Method for controlling chemical and mechanical grinding endpoint

Abstract

The present invention discloses a control method of chemical-mechanical grinding end; with the method, a grinding parameter of grinding chip, a relevant fore process parameter and a grinding correction factor are preset and the grinding time is calculated according to the preset values; and then grind the chip according to the grinding time to promote the confirmation accuracy of the grinding end and ensure the repeated grinding between batch and batch in production; at the same time, the rework rate and reject rate are reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for controlling the end point of chemical mechanical polishing. Background technique [0002] With the rapid development of ULSI (Ultra Large Scale Integration), the manufacturing process of integrated circuits has become more and more complex and refined, and the requirements for the flatness of the wafer surface have become more and more stringent. However, the widely used multi-layer wiring technology will cause the surface of the chip to be uneven, which is extremely unfavorable to the graphics production. Planarization treatment is required to make each layer have a high global flatness. [0003] Although many planarization technologies have been applied, such as back-etching, glass reflow, and spin coating, these traditional technologies are all local planarization technologies and cannot achieve global planarization. At present, chemical mecha...

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Problems solved by technology

[0007] 1. This method is easily affected by interference factors such as grinding liquid and mechanical vibration, and has defects such as low monitoring accuracy, overly complicated signal processing and poor reliability, and cannot ensure the repeatability of the CMP process

[0008] 2. This method needs to modify the appearance and circuit of the grinding equipment, and realize complex

[0009] 3. This method is only suitable for the grinding process with a large change in friction coefficient, not suitable for the grinding process only for the purpose of removing film thickness

However, in this method, only the influence of different grinding layer thicknesses on the grinding time has been considered, and the influence of various other factors such as equipment state, equipment working time, wafer state to be ground, etc. on determining the grinding end point has not been considered, so that the determined by this method The grinding end point is still not accurate enough, which will still lead to high rework rate and scrap rate, and requires multiple monitoring during the production process, resulting in low production efficiency

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