High-Current-Gain Direct-Growth GaN/InGaN Double Heterojunction Bipolar Transistors

Author

Lee, Yi-Che ; Zhang, Yun ; Kim, Hee-Jin ; Choi, Suk ; Lochner, Zachary ; Dupuis, Russell D. ; Ryou, Jae-Hyun ; Shen, Shyh-Chiang

Author_Institution

Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA

Volume

57

Issue

11

fYear

2010

Firstpage

2964

Lastpage

2969

Abstract

We report high-current-gain n-p-n GaN/InGaN double-heterojunction bipolar transistors (DHBTs) using a direct-growth fabrication processing approach. The impact of the indium composition in the base layer was studied, and a burn-in effect using a constant-base-current stressing method was observed. We found that DHBTs with higher indium composition in the InGaN base layer may help reduce the base resistance and lower the surface recombination current but may result in higher bulk recombination current. A device burn-in effect was also studied. The postprocessing current stressing step helps increase free-hole concentration in the base, reduce the bulk recombination current, and enhance the current gain. As a result, a direct-growth GaN/In_0.03Ga_0.97N DHBT with a peak current gain of 105 and a collector current density > 6.5 kA/cm² was demonstrated on a sapphire substrate.

Keywords

III-V semiconductors; current density; gallium compounds; heterojunction bipolar transistors; indium compounds; p-n heterojunctions; sapphire; GaN-InGaN; burn-in effect; constant-base-current stressing; direct-growth fabrication; double heterojunction bipolar transistor; free-hole concentration; high-current-gain n-p-n; sapphire substrate; surface recombination current; Double heterojunction bipolar transistors; Etching; Gallium nitride; Indium; Integrated circuits; Direct growth; GaN; InGaN; heterojunction bipolar transistors (HBTs);

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2010.2064316

Filename

5570940