超高真空中使用的高纯过渡金属蒸发源

设计了一种超高真空使用的低电流过渡金属蒸发源 ,它能产生高纯金属原子束 ,且具有一定的寿命。该蒸发源是将过渡金属Co,Ni或Cr电镀到一个由W丝弯成的U形加热器上构成的。装入超高真空中 ,利用W丝自身的电阻加热 ,去气后 ,可获得数小时的清洁蒸发。实验结果表明 ,在离蒸发源约 5cm处 ,其淀积速率最高可达 1 0nm/min ,总的淀积厚度超过 5 0 0nm ,而且Auger分析结果显示 ,在超高真空中淀积的上述几种过渡金属薄膜 ,其纯度相当高 ,杂质含量均小于仪器的检测灵敏度。本文详细介绍了这种过渡金属蒸发源的制作技术及性能

High-purity Transition Metal Evaporation Source for UHV

We have developed a simple technique for preparing low current evaporation source of transition metal that can produce high purity atomic beams with good lifetimes.The evaporation source is constructed by electroplating metal,such as cobalt,nickel or chromium,onto a Tungsten wire bent into a U shape.Then,the evaporation source is mounted in an ultrahigh vacuum system and heated resistively in situ.After initial out gassing,we have found that many hours of clean evaporation can be obtained with this type of evaporation source.Experimental results showed that at 5 cm from the evaporation source,deposition rate up to 10 nm/min have been obtained,with total deposition thickness in excess of 500 nm.Auger analyses of the metal films deposited in ultrahigh vacuum showed that impurities were below detectable sensitivity (1% atomic concentration).In this paper,we will introduce the technique in detail.