Method for Controlling Polishing Wafer

Abstract

A method for controlling polishing a wafer includes the following step. Firstly, a database storing a number of status data of a polished film of a wafer and a number of polishing parameters corresponding to the status data is established. Each of the polishing parameters includes a head sweep of a polishing head along a redial direction of a polishing platen. The head sweep refers to a movement distance range from a center of the polishing head to a center of the polishing platen during a polishing process. Subsequently, a first wafer having a predetermined status data is provided. Thereafter, the predetermined status data is compared with the status data in the database so as to find out the polishing parameter corresponding to the predetermined status data, thereby determining a first polishing parameter of the first wafer. Afterward, a first polishing process using the first polishing parameter is applied to the first wafer. The method can control the status of a polished film and optimize the polishing parameter.

Description

BACKGROUND[0001]The present invention relates to a polishing process of a wafer, and particularly to a method for controlling polishing a wafer.[0002]With the development of semiconductor technology, it gradually becomes a trend to fabricate high density circuits on a wafer. Thus, it is necessary for the wafer to have a metal film (e.g., a copper film) with a thin thickness and a high uniformity.[0003]Generally, the metal film on the wafer is polished by a chemical mechanical polishing (CMP) process. FIG. 1 is a schematic view of polishing a semiconductor wafer using a chemical mechanical polishing process. Referring to FIG. 1, a polishing head 10 is used to hold a wafer 12 and to apply pressure to the wafer 12 so that the wafer 12 is contacted with a polishing pad of a polishing platen (not shown) to be polished. The polishing head 10 includes a retaining ring 11 for controlling pressure. The polishing head 10 can control a polishing speed of the wafer 12 by applying different pres...

AI Technical Summary

Benefits of technology

The present invention provides a method for controlling polishing a wafer by using a database to store polishing parameters and corresponding status data of the polished film of a wafer. The method includes steps of comparing the status data with the database to find the polishing parameter that optimizes the polishing process. The polishing parameter includes a head sweep of the polishing head along the redial direction of the polishing platen. By adjusting the head sweep, the method can control the status of the polished film and optimize the polishing process. The method can be used to polish multiple wafers with identical polished films sequentially using different polishing parameters. The invention provides a more efficient and effective method for controlling polishing processes and achieving a satisfactory polished film.

Problems solved by technology

However, nowadays, although the thin polished metal film can be obtained using the conventional chemical mechanical polishing process, the conventional chemical mechanical polishing process can not satisfy a thickness uniformity demand of polishing the metal film of the wafer 12.

Therefore, when the metal film of the wafer is polished by a polishing process and is expected to have a special thickness distribution for fabricating circuits, the above-mentioned method for controlling polishing the wafer is not satisfying.

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