Process of reducing density of fast surface states in MOS devices

US4331709A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Lothar Risch · Neubiberg, DE
• Erich Pammer
• Karlheinz Friedrich · Weiden am See, AT

Key dates

• Filing date: Jul 22, 1980
• Grant date: May 25, 1982
• Expiry date: Jul 22, 2000

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/91
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Fast surface states in MOS devices, such as SCCDs, are reduced by depositing a relatively thin amorphous layer containing silicon and hydrogen onto the SiO.sub.2 surface of such devices and annealing the resultant device in a non-oxidizing atmosphere for brief periods of time at a temperature in excess of the deposition temperature for the amorphous layer but below about 500.degree. C. so that free valences at the Si-SiO.sub.2 interface region are saturated with hydrogen. Surface state densities of about 4.times.10.sup.8 cm.sup.-2 eV.sup.-1 and SCCDs having .epsilon.=1.10.sup.-5 can be achieved via this process. The process is useful in producing SCCDs with low surface state densities and other MOS devices having low surface generated dark currents.