Method for corroding germanium wafers

Abstract

The invention provides a method for corroding germanium wafers. The method comprises the following steps of that A) the germanium wafers with the thickness difference within + / -0.025 mm are fixed in the same clamping groove, and then the clamping groove containing the germanium wafers is placed into corrosive liquid to carry out corroding; wherein the corrosive liquid is a mixed liquid of nitric acid and hydrofluoric acid in the volume ratio of (2-5): 1; B) when the corrosive liquid begins to emit red smoke, pure water is slowly added into the corrosive liquid until the red smoke turns yellow smoke, and corroding continues for 1-2 minutes; and C) the corrosive liquid is diluted with pure water, then the clamping groove is taken out, and the germanium wafers are cleaned and dried. According to the method, the pure water is slowly added when the corrosive liquid begins to emit red smoke, so that the germanium wafers can quickly react in the early reaction stage, and it can be avoided that the surfaces of the germanium wafers are blackened due to too high temperature and too intense reaction in the later reaction stage. The method ensures the corrosion efficiency and meanwhile solves the technical problems that the reaction rate is difficult to control and the surfaces of the germanium wafers are likely to blacken in the existing acid corrosion.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, in particular to a method for corroding a germanium sheet. Background technique [0002] For a current-carrying conductor placed in a magnetic field, if the current direction is perpendicular to the magnetic field, an additional transverse electric field will be generated in the direction perpendicular to the current and magnetic field. This phenomenon was discovered by Johns Hopkins University graduate student Hall in 1879 and was later called the Hall effect. According to the Hall effect, people use semiconductor materials such as germanium wafers, silicon wafers, etc. to make Hall elements. Hall elements have the advantages of being sensitive to magnetic fields, simple in structure, small in size, wide in frequency response, large in output voltage changes, and long in service life. The Hall element can be used to measure the magnetic field, to study the types and characteristics of ca...

AI Technical Summary

Problems solved by technology

[0003] For the Hall element made of germanium slices, the germanium slices need to be etched and brightened before the Hall detection. The existing alkali corrosion rate is slow and is greatly affected by temperature. The reaction increases first and then decreases with time, and the obtained germanium slices The roughness is large, the smoothness is small, and the surface is prone to whitening; for example, Lu Fei (the 46th Research Institute of China Electronics Technology Group Corporation, 2007) announced two kinds of alkaline corrosion, potassium hydroxide and hydrogen peroxide, ammonium hydroxide and Hydrogen peroxide corrosion solution

However, the corrosion rate of the existing acid corrosion is too fast, more intense, difficult to control, the removal amount is unstable, and the surface is prone to blackening