High-Performance GaN Vertical <italic>p-i-n</italic> Diodes via Silicon Nitride Shadowed Selective-Area Growth and Optimized FGR- and JTE-Based Edge Termination

• Main Authors: Palash Sarker, Frank P. Kelly, Matthew Landi, Riley E. Vesto, Kyekyoon Kim
• Format: Article
• Language: English
• Published: IEEE 2021-01-01
• Series: IEEE Journal of the Electron Devices Society
• Subjects: Punchthrough (PT); reverse blocking efficiency; silicon nitride shadowed selective-area growth (SNS-SAG); space-modulated junction termination extension (SM-JTE)
• Online Access: https://ieeexplore.ieee.org/document/9269357/

In this work, we develop highly efficient ET schemes based on a selective-area processing methodology that can effectively stymie device leakage, resulting in reliable device operation. In particular, we demonstrate plasma-assisted molecular-beam epitaxy (PAMBE) facilitated silicon nitride shadowed selective-area growth (SNS-SAG) technique, capable of producing smooth GaN interfaces and sidewalls as an enabling technology for high-performance vertical GaN power devices. SNS-SAG is shown to reduce leakage current by at least four orders of magnitude compared to a dry etched device. Floating guard ring (FGR) and junction termination extension (JTE) based ET designs for GaN <italic>p-i-n</italic> diodes for punchthrough operation have been simulated and analyzed in order to develop SNS-SAG compatible space-modulated junction termination extension (SM-JTE) schemes capable of achieving maximum reverse blocking efficiency &#x003E;98&#x0025; while maintaining a wide doping window of up to <inline-formula> <tex-math notation="LaTeX">$\sim \,\,5\times 10^{17}$ </tex-math></inline-formula>cm^&#x2212;3 at a minimum reverse blocking efficiency of &#x007E; 90&#x0025; extending well into high 10¹⁷cm^&#x2212;3 range (<inline-formula> <tex-math notation="LaTeX">$\sim \,\,8\times 10^{17}$ </tex-math></inline-formula>cm^&#x2212;3). In conjunction with the proposed SNS-SAG technique, SM-JTE schemes have the prospects to offer reliable GaN vertical power device operation.