Study on precision polishing method applied ultrasonic vibration for next-generation semiconductor wafers

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06018
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Production engineering/Processing studies
• Research Institution: Nippon Institute of Technology
• Principal Investigator: Jin Masahiko 日本工業大学, 基幹工学部, 教授 (80265371)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 超音波振動 / 研磨 / 半導体基板 / SiC / サファイア / 超硬

Outline of Final Research Achievements

The author has developed an ultrasonic vibration polishing method for next-generation semiconductor wafers such as SiC and sapphire. The main effects are efficiency and low environmental impact. Specifically, the extension of the grinding distance, the effective use of abrasive cutting edges, the reduction of subsurface damage, the reduction of clogging, and the refinement of chips were clarified. The author has developed an ultrasonic vibration stone for experiments, with a diameter of 107 mm, a resonance frequency f of 38.3 kHz, and diamond abrasive grains of grain sizes # 800 and # 1,000. The experimental results show that the polishing efficiency is improved up to 11 times that of conventional polishing, the surface roughness is reduced to about 1/3, chips are refined, and subsurface damage is reduced. And, it was clarified that a unique cross hatch mark was formed on the polished surface.

Free Research Field

機械工作

Academic Significance and Societal Importance of the Research Achievements

次世代半導体ウエハーは，高硬度で科学的に安定しているため研磨加工が非常に難しいといった課題がある．現状では，酸化剤，UVやプラズマ援用加工法などが提案されている．それに対して，本手法は純粋な力学的加工法であるため，低コスト，低環境負荷となる手法を提案した．この学術的研究成果は，国内の関連学会，国際会議での発表，および論文投稿を予定している．
一方，社会実装に関しては，直径φ400㎜，振動数20kHzでシリカの遊離砥粒用ラップを開発した．実験ではSiCに対して効果が得られることが明らかになっており，今後の半導体基板材料への展開が期待される．その成果は適当な時期に公表したい．