Selectively hydrogen-pretreated AlGaAs/InGaAs p-HEMTs and their application to an enhancement/depletion-mode HEMT

• Published in: Solid-state electronics Vol. 49; no. 1; pp. 19 - 24
• Main Authors: Kang, In-Ho, Kim, Jung-Hoon, Kim, Won-Bae, Song, Jong-In
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2005; Elsevier Science
• Subjects: Applied sciences; E/D-HEMT; Electronics; Exact sciences and technology; Gate leakage current; Selective hydrogen pretreatment; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Shallow traps; Transistors; Gate leakage current; Selective hydrogen pretreatment; Shallow traps; E/D-HEMT; Voltage threshold; Depletion mode; Transistor gate; Metallizing; 1/f noise; Enhancement mode; Breakdown voltage; High electron mobility transistor; Reactive ion etching; Donor; Leakage current; Pseudomorphic transistor; Thermal annealing
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2004.07.006

DC, RF, and low-frequency noise characteristics of selectively hydrogen-pretreated Al
0.24Ga
0.76As/In
0.2Ga
0.8As double heterostructure pseudomorphic high electron mobility transistors (p-HEMTs) were investigated. The gate region of the p-HEMTs was exposed to a hydrogen plasma in a reactive ion etching chamber, followed by a thermal annealing, prior to a gate metallization. Strong dependence of the threshold voltage, the gate leakage current, and low-frequency noise characteristics on the RF power of the hydrogen plasma and the annealing temperature was observed. Control of the donor density in the selectively hydrogen-pretreated gate region produced a threshold voltage shift as large as 1
V, which was successfully used for a fabrication of enhancement/depletion HEMTs (E/D-HEMTs). The selective hydrogen pretreatment (SHP) produced improved gate leakage current, breakdown voltage, and low-frequency characteristics. These results indicate the potential of the selective hydrogen pretreatment for use in an easy fabrication of E/D-HEMTs.