Cleaning process of bismuth germanate wafer

Abstract

The invention relates to a cleaning process of a bismuth germanate wafer. The cleaning process comprises: a preliminary cleaning step of cleaning the bismuth germanate wafer by using secondary de-ionized water to remove massive pollutants with relatively weak surface adhesive power; a second cleaning step of cleaning the bismuth germanate wafer by using aviation kerosene to remove organic greasy dirt on a surface; a third cleaning step of cleaning the bismuth germanate wafer by using a CC14 solution to further remove the organic dirt on the surface of the bismuth germanate wafer; a fourth cleaning step of cleaning the bismuth germanate wafer by using a 15%-25% propionic acid and ultrapure de-ionized water mixed solution to remove inorganic dirt on the surface; and a drying step of blow-drying the bismuth germanate wafer.

Description

technical field [0001] The invention relates to a cleaning process for a bismuth germanate wafer, belonging to the technical field of wafer processing. Background technique [0002] Bismuth germanate (Bi 4 Ge 3 o 12 ) crystal is a kind of synthetic scintillation crystal material with excellent performance. It has the advantages of high luminous efficiency, high energy resolution, stable chemical performance, matching emission spectrum and spectral response of photoelectric conversion devices, etc. It is often used as a detector for nuclear Physics, high energy physics, space science, nuclear medicine, geological survey, astrophysics and other fields. The surface of the bismuth germanate wafer after cutting usually has more pollutants such as cutting tool powder, dust in the cutting environment, bismuth germanate crystal fragments, adhesive glue, and oil stains. At present, relatively simple cleaning steps are usually used for cleaning bismuth germanate wafers after cutti...

AI Technical Summary

Problems solved by technology

[0004] (1) Corrosion of bismuth germanate crystals: Bismuth germanate crystals are easily soluble in inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, so corrosion of the crystals is inevitable during the process of using these inorganic acids to remove surface inorganic substances;

[0005] (2) Change the surface shape of the bismuth germanate wafer: Since the inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid in cleaning are highly corrosive to the bismuth germanate wafer, it will change the surface shape of the cut wafer, making it impossible to achieve Requirements for surface shape parameters in subsequent processes;

[0006] (3) Cause environmental pollution and increase the cost of sewage discharge: Inorganic acids such as hydrochloric acid and nitric acid are volatile and will pollute the environment; in addition, these inorganic acids are highly corrosive and require special recycling processes for treatment, which also virtually Increased cost of crystal processing