MOS-transistor for a photo cell

US6489658B2 · kind B2 · utility

Assignee

• Institut fur Mikroelektronik · DE

Inventors

• Harald Richter · Neuenbürg, DE
• Bernd Hofflinger · Sindelfingen, DE
• Uwe Apel · Neckartailfingen, DE
• Ulrich Seger · Renningen, DE

Key dates

• Filing date: Jun 28, 1999
• Grant date: Dec 3, 2002
• Expiry date: Jun 28, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/803

Abstract

The invention relates to a MOS transistor for a photo cell, comprising a semiconductor substrate on which a gate electrode, a drain electrode and a photosensitive source region are configured. An oxide layer is arranged between the gate electrode and the substrate, and in the active region of the MOS transistor this oxide layer is formed as thin oxide film while it is configured as thick oxide film in a passive region. The inventive transistor is distinguished by the provisions that the gate electrode comprises a closed annular section in the active region of the MOS transistor, and that either the drain electrode or the photosensitive source region is arranged within the annular section of the gate electrode so that current will only flow in the active region.