Study on new magnetorheological chemical polishing process for GaN crystals: polishing solution composition, process parameters, and roughness prediction model
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Published:2023-02-14
Issue:3
Volume:32
Page:035031
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ISSN:0964-1726
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Container-title:Smart Materials and Structures
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language:
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Short-container-title:Smart Mater. Struct.
Author:
Wu JinzhongORCID,
Afzal Burhan,
Huang Zhilong,
Yang Maoju,
Sun ShuaishuaiORCID
Abstract
Abstract
High-quality and high-efficiency processing of gallium nitride (GaN) crystals is urgently required for optoelectronic communications and other major industries. This study proposes a novel high-efficiency non-damage magnetorheological chemical polishing (MCP) process to overcome the existing problems of low efficiency and lattice distortion during processing. The effects of the MCP fluid composition and key processing parameters on the surface roughness and material removal rate (MRR) of GaN crystals were studied experimentally. The results showed that a compounded abrasive containing silica fluid exhibited better polishing effects than a single abrasive. The polishing efficiency could be improved by adding NaOH solid particles, and the MRR reached 13.19 nm min−1 when the pH of the MCP fluid was 10. The MRR increased gradually with an increase in the pole rotation speed and worktable speed and a decrease in the polishing gap. The surface roughness of the GaN crystals was improved from Ra 115 nm to Ra 0.375 nm after polishing for 4 h. The surface and sub-surface damage of the polished GaN crystals was analyzed using scanning electron microscope and transmission electron microscope. The results confirmed that the MCP process can realize the non-damage polishing of GaN crystals. Moreover, a prediction model for the surface roughness of GaN crystals in the MCP process was constructed. The overall difference between the actual and predicted surface roughness values for the model was 11.6%.
Funder
Key Technologies Research and Development Program of Anhui Province
USTC start-up funding
the Fundamental Research Funds for the Central Universities
National Natural Science Foundation of China
Natural Science Foundation of Zhejiang Province
Subject
Electrical and Electronic Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science,Atomic and Molecular Physics, and Optics,Civil and Structural Engineering,Signal Processing