Characterization of thermal oxides grown on TaSi2/polysilicon films
作者:
D. Pawlik,
H. Oppolzer,
T. Hillmer,
期刊:
Journal of Vacuum Science&Technology B: Microelectronics Processing and Phenomena
(AIP Available online 1985)
卷期:
Volume 3,
issue 2
页码: 492-499
ISSN:0734-211X
年代: 1985
DOI:10.1116/1.583305
出版商: American Vacuum Society
关键词: SILICON;OXIDATION;TANTALUM SILICIDES;DOPED MATERIALS;CRYSTAL DOPING;ROUGHNESS;THICKNESS;POLYCRYSTALS;DEPTH PROFILES;HIGH TEMPERATURE;TRANSMISSION ELECTRON MICROSCOPY;AUGER ELECTRON SPECTROSCOPY;SIMS;SPUTTERING
数据来源: AIP
摘要:
Oxidation of tantalum disilicide films deposited by cosputtering on highly phosphorus doped polycrystalline silicon was investigated as a function of various film preparation parameters. The thermal oxides, with a thickness of about 100 nm, were characterized by cross‐sectional TEM, AES, and SIMS depth‐profiling as well as breakdown strength measurements on small‐area and large‐area capacitors. No limitation on oxide growth for dry and steam oxidation was found in the investigated temperature range of 800 to 1000 °C. The removal of the native oxide on the poly‐Si prior to TaSi2deposition by an HF dip or by backsputtering is crucial for reproducible oxide growth. The nature of the oxide is similar to thermal SiO2on (100) Si. The TaSi2film integrity is maintained during oxidation. The high surface and interface roughnesses cause oxide thickness variations of about 50%. A high mass fraction of the order of 0.5 wt.% phosphorus was found in the oxides. The breakdown strength of both steam and dry oxides is about one order of magnitude lower than the values for thermal oxides onn+‐poly‐Si. These low breakdown strength values are attributed mainly to large pores in the oxides observed in the TEM. No restrictions on process compatibility were found.
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