高温超导约瑟夫森结工作在液氮温区，制冷成本低，可应用于超导量子干涉器件、量子电压标准器件等。热蒸发方法在SrTiO₃双晶衬底上生长了钇钡铜氧（YBCO）/金（Au）双层膜，通过紫外光刻、离子束刻蚀等技术制备出YBCO双晶约瑟夫森结。在液氮温区测量了YBCO双晶约瑟夫森结的电阻-温度（R-T）特性曲线和不同温度下的电压-电流（V-I）特性曲线。从R-T曲线观察到制备的YBCO双晶约瑟夫森结有明显的电阻拖尾现象。通过几何平均法，选择合适数据范围，用双曲函数拟合方法，消除噪声圆化效应和自热效应对临界电流的影响，得到高温超导约瑟夫森结的本征临界电流值和正常态电阻。将测得V-I数据进行本征临界电流拟合对比，发现每个YBCO双晶结中均出现明显噪声圆化效应。4 μm，6 μm，8 μm，10 μm宽的YBCO双晶结受自热效应影响较小，仅有2 μm宽YBCO双晶结受自热效应影响较大。

The benefits of the high-temperature superconducting Josephson junction works in the liquid nitrogen temperature region， and has low cooling cost， so it can be applied to superconducting quantum interference devices， quantum voltage standard devices， etc. We fabricated yttrium-barium-copper-oxygen （YBCO） / gold （Au） bilayer film on SrTiO₃ bicrystal substrate， and prepared YBCO bicrystal Josephson junction by ultraviolet lithography and ion beam etching. The resistance-temperature （R-T） characteristic curves and voltage-current （V-I） characteristic curves of the YBCO bicrystal Josephson junction were measured in the liquid nitrogen temperature region. From the R-T curve， it was observed that the prepared YBCO bicrystal Josephson junction had obvious resistance tailing. The intrinsic critical current value of the high-temperature superconducting Josephson junction was obtained by using the geometric averaging method from selecting the appropriate data range and applying a hyperbolic function fitting method to eliminate the influence of noise rounding effect and self-heating effect on the critical current. After fitting the intrinsic critical current from the selected V-I data， noticeable noise rounding effects were observed in each YBCO bicrystal structure. Only the 2 μm-wide YBCO bicrystal structure showed significant susceptibility to self-heating effects， whereas the 4 μm， 6 μm， 8 μm， and 10 μm-wide YBCO bicrystal structures exhibited minor influence from self-heating effects.