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:
Oct. 15, 1991
Filed:
Aug. 16, 1989
Peter Roggwiller, Riedt-Neerach, CH;
BBC Brown Boveri AG, Baden, CH;
Abstract
A method for producing a gate turn-off thyristor (GTO) having a semi-conductor substrate (1) with at least one p-conducting anode layer (4), one n-type base layer (6), one p-type base layer (7) which is in electrical contact with a gate, and one n-conducting cathode layer (8) has a cathode layer (8) with a highly doped zone (10) acting as an n.sup.+ emitter and a lightly doped zone (9) in which highly doped zone (10) adjoins the surface of the semi-conductor substrate (1) and has a doping density which is at least an order of magnitude higher than that of the p-type base layer (7), the lightly doped zone (9) is situated between a pn junction J.sub.1, produced by the p-type base layer (7) and the cathode layer (8), and the highly doped zone (10) of the cathode layer (8) including producing the doping profile of the cathode layer in first and second diffusion steps, the depth and the breakdown properties of the pn junction J.sub.1 between cathode layer and p-type base layer being determined in the first diffusion step and the layer properties of the cathode layer being determined in the second diffusion step.