1.7-kV and 0.55-$\text{m}\Omega \cdot \text {cm}^{2}$ GaN p-n Diodes on Bulk GaN Substrates With Avalanche Capability

Abstract

We report vertical GaN-on-GaN p-n diodes with a breakdown voltage (BV) of 1.7 kV and a low differential 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">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> of 0.55 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega \cdot \text {cm}^{2}$ </tex-math></inline-formula> with current spreading considered (or 0.4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega \cdot \text {cm}^{2}$ </tex-math></inline-formula> using the diode bottom mesa size), resulting in a figure-of-merit ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{B}^{2}/R_{\mathrm{\scriptscriptstyle ON}})$ </tex-math></inline-formula> of 5.3 GW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (or 7.2 GW/cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2})$ </tex-math></inline-formula> . These devices exhibit a current swing over 14 orders of magnitude and a low ideality factor of 1.3. Temperature dependent <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I$ </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">$V$ </tex-math></inline-formula> measurements show that the BV increases with increasing temperature, a signature of avalanche breakdown.