An experimental study of the temperature and stoichiometry dependence of diamond growth in low pressure flat flames

Abstract

A study of the temperature and stoichiometry dependence of diamond synthesis in low pressure premixed acetylene-oxygen flames is presented. A specially designed low pressure flat flame operating at 40 Torr is employed to deposit diamond films uniformly over areas of at least 2 cm2. Under optimized conditions of substrate temperatures and flame equivalence ratios, high quality translucent diamond that is well faceted is synthesized exhibiting first-order Raman fullwidths (half maximum) of about 2.5 cm−1. Diamond growth rates under these optimum conditions are approximately 4 μm/h. The film growth rate is found to drop off substantially at high substrate temperatures, with little or no carbon deposited beyond a temperature of 1070 °C. The growth behavior in response to changes in flame equivalence ratio and substrate temperature is discussed in terms of the possible role that oxygen-containing species may have on surface chemistry. The results described here are also used to project a base cost for manufacturing diamond under these process conditions.

In situ mass spectrometry during diamond chemical vapor deposition using a low pressure flat flame

“…A number of researchers [1][2][3][4][5][6] have experimentally demonstrated high rate diamond synthesis using premixed flat flames. Large area uniformity has been demonstrated in both atmospheric 1,2 and reduced pressure systems.…”

“…[3][4][5] Recently, we demonstrated that growth morphology can be controlled in this system, allowing the production of high quality ͗100͘ textured films. [3][4][5][6] The stagnation flow geometry may be accurately described using a one-dimensional similarity solution, 7 permitting the development of detailed chemical kinetic models. [3][4][5][6] The stagnation flow geometry may be accurately described using a one-dimensional similarity solution, 7 permitting the development of detailed chemical kinetic models.…”

The influences of reactant composition and substrate material on the combustion synthesis of diamond

“…The ability to uniformly deposit high quality diamond over significant areas has been demonstrated by a number of groups using flat-flame burners operated at both atmospheric 1,2 and reduced 3,4 pressure. The two most critical variables in combustion CVD of diamond are reactant composition and substrate temperature.…”

Diamond film synthesis in low-pressure premixed methane-oxygen flames

“…12,18 A schematic of the facility is illustrated in Fig. The low-pressure flat-flame facility is the same as that which we employed to study diamond film synthesis in low-pressure acetylene-oxygen and ethylene-oxygen flames.…”

“…The low-pressure flat-flame facility is the same as that which we employed to study diamond film synthesis in low-pressure acetylene-oxygen and ethylene-oxygen flames. The background pressure and substrate-to-burner distance used here is approximately twice that used in our previous acetylene-oxygen 12 and ethylene-oxygen studies. 1.…”