TY - GEN
T1 - (Invited) Selective Area Etching and Doping of GaN for High-Power Applications
AU - Li, Bingjun
AU - Wang, Sizhen
AU - Chang, Alexander S.
AU - Lauhon, Lincoln
AU - Liu, Yafei
AU - Raghothamachar, Balaji
AU - Dudley, Michael
AU - Han, Jung
N1 - Publisher Copyright:
© 2021 ECS - The Electrochemical Society.
PY - 2021
Y1 - 2021
N2 - Selective area doping (SAD) of gallium nitride (GaN), especially p-type doping, is desirable for high-power applications but yet challenging. The lack of this process greatly limits the power device design flexibility, so the reported device figure-of-merits are well below the theoretical calculation/simulation. Selective-area etching followed by regrowth is the approach we choose to overcome this obstacle. For the etching step, instead of adopting conventional Cl-based plasma etching process, we explored in-situ TBCl etching, studied the etching mechanism, and optimized the process to prepare smooth surface and trenches. Room-temperature PL, XPS, and electrical characterizations indicate that TBCl etching creates a low-defect surface. Moreover, selective area growth of p-GaN in a patterned trench was analyzed by atom probe tomography (APT). We found a reverse proportionality between the local growth rate and Mg doping concentration, and the development of fast-growing semi-polar facet from the sidewall. As a consequence, non-uniform Mg doping in non-planar growth is observed.
AB - Selective area doping (SAD) of gallium nitride (GaN), especially p-type doping, is desirable for high-power applications but yet challenging. The lack of this process greatly limits the power device design flexibility, so the reported device figure-of-merits are well below the theoretical calculation/simulation. Selective-area etching followed by regrowth is the approach we choose to overcome this obstacle. For the etching step, instead of adopting conventional Cl-based plasma etching process, we explored in-situ TBCl etching, studied the etching mechanism, and optimized the process to prepare smooth surface and trenches. Room-temperature PL, XPS, and electrical characterizations indicate that TBCl etching creates a low-defect surface. Moreover, selective area growth of p-GaN in a patterned trench was analyzed by atom probe tomography (APT). We found a reverse proportionality between the local growth rate and Mg doping concentration, and the development of fast-growing semi-polar facet from the sidewall. As a consequence, non-uniform Mg doping in non-planar growth is observed.
UR - http://www.scopus.com/inward/record.url?scp=85117881946&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85117881946&partnerID=8YFLogxK
U2 - 10.1149/10407.0103ecst
DO - 10.1149/10407.0103ecst
M3 - Conference contribution
AN - SCOPUS:85117881946
T3 - ECS Transactions
SP - 103
EP - 112
BT - 240th ECS Meeting - Gallium Nitride and Silicon Carbide Power Technologies 11
PB - IOP Publishing Ltd.
T2 - 240th ECS Meeting
Y2 - 10 October 2021 through 14 October 2021
ER -