US 11,688,802 B2
High electron mobility transistor and fabrication method thereof
Chih-Wei Chang, Tainan (TW); Yao-Hsien Chung, Kaohsiung (TW); Shih-Wei Su, Tainan (TW); Hao-Hsuan Chang, Kaohsiung (TW); Ting-An Chien, Tainan (TW); and Bin-Siang Tsai, Changhua County (TW)
Assigned to UNITED MICROELECTRONICS CORP., Hsin-Chu (TW)
Filed by UNITED MICROELECTRONICS CORP., Hsin-Chu (TW)
Filed on Feb. 18, 2021, as Appl. No. 17/179,322.
Prior Publication US 2022/0262939 A1, Aug. 18, 2022
Int. Cl. H01L 29/778 (2006.01); H01L 29/66 (2006.01); H01L 29/20 (2006.01)
CPC H01L 29/7786 (2013.01) [H01L 29/2003 (2013.01); H01L 29/66462 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for forming a high electron mobility transistor, comprising:
providing a substrate;
forming a channel layer on the substrate;
forming an electron supply layer on the channel layer;
forming a dielectric passivation layer on the electron supply layer;
forming a gate recess into the dielectric passivation layer and the electron supply layer;
conformally depositing a surface modification layer on an interior surface of the gate recess;
subjecting the surface modification layer to an oxidation treatment or a nitridation treatment, wherein the surface modification layer is first subjected to the oxidation treatment and is then subjected to the nitridation treatment; and
forming a P-type GaN layer in the gate recess and on the surface modification layer.