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:
Jul. 28, 1981
Filed:
Jan. 23, 1980
Claude L Bertin, South Burlington, VT (US);
Francisco H De La Moneda, Stormville, NY (US);
Donald A Soderman, Saratoga, CA (US);
IBM Corporation, Armonk, NY (US);
Abstract
A diffused MOS (DMOS) device and method for making same are disclosed. The prior art DMOS device is improved upon by ion implanting a depletion extension L.sub.D to the drain. However, the introduction of the depletion extension L.sub.D introduces a manufacturing statistical variation in the characteristics of the resultant devices so produced. The problem of the effects of the variations in the length L.sub.D and thus, variations in the resulting transconductance of the device, is solved by placing two of these devices in parallel. When one device has its L.sub.D relatively shorter, the companion device will also have its L.sub.D correspondingly longer. The method of producing the dual devices is by ion implanting a single conductivity region which forms the L.sub.D for both the left- and right-hand channels for the left- and right-hand DMOS structures. If the mask for the ion-implanted region is misaligned slightly to the right, then the effective L.sub.D for the right-hand channel is somewhat longer but the effective L.sub.D for the left-hand channel is correspondingly shorter, so that the net parallel transconductance for the two devices remains the same as the transconductance for a perfectly symmetric ion-implanted region.