本論文首先介紹metamorphic HEMT在不同銦含量(In content 30％~60％)的磊晶結構。我們在銦含量為30％的功率型mHEMT的磊晶結構中加入了如pHEMT般的假性通道以增加其電流密度，期望能有更加的功率特性。此外我們在銦含量為50％及60％的高速型mHEMT中再以不同的閘極金屬製作出空乏型(Ti/Pt/Au)以及增強型(Pt/Ti/Pt/Au)的電晶體。利用Pt/Ti/Pt/Au閘極在高溫製程之中會擴散到其蕭特基層的特性，控制閘極金屬到通道層的距離以達到增加門檻電壓的效果，進而實現增強型電晶體的目標。再以本實驗室的量測系統分析各種電晶體在直流、高頻以及功率特性的差異。並由直流量測資料計算出Pt/Ti/Pt/Au閘極的擴散深度，由高頻量測資料分析出電子在增強型以及空乏型電晶體中各個部位的延遲時間以及粹取出兩種電晶體的小訊號參數。藉此來比較此兩種型態的電晶體在高頻特性中的影響。 This paper introduces the metamorphic HEMT in different Indium content. We add the pseudomorphic channel like pHEMT in order to increase the current density and the power performance. Besides that, we try to fabricate the depletion & enhancement mode device using different gate metal in the In=50% & 60% mHEMT samples. We use the Pt diffusion to decrease the distance between the gate metal and channel and enhance the device threshold voltage to reach the enhancement mode device purpose.And we use the measurement system in our lab to measure the difference of DC, RF, Power characteristics. By the measurement data we calculate the diffusion depth of Pt gate and using the RF data to extract the small signal model elements and the electron transient time to analyse the performance difference between depletion and enhancement mode device.
