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:
Mar. 17, 1998
Filed:
Sep. 06, 1996
Serge L Rudaz, Sunnyvale, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
N-type doping in III-V-nitride semiconductor compounds, i.e. GaN-based compounds such as GaN, AlGaN, AlInN, InGaN, or AlGaInN, can be optimized to improve N-contact electrical resistance, carrier injection, forward voltage, and recombination characteristics without inducing cracking of the device layers. The N-type layer is constructed of sub-layers such that an N-type sub-layer is provided for each desired characteristic or property. The thickness of each sub-layer is carefully selected to avoid material cracking: the higher the required doping, the smaller the corresponding thickness. In illustration, the buffer layer of a light emitting device (LED) has three sub-layers. The first sub-layer is lightly doped to avoid cracking and is grown to the desired thickness for good material quality. The second sub-layer is heavily doped to provide good N-contact and electrical resistivity characteristics and is kept correspondingly as thin as necessary to avoid material cracking. The third sub-layer is doped to the desired level to provide optimum carrier injection and pair recombination in the active layer of the device.