基於光與偏壓控制耦合之同心環狀金氧半穿隧二極體結構的邏輯閘設計

Abstract

本論文探討同心環金氧半穿隧二極體結構中的電壓與電流耦合行為，並進一步分析其於可重構邏輯閘之應用潛力，研究中製作並比較了兩種結構：一般平面元件與去除邊緣氧化層元件。 第二章中，針對中心與外環之間的耦合機制進行分析，實驗顯示，當適當固定中心偏壓與調整外環電壓時，因穿隧電子流與橫向耦合電子流之間的競爭，中心電流可能出現極性反轉現象，此為邏輯閘運作的基礎，並且針對此現象做理論解釋以及證實了該種邏輯閘的低功耗。第三章中，引入可見光作為額外控制參數，照光產生額外光生載子，進一步調變橫向耦合電子流，實現以光控制的電流極性轉換，從實驗結果可得出，一般平面結構元件在不同光照條件下展現穩定且明確的邏輯切換；相較之下，去除邊緣氧化層結構元件在強光下且所有外環接地時，中心電流無法維持穩定極性，導致邏輯判別不明確，限制其邏輯應用的穩定性。另外，一般平面結構元件在不同輸入與照光條件下皆具有低功率密度，並於連續切換操作下維持穩定輸出，顯示良好的耐久性。第四章中，總結了上述結果，並且提出此研究未來方向之建議。

This thesis investigates the voltage-current coupling behavior in concentric ring metal-insulator-semiconductor tunnel diode (MISTD) structures and further analyzes their potential applications in reconfigurable logic gates. Two types of device structures were fabricated and compared: the planar structure and the edge-removed structure. In Chapter 2, the coupling mechanism between the center and the ring was analyzed. Experimental results show that when the center bias is appropriately fixed and the ring voltage is adjusted, the competition between tunneling electron flow and lateral coupling electron flow can lead to polarity switch in the center current. This phenomenon serves as the basis for logic gate operation. Theoretical explanations were provided, and the low power characteristics of such logic gates were confirmed. In Chapter 3, visible light was introduced as an additional control parameter. Illumination generates additional photogenerated carriers, further increasing the lateral coupling electron flow and enabling light-induced current polarity switching. The experimental results demonstrate that the planar structure exhibits stable and distinct logic transitions under varying illumination conditions. In contrast, the edge-removed structure fails to maintain stable current polarity under strong illumination when all rings are grounded, leading to ambiguous logic states and limited stability in logic applications. The planar structure shows low power density across different input and illumination conditions and maintains stable output under repeated switching operations, confirming its stability. Chapter 4 summarizes the findings and provides suggestions for future research directions.