Selective etching of nanostructured a-Si:Al and its effect on porosity, Al gradient and surface oxidation

THIN SOLID FILMS

卷:702

Article

Kjeldstad, T.¹  Thogersen, A.²  Stange, M.²  Jensen, I. T.²  Nilsen, O.³  Galeckas, A.¹  Monakhov, E.¹ 

[1] Univ Oslo, Dept Phys, Ctr Mat Sci & Nanotechnol, POB 1048 Blindern, N-0316 Oslo, Norway

[2] SINTEF Mat Phys, POB 124 Blindern, N-0314 Oslo, Norway

[3] Univ Oslo, Dept Chem, Ctr Mat Sci & Nanotechnol, POB 1033 Blindern, N-0316 Oslo, Norway

关键词: Amorphous silicon;    Self-assembly;    Aluminum;    Nanowires;    Nanoporous;    Selective etching;   

DOI  :  10.1016/j.tsf.2020.137982

来源: Elsevier

【 摘 要 】

Nanoporous amorphous silicon (a-Si) with <5 nm cylindrical pores have been fabricated by phase separation of aluminum (Al) and silicon, forming self-assembled Al nanowires (NWs), followed by subsequent removal of Al by wet etching. This work studies the removal process of the Al NWs when using the different etchants HCl, H3PO4, and H2SO4. Total reflectance measurements are used in combination with theoretical modeling to estimate the lateral gradient of Al concentration formed during the etching process. X-ray Photoelectron Spectroscopy is used to show that the choice of Al etching agent has implications for the surface states of the remaining a-Si matrix. We have found that H3PO4 is the most efficient etching agent, while HCl provides a less oxidized a-Si matrix in addition to the least reflective surface. By varying the etching agent, the degree of surface oxidation and shape of Al gradient throughout the film can be tuned.

【 授权许可】

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