Nonlinear Etch Rate of Au-Assisted Chemical Etching of Silicon

Keorock Choi; Yunwon Song; Bugeun Ki; Jungwoo Oh

doi:10.1021/acsomega.7b00232

Nonlinear Etch Rate of Au-Assisted Chemical Etching of Silicon

ACS Omega. 2017 May 16;2(5):2100-2105. doi: 10.1021/acsomega.7b00232. eCollection 2017 May 31.

Authors

Keorock Choi^{1

2}, Yunwon Song^{1

2}, Bugeun Ki^{1

2}, Jungwoo Oh^{1

2}

Affiliations

¹ School of Integrated Technology, Yonsei University, 85 Songdokwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea.
² Yonsei Institute of Convergence Technology, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea.

Abstract

We demonstrated time-dependent mass transport mechanisms of Au-assisted chemical etching of Si substrates. Variations in the etch rate and surface topology were correlated with catalyst features and etching duration. Nonlinear etching characteristics were associated with the formation of pinholes and whiskers. Variable rates of mass transport as a function of whisker density accounted for the nonlinear etch rates of Si. Nanopinholes on Au catalysts facilitated the vertical mass transport of reactants and byproducts, which dramatically changed the etch rate, surface topology, and porosity of Si. The suggested transport models describe the transient mass transport and the corresponding chemical reactions.