Method and system for etching wafer back

Abstract

The invention provides a method and a system for etching a wafer back, avoiding a discoloration phenomenon on the front face of a wafer and improving the quality of the wafer by attaching an anti-acid membrane to the front face of the wafer corresponding to the back face of the wafer. The method comprises the following steps of: cleaning the back face of the wafer at a first temperature by adopting a reacted acid cleaning process; and etching the back face of the wafer with a potassium hydroxide solution at a second temperature, wherein the difference value of the first temperature and the second temperature is in a preset range.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a crystal back etching method and system. Background technique [0002] When making semiconductor chips, the back of the wafer is usually rarely processed, but for power component chips such as power chips (Power IC, Power Integrated Circuit), it is usually necessary to grind and deposit metal on the back of the wafer. process to reduce the resistance of power components. [0003] Since the crystal back surface is usually relatively smooth, in order to increase the adhesion between the metal and the crystal back surface when depositing metal, the crystal back etching treatment is generally carried out to increase the roughness of the crystal back surface, which is beneficial to the deposited metal and crystal surface. Adhesion to the back enhances the deposition effect. [0004] The existing crystal back etching method is as follows: firstly, the acid-proof film is glued to the fr...

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Problems solved by technology

[0011] However, when implementing the above etching method, the implementers found that the front of the wafer etched by this etching method has obvious discoloration, which will greatly reduce the quality of the manufactured semiconductor chip

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