KR20040006323A - Method for manufacturing reticle - Google Patents

Abstract

PURPOSE: A method for manufacturing a reticle is provided to be capable of achieving semiconductor chips of small size while using a plurality of dummy patterns. CONSTITUTION: The first mask pattern is formed on a reticle substrate(10) to cover cell and dummy patterns. After aligning the reticle substrate(10) using a stepper, the resultant structure is firstly exposed by using the first mask pattern. After removing the first mask pattern, the second mask pattern(14) is formed to expose the dummy patterns and to cover the cell patterns. The substrate is secondly exposed by using the second mask pattern(14).

Description

Method for manufacturing reticle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device. More specifically, when manufacturing a reticle used in the lithography field of a semiconductor manufacturing process, it is possible to reduce a reticle error to secure process margin and process stability. It relates to a reticle manufacturing method that can be.

As semiconductor devices have been highly integrated and design rules have been gradually reduced, in the photo process for realizing a pattern of high resolution of 0.14 μm or less, they may not be formed in a pattern shape originally designed or an error occurs in reticle fabrication.

Therefore, in order to solve this problem, a dummy pattern is used, and the dummy pattern is an unused pattern, and only exists at the end of the pattern that can appear when forming the actual pattern to protect the actual pattern. As the number of the dummy patterns increases, good results are obtained when the actual patterns are formed, but there is a problem that a sufficient number of dummy patterns cannot be used because the size of the semiconductor chip must be reduced in order to produce highly integrated high efficiency.

Problems that occur during reticle fabrication include refraction and reflection of pattern uniformity and formation errors on the reticle as in the case of wafers due to refraction and reflection at the end of the cell pattern during electron beam exposure formed during pattern formation on a thick reticle substrate. An error problem is occurring. Thus, it causes more problems in the actual pattern formation implemented on the wafer.

Accordingly, an object of the present invention is to provide a reticle manufacturing method applicable to a semiconductor chip of a sufficiently small size while using a sufficient number of dummy patterns.

1A to 1C are plan views illustrating a reticle manufacturing method according to the present invention.

2 is a plan view of a first mask pattern according to the present invention.

3 is a plan view of a second mask pattern according to the present invention;

4 is a SEM photograph showing that the reticle manufacturing method according to the present invention is applied, and finally the actual operating cell is formed.

Explanation of symbols on the main parts of the drawings

10. Reticle substrate 12. First mask pattern

14. Second Mask Pattern a. Cell pattern

b. Dummy pattern

Reticle manufacturing method according to the present invention for achieving the above object comprises the steps of forming a first mask covering a cell pattern and a dummy pattern on the reticle substrate, and aligning the substrate by a stepper, using a first mask Performing a first exposure, removing the first mask, forming a second mask covering the cell pattern and exposing the dummy pattern on the substrate on which the first exposure process is completed, and using the second mask And performing a second exposure and removing the second mask.

In the first and second exposure processes, it is preferable to use any one of I-rays of 365 nm wavelength, KrF of 248 nm wavelength, ArF of 193 nm wavelength, and EUV of 157 nm wavelength as the light source.

Further, in the first and second mask forming step, it is preferable to use a light source of any one of the I line of 365nm wavelength, KrF of 248nm wavelength, ArF of 193nm wavelength and EUV of 157nm wavelength.

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

1A to 1C are plan views illustrating a reticle manufacturing method according to the present invention. FIG. 1A is a view illustrating a first mask pattern formed on a reticle substrate, and FIG. 1B illustrates a second mask pattern formed on a reticle substrate. 1C is a view showing that an actual operation cell is formed by performing double exposure.

2 is a plan view of a first mask pattern according to the present invention, and FIG. 3 is a plan view of a second mask pattern according to the present invention.

4 is a SEM photograph showing that the reticle manufacturing method according to the present invention is applied, and finally, an actual operation cell is formed.

Reticle manufacturing method according to the present invention, first, on the reticle substrate, as shown in Figure 2, the first mask pattern including the cell pattern (a) and the dummy pattern (b) of the peripheral portion of the cell pattern (a) ( 12) form. In this case, the first mask pattern 12 is formed using a light source of any one of 365 nm wavelength I line, 248 nm KrF, 193 nm ArF, and 157 nm wavelength EUV.

Subsequently, the reticle substrate 10 is aligned with a stepper (not shown) which is an exposure apparatus, and then the first reticle substrate 10 is subjected to a primary exposure process by using the first mask pattern 12 as a mask. The cell pattern a and the dummy pattern b are transferred onto the reticle substrate 10. In this case, in the first exposure process, any one of I-rays of 365 nm wavelength, KrF of 248 nm wavelength, ArF of 193 nm wavelength, and EUV of 157 nm wavelength are used as the light source. FIG. 1A is a diagram illustrating that a first mask pattern 12 is formed on the reticle substrate 10.

Then, after removing the first mask pattern, a second mask pattern 14 is formed on the entire surface of the reticle substrate on which the first exposure process is completed, covering the dummy pattern and exposing the cell pattern. do. At this time, the second mask pattern 14 is formed using a light source of any one of a 365 nm wavelength I line, a 248 nm KrF, an 193 nm ArF, and a 157 nm wavelength EUV.

1B is a view showing that the second mask pattern 14 is formed on the reticle substrate 10.

Thereafter, by performing the second exposure process on the reticle substrate with the second mask pattern 14 as a mask without being removed from the stepper, as shown in FIG. By exposing the dummy pattern, unnecessary dummy pattern is removed and the actual working cell is protected by the chrome area. At this time, in the secondary exposure process, any one of I-rays of 365 nm wavelength, KrF of 248 nm wavelength, ArF of 193 nm wavelength and EUV of 157 nm wavelength is used as the light source.

Therefore, according to the present invention, the dummy patterns b of the first mask pattern 12 are exposed by the second mask pattern 14 through the double exposure process, and thus, as shown in FIG. It will form the correct actual cell pattern.

As a result, the present invention can control the abnormal pattern formation that may appear at the end of the cell block using the dummy pattern, and can reduce the size of the semiconductor chip as much as possible.

According to the present invention, by using a mask in which a cell pattern is opened at the time of reticle production, it is applicable to a semiconductor chip of sufficiently small size while using a sufficiently large number of dummy patterns.

In the present invention, as the dummy pattern protects the formation of the actual cell pattern and is removed after the normal pattern is formed, the actual operating cell forms the pattern of the normal form.

As described above, the present invention can use a large number of dummy patterns, and can secure a semiconductor chip of a sufficiently small size even when a dummy pattern is used.

In addition, in the present invention, as the dummy pattern protects the formation of the cell pattern that actually operates and is removed after the normal pattern is formed, the actual operation cell may form a pattern of a normal form.

On the other hand, the present invention can increase the uniformity by adjusting the non-uniform CD value in the wafer due to the pattern failure, thereby improving the process capability in the photo process, significantly reducing the number of rework due to the increase in reproducibility and increase the process yield Can be.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (3)

Forming a first mask covering the cell pattern and the dummy pattern on the reticle substrate; Aligning the substrate by a stepper, and then performing first exposure using the first mask; Removing the first mask; Forming a second mask covering a cell pattern and exposing the dummy pattern on the substrate on which the first exposure process is completed; Secondly exposing the substrate using the second mask; Reticle manufacturing method comprising the step of removing the second mask. The reticle according to claim 1, wherein in the first and second exposure processes, a light source uses any one of 365 nm wavelength I line, 248 nm KrF, 193 nm ArF, and 157 nm wavelength EUV. How to make. The method of claim 1, wherein in the forming of the first and second masks, the photosensitive agent uses a light source of any one of I-line of 365 nm wavelength, KrF of 248 nm wavelength, ArF of 193 nm wavelength, and EUV of 157 nm wavelength. Reticle production method.