Substrate-Coupled Cross-Talk Effects on an AlGaN/GaN-on-Si Smart Power IC Platform

• Published in: IEEE transactions on electron devices Vol. 61; no. 11; pp. 3808 - 3813
• Main Authors: Qimeng Jiang, Zhikai Tang, Chunhua Zhou, Shu Yang, Chen, Kevin J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AlGaN/GaN-on-Si power device platform; Aluminum gallium nitrides; buffer traps; Cross talk; Devices; Electric power generation; Gallium nitride; Gallium nitrides; HEMTs; High electron mobility transistors; Logic gates; Semiconductor devices; Silicon; Silicon substrates; Stress; substrate termination; Substrates; Switches; buffer traps; AlGaN/GaN-on-Si power device platform; cross talk; substrate termination
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2014.2355834

Cross talks between low-voltage peripheral devices and high-voltage (HV) power devices on an AlGaN/GaN-on-Si smart power IC platform are investigated by monitoring the transfer, output, and transient characteristics of a low-voltage AlGaN/GaN high-electron mobility transistor (HEMT) with an HV bias stress applied to an adjacent isolated electrode. The electric measurement was conducted under two types of substrate termination, i.e., floating and grounded. The substrate termination is shown to be the critical factor in the cross talk. The low-voltage HEMT exhibits significant drain-current degradation with a floating substrate, but remains stable with a grounded substrate. It is determined that a coupling path of the switched HV stress is formed from the HV node to the floating low-resistivity Si substrate, and then from the substrate to the HEMT. The negative net charges in the GaN buffer are caused by the electrons injected from the 2DEG channel. It is found that a grounded substrate is helpful for eliminating the cross-talk effect.