Fabrication of Fine Si Dot PN Junction pn junction and its Pseudo-One Dimensional Quantum Effects

本研究是为了阐明在细硅点上制作的pn结所产生的准一维量子效应。首先，利用FTIR-ATR和XPS相结合的方法研究了氟（F）/氢（H）封端的Si（111）表面反应，建立了用于精细硅点无损伤微细加工的原子层数字刻蚀方法。结果表明，在F原子暴露的初始阶段，F原子不与H原子发生反应而进入亚表面，先以原子态存在，然后以五配位态存在。然而，更多的F原子暴露导致自发蚀刻，造成粗糙的表面。因此，我们研究了与Si反应活性低的F_2分子在H端Si（111）表面的暴露。在10^5L-10^7L的F_2辐照剂量下，SiF的生成达到饱和，首次发现了F/Si体系的自限性反应。下一个，水晶def ...更多信息 用透射电镜研究了离子注入形成直径小于10 nm的Si点pn结所引起的效应。在Si点中观察到As和BF_2两种掺杂情况下的平行于{111}面的位错，以及高剂量BF_2的微孪晶。对于直径小于20 nm的Si点，没有引起缺陷。这可能是由于缺陷通过表面和Si/SiO_2界面扩散而被退火消除的结果。最后，在SIMOX衬底上制作了双栅MOS线和SOI线。在4.2K时，观察到由于库仑阻塞而引起的MOS线栅电压变化的电导振荡。SOI和MOS线都表现出负的磁阻，由于较大的线宽度的干扰效应和正的，由于跳跃传导足够小的宽度。此外，在SOI线中制备了精细的pn结，并且在2.5V和室温下观察到大的负电阻。少

This study was carried out to elucidate the pseudo-one dimensional quantum effects generated from a pn junction fabricated in a fine Si dot. First, fluorine (F) /hydrogen (H) -terminated Si (111) surface reaction was studied employing a combined system of FTIR-ATR and XPS in order to establish an atomic layr digital etching which was used for a damageless microfabrication of fine Si dots. It was made clear that at the initial exposure stage of F atoms, F atoms penetrate into the subsurface without their reaction with the terminated-H atoms, existing as an atomic state first, subsequently as a five-coordinated state. However, more exposure of F atoms led to the spontaneous etching, causing the rough surface. Hence, the exposure of F_2 molecule of low reactivity with Si to the H-terminated Si (111) surface was investigated. The formation of SiF was saturated at the F_2 exposure dose of 10^5L-10^7L Thus, the self-limiting reaction was first found out for the F/Si system. Next, crystal def … More ects induced by an ion implantation was studied by TEM for formation of the Si dot pn junction with a diameter less than 10nm. A dislocation parallel to the {111} plane for both cases of As and BF_2 implantations, and a micro-twin for high dose BF_2 were observed in Si dots. No defects was caused for the Si dot with a diameter less than 20nm. This may resulted form annealing-out of defects via their diffusion through surfaces and Si/SiO_2 interfaces. Finally, the double gate MOS wire and teh SOI wire using a SIMOX substrate were fabricated. The conductance oscillation due to the Coulomb blockade was observed at 4.2K for gate voltage changes in the MOS wire. Both the SOI and the MOS wires demonstrated the negative magneto-resistance due to an interference effect for the larger wire width and the positive one due to a hopping conduction for sufficiently small width. In addition, the fine pn junction in the SOI wire was fabricated and the large negative resistance was observed at 2.5 V and a room temperature. Less