The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 2003
Filed:
Oct. 26, 2000
Michio Sasaki, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A MOS type image sensor has an image area that consists of a matrix of pixels and a peripheral circuitry area that drives the image area. To make the MOS type image sensor finer and finer, each of the pixels consists of a second p-well region having a lower impurity concentration than a first p-well region disposed in the peripheral circuitry area; a photodiode having a first main electrode region made of the second p-well region and a second main electrode region formed as a first n-diffusion layer disposed at the surface of the second p-well region; a read transistor having a first main electrode region made of the first n-diffusion layer, a second main electrode region formed as a second n-diffusion layer disposed at the surface of the second p-well region, a gate insulation film disposed on the surface of the second p-well region between the first and second n-diffusion layers, and a gate electrode disposed on the gate insulation film and connected to a read signal line; and an amplification transistor disposed in a third p-well region, having a gate electrode connected to the second main electrode region of the read transistor, a first main electrode region connected to an output signal line, and a second main electrode region. Since the impurity concentration of the second p-well region is low, scaled design rules are employable without causing “white pixels”, sensitivity deterioration, signal read voltage increase, or short-channel effect.