New physics of surface transfer doping

Our diamond transistors are based on a new physics of surface transfer doping (not conventional p/n doping) — a phenomenon in which charge carriers are induced without introducing substitutional dopant atoms into the bulk crystal.

When the surface of a single-crystal diamond wafer is terminated with an atomic layer of hydrogen, its electron affinity becomes negative, allowing electrons to transfer from the diamond valence band to suitable acceptor species (often adsorbates or engineered surface layers) at the surface. This charge transfer leaves behind a high-density two-dimensional hole gas (2DHG) confined within a few nanometers of the surface, producing p-type conductivity while preserving the intrinsic purity, thermal conductivity, and breakdown strength of the diamond bulk.

Because no ion implantation or lattice substitution is required, surface transfer doping avoids defect generation and carrier scattering associated with conventional doping, making it particularly attractive for high-power, high-frequency, and radiation-hard electronic device platforms.