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. 22, 1992
Filed:
Dec. 06, 1991
Murray J Robinson, Falmouth, ME (US);
Christopher C Joyce, Gorham, ME (US);
Tim W Luk, Scarborough, ME (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An improved Schottky diode structure (4) is formed by retrograde diffusing an N.sup.+ concentration of relatively fast diffusing atoms, preferably Phosphorus atoms, to form a localized diode NWell (6) as the diode substrate for the diode. A buried diode layer (5) formed of relatively slow diffusing N type atoms, preferably Antimony atoms, underlies the diode NWell and electrically couples the diode junction (7) to the diode ohmic contact (9). A diode ohmic contact region (31) underlies the ohmic contact, further coupling the diode junction to the ohmic contact. Preferably, the diode junction is a Platinum-Silicide junction. The improved Schottky diode structure may be formed as part of a BICMOS integrated circuit fabrication process wherein the buried diode layer may be formed at the same time as a buried collector layer of a bipolar transistor structure, the diode NWell may be formed at the same time as an NWell of a CMOS transistor structure and the diode ohmic contact region may be formed at the same time as a collector sink region. In the BICMOS fabrication process the buried collector layer definition mask is also a buried diode layer definition mask, the retro NWell definition mask is also a diode NWell definition mask, the collector sink definition mask is also a diode ohmic contact region definition mask, and the BICMOS contacts definition mask is also a diode junction and ohmic contact definition mask.