稀土金属抛光金刚石膜技术

Polishing of Thick Free Standing Films by Rare Earth Metals

研究开发了一种快速有效地抛光化学气相沉积（ＣＶＤ）金刚石厚膜的技术。该技术利用化学活性很强的稀土金属镧（Ｌａ）与金刚石（碳）的化学反应，在一定的工艺条件下可对金刚石膜进行有效的抛光。抛光速率的高低与抛光温度有关，在温度大于９００℃时抛光效率较高，可达３４μｍ／ｈ，表面粗糙度可从原来的Ｒａ１２μｍ降至Ｒａ１．６μｍ，如用于后续的精抛光，可大大减少抛光的时间和提高抛光效率，使表面十分粗糙的金刚石厚膜的精抛光能得以经济地进行。

An effective method for polishing thick free standing diamond films based on the reaction of veryreactive rare earth metals (e. g. La) with carbon (diamond) was studied.It was found that the rate of diamond removal by La largely depended on the polishing temperature. High diamond removal rate was achieved at polishing temperatures higher than 900℃. Removal rate as high as 34m/h was observed at 940℃, and the surface roughness was decreased from its original value of Ra 12μm to as low as 1. 6μm.This level of smoothness is idea for subsequent final polishing by mechanical polishing or other method,and is capable of making the most tedious process more effective and economical.