Diagnosis of Diamond Film Growth

In the past years there have been an increasing number of studies identifying the primary gas-phase diamond growth precursor [65, 67, 80-87] in CVD techniques, which have been the subject of controversy. The growth rate and film quahty of materials synthesized by CVD processes depend critically on the composition of the species generated. 

Maity techniques exist for examining the composition of the species (including radical species) generated in CVD reactors optical emission spectroscopy (OES) [80], FT-IR spectroscopy [81] laser induced fluorescence (LIE) spectroscopy [82], diode laser IR absorption spectroscopy [83], and MS [84-87]. Each has its own strengths and shortcomings. A major advantage of MS over other techniques is its 

A detailed chemical kinetic mechanism was composed to describe the evolution of reaction species [88-92] in the pyrolysis of a hydrogen-diluted CH mixture, simulating the gas-phase conditions of diamond CVD in the MW reactor. Somewhat surprisingly atomic C is predicted [88] to have a large concentration at the surface. C atoms could conceivably play a role in diamond growth [90], 

The lAMS technique is applied in a simulation study of a diamond CVD reactor [93], It is most advantageous when the experimenter does not know a priori what species to expect. A second advantage is its adaptability to a wide variety of process environments. To simulate the reacting plasma environment, a sampling aperture, followed by the skimmer, is fixed at the center of the growth substrate (Fig. 5.8). Mass spectra were obtained (Fig. 5.9) with plasma activation in two modes (i) 

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