Presentation Information
[10p-E301-19]Diffusion suppression of Mg and high performance β-Ga2O3 current blocking layers by N+Mg co-doping approach
〇Fenfen Fenda Florena1, Hironobu Miyamoto1, Yuki Koishikawa1, Hirofumi Shinohara1, Kohei Sasaki1, Akito Kuramata1 (1.NCT)
Keywords:
gallium oxide,current blocking layer,ion implantation
Deep acceptor doping is a promising strategy for forming current-blocking layers (CBLs) in β-Ga2O3 vertical power devices, where p-type doping is not feasible. By compensating donor concentrations, deep acceptors create high-resistivity regions that mimic p-type body layers. While single Mg or N implantation has been demonstrated for CBL formation, these approaches suffer from high leakage current and premature breakdown. In Mg-implanted CBLs, profile distortion due to Mg diffusion during high-temperature post-implantation annealing (PIA) limits performance. To overcome these limitations, a co-doping approach have been explored theoretically to induce shallow acceptor levels via donor-acceptor level repulsion effect. This work presents the first experimental demonstration of N+Mg co-doping in Ga2O3 achieving improved CBL performance.
Multi-energy N and Mg implantations were introduced into Ga2O3 to form CBL, followed by PIA. Figure 1 shows the depth profile of N and Mg as revealed by secondary ion mass spectrometry (SIMS) measurement. In single Mg doping, alteration of Mg profile was detected due to massive Mg diffusion toward epilayer/substrate interface (see Fig 1[a]). Impressively, a remarkable Mg profile stability was achieved by co-implanting with N (see Fig 1[b]). Suppression of leakage current was more prominent in N+Mg co-implanted CBL compared to their single counterparts as shown in Fig. 2. The improvement resulted in an increase in breakdown voltage from 1.78 kV for single N implantation to 2.12 kV for N+Mg co-implantation. This paper is based on results obtained from a project, JPNP22007, commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
Multi-energy N and Mg implantations were introduced into Ga2O3 to form CBL, followed by PIA. Figure 1 shows the depth profile of N and Mg as revealed by secondary ion mass spectrometry (SIMS) measurement. In single Mg doping, alteration of Mg profile was detected due to massive Mg diffusion toward epilayer/substrate interface (see Fig 1[a]). Impressively, a remarkable Mg profile stability was achieved by co-implanting with N (see Fig 1[b]). Suppression of leakage current was more prominent in N+Mg co-implanted CBL compared to their single counterparts as shown in Fig. 2. The improvement resulted in an increase in breakdown voltage from 1.78 kV for single N implantation to 2.12 kV for N+Mg co-implantation. This paper is based on results obtained from a project, JPNP22007, commissioned by the New Energy and Industrial Technology Development Organization (NEDO).