Title :
Ti-gate metal induced PHEMT degradation in hydrogen
Author :
Chao, P.C. ; Hu, W. ; DeOrio, H. ; Swanson, A.W. ; Hoffman, W. ; Taft, W.
Author_Institution :
Lockheed Martin Co., Nashua, NH, USA
Abstract :
Through accelerated life test in hydrogen, we have found, for the first time, that in addition to Pt metal, Ti metal in a Ti/Pt/Au-gate PHEMT can also induce a significant hydrogen effect by reacting with a small amount of hydrogen gas in the ambient. The hydrogen sensitivity of a PHEMT device caused by Ti gate metal is significantly less than that due to Pt. Since Ti is not a hydrogen catalyst, the resulting hydrogen sensitivity indicates that a catalytic reaction between the gate metal and hydrogen gas is not required to have a detrimental hydrogen effect. The data also show that the degradation evident in the PHEMT devices due to the Ti-H/sub 2/ interaction is similar to that from the Pt-H/sub 2/ interaction. It is clear from this work that attempting to solve the hydrogen degradation problem by eliminating the Pt gate metal in a PHEMT is ineffective.
Keywords :
failure analysis; high electron mobility transistors; hydrogen; life testing; semiconductor device metallisation; semiconductor device reliability; titanium; H/sub 2/; H/sub 2/ sensitivity; Ti-H/sub 2/ interaction; Ti-Pt-Au; Ti-gate metal induced degradation; Ti/Pt/Au-gate PHEMT; accelerated life test; hydrogen effect; pseudomorphic HEMT; Chaos; Degradation; Failure analysis; Gallium arsenide; Hydrogen; Life estimation; Life testing; Metallization; PHEMTs; Temperature;
Journal_Title :
Electron Device Letters, IEEE
