Polishing solution for chemically mechanically polishing germanium crystal and application method

Abstract

The invention relates to a polishing solution for chemically mechanically polishing germanium crystal and an application method. The polishing solution comprises a rough polishing solution and a fine polishing solution, wherein the rough polishing solution is mainly prepared from the following raw materials in percentage by weight: 10 to 50% of hydrosol grinding material, 0.2 to 1.5% of an oxidant, 0.5 to 2% of a pH conditioner, 0.2 to 1.5% of a chelating agent, and 0.1 to 1% of a surface active agent, wherein the hydrosol grinding material is 15 to 110nm in particle size and has the concentration being not less than 40wt% (percentage by weight) and hardness being not greater than 7 Mohs; the fine polishing solution is mainly prepared from 0.1 to 0.5% of a surface active agent, and the balance of deionized water. The two-step polishing method is performed for chemical mechanical polishing and comprises two steps of selecting the rough polishing solution and then second the fine polishing solution; the two polishing can be performed through one polishing machine. The polishing solution has the beneficial effect that the problems of low rate, high roughness and pollution of metal ions and particles in chemical mechanical polishing of germanium crystal materials 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. Germanium has a relative atomic mass of 72.59 and a density of 5.35g / cm 3 ; The melting point and boiling point of germanium are higher, respectively 937.4 ℃ and 2830 ℃. 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 great significance t...

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