US 12,278,283 B2
HEMT transistor including an improved gate region and related manufacturing process
Ferdinando Iucolano, Gravina di Catania (IT); and Cristina Tringali, Augusta (IT)
Assigned to STMICROELECTRONICS S.r.l., Agrate Brianza (IT)
Filed by STMICROELECTRONICS S.r.l., Agrate Brianza (IT)
Filed on Sep. 28, 2023, as Appl. No. 18/477,372.
Application 18/477,372 is a division of application No. 16/706,539, filed on Dec. 6, 2019, granted, now 11,799,025.
Claims priority of application No. 102018000011065 (IT), filed on Dec. 13, 2018.
Prior Publication US 2024/0021718 A1, Jan. 18, 2024
Int. Cl. H01L 29/66 (2006.01); H01L 21/285 (2006.01); H01L 29/06 (2006.01); H01L 29/47 (2006.01); H01L 29/778 (2006.01); H01L 29/20 (2006.01); H01L 29/205 (2006.01)
CPC H01L 29/7786 (2013.01) [H01L 21/28581 (2013.01); H01L 29/0649 (2013.01); H01L 29/475 (2013.01); H01L 29/66462 (2013.01); H01L 29/7787 (2013.01); H01L 29/2003 (2013.01); H01L 29/205 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A process for manufacturing a HEMT transistor, comprising:
forming a semiconductor body that includes a semiconductor heterostructure; and
forming a conductive gate region, wherein forming the conductive gate region comprises:
forming a contact region made of a first metal material, which contacts the semiconductor body, thereby forming a Schottky junction with the semiconductor body;
on the contact region, forming a barrier region made of a second metal material; and
on the barrier region, forming a top region made of a third metal material, which has a resistivity lower than a resistivity of the first metal material;
forming, on the contact region, a front dielectric subregion having a front opening that is open to the contact region; and wherein forming the barrier region includes extending the barrier region into the front opening and on at least part of the front dielectric subregion, wherein:
forming the contact region includes carrying out a chemical vapor deposition of said first metal material;
forming the barrier region includes carrying out, after forming said front dielectric subregion and said front opening, a first sputtering operation of the second metal material; and
forming the top region includes carrying out a second sputtering operation of the third metal material.