高崩潰電壓磷化銦鎵通道場效電晶體之研發

Abstract

摘 要 本論文之實驗研究目的是在製作具有高能隙之磷化銦鎵通道的場效電晶體，以期能達到高崩潰電壓與高輸出功率之特性，符合下一代微波無線通訊在高功率放大器模組之需求，同時藉此研發建立本實驗室製程條件與元件製程的穩定性。 本實驗中嘗試製程條件的最佳化並克服縮小元件尺寸後製程的難度，製作出高能隙之磷化銦鎵通道的金-半場效電晶體，而此電晶體在直流特性達到預期的結果，尤其是在崩潰電壓上更是有優異的表現，閘極寬度為125μm的元件具有108 mA/mm的最大電流密度以及55V的閘極-汲極崩潰電壓( gate-to-drain breakdown voltage )，–5V的截止電壓 ( pinch-off voltage ) 和最大互導係數( transconductance )為36 mS/mm；在本研究中，亦獲得極佳之製程的穩定性與再現性。 因此，本實驗驗證了研發出之製程有極佳穩定性，同時高能隙磷化銦鎵通道的金-半場效電晶體具有優異的崩潰電壓，此結果將能應用在高輸出功率放大器上，期能對無線通訊系統的功率放大器發展上有所助益。

Abstract A high breakdown voltage InGaP channel metal-semiconductor field-effect transistor ( MESFET ) has been developed in this study. The device is designed for the high output power amplifier application for wireless communication. The DC characteristics of the InGaP MESFETs and the GaAs MESFETs were measured. For the InGaP MESFETs, the device exhibited a saturation current density of 108 mA/mm with a gate to drain breakdown voltage of 55 volts. The maximum transconductance gm of the device was 36 mS/mm, and the pinch-off voltage was –5 volts. On the other hand, the GaAs MESFETs exhibited a saturation current density of 200 mA/mm with a gate-drain voltage of 39 volts. The maximum transconductance gm of the device was 98 mS/mm, and the pinch-off voltage was –1.6 volts. The fabrications of InGaP MESFETs and GaAs MESFETs were successful. The high band-gap InGaP channel metal-semiconductor field-effect transistor has a high breakdown voltage and it could be used for the high power amplifier application. The InGaP channel MESFETs developed has a good potential for the application in the power amplifier for wireless communication.