Wafer Thinning Methods

Abstract

The invention provides a method for thinning a wafer, which includes the following steps: S1, injecting deposition gas into the reaction chamber, and turning on the power supply of the upper electrode to deposit a thin film on the surface of the wafer to be thinned; S2, turning off the upper electrode electrode power supply, and stop feeding the deposition gas, and then feed the etching gas into the reaction chamber; S3, turn on the upper electrode power supply and the lower electrode power supply to etch the wafer deposited with the film until the film is exhausted and the wafer The thickness of the circle to be thinned reaches the preset thickness; S4, turn off the upper electrode power supply and the lower electrode power supply, stop feeding the etching gas, and then feed the deposition gas into the reaction chamber; S5, judge that the alternate cycle is performed from step S1 to step Whether the current cycle number of S4 is equal to the total cycle number, if so, then end; if not, then make the current cycle number plus 1, and return to step S1. The wafer thinning method provided by the invention is used to improve thickness uniformity and surface roughness.

Description

technical field [0001] The present invention relates to the technical field of microelectronics, in particular to a wafer thinning method. Background technique [0002] Wafers are a very important raw material in industrial manufacturing areas such as integrated circuits (ICs), microelectromechanical systems (MEMS) and advanced packaging (AP). For wafers purchased directly from wafer manufacturers, their thickness and surface conditions generally do not meet the processing conditions, and the wafer thickness and surface roughness need to be adjusted through thinning, polishing, or epitaxial growth processes. For thinning, it is difficult to control the thickness uniformity and surface roughness, and the larger the wafer size, the more difficult it is. Although physical grinding can thin wafers with larger thicknesses, the surface roughness is difficult to control; and although the plasma etching method adopted in the current known technology can obtain better surface roughn...

AI Technical Summary

Problems solved by technology

Since plasma etching has both free radical components for chemical etching and ion components for physical bombardment, affected by the physical bombardment effect, using the traditional plasma method to thin the wafer will cause wafer thinning. The surface roughness is large, and the thickness uniformity of thinning is not ideal

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