Method for bonding and separating silicon wafers

Abstract

The invention discloses a method for bonding and separating silicon wafers, which includes following steps of: 1) selecting polished silicon wafers of which facades are polished surfaces; 2) setting an oxide layer on the facade of any polished silicon wafer or each polished silicon wafer, leading the facades of every two polished silicon wafers to be opposite, and then performing room temperaturebonding; 3) putting a bonding silicon wafer group in a high-temperature furnace for reinforcing; 4) performing corrosion treatment on the reinforced silicon wafer group by using HF solution to removethe oxide layer on the outer surface of the reinforced silicon wafer group; 5) re-blending and diffusing both surfaces of the obtained silicon wafer group and 6) putting the silicon wafer group whichis re-blended and diffused in the HF solution for treatment so as to corrode the oxide layer on the bonding surface of the silicon wafer group and obtain two silicon wafers which are separated from each other. The silicon wafer produced by adopting the method has the characteristic of controllable thickness.

Description

technical field [0001] The invention relates to a method for bonding and separating silicon wafers. The invention can be used to prepare silicon wafers with N- / N+ and P- / N+ structures. Background technique [0002] There are usually two methods to produce silicon wafers with N- / N+ and P- / N+ structures: method one is to epitaxially layer a layer of lightly doped silicon on the surface of heavily doped silicon wafers; method two is to use lightly doped silicon wafers in a diffusion furnace Thermal diffusion is carried out in the surface to form heavy doping, and then one side of the silicon wafer is ground and polished to realize the above structure. Method 1, that is, the silicon wafer with the above structure made by the epitaxial method is of good quality, but the processing cost is high, and the equipment cost of the epitaxial furnace used is also high, and the cost will be higher with the increase of the epitaxial thickness. In order to reduce the cost and process some ...

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Problems solved by technology

[0003] Invention patent CN101186082 provides a method that can reduce the loss of silicon material. The method used (as shown in Figure 2) is to use a multi-wire cutting machine to divide the thin silicon wafer into two. However, this method has the following problems: A defect: 1. The thickness of the silicon wafer is only a few hundred microns. It is very difficult to cut the steel wire of the multi-wire cutting machine to the middle of the silicon wafer measured in microns. It is processed by the above-mentioned wire cutting method. There will be a large deviation in the thickness of the silicon wafer, and the TTV will be large, which will directly affect the consistency and yield of subsequent devices; 2. The silicon wafer after multi-wire cutting will be dirty and difficult to clean; 3. Using wire cutting The method requires the use of steel wire and sand, as well as the manufacture of fixtures, etc., resulting in higher costs

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