KR100882730B1 - Method for fabricating mask - Google Patents

Abstract

A method for manufacturing mask capable of minimizing critical dimension error on wafer due to mask error is provided to rapidly lithograph a minute pattern by using an optical laser device and an electronic beam laser device. A photoresist film is formed on a non-etching film(S100). A preliminary pattern is written on the photoresist film(S110), and has margin range in an edge of a mask layout pattern. The mask layout pattern is written by lithographing the margin range on the photoresist film(S120). The photoresist film is developed(S130). The non-etching film is etched using the developed photoresist film as mask(S140).

Description

Mask manufacturing method {METHOD FOR FABRICATING MASK}

The embodiment relates to a mask manufacturing method.

In recent years, with the rapid spread of information media such as computers, semiconductor devices have also been developed rapidly. In terms of its function, the semiconductor element is required to operate at high speed and to have a large storage capacity and information processing capability. In response to these demands, the manufacturing technology of the semiconductor devices has been rapidly developed to improve the degree of integration, reliability, and response speed.

The semiconductor device is a thin film forming process for forming a thin film on a silicon substrate, a photo process comprising a photo process and a developing process for forming a photoresist pattern on the thin film, and an etching process for patterning the thin film using the photoresist pattern as an etching mask. It is manufactured through thin film processing processes such as an ion implantation process for injecting impurities into the thin film.

Among these thin film processing processes, the photolithography process is an important process having a great influence on the design rule of a semiconductor device. In the photolithography process, a mask having fine patterns for exposure is used.

In order to form a precise pattern of the mask, a layout correction method using optical proximity correction (hereinafter referred to as "OPC") is used.

However, in the actual mask pattern using the optical proximity corrected layout data as shown in FIG. 1 using the optical proximity corrected layout data in FIG. 1 as shown in FIG. 2, the pattern is not implemented in the actual mask as in the circled area O. Eventually has a problem of Erro (Defective pattern) on the wafer.

This problem is due to the fact that the implementation limit of the mask writing tool is not considered when performing the OPC.

The embodiment provides a mask manufacturing method capable of delicate mask patterning and short manufacturing time.

The mask manufacturing method according to the embodiment may include forming an etched film on a base substrate, forming a photoresist film on the etched film, and forming a preliminary pattern having a margin range at an edge of a mask layout pattern on the photoresist film. First writing, exposing the margin range on the photoresist film to second writing the mask layout pattern, developing the first and second exposed photoresist films, and developing Etching the etched film using the photoresist film as a mask.

The mask manufacturing method according to the embodiment may include forming an etched film on a base substrate, forming a photoresist film on the etched film, and first writing a margin range at a mask layout pattern boundary on the photoresist film. And secondly writing an area outside the margin range on the photoresist film, developing the photoresist film to form a photoresist pattern transferred with the mask layout pattern, and using the photoresist pattern as a mask. Etching a.

The embodiment has the effect of quickly and precisely exposing a fine pattern using optical laser equipment and electron beam laser equipment having different characteristics.

 According to the embodiment, since the corner rounding effect of the layout pattern may be minimized by using the electron beam writing equipment, the CD error on the wafer due to the mask error may be minimized.

Hereinafter, a mask manufacturing method according to an embodiment will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a mask manufacturing method according to an embodiment, and FIGS. 4 to 8 are cross-sectional views of masks manufactured in the order of FIG. 3.

3 and 4, the metal film 110 is formed on the base substrate 110, and the photoresist film 120 is formed on the metal film 110 (S100).

For example, the metal layer 110 may include chromium.

3 and 5, primary writing is performed on the photoresist film 120 (S110).

The primary lighting may be performed by using an optical laser lighting equipment.

The optical laser writing equipment has a fast and inexpensive transfer time.

In addition, since the optical laser lighting equipment does not accurately express the details of the mask layout, the embodiment may provide a rough margin from the pattern edge of the mask layout in the primary lighting process using the optical laser lighting equipment. By roughly writing the pattern, the primary exposure area 120a is formed in the photoresist film 120.

3 and 6, secondary writing is performed on the photoresist film 120 (S120).

The secondary lighting may be performed using an electron beam (E-beam) lighting equipment.

The electron beam lighting equipment has a high resolution and has a feature of finely transferring a fine pattern.

The electron beam writing device may write light on the photoresist film 120 firstly written by the optical laser writing device along the pattern edge of the mask layout, thereby forming a secondary exposure area 120b on the photoresist film 120. To form.

That is, the primary lighting may roughly write the pattern of the mask layout, and the secondary lighting may precisely write the pattern of the roughly patterned mask layout.

The first exposure area is wider than the second exposure area, and the mask is manufactured according to the embodiment by exposing the pattern quickly and roughly using the optical laser lighting equipment and delicately exposing the periphery of the pattern using the electron beam writing equipment. By using alternating lighting equipment with two different characteristics in the process, the mask layout can be transferred to the photoresist film in a very short time.

As shown in FIGS. 3 and 7, the photoresist film 120 exposed to the first and second exposures is developed to form a photoresist pattern 121 (S130).

3 and 8, the metal film is etched using the photoresist pattern 121 exposed as the first and second exposures to form a metal pattern 110a (S140).

As a result, a mask in which the metal pattern 110a is formed on the base substrate 100 may be completed (S150).

In the meantime, the electron beam lighting equipment may be used in the primary lighting, and the optical laser lighting equipment may be used in the secondary lighting.

That is, during the primary writing, an electron beam is exquisitely exposed along the edge portion of the mask layout to form a primary exposure area, and a second wide lighting area may be secondly written along the corner of the rounded primary exposure area. It may be.

FIG. 9 is a diagram illustrating a part of a mask layout provided for manufacturing a mask according to an embodiment, FIG. 10 is a pattern of primary writing of the mask layout of FIG. 9, and FIG. 11 is a view of elaborating the primary writing pattern of FIG. 10. This is the second lighting pattern.

As shown in FIG. 9, the mask layout 150 includes fine patterns such as an “A” region. The mask layout 150 may be divided into an exposure area 150a and a light blocking area 150b, which may be inverted according to the type of mask pattern and photoresist to be formed.

As shown in FIG. 10, the mask layout 150 is divided into a plurality of gratings G having a predetermined size.

In the light blocking region 150b of the mask layout, the preliminary pattern 160 may be formed by performing primary writing using an optical laser writing apparatus outside the range of 1 to 2 gratings.

In this case, the fine pattern within one lattice range may overlap the layout pattern when the first writing is performed outside the 1-2 grid range. In this case, as shown in the area "A", primary writing is performed along the outline of the layout pattern. As a result, the primary written preliminary pattern 160 is patterned so as to frame only the layout pattern without being trimmed.

The preliminary pattern 160 is wider than the light blocking area 150b of the mask layout 150.

As illustrated in FIG. 11, the primary writing preliminary pattern 150 may be secondly written using an electron beam writing apparatus to roughly pattern the preliminary pattern 160, which is roughly framed, and may be patterned at high resolution.

The exposure area by the secondary writing is made within a range of 1-2 gratings along the circumference of the preliminary pattern.

As a result, the mask pattern 170 in which the mask layout 150 shown in FIG. 9 is finely transferred can be formed over the primary and the secondary lighting (see an area "A").

The embodiment uses a beam-writing device that transfers delicate and finely, but takes a long time to transfer, and writes a minimum area, while the wide and rough area uses a laser-writing device that has a short transfer time, thereby improving mask quality. And it can be expected to reduce the manufacturing cost. That is, the mask quality can be improved compared to when only the optical laser lighting equipment is used, and the mask writing time and manufacturing cost can be reduced than when only the electron beam lighting equipment is used.

In addition, since the embodiment can minimize the corner rounding effect of the layout pattern by using the electron beam writing equipment, there is an effect that can minimize the CD error on the wafer due to the mask error (mask error).

1 is an example of layout data subjected to optical proximity correction (OPC) by the prior art;

FIG. 2 is an example of a mask pattern using the optical proximity corrected layout data of FIG. 1. FIG.

3 is a flow chart showing a mask manufacturing method according to the embodiment.

4 to 8 are cross-sectional views of masks made in accordance with the sequence of FIG.

9 is an example showing a portion of a mask layout prepared for manufacturing a mask according to the embodiment.

10 is an example of a pattern in which the mask layout of FIG. 9 is primarily written.

FIG. 11 is an example of a pattern in which the secondary transfer pattern of FIG. 10 is finely secondary lit;

Claims (9)

Forming an etched film on the base substrate and forming a photoresist film on the etched film; First writing a preliminary pattern having a margin range at an edge of a mask layout pattern on the photoresist layer; Secondly writing the mask layout pattern by exposing the margin range on the photoresist film; Developing the first and second exposed photoresist films; And And etching the etched film using the developed photoresist film as a mask. The method of claim 1, In the primary writing step, Dividing the mask layout pattern into unit gratings; The margin range is a mask manufacturing method comprising the step of forming a preliminary pattern larger than the mask layout pattern to a 1 to 2 unit grid. The method of claim 1, And the primary lighting uses laser equipment and the secondary lighting uses electron beam equipment. The method of claim 1, And the area exposed by the primary lighting is larger than the area exposed by the secondary lighting. Forming an etched film on the base substrate and forming a photoresist film on the etched film; First writing a margin range at a mask layout pattern boundary on the photoresist film; Secondly writing a region outside the margin range on the photoresist film; Developing the photoresist film to form a photoresist pattern to which the mask layout pattern is transferred; And And etching the etched film using the photoresist pattern as a mask. The method of claim 5, And the primary lighting uses electron beam equipment and the secondary lighting uses laser equipment. The method of claim 5, And the area exposed by the primary lighting is smaller than the area exposed by the secondary lighting. The method of claim 5, In the primary writing step, Dividing the mask layout pattern into unit gratings; And exposing a lattice range of 1 to 2 units from a boundary of the mask layout pattern. The method of claim 5, In the secondary writing step, And an area other than the mask layout pattern and the primary lit area is exposed.

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