Thermal Diffusion Doping of Single Crystal Diamond

TL;DR

This paper introduces a simple thermal diffusion method for boron doping in single-crystal diamond, enabling the creation of high-voltage diamond electronic devices without damaging the crystal structure.

Contribution

It presents a novel, accessible doping technique using heavily doped silicon nanomembranes for effective boron doping in SCD without lattice damage.

Findings

Successfully doped SCD with boron using thermal diffusion at low temperature.

Fabricated high-voltage diodes and rectifiers with doped SCD.

Established a practical pathway for diamond electronics in power systems.

Abstract

With the best overall electronic and thermal properties, single-crystal diamond (SCD) is the extreme wide bandgap material that is expected to revolutionize power electronics and radio-frequency electronics in the future. However, turning SCD into useful semiconductors faces doping challenges, as conventional substitutional doping techniques, such as thermal diffusion and ion-implantation, are not easily applicable to SCD. Here we report a simple and easily accessible doping strategy demonstrating that electrically activated, substitutional boron doping in natural SCD without any phase transitions or lattice damage which can be readily realized with thermal diffusion at relatively low temperature. For the boron doping, we employ a unique dopant carrying medium: heavily doped Si nanomembranes. We further demonstrate selectively doped high-voltage diodes and half-wave rectifier circuits using such doped SCD. Our new doping strategy has established a reachable path toward using SCDs for future high-voltage power conversion systems and for other novel diamond-based electronics.