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:
Jun. 29, 2021
Filed:
Mar. 06, 2019
Suzhou Han Hua Semiconductor Co.,ltd, Suzhou, CN;
SUZHOU HAN HUA SEMICONDUCTOR CO., LTD., Jiangsu, CN;
Abstract
The invention relates to a method to reduce the contact resistance of ohmic contact in group III-nitride high-electron mobility transistor (HEMT). A heavily n-type doped nitride layer with modulation doping is epitaxially grown on selected contact regions for use as ohmic contact layer. The method for producing the n++ ohmic contact layer includes at least the following: deposition of nitride HEMT epitaxial structure on substrates (such as SiC, silicon, sapphire, GaN etc), deposition in-situ or ex-situ mask for selective growth of n-contact, selective etching to create of openings within the mask layer, deposition of modulation doped n++ nitride ohmic contact layer followed by ohmic metal deposition. The modulation doping involves alternating epitaxy of high and low doped nitride layers with common n-type dopant such as Ge, Si etc. The modulation doping significantly increases the range of n-type doping without detrimental effect on the material quality of the contact layer.