Diamond growth with boron addition

Diamond coatings were produced on Si substrates by the hot-filament method, with B(C2H5)(3) added to the gas phase. Ratios of B(C2H5)(3): CH4 up to 0.01 (10000 ppm) were used which gave baron 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 baron 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. (C) 1998 Elsevier Science Ltd. All rights reserved.