大面积高光学质量金刚石自支撑膜的制备

PREMRATION OF LARGE AREA HIGH OPTICAL QUALITY FREESTANDING DIAMOND FILMS AT GAS RECYCLING MODE

介绍了一种新型的磁控／流体动力学控制的大口径长通道直流电弧等离子体炬，并据此设计建 造了 １００千瓦级高功率 ＤＣ Ａｒｃ Ｐｌａｓｍａ Ｊｅｔ ＣＶＤ金刚石膜沉积系统 讨论了该系统采用的半封闭式 气体循环系统的工作原理。

High power DC Arc Plasma Jet CVD is generally considered as one of the most promising techniques in commercialization of CVD diamond films. However the advantage of high growth rate and high quality could be partially offset by the complexity of the technology and high volume consumption of source gases, in most common cases, argon and hydrogen. A new type of magnetic and fluid dynamics controlled large orifice long discharge tunnel plasma torch is introduced in this paper, based on which a 100kW high power DC Arc Plasma Jet CVD diamond film deposition system has been constructed. A specially designed semi-closed gas recycling system has been incorporated in the high power arcjet, which may allow as much as 90% of the source gases being recycled. The principles of the gas recycling system and experimental results in preparation of large area high optical quality freestanding diamond films have been discussed in detail. It was shown that, by proper design of the plasma torch and optimization of process parameters, it was possible to produce large area thick freestanding diamond films with quality close to natural type lla single crystal diamond by DC Arc Plasma Jet operating at gas recycling mode.