Title :
Effect of carbon contamination enhanced by micro-roughness on gate oxide integrity
Author :
Tsugane, Ken ; Yamagisawa, Y. ; Sakai, Satoshi ; Jimbo, Tomoko ; Tomioka, Hideki
Author_Institution :
Device Dev. Center, Hitachi Ltd., Tokyo, Japan
Abstract :
We evaluated the effect on gate oxide integrity of increased carbon contamination due to the microroughness of the Si surface. Carbon contaminants introduced into the sacrificial oxide film during ion implantation are removed during the pre-gate oxidation cleaning, but redeposit on the surface. A rough surface has many physically and chemically active sites, so more carbon adsorbs on a rougher surface. The adsorbed carbon forms Si-C bonds during the preheating step under N 2 ambient before the thermal oxidation process and degrades the integrity of the gate oxide
Keywords :
MOS capacitors; X-ray photoelectron spectra; atomic force microscopy; carbon; oxidation; rough surfaces; surface cleaning; surface contamination; surface topography; AFM; ATR-FTIR spectra; C; C adsorption; C contamination; MOS capacitors; N2; N2 ambient; Si; Si surface microroughness; Si-C bonds; Si-SiO2; XPS spectra; chemically active sites; gate oxide integrity; ion implantation; physically active sites; pre-gate oxidation cleaning; preheating step; rough surface; sacrificial oxide film; thermal oxidation process; Atomic force microscopy; Bonding; Cleaning; Hafnium; Ion implantation; MOS capacitors; Magnetic recording; Postal services; Spectroscopy; Surface contamination;
Conference_Titel :
Semiconductor Manufacturing Conference Proceedings, 1999 IEEE International Symposium on
Conference_Location :
Santa Clara, CA
Print_ISBN :
0-7803-5403-6
DOI :
10.1109/ISSM.1999.808762
