Method for controlling CMP film thickness internal homogeneity

Abstract

The present invention discloses a method for controlling the evenness of the CMP film thick surface; on the basis of control with only optical lens grinding velocity and evenness, the present invention adds the tendency management of the product front film range and optical lens grinding velocity; based on the collected parameters of front film range, grinding velocity tendency and used film range, analyze the relations between the used film range, the front film range and grinding velocity tendency; with these relations, choose the proper machine with parameters similar to the parameter CER according to the front film range and implement CMP exercise. The present invention can effectively control the used film range within specifications.

Description

technical field [0001] The invention relates to a processing technology of a semiconductor device. Background technique [0002] At present, in the chemical mechanical polishing (CMP) process of the semiconductor wafer factory (FAB), the thickness and in-plane uniformity of the film (residual film) after product grinding are mainly controlled by monitoring the size and uniformity of the polishing rate of the optical sheet. to achieve. The polishing rate of the light sheet can reflect the state of the CMP equipment to a certain extent, so the size of the polishing rate of the light sheet is usually used to determine the grinding time of the product so as to control the thickness of the remaining film and control the uniformity of the polishing rate of the light sheet within a certain range To ensure the uniformity of product thickness, and the uniformity of film thickness is generally reflected by the range within the plane, that is, the difference between the maximum and mi...

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Problems solved by technology

Excessive residual film thickness range not only directly affects the focus of subsequent photolithography, but also causes poor opening (via open) in thicker places, and affects the characteristics of through holes (via) in thinner places, resulting in low yield

In order not to affect the yield rate, reprocessing of wafers whose range exceeds the specification is often remedied. The method is to chase the film length of 3000-5000A, and then perform additional grinding; this not only greatly increases the cost of manpower, materials and equipment, but also affects the product life cycle

Although tightening the size and uniformity of the grinding rate can reduce the phenomenon that the range exceeds the specification to a certain extent, it also limits the service life of consumables

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