2023 article

Analysis of Vertical GaN JBS and p-n Diodes by Mg Ion Implantation and Ultrahigh-Pressure Annealing

Stein, S. R., Khachariya, D., Mecouch, W., Mita, S., Reddy, P., Tweedie, J., … Pavlidis, S. (2023, December 12). IEEE TRANSACTIONS ON ELECTRON DEVICES.

By: S. Stein n, D. Khachariya*, W. Mecouch*, S. Mita*, P. Reddy*, J. Tweedie*, K. Sierakowski*, G. Kamler* ...

author keywords: Schottky diodes; Annealing; Ion implantation; Schottky barriers; P-n junctions; Resistance; Gallium nitride; junction barrier Schottky (JBS) diode; Mg activation; p-n diode; power semiconductor device; Schottky contact; ultrahigh-pressure annealing (UHPA); vertical GaN
Source: Web Of Science
Added: January 2, 2024

We report on vertical GaN junction barrier Schottky (JBS) diodes formed by Mg ion implantation and ultrahigh -pressure annealing (UHPA). The static ON-state characteristics of the diodes show an ideality factor of 1.05, a turn-on voltage of ~0.7 V, a current rectification ratio of $\sim 10^{11}$ , and a low differential specific ON-resistance that scales with Schottky stripe width in fair agreement with the analytical model. The reverse leakage dependence on Schottky stripe width also agrees well with the analytical model. Implanted p-n junction diodes fabricated on the same wafer exhibit avalanche breakdown in reverse bias with a positive temperature coefficient, but the forward current is limited by a series barrier. Temperature-dependent current–voltage measurements of th p-n diodes verify the presence of the implanted p-n junction and reveal an additional 0.43-eV barrier, which we hypothesize arises from a p-Schottky contact and forms a second diode back-to-back with the p-n junction. This interpretation is supported by analysis of the capacitance–voltage characteristics of the implanted p-n diodes, epitaxial p-n diodes fabricated with intentional p-Schottky contacts, and comparison to TCAD simulations. Ultimately, the presence of the p-Schottky contact does not hinder JBS diode operation. The use of diffusion-aware designs and/or diffusion reduction represents future directions for Mg implantation technology in GaN power devices.