A Method for Improving Thickness Stability of Interlayer Media Grinding Process

Abstract

The invention provides a method for improving thickness stability of an interlayer medium grinding technology. The method is applied to an interlayer medium grinding system. The method for improving the thickness stability of the interlayer medium grinding technology is characterized in that the method comprises the following steps that a thin film thickness before grinding and a target grinding thickness of a to-be-grinded silicon chip are obtained; a theoretical grinding thickness is obtained according to the thin film thickness before grinding and the target grinding thickness; the grindingspeed and the grinding time are determined according to the theoretical grinding thickness and an adjusting grinding difference, wherein the adjusting grinding difference is the difference value between the previous grinding thickness of the silicon chip and the target grinding thickness, and the grinding time is a quantity varying with the use time of a grinding pad and the use time of a finishing disc; adjusting is conducted according to the time varying amount of grinding the silicon chip given by an interlayer medium grinding feedback system and the grinding time, and then the actual required grinding time is obtained; and interlayer medium grinding is conducted according to the actual required grinding time. The method for improving the thickness stability of the interlayer medium grinding technology has the beneficial effects that by integrating an automatic feedback system and a formula method, the advantages of the automatic feedback system and the formula method are utilized,meanwhile, the disadvantages of the automatic feedback system and the formula method are abandoned, stability of the thin film thickness of an interlayer medium is greatly improved, and meanwhile, benefits from all sides are brought.

Description

technical field [0001] The invention relates to the field of integrated circuit chip manufacturing, in particular to a method for improving the thickness stability of an interlayer media grinding process. Background technique [0002] The interlayer dielectric used as device and metal layer insulator is usually composed of chemical vapor deposition film and plasma enhanced chemical vapor deposition film with high filling ratio performance. The grinding process used for this interlayer media (see figure 1 ) has a certain degree of blindness because there is no clear and effective end point indication. Usually, the film thickness data received by the front layer and the final index are used to determine the required grinding time according to the grinding rate. This method usually leads to deviations between the value after grinding and the index. When the grinding is not enough, the process will carry out the secondary grinding of the back cavity; when the grinding is too m...

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Problems solved by technology

Usually, the film thickness data received by the front layer and the final index are used to judge the required grinding time according to the grinding rate. This method usually leads to deviations between the value after grinding and the index.

When the grinding is not enough, the process will carry out the secondary grinding of the back cavity; when the grinding is too much and the remaining interlayer medium 1 is too thin, the method of secondary deposition will be used to compensate the difference, and a compensation film 2 will be formed on the surface (see figure 2 ), but the electrical damage caused by high-energy ions to the underlying high-filling ratio film usually leads to a drift in device performance, especially for P-type devices (see image 3 )

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