Chemical etching of silicon carbide in pure water by using platinum catalyst

Abstract

Chemical etching of SiC was found to proceed in pure water with the assistance of a Pt catalyst. A 4H-SiC (0001) wafer was placed and slid on a polishing pad in pure water, on which a thin Pt film was deposited to give a catalytic nature. Etching of the wafer surface was observed to remove protrusions preferentially by interacting with the Pt film more frequently, thus flattening the surface. In the case of an on-axis wafer, a crystallographically ordered surface was obtained with a straight step-and-terrace structure, the height of which corresponds to that of an atomic bilayer of Si and C. The etching rate depended upon the electrochemical potential of Pt. The vicinal surface was observed at the potential at which the Pt surface was bare. The primary etching mechanism was hydrolysis with the assistance of a Pt catalyst. This method can, therefore, be used as an environmentally friendly and sustainable technology.

Material Removal Rate of Double-faced Mechanical Polishing of 4H-SiC Substrate

“…MRR was calculated from equation ( 15) by setting m=[-5,-4,-3,-2,-1], n= [1,2,3,4,5], RB= [15,30,45,60,75].…”

A Review on Precision Polishing Technology of Single-Crystal SiC

“…Pho Van Bui et al [64] studied the reaction mechanism of a Pt catalyst on single-crystal SiC etching in In early CARE studies, the catalyzed liquid medium was either HF or H 2 O 2 , which would cause adverse effects on the environment. In 2017, Ai Isohashi et al [63] found that a 3-inch 4H-SiC (0001) surface could still be polished in pure water under the action of a Pt catalyst with a certain electrochemical potential, and the etching mechanism was accelerated by hydrolysis under the action of Pt. In the study, OH − is considered to play the same role as F − in CARE, as shown in Figure 30b, and to proceed with an indirect dissociative adsorption of H 2 O (i.e., indirect hydrolysis).…”

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

“…Because polishing parameters K and polishing pressure P were constants and initial angle 0 has no effect on MRR, in order to facilitate normalization of simulation analysis, we set K=1, P=1Pa, initial angle 0=0°, s=-20r/min, t=1s. Influence of the three parameters (speed rate of the outside ring gear to the inside sun gear m, speed rate of lower plate to the inside sun gear n, SiC substrate distribution radius RB) in formula (15) on MRR was studied.…”

“…MRR was calculated from equation ( 15) by setting m=[-5,-4,-3,-2,-1], n= [1,2,3,4,5], RB= [15,30,45,60,75].…”

“…Many researchers have analyzed the relationship between MRR and surface roughness. [13][14][15] In this paper, kinematic equations of SiC substrate during double-faced polishing were analyzed. An accurate mathematical model of orthogonal rotary regression test of Tri-factor quadratic of MRR was established and the parameters affecting MRR were studied.…”