Toward highly conductive n-type diamond: Incremental phosphorus-donor concentrations assisted by surface migration of admolecules

The realization of low-resistance n-type diamond is required to form novel semiconducting devices. However, heavily doping with phosphorous, the most suitable electron donor, remains challenging. Here we demonstrate that the phosphorus incorporation efficiency in deposited diamond can be maximized when using the largest possible terrace width of vicinal {111}-substrates. Given step-flow-predominant crystal growth, the greater surface migration length of phosphorus-containing admolecules compared with those of carbon-containing parent species explain this. With our findings we create a model which provides a complementary perspective to explain large fluctuations in dopant incorporation efficiencies for p-type and n-type diamond. Our model can also explain conflicting models for admolecule motion responsible for diamond crystallization.