Arrays of pn junctions have been fabricated with n-Si microneedles. In situ doping vapor–liquid–solid (VLS) growth has been carried out with p-Si substrate having metallic catalyst (Au) dots on its surface, using Si₂H₆ and PH₃ for supplying Si and phosphorus to fabricate n-Si microneedles on the surface of p-Si substrate in vertical direction; thus, pn junctions have been fabricated at microneedle-substrate interface. These n-Si microneedles have been grown at the temperature of 680 C, which is about 420 C less than the temperature (at least 1100 C) required by conventional diffusion method of doping. In this work, n-Si microneedles have been successfully fabricated with 100% yield, the highest success ever for n-type VLS growth in micro range. The position and size of these n-Si microneedles are controllable. These n-Si microneedles are highly conductive. Physical and electrical characteristics of n-Si microneedles have been investigated by varying Au dot size and the level of phosphorus doping. The properties of interface pn junction have been investigated and compared with standard diode characteristics and theoretical results. Highly conductive n-Si microneedle arrays, embedded with interface pn junctions, might be used for collecting and processing bio-signals, profiling temperature/pressure inside living cells and many other sensor applications.

已经用 n-Si 微针制造了 pn 结阵列。使用 Si ₂ H ₆和 PH ₃在表面具有金属催化剂 (Au) 点的 p-Si 衬底上进行了原位掺杂气-液-固 (VLS) 生长供给Si和磷，在p-Si衬底表面垂直方向制作n-Si微针；因此，已经在微针-衬底界面处制造了 pn 结。这些 n-Si 微针是在 680 摄氏度的温度下生长的，比传统的掺杂扩散方法所需的温度（至少 1100 摄氏度）低约 420 摄氏度。在这项工作中，n-Si 微针已成功制造，产率为 100%，这是有史以来在微范围内 n 型 VLS 生长的最高成功率。这些 n-Si 微针的位置和尺寸是可控的。这些 n-Si 微针具有高导电性。n-Si 微针的物理和电气特性已经通过改变 Au 点尺寸和磷掺杂水平进行了研究。已经研究了界面 pn 结的特性，并与标准二极管特性和理论结果进行了比较。嵌入界面 pn 结的高导电 n-Si 微针阵列可用于收集和处理生物信号、分析活细胞内的温度/压力以及许多其他传感器应用。