Diamond growth with boron addition

Abstract

Diamond coatings were produced on Si substrates by the hot-filament method, with B(C 2H 5) 3 added to the gas phase. Ratios of B(C 2H 5) 3: CH 4 up to 0.01 (10000 ppm) were used which gave boron concentrations up to 3% in the layer according to secondary ion mass spectrometry (SIMS) and elastic recoil detection (ERD) measurements. The characteristic Raman peak of diamond at 1332 cm −1 decreases with increasing boron incorporation. Studying this effect in detail shows that on (100) facets the Raman peak still can be observed while on (111) it is already severely deteriorated. TEM and localized EELS spectra show high boron incorporation in the (111) growth sectors and low boron concentration in the (100) sectors. With cathodoluminescence spectroscopy measurements electronic properties were determined. The Mott-transition from semiconductor to metal-like conduction was found to occur at 0.11% B, which is in agreement with published Hall-measurements.