(Invited) The Effect of Thermally Induced Piezoelectricity on GaN HEMT Device Characteristics. (10th April 2015)

• Record Type: Journal Article
• Authors: Sengupta, Jonah; McCluskey, Patrick; Khanna, Sumeer
• Is Part Of: ECS transactions. Volume 66:Number 7(2015)
• Page Start: 71
• Page End: 86
• Publication Date: 2015-04-10
• Subjects: Electrochemistry -- Periodicals; Electrochemistry; Periodicals; Electronic journals; Electronic journal; 541.37
• DOI: 10.1149/06607.0071ecst
• Languages: English
• ISSNs: 1938-5862

Abstract

Abstract : GaN is increasingly being used in a wide variety of power electronic applications. The piezoelectric nature of GaN, however, can result in defect generation and can modify the electrical performance of power devices, especially AlGaN/GaN high electron mobility transistors (HEMTs). The cooling mechanisms used to cool the GaN can create thermal gradients that can exaggerate this piezoelectric effect. In this study, multiphysics finite element modeling was used to determine the thermal gradients, the resulting thermo-mechanical stresses, and the attendant changes in the electric fields resulting from piezoelectric interaction seen in the HEMT. Devices were then tested on a probe station to validate the results of the modeling. Evident drain and gate current and on-resistance degradation were observed after a 30 minute voltage and current stress was applied to the HEMT.