KR20020052468A - Manufacturing method for alternating phase shift mask of semiconductor device - Google Patents

Abstract

PURPOSE: A method for fabricating an alternating phase shift mask of a semiconductor device is provided to form fine patterns of high resolution by forming differently thickness of a neighboring reflective layer. CONSTITUTION: A reflective layer(23) is formed on an upper portion of a substrate(21). An absorbing layer(24) is formed on the reflective layer(23). The first photoresist layer pattern is formed on the absorbing layer(24) in order to expose a phase shift region(A). The absorbing layer(24) and a part of the reflective layer(23) are etched by using the first photoresist layer pattern as an etch mask. The first photoresist layer pattern is removed. The second photoresist layer pattern is formed on a whole surface in order to expose a non-phase shift region(B). The reflective layer(23) is exposed by etching the absorbing layer(24).

Description

Manufacturing method for alternating phase shift mask of semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an alternating phase inversion mask of a semiconductor device, and more particularly, in a lithography process using EUV as a light source, by increasing the process margin by inverting the phases of reflected light by varying thicknesses of adjacent reflection layers. The present invention relates to a method of manufacturing an alternating phase inversion mask of a semiconductor device, which favors the implementation of a fine pattern.

The alternating phase shift mask used in the exposure exposure process for the prior art can be used without loss of light amount because the quartz substrate or the phase shift layer is almost transparent to KrF and ArF light sources.

1A and 1B are cross-sectional views showing the structure of an alternating phase shift mask for transmission according to the prior art, wherein the phase inversion mask shown in FIG. 1A is a phase inversion on a quartz substrate 11. A layer 12 is formed to form a phase inversion region, and the phase inversion mask shown in FIG. 1B etches the quartz substrate 11 to form a phase inversion region.

However, light sources having short wavelengths such as EUV and soft X-rays, which are applied to the next-generation exposure technology, have a high absorption rate, making it difficult to use a transmissive mask. Thus, a reflective mask is used instead of the transmissive mask.

In the transmissive mask, a phase inversion mask was used to increase the contrast of the image formed on the photosensitive agent. However, in the reflection mask, the phase inversion layer cannot be used due to the absorbance, and the thickness of the reflective layer is as easy as the method of changing the thickness of the quartz substrate. Can not be removed. In particular, when EUV is used as a light source, it is difficult to fabricate an alternating phase inversion mask because it is difficult to remove the reflective layer with a multilayer structure such as a Mo / Si film or a Mo / Be film.

The present invention is to solve the above problems, in the photolithography process using the EUV as a light source is a semiconductor that can form a high-resolution fine pattern by increasing the phase margin by the phase inversion by changing the thickness of the adjacent reflection layer It is an object of the present invention to provide a method for manufacturing an alternating phase inversion mask of a device.

1A and 1B are cross-sectional views showing the structure of an alternating phase shift mask for transmission according to the prior art.

2A to 2D are cross-sectional views illustrating a method of manufacturing a transmitting alternating phase inversion mask according to a first embodiment of the present invention.

3A to 3E are cross-sectional views illustrating a method of manufacturing a transmission alternating phase inversion mask according to a second embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

11 quartz substrate 12 phase inversion layer

13: chromium layer pattern 21, 31: substrate

23 reflective layer 24 absorbing layer

26, 43: first photosensitive film 27, 44: first photosensitive film pattern

29, 45: second photoresist pattern 33: first reflective layer

35: first buffer layer 37: second reflection layer

39: second buffer layer 41: absorber layer

In order to achieve the above object, an alternating phase inversion mask manufacturing method of a semiconductor device according to the present invention,

Forming a reflective layer having a multilayer structure on the substrate;

Forming an absorbing layer on the reflective layer;

Forming a first photoresist film pattern exposing a phase inversion region on the absorption layer;

Etching the absorption layer and the reflective layer having a predetermined thickness using the first photoresist pattern as an etching mask to form a phase inversion region;

Removing the first photoresist pattern;

Forming a second photoresist film pattern exposing the non-phase inversion region over the entire surface;

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

It is a 1st characteristic that it includes the process of removing the said 2nd photosensitive film pattern.

In addition, in order to achieve the above object, an alternating phase inversion mask manufacturing method of a semiconductor device according to the present invention,

Forming a first reflective layer having a multilayer structure on the substrate;

Forming a first buffer layer on the first reflection layer;

Forming a second reflective layer having a multilayer structure on the first buffer layer;

Sequentially forming a second buffer layer and an absorption layer on the second reflection layer;

Forming a first photoresist film pattern exposing a phase inversion region on the absorption layer;

Etching the absorption layer, the second buffer layer, and the second reflection layer using the first photoresist pattern as an etch mask to expose the first buffer layer;

Removing the first photoresist pattern;

Forming a second photoresist film pattern exposing the non-phase inversion region over the entire surface;

Etching the absorber layer using the second photoresist pattern as an etch mask to expose a second buffer layer;

Removing the second photoresist pattern;

And etching the first buffer layer and the second buffer layer exposed in the phase inversion region and the non-phase inversion region to form an alternating phase inversion mask exposing the first reflection layer and the second reflection layer. do.

In the present invention, the thickness difference (h) of the reflective layer of the multilayer structure for reversal of phase should be set such that the optical path difference of the two reflected lights differs by an odd multiple of λ / 2 when the wavelength of the light source is λ. And the thickness difference (h) of the reflective layer of the multilayer structure is when the refractive index with respect to the wavelength of the light source is n,

h = (λ / 2n) x odd times

Becomes

For example, in the case of EUV, λ is 13.4 nm and the process is performed in a vacuum state, and since n is 1, the thickness difference h of the reflective layer is an odd multiple of 6.2 nm. In general, since the reflective layer is a multilayer structure in which Mo films and Si films are alternately deposited, 6.2 nm is a thickness in which the Mo films and Si films are deposited one by one, that is, a periodic thickness.

Hereinafter, a method of manufacturing an alternating 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 2D are cross-sectional views illustrating a method of manufacturing a transmitting alternating phase inversion mask according to a first embodiment of the present invention.

First, the reflective layer 23 is formed on the substrate 21. The reflective layer 23 is formed of a stacked structure of Mo film and Si film or a stacked structure of Mo film and Be film, and the stacked structure is formed into a multi layer structure in which several layers are stacked.

Next, an absorbing layer 24 is formed on the reflective layer 23.

Next, a first photoresist pattern 27 exposing the phase inversion region A is formed on the absorber layer 24. (See Figure 2A)

Next, the absorption layer 24 and the reflective layer 23 having a predetermined thickness are etched using the first photoresist pattern 27 as an etch mask.

Next, the first photoresist pattern 27 is removed. (See Figure 2b)

Next, a second photoresist pattern 29 exposing the non-phase inversion region B is formed on the entire surface. (See Figure 2c)

Next, the absorbing layer 24 is etched using the second photoresist pattern 29 as an etch mask to expose the reflective layer 23.

At this time, the thickness difference h between the phase inversion region A and the non-phase inversion region B is an odd multiple of the period thickness. In this case, the period thickness is one layer thickness of the laminated structure forming the reflective layer. (See FIG. 2D)

3A to 3E are cross-sectional views illustrating a method of manufacturing a transmission alternating phase inversion mask according to a second embodiment of the present invention.

First, the first reflection layer 33 is formed on the substrate 31.

Next, a first buffer layer 35 is formed on the first reflection layer 33.

Next, a second reflection layer 37 is formed on the first buffer layer 35. In this case, the first reflection layer 33 and the second reflection layer 37 may be formed of a stacked structure of Mo film and Si film or a stacked structure of Mo film and Be film, and the stacked structure is a multi-layer in which several layers are stacked. Form into structure.

Next, a second buffer layer 39 is formed on the second reflection layer 37.

Next, an absorbing layer 41 is formed on the second buffer layer 39 to have a predetermined thickness.

Next, a first photoresist pattern 44 exposing the phase inversion region A is formed on the absorber layer 41. (See Figure 3A)

Next, the first buffer layer 35 is exposed by etching the absorbing layer 41, the second buffer layer 39, and the second reflecting layer 37 using the first photoresist pattern 44 as an etching mask.

Next, the first photoresist pattern 44 is removed. (See Figure 3b)

Next, a second photosensitive film pattern 45 exposing the non-phase inversion region B is formed on the entire surface. (See Figure 3c)

Next, the second buffer layer 39 is exposed by etching the absorbing layer 41 using the second photoresist pattern 44 as an etch mask.

Next, the second photoresist pattern 44 is removed. (See FIG. 3D)

Next, the exposed first buffer layer 35 of the phase inversion region A and the exposed second buffer layer 39 of the non-phase inversion region B are etched to form a first reflection layer 33 and a second reflection layer ( 37). At this time, the thicknesses of the second reflection layer 37 and the first buffer layer 35, which are the thickness difference h 'between the phase inversion region A and the non-phase inversion region B, are different by an odd multiple of the period thickness. (See Figure 3E)

As described above, according to the second embodiment of the present invention, since the buffer layer is provided on the reflective layer, the thickness of the reflective layer can be adjusted without damaging the reflective layer, and the reflective layer etching process is easier because the buffer layer is used as an etching barrier.

As described above, according to the method for manufacturing an alternating phase inversion mask of a semiconductor device according to the present invention, a specific thickness at which a reflectance becomes the highest at a specific wavelength in a photo lithography process using EUV as a light source is described. As a reference, the thickness of the reflective layer may be etched by the thickness causing the phase difference, or the buffer layer may be added to adjust the thickness of the reflective layer without damaging the reflective layer, thereby allowing the phase reversal of the reflected light to increase the process margin, thereby forming a high-resolution micro pattern. There is an advantage of facilitating high integration of the device.

Claims (10)

Forming a reflective layer having a multilayer structure on the substrate; Forming an absorbing layer on the reflective layer; Forming a first photoresist film pattern exposing a phase inversion region on the absorption layer; Etching the absorption layer and the reflective layer having a predetermined thickness using the first photoresist pattern as an etching mask to form a phase inversion region; Removing the first photoresist pattern; Forming a second photoresist film pattern exposing the non-phase inversion region over the entire surface; Forming a non-phase inversion region exposing the reflective layer by etching the absorbing layer using the second photoresist pattern as an etch mask; And removing the second photoresist layer pattern. The method of claim 1, And the reflecting layer is formed of a multilayer structure having a Mo film and Si film stacking structure or a Mo film and Be film stacking structure with a periodic thickness. The method according to claim 1 or 2, The thickness difference between the reflective layer of the phase inversion region and the reflective layer of the nonphase inversion region is an odd multiple of the periodic thickness of the reflective layer. The method of claim 1, The alternating phase inversion mask manufacturing method of the alternating phase inversion mask of a semiconductor device, characterized in that applied in the photolithography process using the EUV as a light source. The method of claim 1, The manufacturing method of the alternating phase inversion mask according to the present invention is characterized in that when the wavelength of the light source is λ, the difference in thickness of the reflective layer between the phase inversion region and the nonphase inversion region is an odd multiple of λ / 2. Manufacturing method. Forming a first reflective layer having a multilayer structure on the substrate; Forming a first buffer layer on the first reflection layer; Forming a second reflective layer having a multilayer structure on the first buffer layer; Sequentially forming a second buffer layer and an absorption layer on the second reflection layer; Forming a first photoresist film pattern exposing a phase inversion region on the absorption layer; Etching the absorption layer, the second buffer layer, and the second reflection layer using the first photoresist pattern as an etch mask to expose the first buffer layer; Removing the first photoresist pattern; Forming a second photoresist film pattern exposing the non-phase inversion region over the entire surface; Etching the absorber layer using the second photoresist pattern as an etch mask to expose a second buffer layer; Removing the second photoresist pattern; And forming an alternating phase inversion mask exposing the first and second reflection layers by etching the first and second buffer layers exposed in the phase inversion region and the non-phase inversion region. Method for fabricating alternating phase inversion mask of a device. The method of claim 6, The first reflection layer and the second reflection layer is an alternating phase inversion mask manufacturing method of a semiconductor device, characterized in that formed in a multi-layer structure having a Mo film and Si film stack structure or a Mo film and Be film stack structure. The method according to claim 6 or 7, The thickness difference between the first reflection layer of the phase inversion region and the second reflection layer of the nonphase inversion region is an odd multiple of the periodic thickness of the reflective layer. The method of claim 6, The alternating phase inversion mask manufacturing method of the alternating phase inversion mask of a semiconductor device, characterized in that applied in the photolithography process using the EUV as a light source. The method of claim 6, The method of manufacturing the alternating phase shift mask according to claim 1, wherein the thickness difference between the first reflection layer of the phase inversion region and the second reflection layer of the nonphase inversion region is an odd multiple of lambda / 2 when the wavelength of the light source is λ. Method for producing an alternating phase inversion mask.