title: Surface cleaning and etching of 4H-SiC(0001) using high-density atmospheric pressure hydrogen plasma.
abstract: We propose low-damage and high-efficiency treatment of 4H-SiC(0001) surfaces using atmospheric pressure (AP) hydrogen plasma. Hydrogen radicals generated by the AP plasma was found to effectively remove damaged layers on SiC wafers and improve surface morphology by isotropic etching. Localized high-density AP plasma generated with a cylindrical rotary electrode provides a high etching rate of 1.6 microm/min and yields smooth morphology by eliminating surface corrugation and scratches introduced by wafer slicing and lapping procedures. However, high-rate etching with localized plasma was found to cause an inhomogeneous etching profile depending on the plasma density and re-growth of the poly-Si layer at the downstream due to the decomposition of the vaporized SiH(x) products. On the other hand, for the purpose of achieving moderate etching and ideal cleaning of SiC surfaces, we demonstrated the application of a novel porous carbon electrode to form delocalized and uniform AP plasma over 4 inches in diameter. We obtained a reasonably moderate etching rate of 0.1 microm/min and succeeded in fabricating damage-free SiC surfaces.
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Heiji
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ohmi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kakiuchi
authors.forename: Takuji
authors.initials: T
authors.lastname: Hosoi
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shimura
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yasutake
mesh_terms: D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D058626:Plasma Gases / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D017554:Carbon Compounds, Inorganic; D058626:Plasma Gases; D017655:Silicon Compounds; D006859:Hydrogen; C022088:silicon carbide