Investigation of Traps Impact on PAE and Linearity of AlGaN/GaN HEMTs Relying on a Combined TCAD–Compact Model Approach
Petros Beleniotis, Christos Zervos, Sascha Krause, Serguei Chevtchenko, D. Ritter, Matthias Rudolph
Abstract
This article proposes a novel modeling approach for the analysis of the microwave power performance of GaN HEMTs. By combining Technology Computer-Aided Design (TCAD) physical and circuit design standard compact trap models, surface and buffer traps can be directly correlated, for the first time, with power-added efficiency (PAE) and output power ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{P}_\text{out}$</tex-math> </inline-formula> ). A new trap model topology is created with an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> subnetwork and nonlinear scaling functions, encouraged by TCAD analysis on trap localization. The effects of surface trapping were quantified using a TCAD-based extraction of the proposed trap model, observing a loss on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{P}_\text{out}$</tex-math> </inline-formula> of 3 dBm and a maximum PAE ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{PAE}_\text{MAX}$</tex-math> </inline-formula> ) loss of 12% due to surface traps. In addition, the correlation of 2-D electron gas (2DEG) at the drain access region with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{PAE}_\text{MAX}$</tex-math> </inline-formula> and the 1-dB compression point of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{P}_\text{out}$</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">$\text{OP}_\text{1\,dB}$</tex-math> </inline-formula> ) is investigated and transformed into a correlation between the density of traps ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{N}_\text{T}$</tex-math> </inline-formula> ) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{PAE}_\text{MAX}$</tex-math> </inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{OP}_\text{1\,dB}$</tex-math> </inline-formula> , creating a new direct method to connect TCAD with RF large-signal simulations.