Title :
Selective etching of native oxide by dry processing using ultra clean anhydrous hydrogen fluoride
Author :
Miki, N. ; Kikuyama, H. ; Maeno, M. ; Murota, J. ; Ohmi, T.
Author_Institution :
Hashimoto Chem. Ind. Co. Ltd., Sakai, Japan
Abstract :
An ultraclean dry etching system using HF gas has been developed. It has been demonstrated experimentally that there exists a critical concentration of HF in N/sub 2/ gas for etching of various Si oxide films. The critical concentration for native oxide obtained in wet processing or UV O/sub 3/ organic contamination cleaning is lower than those for thermal oxide, CVD (chemical vapor deposition) oxide, and CVD BSG. The difference becomes large with decreasing moisture level. Based on the results obtained, dry processing using HF gas is proposed as a surface cleaning technique in the ULSI process.<>
Keywords :
VLSI; etching; integrated circuit technology; silicon; silicon compounds; HF-N/sub 2/ gas mixture; SiO/sub 2/ etching; ULSI process; UV O/sub 3/ organic contamination cleaning; anhydrous HF; critical concentration; dry processing; moisture level; selective etching of native oxide; surface cleaning technique; ultraclean dry etching system; wet processing; Dry etching; Hafnium; Hydrogen; Impurities; Moisture; Rough surfaces; Surface cleaning; Surface roughness; Surface treatment; Ultra large scale integration;
Conference_Titel :
Electron Devices Meeting, 1988. IEDM '88. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
DOI :
10.1109/IEDM.1988.32916
