Demonstration of 1200-V E-Mode GaN-on-Sapphire Power Transistor With Low Dynamic ON-Resistance Based on Active Passivation Technique
Jiawei Cui, Maojun Wang, Yanlin Wu, Junjie Yang, Han Yang, Jingjing Yu, Teng Li, Xuelin Yang, Xiaosen Liu, Kai Cheng, Jinyan Wang, Bo Shen, Jin Wei
Abstract
This letter demonstrates a 1200-V E-mode GaN-on-sapphire power transistor based on active passivation technique. The active passivation concept utilizes a thin p-GaN layer extending from the p-GaN gate towards near the drain to screen the surface traps. The fabricated active-passivation HEMT (AP-HEMT) with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${L}_{\text {GD}}$ </tex-math></inline-formula> of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$27 ~\mu \text{m}$ </tex-math></inline-formula> exhibits a low <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}}$ </tex-math></inline-formula> of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$16.9 \Omega \cdot $ </tex-math></inline-formula> mm, corresponding to a specific <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}}$ </tex-math></inline-formula> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$({R}_{\text {ON, SP}})$ </tex-math></inline-formula> of 6.42 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega \cdot $ </tex-math></inline-formula> cm2. A breakdown voltage (BV) over 2000 V is obtained for the AP-HEMT. Besides, the AP-HEMT showcased excellent dynamic performance due to the surface shielding effect provided by the active passivation. Dynamic ON-resistance was characterized <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$120 ~\mu \text{s}$ </tex-math></inline-formula> after a 10-ms VDS-OFF stress. At VDS-OFF = 1200 V, the ratio of dynamic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}}$ </tex-math></inline-formula> to static <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}}$ </tex-math></inline-formula> is 1.09. The results highlight the superior capabilities of active passivation technique for 1200-V GaN power transistors.