Articles
  • The effect of mixed abrasive slurry on CMP of 6H-SiC substrates
  • Hojun Lee, Boumyoung Park, Sukhoon Jeong, Sukbae Joo and Haedo Jeong*
  • Department of Precision & Mechanical Engineering, Pusan National University, Busan, Korea
Abstract
Silicon Carbide (SiC) is a wide band gap semiconductor, being developed for high temperature, high power, and high frequency device applications. Many researchers have studied SiC polishing for the manufacturing of SiC and semiconductor substrates. However, these researchers have faced difficulties with a wafer preparation prior to epitaxial growth due to its hardness and remarkable chemical stability. A smooth and defect-free substrate surface is important to obtain good epitaxial layers. Therefore, a hybrid process, chemical mechanical polishing (CMP) has been proposed as a solution for preparing an epi-ready surface. During the experiments, the material removal rate (MRR) was investigated to learn how long the CMP process continues to remove a damaged layer by mechanical polishing using 100 nm diamond. Furthermore, the dependency of mechanical factors, such as pressure, velocity, and abrasive concentration, were researched using a single abrasive slurry (SAS). The experiments especially focused on the epi-ready surface with a mixed abrasive slurry (MAS). The addition of nanometre sized diamond in the MAS provided a strong synergy between mechanical and chemical effects. Through the experiments, a chemical effect (KOH based) was essential, and the atomic-bit mechanical removal was found to be efficient to remove residual scratches from on MAS. In conclusion, the SiC CMP mechanism was quite different from that of relatively softer materials to gain both high quality surfaces and a high MRR

Keywords: SiC, CMP, epi-ready surface, SAS, MAS

This Article

  • 2009; 10(3): 378-381

    Published on Jun 30, 2009