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:
Nov. 16, 1982
Filed:
Aug. 18, 1981
Lawrence G Heller, Essex Junction, VT (US);
Harry J Jones, Underhill, VT (US);
Harish N Kotecha, Essex Junction, VT (US);
Donald A Soderman, Vienna, VA (US);
IBM Corporation, Armonk, NY (US);
Abstract
The invention is the structure and process for making a bucket brigade device which comprises the merger of an MOS capacitor with an MOSFET device to form the charge transfer cell. A first thin N-type region is implanted at a first concentration in a portion of the P-type channel region of an FET device adjacent to the drain diffusion. A second region is implanted with N-type dopant at a second concentration less than the first concentration, adjacent to and continuous with the first implanted region. The N-type concentration in the second region is just sufficient to compensate for the P-type background doping in the channel region. This structure increases the charge transfer efficiency for the cell and reduces its sensitivity of the threshold voltage to the source-drain voltage. The gate for the device has a substantial overlap over the drain and a minimal overlap over the source and the gate to drain capacitance per unit area is maximized by maintaining a uniformly thin oxide layer across the gate region.