Image sensor

US4910568A · kind A · utility

Assignee

• FUJITSU LIMITED · JP

Inventors

• Akira Takei · Yokohama, JP
• Tetsuo Nishikawa · Uda, JP

Key dates

• Filing date: May 1, 1989
• Grant date: Mar 20, 1990
• Expiry date: May 1, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/153

Abstract

Field isolation between arrayed picture cells of an image sensor is fabricated thinner than the insulation layer for the peripheral portion of CCD operatively connected to picture cells. The field isolation is fabricated by a selective thermal oxidization, by which the isolation film inflates not only vertically but also laterally, therefore the thinner isolation layer can be narrower. And, the lower applied voltage to the picture cell than applied voltage to the CCD portion allows the narrower isolation. The narrower field isolation between the picture cells allows greater density of integration of the picture cells. Procedures to embody the invention are disclosed, one of which is to fabricate the thinner isolation first, and another one is the thicker insulation layer first.