KR100257770B1 - Method for forming fine conduction film of semiconductor device - Google Patents

Abstract

PURPOSE: A method for forming a fine conductive layer pattern of a semiconductor device is provided to improve the reliability of a semiconductor device by forming easily a fine conductive layer pattern. CONSTITUTION: The first conductive layer(12) and a sacrificial layer are formed on a substrate(11). The sacrificial layer is etched selectively to expose the first area of the first conductive layer(12) and a sacrificial layer pattern is formed thereby. An insulating layer spacer is formed at a side face of the sacrificial layer pattern. The second area of the first conductive layer(12) is exposed by removing the sacrificial layer pattern. The second conductive layer(15) is formed selectively on the first area and the second area of the first conductive layer(12). The insulating layer spacer is removed and the first conductive layer(12) is etched selectively by using the second conductive layer(15) as an etching mask pattern.

Description

Fine conductive film pattern formation method of semiconductor device

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device having a fine conductive film pattern for the electrical connection of the device.

First, a pattern of a general semiconductor device is formed by a lithography process. The lithography process is performed by performing an etching process using an etching mask pattern formed through a series of photolithography processes using a photomask. The above-described series of photolithography processes include HMDS coating, spin coating of the photoresist film, soft bake process, exposure, post-exposure bake process, and development process steps. The etching process is divided into anisotropic etching to obtain an isotropic profile and anisotropic etching to obtain an anisotropic profile according to the profile after etching. Isotropic etching is a technique that uses almost chemical reactions, and it means that the etching reaction proceeds the same in all directions. On the contrary, anisotropic etching is a case where the etching reaction occurs only in a specific direction. At this time, unlike the isotropic etching, the physical reaction and the chemical reaction occur simultaneously. Here, wet etching showing anisotropic properties is used to obtain an isotropic profile, and dry etching showing anisotropic properties is used to obtain anisotropic profile.

As is well known, as the device is highly integrated, a method of forming a device having a stacked structure is prevalent, and various problems have arisen. For example, as the device is highly integrated, the minimum line width for device fabrication is rapidly decreasing and an etching pattern defect is caused. In addition, due to the limitation of the exposure equipment, problems such as poor depth of focus and poor exposure appear during the lithography process to obtain the minimum line width.

Therefore, it is necessary to develop a semiconductor device manufacturing method having a fine conductive film pattern that can overcome this problem.

An object of the present invention is to provide a method for manufacturing a semiconductor device having a fine conductive film pattern according to the high integration of the device to solve the problems as described above.

1A to 1D are cross-sectional views illustrating a method of forming a fine conductive film pattern according to an embodiment of the present invention.

* Brief description of the main parts of the drawing

11: silicon substrate

12: Ti / TiN

13: polysilicon film

14: oxide film and oxide spacer

15: upper conductive film

In order to achieve the above object, the semiconductor device manufacturing method of the present invention includes a first step of sequentially forming a first conductive film and a sacrificial film on the substrate; Forming a sacrificial layer pattern by selectively etching the sacrificial layer to expose the first region of the first conductive layer; Forming an insulating film spacer on a side of the sacrificial film pattern; A fourth step of exposing the second region of the first conductive layer by removing the sacrificial layer pattern; A fifth step of selectively forming a second conductive film in the first and second regions of the exposed first conductive film; And removing the insulating film spacer and selectively etching the first conductive film using the second conductive film as an etching mask pattern.

According to the present invention, a polysilicon film pattern is formed by conducting a conventional exposure and etching process by depositing a conductive material on the silicon substrate as a lower conductive layer on a silicon substrate and then depositing a polysilicon film. Form. An insulating film is deposited to a predetermined thickness on the formed polysilicon film pattern, and the entire surface is etched to form an insulating film spacer on the side of the polysilicon film pattern. Then, the conductive film is selectively formed using the lower conductive layer exposed by removing the polysilicon film pattern, that is, by forming a conductive film selectively without performing a lithography process for a fine pattern, thereby forming a fine conductive film pattern. To provide.

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

1A to 1D are cross-sectional views illustrating a method of forming a fine conductive film pattern according to an embodiment of the present invention.

First, as shown in FIG. 1A, a Ti / TiN film 12 is formed on the silicon substrate 11 as a lower conductive film. Then, a polysilicon film 13 is formed, and a lithography process is performed to form a polysilicon film 13 pattern that opens to a first size to expose the Ti / TiN film 12 at a first size. The line width of the polysilicon layer 13 pattern may have a second size relatively smaller than the first size. An oxide film 14 having the polysilicon film 13 pattern and an etching selectivity is formed on the entire structure. In some cases, the lower conductive film may be formed of a Ti film or a TiN film.

Next, as shown in FIG. 1B, the oxide film 14 is etched entirely to form an oxide spacer 14 on the side surface of the polysilicon film 13 pattern, thereby exposing the Ti / TiN film 12 exposed to the first size. ) To the third size.

Next, as shown in FIG. 1C, the polysilicon film 13 pattern is removed, and since the oxide spacer 14 on the side has a selective etching ratio with the polysilicon film 13, a considerable portion remains even if etched to some extent. Should be. After the above process, the upper conductive film 15 is selectively formed on the Ti / TiN film 12 exposed to the second size and the third size. Note that the height of the upper conductive film 15 formed here should not be higher than the oxide spacer 14. In addition, while the second size is determined in the above-described lithography process, it is noted that the third size may vary depending on the etching conditions in the process of forming the oxide spacer 14. For reference, in the present invention, the second size: the third size is formed to have a ratio of 1: 1.

Next, as shown in FIG. 1D, after the oxide spacer 14 is removed, the silicon substrate 11 is exposed by etching the exposed Ti / TiN film 12 using the upper conductive film 15 as an etch mask. Let's do it. The etching process of the Ti / TiN film 12 is performed using chlorine-based gas.

As described above, after forming a sacrificial layer pattern having a first critical line width on the first conductive layer, a spacer is formed on the side of the sacrificial layer pattern, and the spacer has an etching ratio different from that of the sacrificial layer pattern. By selectively forming the second conductive film on the exposed first conductive film by removing the sacrificial film pattern, it is possible to easily obtain a fine conductive film pattern that is difficult to reproduce due to the limitations of conventional exposure equipment, resulting in yield and reliability of the device. To improve. That is, even using a lithography process technology capable of reproducing the first critical line width, another conductive film may be formed on the lower layer exposed to the first critical line width.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

According to the present invention, the sacrificial film pattern having the first critical line width is formed on the first conductive film during the metal pattern process of the semiconductor device, and the sacrificial film pattern has an etch selectivity on the sacrificial film pattern side. By forming a spacer and selectively forming a second conductive film on the exposed first conductive film by removing the sacrificial film pattern, it is possible to easily obtain a fine conductive film pattern that is difficult to reproduce due to the limitations of conventional exposure equipment. Improve yield and reliability.

Claims (7)

A first step of sequentially forming a first conductive film and a sacrificial film on the substrate; Forming a sacrificial layer pattern by selectively etching the sacrificial layer to expose the first region of the first conductive layer; Forming an insulating film spacer on a side of the sacrificial film pattern; A fourth step of exposing the second region of the first conductive layer by removing the sacrificial layer pattern; A fifth step of selectively forming a second conductive film in the first and second regions of the exposed first conductive film; And A sixth step of removing the insulating layer spacer and selectively etching the first conductive layer using the second conductive layer as an etch mask pattern A semiconductor device manufacturing method comprising a. The method of claim 1, And a first region exposed by the sacrificial layer pattern in the second step is larger than a second region exposed in the fourth step. The method of claim 1, And the second conductive film is a film having an etching ratio different from that of the first conductive film. The method of claim 1, And allowing the insulating film spacer to remain during the fourth step. The method of claim 3, The first conductive film is A semiconductor device manufacturing method comprising at least one of a Ti film, a TiN film, and a Ti / TiN film. The method of claim 1, And the sacrificial film is a polysilicon film. The method according to claim 1 or 4, The insulating film spacer is an oxide film manufacturing method.

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