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:
Aug. 26, 2008
Filed:
Apr. 27, 2006
Stewart Edward Hooper, Oxford, GB;
Valerie Bousquet, Oxford, GB;
Jonathan Heffernan, Oxford, GB;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A method of manufacturing a nitride semiconductor device comprises the steps of: growing an InGaN (0≦x≦1) layer, and growing an aluminium-containing nitride semiconductor layer over the InGaN layer at a growth temperature of at least 500° C. so as to form an electron gas region at an interface between the InGaN layer and the nitride semiconductor layer. The nitride semiconductor layer is then annealed at a temperature of at least 800° C. The method of the invention can provide an electron gas having a sheet carrier density of 6×10cmor greater. An electron gas with such a high sheet carrier concentration can be obtained with an aluminium-containing nitride semiconductor layer having a relatively low aluminium concentration, such as an aluminium mole fraction of 0.3 or below, and without the need to dope the aluminium-containing nitride semiconductor layer or the InGaN layer.