Substrate corrosive liquid for preparing Si-based mercury cadmium telluride chip dislocation observation sample

Abstract

The invention discloses a substrate corrosive liquid for preparing a Si-based mercury cadmium telluride chip dislocation observation sample. The substrate corrosive liquid is characterized in that the substrate corrosive liquid is prepared by organic base solution tetramethylammonium hydroxide, deionized water and oxidizing agent ammonium persulfate; a preparation method of the substrate corrosive liquid comprises the steps that: first, tetramethylammonium hydroxide and the deionized water are mixed to form a mixed solution with the concentration of 5-20%; then, 1-3g/l ammonium persulfate is added according to the volume of the mixed solution; and finally the mixed solution is placed in a water bath with the temperature over 80 degrees to be heated, and used at the temperature of 50-65 degrees. The substrate corrosive liquid has the characteristics that using conditions of the corrosive liquid are compatible with a mercury cadmium telluride technology, so that the physical properties of a mercury cadmium telluride chip are not changed, and the precision of analysis results is ensured. The corrosive liquid is good in selectively, can remove a Si substrate completely, but does not corrode buffer layer cadmium telluride and epitaxial film mercury cadmium telluride, so that a complete clear epitaxial material observation interface is obtained, and the good observation sample is provided for dislocation observation from a buffer layer cadmium telluride interface.

Description

technical field [0001] The invention relates to a semiconductor crystal Si etching solution, which is especially suitable for Si substrate corrosion when preparing Si-based mercury cadmium telluride chip dislocation observation samples. Background technique [0002] Si-based HgCdTe (mercury cadmium telluride) detectors are one of the mainstreams in the development of third-generation infrared focal plane detectors. Relying on the mature Si wafer preparation process and the development of molecular beam epitaxy growth process, the Si-based HgCdTe material has a larger usable area, higher flatness and high mechanical strength, so that it can produce ultra-large pixel scale, super Infrared detector with high resolution, longer detection distance and high reliability. The biggest challenge in the fabrication of Si-based HgCdTe detectors lies in the growth of HgCdTe epitaxial materials with low dislocation density and the suppression of the influence of dislocations on device pe...

AI Technical Summary

Problems solved by technology

There are many strong acids in the isotropic etching solution, such as nitric acid, hydrofluoric acid, etc. (patent, application number: 201210506767.2, authorization number: CN 103022246, substrate removal technology for mercury cadmium telluride detectors based on selective wet etching process ), although it is selective to mercury cadmium telluride, the selectivity to buffer layer cadmium telluride is poor; the anisotropic etching solution mostly adopts alkaline solution, which has good selectivity and uniform corrosion rate, but it is used at high temperature, which is different from that of Low temperature operating process of mercury cadmium telluride is not compatible