Material removal rate of double-faced mechanical polishing of 4H-SiC substrate

Peng Zhang,Jingfang Yang,Huadong Qiu

doi:10.1007/s00170-021-08186-w

Abstract

Silicon carbide (SiC) has been a promising the third-generation semiconductor power device material for high-power, high-temperature, and substrate applications. However, under certain surface quality requirement, its current processing efficiency is the bottleneck. Therefore, it aims to improve the material removal rate (MRR), on the premise of ensuring the surface roughness requirements. To obtain the relationship between any point on SiC substrate and polishing pads, the model about double-faced mechanical polishing has been established, and the kinematics equations have been created. Best optimized material removal rate parameters were obtained. MRR reached the maximum when speed rate of the outside ring gear to the inside sun gear m = − 1, speed rate of lower plate to the inside sun gear n = 5, and SiC substrate distribution radius RB = 75. The primary and secondary order of MRR (n>m>RB) was obtained. An accurate mathematical model of orthogonal rotary regression test of Tri-factor quadratic of MRR was established, and the regression model was significant. Surface quality of SiC substrate was observed and characterized with SEM and AFM. It greatly provides a key guarantee for the next process of CMP, confirms the importance of MRR to ultra-smooth polishing, and provides a guarantee for its application in semiconductor equipment and technology.

Highlights

Development of semiconductor industry has been closely related to the national defense, military, aerospace, energy and other important areas of science and technology.[1,2]
As the representative of the semiconductor material, silicon carbide (SiC) single crystal was an important new wide band gap semiconductor material, which can be used as a substrate for the growth of gallium nitride (GaN) and grapheme.[3,4,5]
It can be widely used in the production of high temperature, high frequency and high power devices.[6,7]

Summary

Introduction

Development of semiconductor industry has been closely related to the national defense, military, aerospace, energy and other important areas of science and technology.[1,2] As the representative of the semiconductor material, silicon carbide (SiC) single crystal was an important new wide band gap semiconductor material, which can be used as a substrate for the growth of gallium nitride (GaN) and grapheme.[3,4,5] At the same time, it can be widely used in the production of high temperature, high frequency and high power devices.[6,7]Ultra-smooth polishing of the SiC substrate was required atomic surface roughness.[8,9,10] The biggest problem at present was that the processing efficiency was too low on the premise of ensuring the surface quality. The double-faced mechanical polishing (MP) process was the key to guarantee a certain surface roughness (Ra) and the high efficient material removal rate (MRR) of the SiC substrate. Kinematic equations of SiC substrate during double-faced polishing were analyzed.

Results

Conclusion