930V and Low-Leakage Current GaN-on-Si Quasi-Vertical PiN Diode With Beveled-Sidewall Treated by Self-Aligned Fluorine Plasma

Abstract

In this work, a high performance GaN-on-Si quasi vertical PiN diode was demonstrated by the combination of a beveled sidewall and self-aligned fluorine plasma treatment. The didoes achieved a remarkable breakdown voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}_{\text {BR}}{)}$ </tex-math></inline-formula> of 930 V and an ultra-low reverse leakage current. Meanwhile the didoes showed a low specific on-resistance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{R}_{ \mathrm{\scriptscriptstyle ON},\textit {sp}}$ </tex-math></inline-formula> ) of 0.43 <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> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , a high on/off current ratio ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{I}_{ \mathrm{\scriptscriptstyle ON}}/\text{I}_{ \mathrm{\scriptscriptstyle OFF}}$ </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">$10^{{11}}$ </tex-math></inline-formula> , and an excellent Baliga’s figure of merit (BFOM) of 2.01 GW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measurement results of X-ray spectroscopy (XPS) and Kelvin Probe Force Microscopy (KPFM) proved the presence of F ions and the decrease of surface potential, which reduced the electric field peak and suppressed the leakage current. These results show a great potential of GaN on Si PiN diode for power applications.