Novel Acceptor Layer Technology For Diamond Electronics

Surface induced transfer doping (SITD) is a novel, highly efficiency doping technique that is being used to invoke the p-type surface conductivity of intrinsic diamond for high-frequency, high-power electronic devices. In the SITD process, a high electron affinity (EA) thin-film acceptor layer is interfaced with the hydrogenated diamond surface with negative electron affinity (NEA) to induce the effective p-type doping on the diamond surface. Overall, surface mobility, carrier density, and operational characteristics of the SITD-doped devices are contingent on the type and quality of the interface between the acceptor layer and hydrogenated diamond surfaces. Initial device designs used atmospheric molecules as the acceptor layer. In recent times, transition metal oxides (TMOs) have attracted considerable attention due to their large EA resulting in increased charge density and surface stability. However, TMO's tendency to exhibit stoichiometry degradation makes them vulnerable to the device fabrication process. Motivated by this, our internal theoretical modeling efforts based on a hybrid approach of machine learning and first principle calculations have focused on performing bottom-up design of novel acceptor layers with higher stability and improved device performance using two-dimensional (2D) material. Recent predictions regarding the role of acceptor layers on modifying device-related materials parameters such as stability, band alignment, carrier effective mass, and charge transfer will be presented in this paper. The theoretical modeling results presented here provides guidance to the in-house materials and device design efforts by supplying fundamental insights into the viability of these novel acceptor layer technologies for future device designs.