在本文中，我們使用磷化銦鎵/砷化鎵異質結構，來探討自行對準T型閘駝峰式場效電晶體。和傳統的駝峰式場效電晶體比起來，以磷化銦鎵/砷化鎵異質結構低參雜之通道，來做成一高行能駝峰式二極體，而能表現出高位障之特性。在者，高參雜之磷化銦鎵層被使用來加強轉倒值，且改善元件的線性度。藉由磷化銦鎵/砷化鎵層之高選擇性蝕刻，磷化銦鎵/砷化鎵異質結構之過蝕刻製程，提供自行對準T型閘與短閘極寬度之可行性。其次，由於所探討結構之降低寄生電阻與電容，高頻特性可獲得改善。此外，P型磷化銦鎵層之高導帶不連續特性，可使電子侷限能力更好，此可克服因自行對準T型閘駝峰式場效電晶體所伴隨之小崩潰電壓問題。以此材料與有效閘極寬度為1.5×100 (0.6×100) 平方微米，其得自2×100 (1×100) 平方微米之閘極金屬長度。此可知外質轉倒為78 (80) mS/mm，單位功率增益頻率為9 (19.5) 和 28 (30) GHz。

In this thesis, we present the performance of self-aligned T-gate camel-diode field effect transistors using n+-GaAs/N+-InGaP/d(P+)-InGaP/n-GaAs heterojunction structure. As compared with the conventional CAMFET
, a low-doped active channel along with n+-GaAs/N+-InGaP/d(P+)-InGaP layers is used to form a high-performance
camel diode, which exhibits a large potential barrier. In addition, the n+/N+/d(P+) layers doped heavily are used to
enhance the transconductance, and to improve the device linearity. By highly selective etch between the InGaP and
GaAs layers, the fabrication of over-etching n+-GaAs/N+-InGaP structure is employed to offer the implement of
self-aligned T-gate with a reduced gate length. And next, due to the reduced parasitic resistance and capacitance of
this studied structure, the improved frequency-performances are obtained.Moreover, the d(P+)-InGaP layer offers
a high valence band, offset potential as a barrier of hole; as well as an enhanced conduction band, for better election
confinement, which overcome the inherent problem of small breakdown voltage associated with the structure of
the self-aligned T-gate camel-diode heterojunction field effect transistors. A fabricated device using this material
structure with effective gate dimension of 1.5’100 (0.6’100) um2 obtained from 2’100 (1’100) um2 gate
metal length. It is found to have an extrinsic transconductance, unity-current gain frequency, and unity-power gain
frequency of 78(80) mS/mm, 9 (19.5), and 28 (30) GHz, respectively.

Abstract
Table Captions
Figure Captions
Chapter 1 Introduction
Chapter 2 Investigation of Self-Aligned T-gate
2-1 Introduction
2-2 Device Fabrication
2-3 Experimental Results and Discussion
2-4 Conclusions
Chapter 3 InGaP/GaAs CAMFET using n+/N+/d(P+)/n structure
3-1 Introduction
3-2 Device Structure and Fabrication
3-3 Experimental Results and Discussion
3-4 Theoretical Consideration and Analysis of CAMFET
3-5 Conclusions
Chapter 4 Conclusions and Expectations
References
Figure Captions

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