臺灣博碩士論文加值系統

　　本篇論文主要探討超薄氧化層p型金氧半穿隧閘二極體元件在正偏壓之下，其飽和電流受到鄰近閘極電壓之影響與其應用。我們利用同心圓電極圖案的元件來量測飽和電流受到鄰近電極的影響，即飽和電流會受到周邊因電子濃度分布而造成的擴散電流而改變，透過側向電子電流的補充，元件周邊的氧化層壓降增加，使得電洞的蕭基特（Schottky）位障降低，造成大量的電洞電流流過元件周邊，使得飽和電流增大，且因此可以利用周邊電極來改變飽和電流。
　　在第二章中，我們探討 Al/SiO2/Si ｐ型金氧半穿隧二極體元件在較大的正偏壓之下產生的自我保護之局部變薄現象。經過較大的正偏壓之後再進行量測時，其正偏壓電流仍會飽和，並且電流飽和對應到的電壓變小。此外，金氧半穿隧閘二極體元件中心的穿隧二極體經過正偏壓後，我們發現元件中心電流仍然能夠被周邊電極控制，且我們可藉由氧化層等效局部變薄來提升金氧半穿隧閘二極體元件的轉移電導的靈敏度和電流開關比。
　　在第三章中，我們探討鄰近的元件氧化層的電子抓陷現象影響中心元件正偏壓下之飽和電流。在第一部分中，我們發現在Al/SiO2/Si ｐ型金氧半穿隧二極體元件中，正偏壓的飽和電流亦具有兩態現象。第二部分則是解釋電流的兩態現象機制。在第三部分中，我們利用讀寫分離的方法與同一電極讀寫來比較兩態的保存性。讀寫分離的方法可以增進兩態的保存性，在第四部分中，由於Al/Al2O3/HfO2/SiO2/Si (AHO）結構較不易使電子流失，我們製備該結構並發現該結構在保存性上比純二氧化矽結構具有更優異的表現。對於超薄的氧化層而言，使用閘極耦合結構與AHO堆疊的氧化層結構有益於記憶體的應用。
　　在第四章，我們將對論文進行總結，並且提出一些未來的研究與方向去增進p型金氧半穿隧閘二極體元件的電特性。

In this thesis, we demonstrate the ITD-VTD of gated-MIS(p) tunnel diode with ultrathin oxide under positive voltage bias is affected by the voltage on remote gate and the applications. The pattern which consists of an inner circle and a concentric ring is used to measure the saturation current affected by adjacent electrode. In other words, the saturation tunneling current is changed by the lateral diffusion current which was caused by the gradient of electron concentration. By the supplement of the lateral diffusion current, the voltage drop at the edge of oxide increases, and the Shottky barrier height of hole decreases, which lead to large hole current at the edge of MIS(p) tunnel diode and the increase of saturation tunneling current. Thus, the tunneling saturation current could be control by neighboring electrode.
In chapter 2, the self-protective local thinning effect of Al/SiO2/Si MIS(p) tunnel diode under high positive voltage stress is discussed. After high positive voltage stress, the I-V curve is still saturated under inversion region, which is different from the breakdown behavior under negative voltage bias, and the tunneling current is saturated early. In addition, for gated-MIS tunnel diode, after positive voltage stress at the center MIS tunnel diode, the saturation current is still controlled by nearby electrode, and the transconductance sensitivity and the on/off current ratio are strongly enhanced by the creation of effective local thinning.
　　In chapter 3, the saturation current in positive voltage bias which is affected by the electron trapping in the remote gate oxide is discussed. In the first part of this chapter, the two states phenomenon of the saturation current on Al/SiO2/Si (SiO2 structure) gated-MIS(p) tunnel diode is demonstrated. In the second part, the mechanism of the two states is explained. In the third part, the retention by separation of read and write operation is compared with it by not separation. The retention of two states phenomenon can be enhanced by separation of read and write operations. In the fourth part, because of low charge loss, the structure Al/Al2O3/HfO2/SiO2/Si (AHO structure) is fabricated. It is demonstrated that the retention of AHO structure is better than it of SiO2 structure. For the ultra-thin oxide device, using gate coupling structure and AHO stack oxide are believed to be useful for memory application.
In chapter 4, we summarize the thesis and give some future works for the improvement of the electrical characteristics of gated-MIS(p) tunnel diode.

Abstract (Chinese)……………………………………………………........................I
Abstract (English)…………………………………………………….......................II
Contents………………………………………………………………......................IV
Figure Captions………………………………………………………......................VI
Table Captions………………………………………………………........................IX
Chapter 1 Introduction…………………………………………………......................1
1-1 Motivation……………………………………………………...................1
1-2 Mechanism of Inversion Current in MIS(p) Tunnel Diode.…....................3
1-3 Effect of Electron Diffusion Current in Tunneling Current…....................5
1-4 Anodization System…………………………………………....................6
1-5 Determination of Dielectric Thickness………………………....................7
1-6 Summary…………………………………………………….....................9
Chapter 2 Effects of Oxide Thickness and Neighboring Device Coupling in MIS(p) Inversion Tunneling Current……………...…….......................................................19
2-1 Introduction……………………………………………...……....................19
2-2 Experiments……………………………………………...……...................20
2-3 Results and Discussion……………………………...………......................21
2-3-1 Current Behavior of the Tunnel Diode with Thicker Oxide................21
2-3-2 Local Thinning Effect in MIS Tunnel Diode.......................................22
2-3-3 Neighboring Device Coupling.............................................................24
2-4 Summary……………………………………………..……….....................26
Chapter 3 Two States Phenomenon Induced by Neighboring Device Coupling Effect in MIS(p) inversion Tunneling Current…………..........................................34
3-1 Introduction………………………………………….………......................34
3-2 Experiments…………………………………………..……........................36
3-3 Results and Discussion……………………………………….....................37
3-3-1 Two State Inversion Tunneling Current Behavior in Gated-MIS
Tunnel Diode..................................................................................37
3-3-2 Mechanism of the Two State Inversion Tunneling Current in
Gated-MIS Tunnel Diode...………….............................................38
3-3-3 Improvement of Retention in Gated-MIS Tunnel Diode.................39
3-3-4 Improvement of Retention by Dielectric of AHO Stacks................40
3-4 Summary…………………………………………..………….....................41
Chapter 4 Conclusion and Future Work……………..………………......................51
4-1 Conclusion……………………………………………………....................51
4-2 Future Work…………..………………………………………....................52
References……………………………….….………………………….....................56

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