2018/01/09 by Dong Ji, Anchal Agarwal, Wenwen Li +3 · 2 citations
Physics and Astronomy · Materials Science · #GaN-based semiconductor devices and materials #Ga2O3 and related materials #Semiconductor Quantum Structures and Devices
paper · doi:10.1109/ted.2017.2786141
In this paper, we report the successful demonstration of current aperture vertical electron transistors (CAVETs) obtained by using a novel implantation-based compensation method to achieve a conductive aperture. This innovation leads to the first demonstration of “regrowth-free” CAVETs. Two gallium nitride (GaN) CAVETs were fabricated using the ion-implantation-compensated aperture regions, both with Mg-doped p-GaN as currentblocking layers (CBLs). The aperture regions were formed by implanting Si into the p-GaN CBL. In one of the CAVET samples, the Si-implantation-based aperture was formed prior to the regrowth of AlGaN/GaN layers on top. The other CAVET sample was subjected to aperture formation via Si implantation after all the device layers were grown. An ion-implantation scheme using multiple-energy levels was designed to realize a 250-nm Si box profile with a total dose of 4.2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> , converting a 250-nm p-GaN (Mg: 8 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">19</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ) to conductive(n-type)GaN successfully. This novel fabrication method enables the use of Mg-doped CBLs without conventional etch and regrowth steps. Moreover, the proposed scheme can ultimately lead to regrowthfree CAVETs..