Method of producing a defined arsenic doping in silicon semiconductor substrates

US4755486A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Helmuth Treichel · Augsburg, DE
• Frank Becker · Munich, DE

Key dates

• Filing date: Oct 15, 1987
• Grant date: Jul 5, 1988
• Expiry date: Oct 15, 2007

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02129
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of producing a defined arsenic doping in silicon semiconductor substrates is provided. Preferably, the arsenic doping is produced in the sidewalls and floors of trenches having high aspect ratio which are etched into the substrates. An arseno-silicate glass layer is deposited into these trenches to be used as a diffusion source, the glass layer being removed after the diffusion. The arseno-silicate glass layer is deposited by thermal decomposition from the vapor phase of tetraethylortho silicate Si)OC.sub.2 H.sub.5).sub.4 and triethylarsenate AsO(OC.sub.2 H.sub.5).sub.3. A steep and reproducible doping profile having constant, maximum penetration depth and high arsenic concentration in the substrate surface which is needed for VLSI semiconductor circuits is obtained through the process of the present invention.