Dynamic Gate Stress-Induced $V_{\text {TH}}$ Shift and Its Impact on Dynamic $R_{\mathrm {ON}}$ in GaN MIS-HEMTs

Abstract

Very fast transients of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{ {\text {TH}}}$ </tex-math></inline-formula> shift and their impact on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> under dynamic AC (1 k–1 MHz) positive gate stress in depletion-mode (D-mode) metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) are revealed. We achieve data acquisition within 120 ns right after each stress pulse throughout the entire stress time range from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{ { {-7}}}$ </tex-math></inline-formula> up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{ { {3}}}$ </tex-math></inline-formula> s, by virtue of a short stress-to-sense delay of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 100$ </tex-math></inline-formula> ns and high sampling rate up to 50 MSa/s. Despite the considerable <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{\mathrm {\mathbf {TH}}}$ </tex-math></inline-formula> shift, its impact on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> in D-mode MIS-HEMT is modest, if the device is under sufficient gate overdrive. Furthermore, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{\mathrm {\mathbf {TH}}}$ </tex-math></inline-formula> shift and the consequent <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> increase under dynamic stress, which are more relevant to high-frequency switching operation, exhibits frequency dependence within 1 k–1 MHz and is always smaller than that under conventionally used static (constant) stress.