Photo-transistor in MOS thin-film technology and method for production and operation thereof

US4823180A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Armin Wieder · Gauting, DE
• Lothar Risch · Neubiberg, DE

Key dates

• Filing date: Oct 28, 1982
• Grant date: Apr 18, 1989
• Expiry date: Oct 28, 2002

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F30/282

Abstract

A photo-transistor in MOS thin-film technology operable with alternating voltages is comprised of a semiconductor body (3) composed of polycrystalline silicon having source (4) and drain (5) zones therein spaced apart by an undoped channel region (13) and having a gate electrode (1, 10) separated from the semiconductor body (3) by a SiO.sub.2 layer (2) produced by thermal oxidation. These phototransistors are easily and reproducably produced and are characterized by low threshold voltages and a good transistor characteristic curve. Thus, these photo-transistors are well suited for use as sensor elements, opto-couplers, time-delay elements and as photo-transistors in VLSI circuits.