发表机构
Cardiff University（卡迪夫大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在4英寸硅晶圆上通过微波等离子体CVD生长超导硼掺杂金刚石，发现B/C比影响超导转变温度，最高T_c为4.03 K，并验证了大面积生长的可行性。
AI 中文摘要
通过微波等离子体化学气相沉积法，在4英寸硅晶圆上生长了超导硼掺杂金刚石（BDD）薄膜，气相B/C比范围为6536至36421 ppm。研究了表面形貌、硼掺入量及超导性能随气相硼浓度的变化。在整个系列中，表观横向晶粒尺寸未观察到系统性变化。在测量温度低至2 K的范围内，除B/C比为6536 ppm生长的薄膜外，所有薄膜均观察到超导性。超导转变温度随B/C比的增加先升高，在24691 ppm时达到最大T$_c$为4.03 K，随后在更高气相B/C比下降低。相应的2 K电阻性上临界场达到3.091 T。拉曼光谱显示，硼掺入量随气相B/C比增加至30303 ppm而增加，随后在36421 ppm时略有下降。对24691 ppm生长的薄膜进行空间测量，中心、中间和边缘位置的T$_c$值分别为4.02、4.19和3.33 K，拉曼光谱显示硼浓度存在相应的空间变化。与之前在2英寸晶圆上的生长相比，在4英寸晶圆上获得相当的硼浓度和超导性能需要显著更高的气相B/C比，表明大面积生长期间硼掺入效率降低。这些结果证明了在4英寸硅晶圆的大面积上生产超导BDD的可行性，同时确定硼掺入和径向均匀性为进一步晶圆级优化的关键参数。
英文摘要
Superconducting boron-doped diamond (BDD) films were grown on 4-inch silicon wafers by microwave plasma chemical vapour deposition using gas-phase B/C ratios ranging from 6536 to 36421 ppm. Surface morphology, boron incorporation and superconducting properties were investigated as a function of gas-phase boron concentration. No systematic variation in apparent lateral grain size was observed across the series. Superconductivity was observed in all films except that grown at a B/C ratio of 6536 ppm within the measured temperature range down to 2 K. The superconducting transition temperature initially increased with increasing B/C ratio, reaching a maximum T$_c$ of 4.03 K at 24691 ppm, before decreasing at higher gas-phase B/C ratios. The corresponding resistive upper critical field at 2 K reached 3.091 T. Raman spectroscopy showed an increase in boron incorporation with increasing gas-phase B/C ratio up to 30303 ppm, followed by a slight decrease at 36421 ppm. Spatial measurements across the film grown at 24691 ppm showed T$_c$ values of 4.02, 4.19 and 3.33 K at the centre, intermediate and edge positions, respectively, with Raman spectroscopy showing a corresponding spatial variation in boron concentration. Comparison with previous growth on 2-inch wafers showed that substantially higher gas-phase B/C ratios were required to obtain comparable boron concentrations and superconducting properties on 4-inch wafers, indicating reduced boron incorporation efficiency during large-area growth. These results demonstrate the feasibility of producing superconducting BDD over a substantial area of a 4-inch silicon wafer while identifying boron incorporation and radial uniformity as key parameters for further wafer-scale optimisation.
