Polishing pad and polishing device

Abstract

The present invention relates to a polishing pad which is characterized in that it has a polishing layer of rubber A-type microhardness at least 80 DEG and a cushioning layer of bulk modulus at least 40 MPa and tensile modulus in the range 0.1 MPa to 20 MPa, and to a polishing device which is characterized in that a semiconductor substrate is fixed to the polishing head, and an aforesaid polishing pad is fixed to the polishing platen so that the polishing layer faces the semiconductor substrate, and by rotating the aforesaid polishing head or the polishing platen, or both, the semiconductor substrate is polished. With the polishing device or polishing pad of the present invention for use in the mechanical planarizing process wherein the surface of the insulating layers or metal interconnects formed on a semiconductor substrate are smoothened, it is possible to uniformly planarize the entire semiconductor face and perform uniform polishing close up to the wafer edge and, furthermore, it is possible to provide a technique for achieving both uniformity and planarity under conditions of high platen rotation rate.

Description

[0001] technology area [0002] The present invention relates to a polishing device and a polishing pad for a semiconductor substrate, and more particularly to a polishing device and a polishing pad for mechanically flattening the surface of an insulating layer and the surface of a metal wiring formed on a semiconductor substrate such as silicon. Background technique [0003] With the year-by-year integration of large-scale integrated circuits (LSI) represented by semiconductor memory, the manufacturing technology of large-scale integrated circuits is also developing towards high density. Furthermore, along with such densification, the number of layers of semiconductor devices is also increasing. As the number of layers is increased, unevenness of the main surface of the semiconductor substrate caused by layering, which was not a problem until now, becomes a problem. For example, "Nikkei Microdevices" (Nikkei Microdevices) July 1994, pp. 50-57, discusses how to make up for th...

AI Technical Summary

Problems solved by technology

First of all, even if the bulk modulus of the polishing layer is larger than that of the buffer layer, sometimes the flatness of the local unevenness on the surface of the semiconductor substrate is poor, and the local flatness is not necessarily the same as the bulk modulus of the polishing layer. There are relationships

Second, since the bulk modulus of the buffer layer is 250 psi / psi in the stress range of 4 psi to 20 psi, the bending tracking of the entire surface of the semiconductor substrate is poor, and as a result, the uniformity (uniformity) of the entire surface of the semiconductor substrate cannot be obtained sufficiently.

Moreover, as described in "CMP Science" p177-p183 published by the Science Research Forum (サイエンスフオ-ラム) of the company, there is no question of how close to the edge in the wafer plane the necessary planarization is to be performed. Fully resolved

Third, when the rotation speed of the polishing table is increased to a high speed, the flatness is good, but the bending tracking of the entire surface of the semiconductor substrate is deteriorated