Poster Presentation Royal Australian Chemical Institute National Congress 2026

Probing the Inherent Surface Roughening of P-type Si (111) in 40 % NH4F Solution: Toward Atomically Flat Surfaces (#403)

Gopal Mr. Rizal 1 , Simone Prof. Ciampi 1
  1. School of Molecular and Life Sciences , Curtin University , Bentley , WA, Australia

Wet chemical etching of Si (111) in 40% NH4F solution has been promising approach in producing atomically flat surfaces for electronic applications. However, the flattening behaviour is strongly dependent on the doping type and doping density. Previous studies have reported successful surface flattening in low-doped substrates, whereas identical etching conditions causes surface roughening on highly doped, particularly on p-type substrates. Despite intensive investigation, the complex etching dynamics of Si (111) in fluoride solution is yet to be understood fully to produce flat surfaces across all samples, irrespective of their doping identity. In this study electrochemical measurements are employed to translate the etching dynamics into electrical signals, enabling deeper understanding of the underlying etching dynamics and as well as for probing the etching controls to produce atomically flat surfaces across all samples irrespective of their doping type and doping concentration. This work represents the initial phase of a broader project where atomically flat Si (111) surfaces will be grafted with dipolar molecules and the resulting effect on the surface electrical properties will be investigated for various applications in devices including diodes and transistors.