Fabrication study of multiply connected SETs by sequential depositions of semiconductor and insulator

我们研究了通过将半导体和绝缘体连续沉积到纳米孔中的多连接集。这套装置是在硅衬底上的多晶硅反应离子刻蚀(RIE)和随后的干式氧化以缩小孔直径形成的硅纳米孔中形成的。量子点的制备是通过交替进行Si LPCVD淀积、刻蚀和氧化的顺序来实现的。最后，我们制作了多个带有侧栅的Q点，并测量了其电学特性。不幸的是，大多数器件在顶栅和点之间表现出严重的泄漏电流。失效机制被认为是由于使用CDE的蚀回工艺的重现性较差。采用RIE刻蚀回刻法研究了减小漏电流的交替方法，得到了抑制漏电流的方法。然而，最初提出的SET的制备工艺难以均匀地控制点的尺寸，进一步研究了利用阳极氧化的铝纳米孔阵列的替代方法，并提出了一种制备二维SET阵列的新方法。

We have studied the multiply connected SETs by sequential depositions of semiconductor and insulator into a nano holes. This SET is formed in a Si nano hole which is formed by RIE (reactive ion etching) of polysilicon on Si substrate and subsequent dry oxidation to shrink the hole diameter. Quantum dots are fabricated by alternating sequence of Si LPCVD deposition, etching-back, and oxidation. Finally, we have fabricated multiple Q-Dots with a surrounding side gate, and measured electrical characteristics. Unfortunately, the most devices exhibited serious leakage current between a top gate and dots. The failure mechanisms are considered to come from poor reproducibility of etching-back process using CDE. Al ; ternative approach to reduce leakage current was investigated by RIE etching-back, and suppression of the leakage current was obtained. However, the initially proposed fabrication process of SETs have difficulties in controlling dots size uniformly, and alternative approach using anodically oxidized aluminum nano holes array was investigated further, and a new methods to fabricated two dimensional array of SETs is proposed.