Method of forming a pattern in a semiconductor device and method of forming a gate using the same

Abstract

A method of forming a pattern in a semiconductor device is described. A substrate divided into cell and peripheral regions is provided, and an object layer is formed on a substrate. A buffer pattern is formed on the object layer in the cell region along a first direction. A spacer is formed along a sidewall of the buffer pattern in the cell region, and a hard mask layer remains on the object layer in the peripheral region. The buffer layer is removed, and the spacer is separated along a second direction different from the first direction, thereby forming a cell hard mask pattern. A peripheral hard mask pattern is formed in the peripheral region. A minute pattern is formed using the cell and peripheral hard mask patterns in the substrate. Therefore, a line width variation or an edge line roughness due to the photolithography process is minimized.

Description

CROSS-REFERENCE OF RELATED APPLICATIONS [0001] This application relies for priority upon Korean Patent Application No. 2003-97427 filed on Dec. 26, 2003, the contents of which are herein incorporated by reference in their entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method of forming a pattern for a semiconductor device. More particularly, the present invention relates to a method of forming a pattern of which line width is much smaller and finer in a cell region than in a peripheral region of a semiconductor device. [0004] 2. Description of the Related Art [0005] Forming a fine circuit on a semiconductor substrate includes an impurity implantation, a patterning process and an electrical connection between separated portions. Impurities are implanted on a small surface portion of a silicon substrate in a precise amount, and then a sacrificial layer is formed on the substrate including the impurities. Then, the sacri...

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Benefits of technology

[0018] Since the cell hard mask pattern is formed on sidewalls of the buffer pattern, a pair of patterns is repeatedly formed at regular intervals in the cell region. That is, the present invention may be applied to a method of manufacturing the semiconductor device in which a pair of patterns is repeated at regular intervals in the cell region. In addition, since the peripheral hard mask pattern is always formed without a limitation in its shape, the minute pattern in the peripheral region is readily formed in accordance with various design conditions.

[0020] Therefore, the pattern in the wafer may have a different line width according to the region of the wafer, and the line width may be less than the CD of the photolithography process. In addition, the line width variation due to the photolithography process may be minimized. Further, since the hard mask layer is uniformly etched away, line edge roughness due to a non-uniform etching may also be minimized.

[0027] Therefore, the gate pattern formed to have a smaller line width in the cell region than in the peripheral region. In addition, the line width variation and the line edge roughness due to the photolithography process may be minimized.

Problems solved by technology

Thirdly, when an etching process is performed using the photoresist pattern as a mask, an edge line of an etched portion of the thin layer becomes very rough since the photoresist pattern becomes non-uniform, which is referred to as a line edge roughness phenomenon.

Non-uniformity of the line width distribution causes electrical characteristics of each unit device in a chip or in a wafer to be non-uniform, thus causing various process failures in the semiconductor device.

In addition, a non-uniform etching of the photoresist film degrades a short channel characteristic of the device, and a gate size reduction accelerates the degradation of the short channel characteristic of the device.

However, when the second insulating layer is used as an etching mask, the pattern has the same line width across a whole surface of a substrate, and as a result, the pattern may not have a line width greater than that of the second insulating layer at any local area on the substrate.

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