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:
Sep. 30, 1997
Filed:
Sep. 12, 1995
Shigeru Nakajima, Yokohama, JP;
Sumitomo Electric Industries, Osaka, JP;
Abstract
It is an object of the present invention to provide a structure of a field effect transistor, which effectively suppresses a leakage current from a source/drain region to a substrate side without increasing a parasitic capacitance, and a method of manufacturing the same. According to the present invention, when an LDD structure is to be constituted by forming, in a semiconductor substrate, an active layer of a first conductivity type, a heavily doped layer of the first conductivity type, which is separated from the active layer by a predetermined distance and has a high impurity concentration; and an intermediate concentration layer of the first conductivity type, which is formed between the active layer and the heavily doped layer and has an impurity concentration lower than that of the heavily doped layer, regions of a second conductivity (these regions are converted into depletion layers upon contact with the corresponding regions of the first conductivity), which cover the entire bottom portion of the corresponding region are formed.