Method and apparatus for etching semiconductor substrate

Abstract

The invention relates to the field of semiconductor and microelectromechanical system device manufacturing technology, and more particularly, to a method of etching a semiconductor substrate. The method comprises the steps of converting a hydrofluoric acid liquid into hydrofluoric acid vapor, and converting an alcohol liquid into an alcohol gas; and introducing the hydrofluoric acid vapor and the alcohol gas simultaneously into a process chamber, the hydrofluoric acid vapor etching the substrate in the process chamber, and the alcohol gas acting as a wetting gas to form a uniform micro-coagulation layer on the surface of the substrate. In order to achieve the above method, the invention also provides an apparatus for etching a semiconductor substrate. In the invention, an etching gas and a wetting gas are collectively introduced into the process chamber, the etching gas etches a substrate, the wetting gas forms a uniform micro-coagulation layer on the surface of the substrate, and the wetting gas in the process chamber and on the surface of the substrate can be combined with water to prevent the liquid water coagulation phase from forming on the surface of the substrate to improve the etching uniformity.

Description

technical field [0001] The invention relates to the technical field of semiconductor and micro-electromechanical system device manufacturing, in particular to a method and device for etching a semiconductor substrate. Background technique [0002] Epitaxial growth of Si, SiGe, TiSi 2 and Si 3 N 4 Before film deposition, in-situ SiO on the wafer surface needs to be 2 Just remove it. In some applications, such as Si epitaxial growth, high temperature baking is a method of removing in situ silicon oxide. However, in many cases a low temperature environment is required for processing because high temperatures may damage the structure of the device. In this case, wet immersion with HF chemical solution is generally used, but this HF solution immersion still has many disadvantages, such as removal of SiO 2 After that, the surface of the silicon wafer is hydrophobic, and the impurities in the HF solution are easily adsorbed on the surface to form pollution. [0003] Microele...

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Problems solved by technology

However, if there is no condensation layer, the gas phase etching rate will be too slow to lose practical application value, and the uniformity of etching will be poor.

[0006] Vapor-phase HF can effectively etch SiO 2 Thin film, but usually with other reaction by-products

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