KR100772784B1 - Phase Shift Mask for Performing Exposure Process using Extreme Ultra-Violet Light Source and Method for Manufacturing the its - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase shift mask for an Extreme Ultra-Violet (hereinafter referred to as “EUV”) exposure process and a method of manufacturing the same. After the absorption layer is formed on the reflective layer, the absorption layer spacer may be formed by performing a dry etching process on the entire surface of the substrate to facilitate bias adjustment, thereby increasing the manufacturing time and cost of the semiconductor device. A phase inversion mask for an EUV exposure process that can be reduced and a method of manufacturing the same.

Description

Phase Shift Mask for Performing Exposure Process using Extreme Ultra-Violet Light Source and Method for Manufacturing the its}

1A and 1B are cross-sectional views illustrating a conventional phase inversion mask structure.

2A to 2F are cross-sectional views illustrating a process of manufacturing a phase shift mask according to the prior art.

3A to 3D are cross-sectional views illustrating a process of manufacturing a phase shift mask according to an embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

1: quartz substrate

3, 3-1, 3-2: Reflective layer pattern 5: Absorption layer pattern

7: buffer layer 21, 31: first reflective layer

23, 33: second reflective layer 23-1, 33-1: second reflective layer pattern

25, 37: absorber layer 25-1: first absorber layer pattern

25-2: second absorption layer pattern 27, 35: first photosensitive film

27-1, 35-1: First photosensitive film pattern 29: Second photosensitive film

29-1: second photosensitive film pattern 39: absorber layer spacer

The present invention relates to a phase shift mask for an Extreme Ultra-Violet (hereinafter referred to as "EUV") exposure process and a method of manufacturing the same.

In the process of manufacturing a semiconductor device, various patterns including contact holes are formed through a photolithography process. The photolithography process is a process of forming a photoresist pattern on the etched layer, a process of etching the lower etched layer using the photoresist pattern as an etch mask, and after completion of the etching process, It includes a process of removing. In addition, the process of forming the photoresist pattern is a process of applying a photoresist material on the layer to be etched, selectively exposing the photoresist using a specific exposure mask and exposed or unexposed using a predetermined chemical solution And a developing process for removing the photoresist material in the region.

On the other hand, the critical dimension of the etched layer pattern that can be implemented by the photolithography process is largely dependent on the wavelength of the light source used in the exposure process. This is because the critical dimension of the actual etched layer pattern is determined by the width of the photoresist pattern that can be realized through the exposure process.

When performing an exposure process using a conventional G-line (λ = 436 nm) or I-line (λ = 365 nm) light source, a photoresist pattern having a resolution of about 0.5 μm may be implemented. In this case, the pattern having a resolution of 0.5 μm means that the critical dimension of the pattern width that can be realized by the photolithography process is about 0.5 μm, and thus, the highly integrated fine pattern at the present time when the effective channel length of the semiconductor device is reduced to within 0.30 μm is used. It is very difficult to get.

As a remedy for this, an exposure process using a shorter wavelength than the light sources, for example, a deep ultra violet (DUV) light source such as KrF (λ = 248 nm) or ArF (λ = 193 nm) has been developed, and further, 13.5 nm. EUV exposure processes using wavelength light sources have been developed.

In this case, in the EUV exposure process, a phase inversion mask using reflective optical for increasing the contrast of an image formed on the photosensitive agent is used instead of a KrF or ArF light-transmitting mask having high absorption.

The phase shift mask for the EUV exposure process is formed by an etching process on a specific portion of the quartz substrate 1 and includes a multilayer reflective layer pattern 3 including a phase shift region capable of inverting the phase of the projected light by 180 degrees. 3-1, 3-2, the buffer layer pattern 7, and the absorption layer pattern 5 are provided (refer FIG. 1A and 1B).

When the exposure process is performed using the phase shift mask for the EUV exposure process, light incident on the absorbing layer is blocked from being irradiated onto the wafer, while light incident on the reflective layer is reflected and irradiated onto the wafer. The resolution is improved by generating a destructive interference effect due to the phase difference between the reflected light and the absorbed light.

A process for manufacturing a phase inversion mask for an EUV exposure process according to the prior art will be briefly described with reference to FIGS. 2A and 2F.

First, referring to FIG. 2A, a multilayer reflective layer in which a first reflective layer 21 and a second reflective layer 23 are stacked is formed on an entire surface of a quartz substrate (not shown), and an absorbing layer 25 and a first photosensitive film are formed thereon. (27) is formed.

Referring to FIG. 2B, a first photoresist layer pattern 27-1 is formed by a first exposure and development process on the resultant, and then a second reflective layer is formed by using the first photoresist layer pattern 27-1 as an etching mask. The absorption layer pattern 25-1 is formed by performing an etching process until the (25) is exposed.

Subsequently, the second reflective layer 23 is etched using the patterns of FIG. 2B as an etching mask to form a second reflective layer pattern 23-1 as shown in FIG. 2C.

A second photoresist layer 29 is formed on the entire surface of the resultant substrate of FIG. 2C, as shown in FIG. 2D, and then a second exposure and development process is performed to form a second photoresist layer pattern 29-1 as illustrated in FIG. 2E. To form.

The first absorbing layer pattern 25-1 is etched by an etching process using the second photoresist layer pattern 29-1 of FIG. 2E as an etching mask, and the second absorbing layer pattern 25-2 is illustrated in FIG. 2F. To form.

However, the above-described phase inversion mask manufacturing process for EUV exposure process has the following problems. That is, in order to form the second absorbing layer pattern, the process step is very complicated because the photosensitive film forming process, the exposure and development process thereof, and the process of etching the absorbing layer using the photosensitive film as an etching mask are performed twice. In addition, in order to give a selective bias, the layout drawing of the mask for the exposure process of the two steps must be performed in two steps, so that the size of the absorbing layer pattern needs to be changed. Increases.

Accordingly, the present inventors have completed the present invention by developing a phase inversion mask and a method of manufacturing the same, which can overcome the above-mentioned conventional problems without developing expensive equipment.

Disclosure of Invention The present invention has been made to solve a problem occurring in a conventional process of manufacturing a phase inversion mask for an EUV exposure process, and an object thereof is to provide a phase inversion mask having an absorption layer spacer formed on a sidewall of a reflective layer pattern and a method of manufacturing the same. .

Phase inversion mask for EUV exposure process according to an embodiment of the present invention for achieving the above object,

Quartz substrates;

A reflection layer pattern formed on the substrate and including a phase inversion region formed by alternately stacking a stacked structure of several Mo films and Si films or a stacked structure of Mo films and Be films; And

It characterized in that it comprises an absorption layer spacer formed on the reflective layer pattern side.

In order to achieve the above object, in the present invention,

Depositing a reflective layer formed by alternately stacking a stacked structure of several Mo films and Si films or a stacked structure of Mo films and Be films on the entire quartz substrate;

Forming a photoresist pattern on the reflective layer by exposure and development processes;

Performing an etching process using the photoresist pattern as an etching mask to form a reflective layer pattern including a phase inversion region;

Removing the photoresist pattern, and then forming an absorbing layer on the entire surface of the resultant; And

A method of manufacturing a phase shift mask for an EUV exposure process includes performing a dry etching process on the absorber layer to form an absorber layer spacer on sidewalls of a reflective layer pattern.

In this case, the absorbing layer is not particularly limited as long as it absorbs the EUV light source and is a metal that is easy to perform a dry etching process, it is preferable to use a metal such as chromium (Cr) or aluminum (Al).

In addition, the absorber layer spacer formed by the method can be appropriately adjusted to the selective bias value according to the formation thickness of the absorber layer or the dry etching process time for the absorber layer, for example, the thickness of the absorber layer is preferably 500 Å or more, the etching The process is not particularly limited as long as it is a general etching process condition performed in the mask manufacturing process, and the absorption layer width is performed by adjusting the etching time.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3A to 3D are cross-sectional views illustrating a method of manufacturing a phase shift mask for an EUV exposure process according to an exemplary embodiment of the present invention.

First, as shown in FIG. 3A, a first reflective layer 31 and a second reflective layer formed by alternately stacking a stacked structure of several Mo films and Si films or a stacked structure of Mo films and Be films on the entire surface of a quartz substrate (not shown). 33 and the photosensitive film 35 are formed.

The photosensitive film pattern 35-1 is formed by performing the exposure and development processes of the photosensitive film 35 of FIG. 3A, and then, the photosensitive film pattern 35-1 is used as an etching mask to the second reflective layer 33. The selective etching process is performed to form the second reflective layer pattern 33-1 as shown in 3b.

After removing the photoresist pattern 35-1 of FIG. 3B, an absorbing layer 37 is formed on the entire surface including the exposed second reflective layer pattern 33-1 as shown in FIG. 3C.

At this time, the absorption layer is formed to a thickness of 500Å or more, using chromium or aluminum,

A dry etching process is performed on the entire surface of the substrate including the absorber layer 37 of FIG. 3C to form an absorber layer spacer 39 as shown in FIG. 3D.

In this case, the etching process is performed under the etching process conditions performed during the mask manufacturing process.

As described above, since the method of the present invention performs the etching process for the absorber layer in one step, the process method is simple, the manufacturing time is reduced, and the photoresist pattern for forming the absorber layer pattern is formed in two portions. Process cost is reduced. In addition, since the absorbing layer spacer is formed on the stepped boundary of the reflective layer pattern including the phase inversion region to perform the subsequent step, the selective bias can be easily adjusted and the process margin for performing the EUV exposure process can be increased. Therefore, it is possible to produce a stable semiconductor device.

As described above, in the present invention, by forming the absorber layer on the reflective layer pattern, and then performing an entire dry etching process on the reflective layer pattern to form the absorber layer spacer on the sidewall of the reflective layer pattern, the manufacturing time and the process cost of the semiconductor device can be reduced. In addition, it is possible to produce a stable semiconductor device with high process margin.

Claims (4)

Quartz substrates; A reflection layer pattern formed on the substrate and including a phase inversion region formed by alternately stacking a stacked structure of several Mo films and Si films or a stacked structure of Mo films and Be films; And And an absorption layer spacer formed on a side surface of the reflective layer pattern. Depositing a reflective layer formed by alternately stacking a stacked structure of several Mo films and Si films or a stacked structure of Mo films and Be films on the entire quartz substrate; Forming a photoresist pattern on the reflective layer by exposure and development processes; Performing an etching process using the photoresist pattern as an etching mask to form a reflective layer pattern including a phase inversion region; Removing the photoresist pattern, and then forming an absorbing layer on the entire surface of the resultant; And And performing a dry etching process on the absorbing layer to form an absorbing layer spacer on a side of the reflective layer pattern. The method of claim 2, The absorbing layer is a phase inversion mask manufacturing method for EUV exposure process, characterized in that formed of chromium (Cr) or aluminum (Al). A semiconductor device manufactured by the method of manufacturing a semiconductor device comprising the method of claim 2.

Images