研究了在高阻硅衬底上Al/AlOx/Al隧道结的制备技术,采用电子束蒸发制备Al/AlOx/Al三层材料,湿法刻蚀制备底电极和上电极以及电路连线,PECVD法生长绝缘层(SiO2)保护超导隧道结,RIE刻蚀上电极窗口。在400mK温度下测量了Al/AlOx/Al隧道结样品,得到了较好的隧道结I-V曲线,能隙电压增为0.325mV,超导临界电流Ic为55nA,漏电流为5nA。
Al/AlOx/Al tunnel junctions were fabricated on high resistivity silicon substrate. The Al/AlOx/Al layers were deposited by electron beam evaporation, and the base and top electrodes or circuit connection lines were defined by chemical wet etching. The two layers of A1 were deposited by electron beam evaporation and the barrier layer was fabricated by delivering oxygen after the first layer of A1 was deposited. Insolation layer( SiO2 ) was prepared by PECVD to protect junctions, while top electrode window was opened by RIE. We measured Al/AlOx/Al tunnel junction samples at 400mK, and obtained the preferable I - V curve of tunnel junction, which shows that gap voltage as 0. 325mV, critical current Ic as 55hA and leakage curent as 5nA.