Low-temperature synthesis of diamond films in thermoassisted rf plasma chemical vapor deposition

The synthesis of diamond films using radio-frequency (13.56 MHz) glow discharge plasma chemical vapor deposition (CVD) is investigated. A variety of films are prepared from a mixture of ethyl alcohol-and hydrogen; and they are evaluated using Raman spectroscopy. Diamond films grow when external heating is used in combination with the radio-frequency glow discharge. The films grow at temperatures between 350 and 800°C. In this temperature range, film of reasonable quality is obtained at 550 approximately 600°C. The diamond grows even at the low temperature of 350°C although it contains a few nondiamond carbons. These temperatures are considerably lower than those generally regarded as the optimal regime for diamond growth.