Polishing liquid for germanium crystal chemical and mechanical polishing and use method thereof

Abstract

The invention relates to polishing liquid for germanium crystal chemical and mechanical polishing and a use method thereof. The polishing liquid comprises coarse polishing liquid and fine polishing liquid, wherein the coarse polishing liquid is mainly prepared from the following raw materials in percentage by weight: 10 to 50 percent of SiO2 hydrosol abrasive grinding materials with the grinding material particle diameter being 15 to 110nm, the concentration being higher than or equal to 40 weight percent and the hardness being smaller than or equal to 7Mohs, 0.2 to 1.5 percent of oxidizing agents, 0.5 to 2 percent of pH regulating agents, 0.2 to 1.5 percent of chelating agents and 0.1 to 1 percent of surfactants; the fine polishing liquid is mainly prepared from 0.1 to 0.5 percent of surfactants and the balance deionized water. A two-step polishing method is used for chemical mechanical polishing; coarse polishing liquid is selected in the first step; the fine polishing liquid is selected in the second step; the two steps of polishing are completed on the same polishing machine. The polishing liquid has the beneficial effects that the problems of low speed, high roughness, metal ion and particle staining and the like of the germanium crystal materials in the chemical and mechanical polishing process can be solved.

Description

technical field [0001] The invention belongs to a CMP polishing liquid, in particular to a polishing liquid for germanium crystal chemical mechanical polishing and a use method. Background technique [0002] Germanium (Ge) is not only a rare metal, but also an extremely important semiconductor material. The relative atomic mass of germanium is 72.59, and the density is 5.35g / cm3; the melting point and boiling point of germanium are relatively high, which are 937.4°C and 2830°C respectively. The surface of germanium is silver-gray, and the lattice is diamond-type. [0003] Germanium plays an irreplaceable role in the guarantee of national security and the construction of the national economy. It is considered a very important strategic resource. At present, it has become a new type of clean energy material. Germanium single crystals have been widely and successfully used in the field of solar cells. Solar cells can convert light energy into electrical energy, which is of ...

AI Technical Summary

Problems solved by technology

However, the cost of germanium materials is relatively high. If traditional grinding and polishing methods are used for processing, it will not only waste raw materials but also fail to guarantee the processing quality; the research and development and wide application of germanium materials are driving the demand for germanium polishing sheets to increase year by year. Although my country's germanium resource reserves rank first in the world, germanium materials still need to be imported from abroad at this stage, so research on chemical mechanical polishing technology for germanium single crystals has become a hot spot of concern