Исследование влияния содержания водорода на проводимость нанокристаллических алмазных пленок

The results are presented for investigation of electrical conductivity of nanocrystalline diamond (NCD) films with thickness of 0.5-0.6 microns grown on silicon Si(100) substrate by CVD method using methane-hydrogen and methane-hydrogen-oxygen mixtures. By method of heating in vacuum with use of hydrogen analyzer AB-1 the concentration of hydrogen in the studied films was determined and the relationship between the content of hydrogen in the NCD film and its conductivity was estimated. It was shown that high-temperature processing in vacuum at temperature 6000 C leads to desorbtion of hydrogen from the films and a significant increase in their resistance.

Highly Conductive Nanocrystalline Diamond Films and Electronic Metallization Scheme

By using a methane and hydrogen process gas mixture in an appropriate hot-filament CVD process without further dopant, high electrical conductivity of over 100 S/cm has been achieved in nanocrystalline diamond films deposited on silicon single-crystalline substrates. Furthermore, it was found that an oxygen reactive-ion etching process (O-RIE) can improve the diamond film surface’s electron affinity, thus reducing the specific contact resistance. The reduction of the specific contact resistance by a factor of up to 16 was realized by the oxygen ion etching process, down to 6×10−6 Ωcm2 We provide a qualitative explanation for the mechanism behind the contact resistance reduction in terms of the electron affinity of the diamond surface. With the aid of XPS, AFM, and surface wetting measurements, we confirmed that a higher surface electron affinity is responsible for the lower specific contact resistance of the oxygen-terminated nanocrystalline diamond films.