A Study on Substrate Orientation Dependence of Si Surface Flattening Process by Sacrificial Oxidation and Its Effect on MIS Diode Characteristics

Sohya KUDOH  Shun-ichiro OHMI  

IEICE TRANSACTIONS on Electronics   Vol.E99-C   No.5   pp.504-509
Publication Date: 2016/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E99.C.504
Type of Manuscript: Special Section PAPER (Special Section on Fundamentals and Applications of Advanced Semiconductor Devices)
Si surface roughness,  oxidation process,  substrate orientation,  MIS diode,  

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In this study, we investigated Si(100), Si(110) and Si(111) surface flattening process utilizing sacrificial oxidation method, and its effect on Metal-Insulator-Semiconductor (MIS) diode characteristics. By the etching of the 100 nm-thick sacrificial oxide formed by thermal oxidation at 1100°C, the surface roughness of Si(100), Si(110) and Si(111) substrates were reduced. The obtained Root-Mean-Square (RMS) roughness of Si(100) was reduced from 0.22 nm (as-cleaned) to 0.07 nm (after etching), while it was reduced from 0.23 nm to 0.12 nm in the case of Si(110), and from 0.23 nm to 0.11 nm in the case of Si(111), respectively. Furthermore, it was found that time-dependent dielectric breakdown (TDDB) characteristics of MIS diodes for p-Si(100), p-Si(110) and p-Si(111) were improved with the reduction of Si surface RMS roughness.