KR20020052470A - Manufacturing method for phase shift mask of semiconductor device - Google Patents

Abstract

PURPOSE: A method for fabricating a phase shift mask of a semiconductor device is provided to improve resolving power by generating destructive interference between the light reflected from a phase shift layer and the light reflected from a non-phase lift region. CONSTITUTION: A reflective layer(23) having a structure of a multi-layer is formed on a transparent substrate(21). A phase shift layer is formed on an upper portion of the reflective layer(23). An absorbing layer is formed on an upper portion of the phase shift layer. The absorbing layer is formed by a TiN layer, a Cr layer, an Nisi layer, a Ti layer, a TaSi layer, or an Al layer. The first photoresist layer pattern is formed on an upper portion of the absorbing layer in order to expose an expected pattern part. An absorbing layer pattern(28) is formed by etching the absorbing layer. The first photoresist layer pattern is removed. The second photoresist layer pattern is formed on a whole surface. A phase shift layer pattern(26) is formed by etching the phase shift layer of a non-phase shift region(B). The second photoresist layer pattern is removed.

Description

Manufacturing method for phase shift mask of semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a phase inversion mask of a semiconductor device, and more particularly, to a process using a phase shift mask (hereinafter referred to as a PSM) in a lithography process using EUV (extreme ultraviolet) as a light source. The present invention relates to a method for fabricating a phase reversal mask of a semiconductor device, by securing a margin, improving processing capability of a photo process, and facilitating realization of a fine pattern.

In general, in order to form the circuit elements arranged by the design on the actual silicon wafer surface, the circuit diagram must be transferred to several masks, which are made by using a PG tape containing data of the design drawings. ) Mask is created through a series of steps to move the mask into a mask.

Lithography technology using EUV as a light source needs time to be commercialized with the lithography technology currently being developed.

The phase inversion mask used in the conventional exposure technique improves contrast by using a destructive interference effect between two lights by creating a phase difference between light passing through the phase inversion layer and light passing through a portion other than the phase inversion layer.

However, since EUV technology uses reflective optics as opposed to current KrF, ArF, and 157 nm, the EUV technology has a structure different from that of the conventional exposure technology. Rather, it is more like a wafer process than a mask manufacturing technique.

With reference to the accompanying drawings will be described in the prior art.

1A to 1D are cross-sectional views and graphs showing a mask and exposure principle for EUV according to the prior art.

FIG. 1A shows a cross-sectional view of a mask for EUV formed by the prior art, wherein a reflective layer 13 formed of a multilayer thin film is formed on the substrate 11, and a portion intended as a pattern is exposed on the reflective layer 13. It shows that the absorption layer pattern 15 is formed. In this case, the light used as the light source during the exposure process using the mask as the exposure mask is reflected and absorbed through the reflective layer 13 and the absorber layer pattern 15.

1B shows the energy of the light source on the mask.

FIG. 1C shows the energy of the light source on the wafer, and FIG. 1D shows the intensity of the light source on the wafer.

As described above, according to the related art, light incident on the reflective layer 13 having the multilayer structure reflects and contributes to patterning on the wafer, and light incident on the absorbing layer 15 is absorbed and cannot contribute to patterning of the wafer. Although the pattern is embodied based on this principle, as the size of the pattern becomes smaller, as shown in FIG. 1D, intensity is overlapped, resulting in a decrease in contrast, making it difficult to form a pattern having an angle.

Accordingly, the present invention relates to a method of manufacturing a phase inversion mask of a semiconductor device in view of the above-mentioned conventional problems, and the phase in accordance with the principle of the phase inversion mask using transmission optical in a lithography process using EUV as a light source. Phase-inverts the light reflected through the inversion layer 180 ° so that the light reflected from the non-phase inversion layer interferes with each other to improve resolution to secure process margins, and to improve the yield and high integration of semiconductor devices. It is an object of the present invention to provide a method for manufacturing a phase inversion mask of a semiconductor device.

1A to 1D are cross-sectional views and graphs showing the mask and exposure principle for EUV according to the prior art.

2A to 2H are cross-sectional views illustrating a method of manufacturing a phase shift mask for EUV according to the present invention.

3A to 3D are cross-sectional views and graphs showing the mask and exposure principle for EUV according to the present invention.

<Description of the symbols for the main parts of the drawings>

11, 21: substrate 13, 23: reflective layer

15, 28: absorber layer pattern 25: phase inversion layer

26: phase inversion layer pattern 27: absorbing layer

29: first photosensitive film pattern 31: second photosensitive film pattern

Method for manufacturing a phase inversion mask of a semiconductor device according to the present invention for achieving the above object,

In the manufacturing method of the phase inversion mask using EUV as a light source,

Forming a stacked structure of a reflective layer, a phase inversion layer and an absorbing layer on the transparent substrate;

Forming a first photoresist pattern on the absorber layer, the first photoresist pattern being exposed as a pattern;

Forming an absorption layer pattern exposing the phase inversion layer by etching the absorption layer using the first photoresist pattern as an etch mask;

Removing the first photoresist pattern;

Forming a second photoresist pattern on the entire surface, the second photoresist pattern exposing a portion intended to be a non-phase inversion region among the portions intended to be the pattern;

Forming a phase inversion layer pattern exposing the reflective layer in the non-phase inversion region by etching the phase inversion layer using the second photoresist pattern as an etch mask;

And removing the second photoresist pattern.

The present invention relates to a method of applying a transmission optical phase inversion mask technology to EUV in order to overcome the limitation of resolution and a method of manufacturing a phase inversion mask for EUV to apply the same.

Hereinafter, a method of manufacturing a phase inversion mask of a semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings.

2A to 2H are cross-sectional views illustrating a method of manufacturing a phase shift mask for EUV according to the present invention.

First, a reflective layer 23 formed of a multilayer thin film is formed on the transparent substrate 21. (See Figure 2A)

Next, a phase inversion layer 25 is formed on the reflective layer 23. (See Figure 2b)

Next, an absorption layer 27 is formed on the phase inversion layer 25. The absorbing layer 27 is formed of a TiN film, Cr film, NiSi film, Ti film TaSiN film or Al film. (See Figure 2c)

Next, a first photoresist pattern 29 is formed on the absorber layer 27 to expose a portion, which is intended as a pattern. (See FIG. 2D)

Next, the absorption layer 27 is etched using the first photoresist pattern 29 as an etch mask to form an absorption layer pattern 28 exposing a portion intended as a pattern.

Next, the first photoresist pattern 29 is removed. (See Figure 2E)

Next, a second photoresist pattern 31 is formed on the entire surface to expose a portion of the portion, which is supposed to be the pattern, to the portion of the non-phase inversion region B. (See Figure 2f)

Next, a phase inversion layer pattern 26 exposing the reflective layer 23 is formed by etching the phase inversion layer 25 of the non-phase inversion region B using the second photoresist layer pattern 31 as an etch mask. (See Figure 2g)

Then, the second photoresist pattern 31 is removed to complete the phase shift mask for EUV. (See Figure 2H)

3A is a cross-sectional view of a phase shift mask for EUV formed by the method of FIGS. 2A to 2H.

3B shows the energy of the light source on the mask.

FIG. 3C shows the energy of the light source on the wafer, and FIG. 3D shows the intensity of the light source on the wafer. FIG. 3D shows that the light reflected by the reflective layer 23 in the phase inversion region A is phase inverted by the phase inversion layer pattern 26 to cancel the interference at portions other than the pattern to improve contrast. do.

As described above, according to the method for manufacturing a phase inversion mask of a semiconductor device according to the present invention, in the lithography process using EUV as a light source, a phase inversion layer is formed between the reflection layer and the absorption layer to use transmission optical. Like the principle of the mask, the light reflected from the reflective layer through the phase inversion layer is 180 ° phase inverted so that the light reflected from the non-phase inversion layer interferes with each other to improve resolution to secure a process margin. Accordingly, there is an advantage in that it is possible to improve the yield and high integration of the semiconductor device.

Claims (3)

In the manufacturing method of the phase inversion mask using EUV as a light source, Forming a stacked structure of a reflective layer, a phase inversion layer and an absorbing layer on the transparent substrate; Forming a first photoresist pattern on the absorber layer, the first photoresist pattern being exposed as a pattern; Forming an absorption layer pattern exposing the phase inversion layer by etching the absorption layer using the first photoresist pattern as an etch mask; Removing the first photoresist pattern; Forming a second photoresist pattern on the entire surface, the second photoresist pattern exposing a portion intended to be a non-phase inversion region among the portions intended to be the pattern; Forming a phase inversion layer pattern exposing the reflective layer in the non-phase inversion region by etching the phase inversion layer using the second photoresist pattern as an etch mask; A method of manufacturing a phase inversion mask of a semiconductor device comprising the step of removing the second photoresist pattern. The method of claim 1, The absorbing layer is selected from the group consisting of TiN film, Cr film, NiSi film, Ti film TaSiN film and Al film. The method of claim 1, The reflective layer is a phase inversion mask manufacturing method of a semiconductor device, characterized in that formed of a multilayer structure of Mo / Si.