Regensburg 2000 – scientific programme

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HL: Halbleiterphysik

HL 10: Diamant

HL 10.1: Talk

Monday, March 27, 2000, 16:30–16:45, H13

Optical examination of the surfaces of thermochemically polished CVD diamond films — •James A. Weima, Wolfgang R. Fahrner, Reinhart Job, and Alexander M. Zaitsev — FernUniversitaet Hagen, FB Elektrotechnik, Haldener Str. 182, 58084 Hagen

As-grown diamond films of both mechanical and optical grade, produced by the microwave plasma enhanced chemical vapor deposition (CVD) technique were polished using the thermochemical polishing apparatus. Stylus profilometer measurements done before polishing revealed that the average surface roughness of the films were 25 and 7 microns on the growth and substrate sides, respectively. The surface morphologies of the films were investigated by the optical microscope and the scanning electron microscope (SEM) before and after polishing. Atomic force microscopy (AFM) measurements on the final polished surfaces showed that the average surface roughness was thinned down to about 2.1 nm on both sides of the films. Such exceptional smooth polishing is required when diamond substrates are used for the manufacturing of electronic devices. Photoluminescence spectra of defect centers studied with the confocal *LABRAM* micro-Raman spectrometer revealed that the only detectable impurities in the samples were nitrogen with zero-phonon lines at 2.156 eV and 1.945 eV and silicon with a zero-phonon line at 1.681 eV, accompanied by their respective phonon replicas. Depth distribution measurements showed that the silicon defect centers are concentrated on the substrate side of the film while the nitrogen defect centers are almost uniformly distributed throughout the films.