本論文主題在於製作以及研究單電子電晶體及其相關之應用。首先，我們使用矽鍺圖案相依性的氧化行為以及氣相化學沉積(CVD)沉積薄膜的穩定性已經成功展示以一個有組織性的方式精準地在電極間放置單一顆鍺量子點並且以對稱的二氧化矽/氮化矽複合式之穿隧介電層相隔。為了能更有效率地以選擇性氧化被定義圖案的矽鍺結構之方式來實現一顆鍺量子點單電子電晶體，以電子束微影定義圖案和以蝕刻整修溝渠形貌此兩項技術必須被最佳化設計。利用上述的技術，我們研發出一個擁有11奈米大小鍺量子點的單電洞電晶體。在溫度為凱氏溫度77度到150度的區間，此單電洞電晶體在閘極與汲極偏壓的調變下展示了沒有背景雜訊的庫侖振盪以及有著明顯節點的菱形圖。此結果意味著單電洞電晶體提供了一種方式，能透過載子穿隧量子點分裂能階的頻譜來解析量子點內部電子能階。 另一方面，基於鍺量子點單電洞電晶體在少數電洞的狀況下微分轉導(GD)突出的溫度相依性，鍺量子點溫度量計已經被展示出。微分轉導所形成的波谷萃取出的半高寬(V1/2)與量子點內的電子數(n)以及溫度(T)呈現一個線性的關係，此關係為eV1/2 (1-0.11n)5.15kBT，此關係式提供了檢測溫度的一個基準量。另外，微分轉導所形成的波谷萃取出的深度與量子點充電位能及溫度的倒數成一個比例關係，此關係式為GD EC/9.18kBT，提供了檢測溫度的另一個基準量。這些實驗上的結果以表示我們所研製的單電洞電晶體確實是能作為一個奈米溫度量計，去偵測出量子點中的溫度變化。而且擁有10奈米大小鍺量子點的單電洞電晶體所能偵測到的最高溫度為凱氏溫度155度。並且偵測溫度的精準度能達到千分之一度以下。;In this thesis, fabrication and characterization of germanium (Ge) quantum-dot (QD) single-electron transistors (SETs) as well as the associated applications were investigated. Using the fidelity of spacer-layer deposition and nanopattern-dependent oxidation of SiGe we have demonstrated the precise placement of a single Ge QD between nanoelectordes through symmetrical tunneling barriers of Si3N4/SiO2 in self-organized approach. In order to effectively realize a Ge-QD SET using selectively oxidizing SiGe patterned structure, the lithographical patterning and etching profile of the nanostructure are to be optimally designed. The fabricated 11-nm Ge-QD SHT exhibits clear Coulomb oscillation and Coulomb diamond features under gate and drain modulation from T = 77 K to 150 K, providing a way to resolve the electronic structure of the QD through tunneling spectroscopy. On the other hand, Ge-QD thermometry has demonstrated based on extraordinary temperature-dependent oscillatory differential conductance (GD) characteristics of Ge-QD SHTs in the few-hole regime. Full-voltage width-at-half-minimum, V1/2, of GD valleys appears to be fairly linear in the charge number (n) within the QD and temperature in a relationship of eV1/2 (1-0.11n)5.15kBT, providing the primary thermometric quantity. The depth of GD valley is proportional to charging energy (EC) and 1/T via GD EC/9.18kBT, providing another thermometric quantity.The experimental results reveal that our Ge-QD SHT truly paves an affirmatory path for nanothermometry to measure temperature in the local QD with detection temperature as high as 155 K with temperature accuracy of sub-millikelvin in a spatial resolution on the order of the QD size (~10 nm).
