Enhancement to the conductivity of surface transfer-doped (111) diamond through thermochemical surface etching

Abstract

The use of a transition metal catalyzed thermochemical etching method for improving the carrier transport properties of the near-surface two-dimensional (2D) hole gas in surface transfer-doped hydrogen-terminated (111) diamond is demonstrated. Using Ni0.8Cr0.2 films deposited and annealed to a temperature of 900 ° C , with up to three etch cycles, preferential (111) surface etching produces large terraces exceeding 10 μ m in size with a surface microroughness, σ RMS 2 λ , that is two orders of magnitude lower than for the pre-etched (111) surface. Magnetotransport measurements on hydrogen-terminated Hall bars engineered on the pre- and post-etched surfaces and rendered conductive by the adso..