Dynamic Interplays of Gate Junctions in Schottky-type p-GaN Gate Power HEMTs during Switching Operation
Han Xu, Zheyang Zheng, Li Zhang, Jiahui Sun, Song Yang, Jiabei He, Jin Wei, Kevin J. Chen
Abstract
Dynamic behaviors of threshold voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> ) of the Schottky-type p-GaN gate high-electron-mobility transistor (HEMT) have been intensively studied in recent years, which is vital to properly operate the device and leverage its full potential. Most research has focused on impacts of individual terminal biases, i.e., either drain-to-source (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf> ) or gate-to-source (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</inf> ) voltages. However, devices are subject to continuous switching with alternating V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</inf> and V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf> in actual application scenarios. This work reveals that the charge storage mechanism of V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf> -induced dynamic V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> , which is associated with the two back-to-back junctions in the gate stack, also governs the V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</inf> -induced V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> variation. Therefore, both V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf> -and V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</inf> -induced dynamic V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> behaviors could be accurately described with a unified equivalent circuit-based SPICE model, which in turn visualizes the dynamic interplays of the two gate junctions and demonstrates the capability of predicting devices’ dynamic behaviors in real switching operations.