High-Performance E-Mode <i>p</i>-Channel GaN FinFET on Silicon Substrate With High <i>I</i> <sub>ON</sub>/<i>I</i> <sub>OFF</sub> and High Threshold Voltage
Hanghai Du, Zhihong Liu, Lu Hao, Huake Su, Tao Zhang, Weihang Zhang, Jincheng Zhang, Yue Hao
Abstract
In this letter, we report on demonstrating high-performance enhancement-mode (E-mode) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula> -channel GaN Fin Field-Effect Transistors (FinFETs) fabricated on a proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula> -GaN/AlN/AlGaN epitaxial structure with a low sheet resistance of 14 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{k}\Omega / {\unicode{0x25A1}} $ </tex-math></inline-formula> . Benefiting from the 25-nm-wide GaN nanowires channel and tri-gate architecture, high threshold voltage ( <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> ) of −2.2 V and low subthreshold swing ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SS</i> ) of 130 mV/dec were obtained. Meanwhile, owing to the removal of etching damage in the recessed region and the post gate annealing, high drain current density of 18.5 mA/mm and high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{ \mathrm{\scriptscriptstyle ON}} / I_{ \mathrm{\scriptscriptstyle OFF}}$ </tex-math></inline-formula> ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3\times10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> were acquired. The E-mode <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula> -channel GaN FinFET fabricated on the reformative epitaxial structure with lower sheet resistance shows the potential to be one step closer to realizing the vision of GaN CMOS technology.