Gallium nitride wafer photoelectrochemistry mechanical polishing fluid and polishing method

Abstract

The invention discloses gallium nitride wafer photoelectrochemistry mechanical polishing fluid and a polishing method. The polishing fluid comprises nanometer abrasive particle and oxidant; the content of the nanometer abrasive particle is 0.05-20wt%, and the content of the oxidant is 0.1-10wt%. The polishing fluid provided by the invention is mainly used for the ultraviolet chemical machinery polishing process of a gallium nitride wafer; the polishing fluid applied to polish the gallium nitride wafer can acquire higher removal rate and low surface roughness; meanwhile, the polishing fluid issimple in component; the concentration of nanometer silicon dioxide or cerium oxide is extremely low; the post treatment of the polishing fluid is convenient; besides, the polishing fluid is less in environment pollution.

Description

technical field [0001] The invention belongs to the technical field of polishing processing, in particular to a gallium nitride wafer photoelectrochemical mechanical polishing liquid and a polishing method. technical background [0002] The third-generation semiconductor representative materials such as gallium nitride, compared with the first and second-generation semiconductor materials, have a large band gap, high thermal conductivity, high breakdown electric field, high electron saturation rate and strong radiation resistance, and are more suitable for production High temperature, high frequency, high power, radiation resistant high power devices. When gallium nitride wafers are used as devices or LED substrates, materials are required to have high surface integrity (such as low surface roughness, no surface / subsurface damage such as scratches, microcracks, dislocations, and residual stress), and in The surface / subsurface damage of the material will occur during the gri...

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Problems solved by technology

However, the use of high-abrasive-concentration polishing fluid leads to a high proportion of the cost of the polishing fluid in the polishing process, and also increases the difficulty of post-processing of the polishing fluid

D.E.Speed ​​pointed out in Advances in Chemical Mechanical Planarization (CMP), p.27, Woodhead Publishing (2016) that polishing production units need to pretreat the polishing liquid before discharge, and manufacturers usually use coagulation and flocculation to treat the waste liquid , after sedimentation, filtration, flotation and other steps, the treatment process is complicated, and the post-treatment cost is high, which in turn increases the cost of the polishing manufacturer. In addition, once the treatment is not done properly, the polishing solution with high abrasive particle concentration will cause serious pollution to the environment

[0005] Therefore, in view of the low removal rate of gallium nitride wafer materials in the current chemical mechanical polishing process, the processing time is long, the composition of the polishing liquid used is complex, and the high concentration of abrasive particles is likely to cause environmental pollution. It is urgent to find a A polishing liquid with higher removal rate, simpler and more environmentally friendly ingredients, and lower abrasive particle concentration can meet the efficient manufacturing of semiconductor devices and increasingly stringent environmental protection requirements

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