低噪声HT_c rf SQUID芯片可控制备的实验研究

针对低内禀噪声要求条件下HTcrf SQUID芯片制备成品率和优质率低等问题,通过对YBCO薄膜的PLD制备工艺参数及所制作的YBCO薄膜性能与微观形貌的观测分析,提出晶界结构的非均匀和不一致性可能是影响低噪声台阶边沿型晶界结制备质量的观点,进而以淀积温度为典型控制参数设计了一组实验,对实验获取的YBCO薄膜和SQUID芯片的性能测试表明:YBCO薄膜生长的三高条件(高淀积温度、高氧分压和高激光能量密度)易造成薄膜表面平整度恶化和晶界构型的不均匀,而选择合适的淀积温度可有效提高SQUID芯片的噪声性能。

Experimental research on the controllable preparation of low noise HTc rf SQUID

Aiming at solving the problem of low production yield and bad quality of HTc rf SQUID chip with low intrinsic noise,this paper studied the relationship between morphology and performances of YBCO thin films prepared with PLD method and claimed that the inconsistency of grain boundary structure might affect the quality of preparing low-noise step-edge grain boundary junction.A set of experiments were conducted under different deposition temperatures and the performance of the YBCO thin films and SQUID chip obtained from the experiments were measured.The results show that the common requirements of high deposition temperature,high oxygen pressure and high laser energy density in the PLD method could lead to roughness of the film surface and inconsistency of the grain boundary structure,and so choosing the proper deposition temperature can effectively improve the noise performance of the SQUID chip.