TY - JOUR
AU - Lai, Kafai
AB - A new wafer cleaning procedure has been developed for ultra-thin thermal oxidation process (<EQ 50 angstrom). This involves a modified RCA clean and a two-step dip, first in diluted HF and then in a methanol/HF solution, with no final DI water rinse. Ultrathin thermal oxides (48 angstrom) and oxynitrides grown in N 2 O (42 angstrom) were prepared using this new cleaning and other commonly used cleaning methods to investigate the effects of surface preparation on dielectric integrity. It has been found that this two-dip method produces dielectrics with reduced leakage current and stress-induced leakage current, which are believed to be the critical parameters for ultrathin oxides. Furthermore, this new cleaning procedure improves both intrinsic and defect-related breakdown as well as the uniformity of the current- voltage characteristics across a 4-inch wafer. The methanol/HF dip time has also been optimized. The improvement is believed to be due to enhanced silicon surface passivation by hydrogen, the reduced surface micro-roughness and the absence of native oxide.
TI - Surface cleaning effects on reliability for devices with ultrathin oxides or oxynitrides
JO - Proceedings of SPIE
DO - 10.1117/12.186742
DA - 1994-09-14
UR - https://www.deepdyve.com/lp/spie/surface-cleaning-effects-on-reliability-for-devices-with-ultrathin-3V0MCRVumV
SP - 137
EP - 143
VL - 2334
IS - 1
DP - DeepDyve
ER -