利用电子束蒸发制备铝隧道结工艺研究

The research of the fabrication of Al/Al_2O_3/Al superconductor tunnel junctions by electron beam vapour

采用电子束蒸发的方法在Si片上制备超导铝(Al)薄膜。利用X射线衍射和直流四电极电阻法分别测试了厚度从100埃到5000埃的Al薄膜物向组成,超导转变温度(Tc)和临界电流密度(Jc)。当Al薄膜厚度大于500埃时,超导转变温度Tc=1.2K。电子束蒸发制备的Al薄膜性能良好,具有较高的结晶质量,为制备Al超导隧道结奠定了良好基础。对小面积的Al超导隧道结工艺进行了研究,该超导隧道结两层的超导体材料为Al薄膜,中间势垒层材料为Al2O3。其中Al薄膜利用电子束蒸发制备,势垒层通过直接氧化Al薄膜表面实现,该工艺和采用直接蒸发氧化物薄膜工艺相比不仅简单而且能有效防止势垒层不连续造成的弱连接。

Fabricating supeconductor Al film on Si substrate by electron beam vapour. The films with different thickness from 100nm to 500nm were measured by the methods of resistance - temperature and X - rays diffusion（ XRD）, and have the superconducting transition temperature of 1.2K. After successfully fabricating the Al film, we tried to fabricate Al/Al2O3/Al tunnel junctions. Al film was fabricated by electron beam vapour. The insulated layer （ Al2O3 ） could formed achieve by oxidating the surface of Al film. So it could prevent weakly connected efficiently.