Formation and characterization of porous SiC by anodic oxidation using potassium persulfate solution

Iwasa, Yoshimi; Kamiyama, Satoshi; Iwaya, Motoaki; Takeuchi, Tetsuya; Akasaki, Isamu

doi:10.1117/12.2283026

Cited by 2 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When electrochemical etching is used to etch SiC wafers [16][17][18][19][20], a porous layer is formed in the wafers, regardless of supplying constant voltage, constant current density or pulsed voltage. However, compared with anodic etching in potentiostatic mode, anodic etching in galvanostatic mode is less studied.…”

Section: Resultsmentioning

confidence: 99%

Study on the layering phenomenon of SiC porous layer fabricated by constant current electrochemical etching

Wang¹,

Huang²,

Guo³

et al. 2020

Nanotechnology

View full text Add to dashboard Cite

Electrochemical etching of silicon carbide (SiC) material has received increasing attention in recent years, due to its simple procedure, low cost and significance in the exploration of novel optoelectronic devices. In this paper, 4H-SiC substrates were electrochemically etched at a constant current density of 392.98 mA cm−2 in an electrolyte made up of hydrofluoric acid and deionized water. The layering of a SiC porous layer and periodic fluctuation of the voltage were witnessed for the first time, with the layering phenomenon corresponding well to the voltage period. However, no such phenomenon was observed when the SiC substrates were anodic etched under the same conditions with magnet stirring. As a result, the periodic variation of voltage was hypothesized to be the cause of regular layering during constant current electrochemical etching. Electrochemical etching in potentiostatic mode was thus performed at different voltages. We found that the diameter of the SiC nanopores increased while the thickness of the sidewall decreased with the increasing voltage. Based on the experimental findings, a model of mass transport was proposed. The mass transport process leads to periodic changes in resistance, hence the periodic change in voltage. This successfully explained the reason for the layering. Furthermore, SiC substrates were also electrochemically etched at high and low current densities, finding the existence of a threshold current density for the occurrence of the layering. Energy dispersive x-ray spectroscopy analysis showed that the composition of the SiC porous layer remained unchanged compared to the pure SiC wafer, implying that the peeling-off of the SiC porous layer obtained by electrochemical etching can be directly adopted for use on devices requiring a SiC porous structure.

show abstract

Section: Resultsmentioning

confidence: 99%

Study on the layering phenomenon of SiC porous layer fabricated by constant current electrochemical etching

Wang¹,

Huang²,

Guo³

et al. 2020

Nanotechnology

View full text Add to dashboard Cite

show abstract

Electrochemical etching modes of 4H-SiC in KOH solutions

Yang

Zhao

Chen

et al. 2023

Semicond. Sci. Technol.

View full text Add to dashboard Cite

Electrochemical etching is a promising wet etching technology for preparing porous structures and the flat surface etching of 4H-SiC. In this study, the effects of current density and KOH concentration on the etching of 4H-SiC were investigated. We found that the respective mechanisms for preparing porous structures and flat surface etching differed. The porous and flat etching modes were proposed to clarify the mechanistic differences. In addition, we achieved an etch rate of 1μm/h in flat etching mode, and the sample surface was improved for 4H-SiC applications in the field of optoelectronics and microelectronics through the thermal oxidation of SiC.

show abstract

Formation and characterization of porous SiC by anodic oxidation using potassium persulfate solution

Cited by 2 publications

References 15 publications

Study on the layering phenomenon of SiC porous layer fabricated by constant current electrochemical etching

Study on the layering phenomenon of SiC porous layer fabricated by constant current electrochemical etching

Electrochemical etching modes of 4H-SiC in KOH solutions

Contact Info

Product

Resources

About