown in FIG. Focused Ion Beam (FIB)
In the apparatus according to the method, since the defect portion is made of the same material as the base material, there is a problem that the defect detection becomes difficult and the correction accuracy deteriorates.

Further, in the case of the former conventional example described above, since a part of the light shielding film is exposed during the etching of the quartz substrate for forming the phase shift portion, the light shielding film is exposed by the etching. The pattern may be damaged, and the surface of the quartz substrate may be roughened. In the case of the latter conventional example for avoiding this,
The process becomes extremely complicated, such as providing a back exposure process.

The present invention has been made under the background described above, and provides a phase shift mask and a manufacturing method thereof capable of obtaining a phase shift mask having an accurate phase shift amount by a relatively simple process. The purpose is to provide.

[0025]

In order to solve the above-mentioned problems, a phase shift mask according to the present invention comprises (Structure 1) a transfer pattern comprising a transparent portion and a light-shielding portion on a transparent substrate. , At least a part of this transfer pattern has a part where the light transmitting part exists on both sides of the light shielding part,
A phase shift mask provided with a light-transmitting portion on both sides of the light-shielding portion is provided with a phase shift portion that shifts the phase of the exposure light passing through one of the light-transmitting portions with respect to the phase of the exposure light passing through the other. The transfer pattern is formed by forming a light shielding layer directly on a transparent substrate or via a transparent layer, and selectively removing a part of the light shielding layer along a predetermined pattern shape to form a light shielding layer. A pattern having light-transmitting portions on both sides of the light-shielding portion is formed by using the existing portion as the light-shielding portion and the portion where the light-shielding layer is removed as the light-transmitting portion. Of the exposure light passing through the transparent portion by removing the transparent substrate or a part of the transparent layer in the thickness direction by an etching method after at least one side of the transparent portion existing in the transparent portion is removed. Transparency of the other phase The light-shielding layer is common to the etching method used when removing a part of the transparent substrate or the transparent layer to form the phase shift portion. In the phase shift mask of the configuration 1, the phase shift portion is formed in the phase shift mask of the configuration 1. The transparent substrate or transparent layer, a part of which is removed in the case of, is made of a material containing SiO2 as a main component, and the light-shielding layer is made of molybdenum, tungsten, tantalum or titanium, and at least one metal and silicon. The composition is characterized in that it is composed of a material having a composition ratio of the metal and silicon as an main component and an atomic ratio of 5: 1 to 1: 3.

A method of manufacturing a phase shift mask according to the present invention is (Structure 3) In the method of manufacturing a phase shift mask for manufacturing the phase shift mask of Structure 1 or 2, a transparent layer is formed on the transparent substrate via a transparent layer. Alternatively, a light-shielding layer forming step of forming a light-shielding layer without intervention, a first resist layer forming step of forming a first resist layer on the light-shielding layer, and a first resist layer,
The pattern that constitutes one of the light-transmitting portions of the light-transmitting portions formed on both sides of the light-shielding portion that is a part of the transfer pattern is exposed,
A first resist pattern forming step of developing and forming a first resist pattern forming the pattern of the one light-transmitting part; and etching using the resist having the first resist pattern as a mask, First, while removing the light-shielding layer along a pattern forming one of the light-transmitting portions, and subsequently removing a predetermined amount of a part of the transparent layer or the transparent substrate below the removed light-shielding layer in the thickness direction. An etching step; a second resist layer forming step of removing a used resist of the first etching step and performing a predetermined cleaning to form a second resist layer on a surface on which the pattern is formed; The resist layer is exposed with a pattern forming the other of the light-transmitting portions formed on both sides of the light-shielding portion, which is a part of the transfer pattern, and is developed to transmit the light-transmitting portions formed on both sides of the light-shielding portion. A second resist pattern forming step of forming a second resist pattern forming the other pattern of the above, and a pattern forming the other of the above-mentioned light-transmitting part by performing etching using the resist on which the second resist pattern is formed as a mask And a second etching step for removing at least the light-shielding film along the line. As an aspect of this configuration 3, (configuration 4) is a method of manufacturing a phase shift mask of configuration 3, In the etching step, after removing the light shielding film, a predetermined phase shift amount is obtained by further removing a predetermined amount in the thickness direction of the transparent layer or the transparent substrate under the removed light shielding film. As a mode of this configuration 4, there is provided a method of manufacturing a phase shift mask of configuration 4, wherein The amount in the thickness direction of the transparent layer or transparent substrate to be removed in one etching step is set to be larger than an amount that can obtain a desired phase shift amount, and the removal amount is measured after the completion of the first etching step. Based on the result, a predetermined phase shift amount is obtained by setting and removing the amount in the thickness direction of the transparent layer or transparent substrate to be removed in the second etching step. As a mode of Configurations 3 to 5, (Configuration 6) In the method of manufacturing a phase shift mask according to any one of Configurations 3 to 5, a reticle alignment mark formed in a region other than a transfer pattern forming region for transfer alignment. Is divided into two and one of them is divided into the first
Alignment accuracy is improved by simultaneously forming the resist pattern forming step and the first etching step, and forming the other side simultaneously during the second resist pattern forming step and the second etching step. The configuration is characterized by that.

[0027]

[Embodiment]

(Embodiment 1) FIG. 1 is a schematic sectional view showing a structure of a phase shift mask according to Embodiment 1 of the present invention, and FIG. 2 is an explanatory view of a method for manufacturing a phase shift mask according to Embodiment 1. . Hereinafter, the phase shift mask and the manufacturing method thereof according to the first embodiment will be described with reference to these drawings.

In FIG. 1, in the phase shift mask according to the first embodiment, a light shielding film pattern 2a forming a transfer pattern by a light shielding portion 21 and a light transmitting portion 22 is formed in a transfer region E1 on a transparent substrate 1. It was done. Further, at least a part of the light shielding film pattern 2a is provided with a pattern in which the light transmitting portions 22 are arranged on both sides of the light shielding portion 21. Then, the translucent portions 22 arranged on both sides of the light shielding portion 21.
On one side, the transparent substrate 1 is removed by a predetermined depth in the thickness direction to form a phase shift portion 23. The depth of the phase shift portion 23 is such that the phase of the exposure light passing through the light transmitting portion 22 in which the phase shift portion 23 is formed is the light transmitting portion 2.
The depth is set to be shifted by about 180 ° with respect to the phase of the exposure light passing through the light-transmitting portion 22 that is adjacent to the light-transmitting portion 2 and the light-shielding portion 21 and has no phase shift portion. .

Further, a first reticle alignment mark 241 and a second reticle alignment mark 242 are formed in the non-transfer area E2 on the transparent substrate 1.

The transparent substrate 1 is a quartz substrate having a length of 6 inches, a width of 0.25 inches, a thickness of 0.25 inches, and a refractive index of 1.508 at a wavelength of 250 nm.

The light-shielding film pattern 2a has a composition of 65% of Mo, 30% of Si and 5% of O in atomic ratio, and a part of the Mo-Si film having a thickness of 80 nm is formed into a predetermined pattern ( It is removed by the transfer pattern).

By removing the quartz substrate 1 from the surface thereof to a depth of 244 nm, the phase shift unit 23 can shift the phase of the exposure light having a wavelength of 250 nm that is passed by 180 ° in the state before the removal. It was done like this.

The above phase shift mask is manufactured by the following procedure.

First, an M of 80 nm thickness is formed on the quartz substrate 1.
An o-Si light-shielding film 2 is formed by a sputtering method, and an EB resist ZEP-520 (trade name of Nippon Zeon Co., Ltd.) is spin-coated to a thickness of 500 n.
m, and a pre-baking process is performed to form a resist film 3 to obtain mask blanks (see FIG. 2 (a)). The composition of the Mo-Si light-shielding film 2 is 6 in terms of atomic ratio.
5%, Si is 30%, and O is 5%.

Next, the resist film 3 is subjected to pattern exposure (sometimes called EB drawing) by an electron beam drawing apparatus. This drawing pattern is a pattern that occupies approximately half of the entire transfer pattern, and is one of the light-transmitting portions of the pattern in which the light-transmitting portions are present on both sides of the light-shielding portion, that is, the light-transmitting portion where the phase shift portion is formed. A pattern (hereinafter, may be referred to as a half pattern for convenience). In this case, only the drawing for forming the first reticle alignment mark is performed in the non-transfer area. Then, this is developed to form a resist pattern 3a (see FIG. 2 (b)).

Next, the MoSi light-shielding film 2 is dry-etched using the resist pattern 3a as a mask to form a half pattern 20a (see FIG. 2 (c)). The dry etching in this case was performed using a parallel plate type RIE dry etching apparatus in a CF ₄ / O ₂ mixed gas atmosphere with a gas pressure of 0.3 Torr and a power of 100 W.

Then, only the etching conditions are changed without taking out the substrate from the dry etching apparatus, and the dry etching apparatus is used to subsequently carry out etching to remove the transparent substrate 1 to a predetermined depth by using the resist pattern as a mask. To form the phase shift portion 23 (see FIG. 2 (d)). The etching condition in this case is C
Gas pressure is 0.05 Torr in F ₃ / O ₂ mixed gas atmosphere
r and power was 150 W. As the exposure light, Kr
In the case of using the F excimer laser (wavelength 248 nm), in order to shift the phase by 180 °, the removal depth needs to be 244 nm. However, in the case of this embodiment, the etching depth here is formed to be slightly deeper than this, for example, a depth corresponding to a phase difference of about 5 °. This is because there is a possibility that an error may occur in the etching depth due to variations in the pattern type or the etching state, and it is difficult to etch exactly to the desired depth. By utilizing the fact that the phase difference can be adjusted at the time of forming the light portion, it is deepened in advance by the amount that an error may occur.

Next, after the resist is stripped / cleaned, a defect inspection is carried out, and a defect is repaired if necessary (see FIG. 2 (e)). At the time of this inspection, the phase difference by the phase shift unit 23 is obtained by an optical method or a stylus method. In this case, only the first reticle alignment mark 241 is formed in the non-transfer area.

Next, a resist film 4 for forming a pattern corresponding to the remaining pattern of the transfer pattern is formed on the transparent substrate 1 on which the above pattern is formed. In addition,
The resist film 4 is the same as the resist film 3 described above, but is formed so as to completely close the light transmitting portion 22 and the phase shift portion 23 formed in the above steps (FIG. 2).
(f)).

Next, electron beam alignment drawing is performed. This drawing pattern is a pattern that occupies approximately the other half of the entire transfer pattern, and is the other light-transmitting portion of the pattern in which light-transmitting portions are present on both sides of the light-shielding portion, that is, a light-transmitting portion in which no phase shift portion is formed. Pattern. At this time, drawing is performed on the non-transfer area to form the second reticle alignment mark. Then, this is developed to form a resist pattern 4a (see FIG. 2 (g)).

Next, using the resist pattern 4a as a mask, the light-shielding film on which the half pattern 20a is formed is dry-etched to form the light-shielding film pattern 2a (FIG. 2).
(c)). In this case, dry etching is performed using a parallel plate type RIE dry etching apparatus, a gas pressure of 0.3 Torr and a power of 100 in a CF ₄ / O ₂ mixed gas atmosphere.
The condition is set to W, and if necessary, the quartz substrate is continuously etched by a predetermined amount according to the amount of the phase difference of the phase shift unit 23 measured in the previous step. After etching, the phase difference between the phase of the exposure light passing through the light transmitting portion formed in this step and the phase of the exposure light passing through the light transmitting portion having the phase shift portion 23 formed in the previous step is measured, In some cases, etching is further performed for an appropriate time to control to a predetermined phase difference (usually 180 °).

Next, the resist is stripped, washed, and inspected, and correction work is performed if necessary.

The line width of the phase shift portion 23 needs to be set to be slightly larger than the desired size on the wafer to be transferred. This is done in order to correct the phenomenon that the light intensity passing through the concave portion is lower than the light intensity passing through the non-concave portion due to the so-called wave guide effect (for details, see SPIE Vol.1927 p.28 etc. reference).

According to the phase shift mask and the method for manufacturing the same according to the first embodiment described above, when the light shielding film forming the light shielding film pattern is partially removed from the transparent substrate to form the phase shift portion, Since it is composed of a material that can be removed by the etching method common to the etching method used for, the exposure pattern of approximately half the light-shielding film pattern can be obtained without separately performing the pattern exposure for forming the phase shift portion. The common pattern exposure can also be used, and thus the exposure drawing time can be shortened. At the same time, control of the amount of phase shift has become significantly easier.

Further, since the non-conductive portion is not drawn at the time of drawing, even when the electronic drawing method is used, there is no problem caused by charge-up.

Further, the reticle alignment mark is set to 2
The reticle alignment mark is used to form the remaining transfer pattern, and at the same time the other alignment mark is formed. By forming the pattern, it is possible to suppress deterioration of pattern alignment accuracy.

In the above-described first embodiment, the example in which the light shielding layer is directly formed on the transparent substrate 1 is shown. However, as shown in FIG.
It is also possible to form the etching stopper layer 12 made of, form the transparent layer 11 made of SOG (Spin On Glass) on the etching stopper layer 12, and form the light shielding film pattern 2a thereon. In this case, the transparent layer 11 and the material forming the light-shielding film pattern 2a can be etched by a common etching method.

Although CF4 and CF3 are listed as the etching gas in the first embodiment, any one of C2 F6, C3 F8, C4 F8 and SF6, or a mixed gas thereof may be used. Or O2 to these
A mixed system containing gas or N2 gas may be used.

Furthermore, the thickness of the light-shielding film is sufficient if it has a light-shielding effect within a range that does not adversely affect the transfer characteristics, and is approximately 30 n.
It may be in the range of m to 200 nm.

The example of the first embodiment is a so-called "Levenson" type phase shift mask in which the line widths of the light-shielding portions and the light-transmitting portions which are alternately arranged are set to be substantially equal to each other. It can also be applied to a so-called "auxiliary pattern" type phase shift mask. 4 is a schematic plan view of the pattern of the auxiliary pattern type phase shift mask, and FIG. 5 is a sectional view taken along line VV of FIG. As shown in these drawings, in this "auxiliary pattern" type phase shift mask, an auxiliary pattern portion is provided in the vicinity of the main pattern portion, and the phase of the exposure light passing through the main pattern portion is changed to the auxiliary pattern portion. This is intended to improve the resolution by offsetting the diffracted light at the boundary of the main pattern by shifting it by 180 ° with respect to the phase of the exposure light passing through. The dimensions of the main pattern portion and the auxiliary pattern portion are, for example, as shown in FIG. 5, when the inner diameter of the main pattern portion is 2 μm, the auxiliary pattern portion is 0.75 μm across the light shielding portion of 0.75 μm. The light-transmitting part is arranged. As a method of performing the phase shift, as shown in FIG. 5, the substrate portion of the auxiliary pattern portion may be removed to a predetermined depth in the thickness direction, or conversely, FIG. As shown in, the substrate portion of the main pattern portion may be removed to a predetermined depth in the thickness direction. In the case of this "auxiliary pattern" type phase shift mask, since only the main pattern portion is transferred, it is not necessary to separately form the reticle alignment mark into two and to form the main pattern portion separately. All should be formed in.

Further, in the above-mentioned embodiment, the pattern formation is carried out by using the electron beam exposure, but this can also be carried out by light exposure such as laser. In that case, the antistatic treatment becomes unnecessary. In addition, in that case, it goes without saying that a resist suitable for the exposure method is used.

Further, in the first embodiment, one reticle alignment mark is formed in each step of forming the shifter portion and the non-shifter portion. However, the number of reticle alignment marks naturally varies depending on the type of stepper. It is desirable to draw half of the total number of reticle alignment marks.

[0053]

As described above in detail, the phase shift mask and the method for manufacturing the same according to the present invention, the etching method using the light shielding layer when removing a part of the transparent substrate for forming the phase shift portion. Since it is made of a material that can be removed by the same etching method as that of the above, the pattern exposure common to the exposure pattern of approximately half the light shielding film pattern can be performed without separately performing the pattern exposure for forming the phase shift portion. This makes it possible to shorten the exposure drawing time and, at the same time, significantly facilitate the control of the amount of phase shift, and at the same time, prevent omission of defect inspection and improve the accuracy of defect correction. Etc. are obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a configuration of a phase shift mask according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process of the phase shift mask according to the first embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a configuration of a phase shift mask according to another embodiment of the present invention.

FIG. 4 is a schematic plan view showing a configuration of a phase shift mask according to another embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a configuration of a phase shift mask according to another embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a configuration of a phase shift mask according to another embodiment of the present invention.

FIG. 7 is an explanatory view of a manufacturing process of a phase shift mask according to a conventional example.

FIG. 8 is a diagram illustrating a manufacturing process of a phase shift mask according to a conventional example.

FIG. 9 is an explanatory diagram of a phase shift mask according to a conventional example.

FIG. 10 is an explanatory diagram of a phase shift mask according to a conventional example.

[Explanation of symbols]

1 ... Transparent substrate, 2 ... Shading film, 2a ... Shading film pattern,
3, 4 ... Resist film, 3a, 4a ... Resist pattern,
21 ... Shading part, 22 ... Translucent part, 23 ... Phase shift part, 2
41 ... First reticle alignment mark, 242 ... Second reticle alignment mark.

Claims (6)

[Claims] 1. A transfer pattern comprising a light-transmitting portion and a light-shielding portion is provided on a transparent substrate, and at least a part of the transfer pattern has portions having light-transmitting portions on both sides of the light-shielding portion, A phase shift mask provided with a light-transmitting portion on both sides of the light-shielding portion is provided with a phase shift portion that shifts the phase of the exposure light passing through one of the light-transmitting portions with respect to the phase of the exposure light passing through the other. In the transfer pattern, a light-shielding layer is formed directly or through a transparent layer on a transparent substrate, and the light-shielding layer is formed by selectively removing a part of the light-shielding layer along a predetermined pattern shape. A pattern having light-transmitting portions on both sides of the light-shielding portion is formed by using the existing portion as the light-shielding portion and the portion where the light-shielding layer is removed as the light-transmitting portion. At least one of the light-transmitting parts present in After removing the light shielding layer, a part of the transparent substrate or the transparent layer is removed in the thickness direction by an etching method so that the phase of the exposure light passing through the light transmitting portion passes through the other light transmitting portion. The light shielding layer is shifted with respect to the phase of the exposure light, and the light shielding layer is an etching method common to the etching method used when removing a part of the transparent substrate or the transparent layer for forming the phase shift portion. A phase shift mask, which is made of a material that can be removed by. 2. The phase shift mask according to claim 1, wherein a transparent substrate or a transparent layer, a part of which is removed when the phase shift portion is formed, is made of a material containing SiO 2 as a main component. The light-shielding layer contains, as a main component, one or more metals selected from molybdenum, tungsten, tantalum, and titanium and silicon, and the composition ratio of the metal and silicon is 5: 1 in atomic ratio.
To a phase shift mask composed of a material in the range of 1: 3. 3. The method of manufacturing a phase shift mask according to claim 1, wherein the light shielding layer is formed on the transparent substrate with or without a transparent layer. A first resist layer forming step of forming a first resist layer on the light-shielding layer, and a step of forming a first resist layer on the first resist layer on both sides of a light-shielding portion that is a part of a transfer pattern. A first resist pattern forming step of exposing and developing a pattern forming one light transmitting portion to form a first resist pattern forming this one light transmitting portion pattern; Etching is performed using the formed resist as a mask to remove the light-shielding layer along a pattern that constitutes one of the light-transmitting portions, and subsequently, the transparent layer below the removed light-shielding layer or A first etching step of a predetermined amount of removing a portion of the bright substrate in a thickness direction, the performed cleaning spent resist is removed in the predetermined first etching step, the second to the pattern formed surface
A second resist layer forming step of forming a resist layer, and exposing and developing a pattern forming the other of the light-transmitting portions formed on both sides of the light-shielding portion, which is a part of the transfer pattern, on the second resist layer. Then, a second resist pattern forming step of forming a second resist pattern forming the other pattern of the light transmitting portion formed on both sides of the light shielding portion, and using the resist on which the second resist pattern is formed as a mask. And a second etching step of removing at least the light-shielding film along a pattern forming the other of the light-transmitting portions, the method of manufacturing a phase shift mask. 4. The method of manufacturing a phase shift mask according to claim 3, wherein in the second etching step, after removing the light shielding film, the transparent layer or the transparent substrate under the removed light shielding film is further formed. A method for manufacturing a phase shift mask, wherein a predetermined amount of phase shift is obtained by removing a predetermined amount in the thickness direction. 5. The method for manufacturing a phase shift mask according to claim 4, wherein the amount of the transparent layer or the transparent substrate removed in the first etching step in the thickness direction is set to be larger than an amount that provides a desired phase shift amount. A large amount is set, the removal amount is measured after the completion of the first etching step, and the removal amount is set by setting the amount in the thickness direction of the transparent layer or the transparent substrate to be removed in the second etching step based on the result. A method of manufacturing a phase shift mask, wherein a predetermined amount of phase shift is obtained by performing the above. 6. The method for manufacturing a phase shift mask according to claim 3, wherein a reticle alignment mark formed in a region other than a transfer pattern forming region for transfer alignment is divided into two. One of them is formed simultaneously during the first resist pattern forming step and the first etching step, and the other is formed simultaneously during the second resist pattern forming step and the second etching step. A method of manufacturing a phase shift mask, characterized in that alignment accuracy is improved.