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. 15, 1992
Filed:
Jun. 06, 1991
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A device such as a phototransistor, a photodiode, a laser diode or the like including a compound semiconductor coated with a stable passivation film to reduce leakage current is disclosed. The passivation film includes oxygen, a metallic element and constituent elements of the device, and the concentration of the elements included in the passivation film changes gradually through the interface between the passivation film and the device. Such a passivation film is formed by the oxidation or anodic oxidation of a device soaked in an aqueous solution of hydrogen oxide containing metallic ions such as Fe.sup.2+, Fe.sup.3+, Cu.sup.+, Cu.sup.2+, Co.sup.2+ or Cr.sup.2+ under the control of the temperature of the solution.