Image sensor with large-area, high-sensitivity and high-speed pixels

US7701028B2 · kind B2 · utility

Assignee

• MESA Imaging AG · CH

Inventors

• Rolf Kaufmann · Schneeberg, DE
• Michael Lehmann · Winterthur, CH
• Peter Seitz · Munich, DE

Key dates

• Filing date: Mar 31, 2005
• Grant date: Apr 20, 2010
• Expiry date: Oct 3, 2026

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/548

Abstract

The pixel for use in an image sensor comprises a low-doped semiconductor substrate (A). On the substrate (A), an arrangement of a plurality of floating areas e.g., floating gates (FG2-FG6), is provided. Neighboring floating gates are electrically isolated from each other yet capacitively coupled to each other. By applying a voltage (V2-V1) to two contact areas (FG1, FG7), a lateral steplike electric field is generated. Photogenerated charge carriers move along the electric-field lines to the point of highest potential energy, where a floating diffusion (D) accumulate the photocharges. The charges accumulated in the various pixels are sequentially read out with a suitable circuit known from image-sensor literature, such as a source follower or a charge amplifier with row and column select mechanisms. The pixel of offers at the same time a large sensing area, a high photocharge-detection sensitivity and a high response speed without any static current consumption.