LOW-TEMPERATURE DEPOSITION OF OPTICALLY TRANSPARENT DIAMOND USING A LOW-PRESSURE FLAT FLAME

The radial uniformity and scaleable nature of flat flames make them an attractive technique for diamond deposition. Due to the high temperat ures involved in combustion synthesis, typically molybdenum and silico n have been used as substrates. Here we report low-temperature diamond deposition on glass substrates. Diamond deposition was achieved on or dinary sodium silicate glass at substrate temperatures of similar to 5 00 degrees C; however, film delamination occurred during cooling after deposition. Vycor(R) and Pyrex(R) are two glasses that have thermal e xpansion coefficients that are similar to diamond. Continuous, optical ly transparent films were successfully deposited on both glasses. The diamond films have been characterized by scanning electron microscopy, Raman spectroscopy and secondary ion mass spectroscopy (SIMS). The de pendence of hydrogen and sp(2)-bonded carbon incorporation in the film s on reactant composition was quantified. These films were optically t ransparent and showed good adhesion as measured by a simple tape test. (C) 1997 Elsevier Science S.A.