KR20040022077A - Method for manufacturing metal insulator metal capacitor - Google Patents

Abstract

PURPOSE: A method for manufacturing an MIM(Metal Insulator Metal) capacitor is provided to be capable of preventing degradation of a lower metal line due to ununiform residues. CONSTITUTION: The first metal film(12), an insulating layer(14) and the second metal film(16) are sequentially stacked on an interlayer dielectric(10). The second metal film and the insulating layer are selectively etched by using a photoresist pattern for defining a capacitor region. An anti-reflective layer(18) is formed on the resultant structure after the photoresist pattern is removed. A DUV(Deep UltraViolet) pattern(20) is formed on the resultant structure to define a lower metal line region. The anti-reflective layer and the first metal film are selectively etched by using the DUV pattern as a mask.

Description

METHOD FOR MANUFACTURING METAL INSULATOR METAL CAPACITOR

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a metal insulator metal (hereinafter referred to as MIM) capacitor, and more particularly, to a method of forming a MIM structure in the form of a top plate on a metal wiring.

Recently, the MIM structure has been formed in the form of a metal top plate in the form of a via hole. This is because it is considered a more advantageous process for the problem of leakage due to step coverage. In particular, with the integration of devices, the MIM process has been introduced in the fine line width metal process using DUV.

In the conventional MIM capacitor manufacturing process, it is difficult to control residues such as a capacitor material that is used as a capacitor.

Therefore, when depositing an antireflective layer to form a lower metal wiring used as the MIM lower electrode, it is difficult to form the lower metal wiring due to the thickness of the MIM capacitor and the antireflective layer.

The present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a method for manufacturing a MIM capacitor that solves the difficulty of forming a lower metal wiring caused by a capacitor material that remains unevenly when the MIM capacitor is formed.

The present invention for achieving the above object comprises a first step of sequentially stacking a first metal, an insulator, and a second metal on the interlayer insulating film; A second step of forming a photo resist (PR) in the MIM capacitor region on the second metal; A third step of removing the second metal and the insulator other than the photoresist region; A fourth step of removing the photoresist; A fifth step of forming an anti-reflection layer on the entire surface; A sixth step of forming a DUV pattern on the surface of the lower metal wiring region; And a seventh step of removing the antireflection layer and the first metal other than the DUV pattern region.

1A to 1D are cross-sectional views showing a method of manufacturing a metal insulator metal capacitor according to the present invention step by step.

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

1A to 1D are cross-sectional views illustrating a method of manufacturing a metal insulator metal capacitor according to the present invention.

First, as illustrated in FIG. 1A, a first metal 12, an insulator 14, and a second metal (TiN or Al) 16 are sequentially stacked on the interlayer insulating layer 10. A photoresist (not shown in the figure) is formed in the MIM capacitor region on the second metal 16. The dry etching process is performed to remove the second metal 16 and the insulator 14 other than the photoresist region. In the dry etching, an etching gas having a ratio of CHF 3 to AR in a ratio of 1 to 1 or more is used. Remove photoresist. That is, in the past, the capacitor material remained to a certain thickness on the lower electrode other than the MIM capacitor region, but the present invention hardly retains the capacitor material through a process in which the selectivity between the first metal 12 and the insulator 14 is good. .

As illustrated in FIG. 1B, an antireflection layer 18 is deposited on the entire surface of the bottom metal wiring.

As shown in FIG. 1C, the DUV pattern 20 is formed on the surface of the lower metal wiring region.

As shown in FIG. 1D, a dry etching process is performed to remove the antireflection layer 18 and the first metal 12 other than the DUV pattern 20 region, thereby completing the MIM capacitor. The DUV pattern 20 is removed. Conventionally, the photoresist margin may be insufficient due to the thickness of the anti-reflection layer and the capacitor material on the lower metal interconnection. The bottom metal wiring can be obtained stably without modification.

Here, the second metal 16 of the MIM capacitor region is used as the upper electrode. The insulator 14 in the MIM capacitor region is used as the capacitor material. The first metal 12 of the MIM capacitor region is used as the lower metal wiring.

As described above, the present invention solves the difficulty of forming the lower metal wiring caused by the capacitor material remaining unevenly when forming the MIM capacitor. Therefore, capacitors of various thicknesses can be easily configured.

Claims (6)

A first step of sequentially stacking a first metal, an insulator, and a second metal on the interlayer insulating film; Forming a photoresist in a MIM capacitor region over said second metal; A third step of removing the second metal and the insulator other than the photoresist region; A fourth step of removing the photoresist; A fifth step of forming an anti-reflection layer on the entire surface; A sixth step of forming a DUV pattern on the surface of the lower metal wiring region; And A method of manufacturing a metal insulator metal capacitor comprising a seventh step of removing the anti-reflective layer and the first metal other than the DUV pattern region. The method of claim 1, wherein the second metal is TiN. The method of claim 1, wherein the second metal is Al. 2. The method of claim 1, wherein the third step removes the second metal and the insulator other than the photoresist area by performing a dry etching process. 3. 5. The method of claim 4, wherein an etching gas having a ratio of CHF 3 to AR in a ratio of 1 to 1 or more is used in the dry etching process. The method of claim 1, wherein the seventh step is to perform a dry etching process to remove the anti-reflective layer and the first metal other than the DUV pattern region.