本論文探討氮化硼（boron nitride, BN）成長於矽（Si）基板上的異質結構特性，並嘗試以此磊晶結構所形成的二維電洞氣（two-dimensional hole gas, 2DHG），研製P型異質場效電晶體。 在實驗部分，我們使用金屬有機化學氣相沉積法（metal-organic chemical vapor deposition, MOCVD）於 Si(100) 基板上成長 BN 薄膜，形成BN/Si 異質結構。藉由低溫霍爾量測，我們發現BN/Si介面在 13 K 至 300 K 溫度範圍內，有極高的電洞濃度，穩定維持在 1.7~2.0 × 1015 cm−2，遷移率則介於 48~54 cm2/V⋅s，不會隨著溫度改變，呈現明顯的2DHG特性，與常見的摻雜(acceptor-doped)電洞不同。 為驗證此結構於元件上的應用潛力，我們製作具閘極控制之 P-channel 高電子遷移率電晶體（Heterostructure Field Effect Transistors, HFET），並進行直流電性量測。元件展現常開（depletion-mode）特性，且具備初步的閘極調變能力，顯示出 BN on Si 結構具備場效應控制特性，有機會應用在寬能隙 CMOS 邏輯電路。 ;This study aims to fabricate a p-channel heterostructure field effect transistor (HFET) with the boron nitride (BN) grown on Si(100) substrates. The BN layer was deposited on a Si (100) substrate using metal-organic chemical vapor deposition (MOCVD). According to the results of low-temperature Hall measurements (13K ~ 300K), the BN/Si interface delivered a stable hole density at 1.7~2.0 × 1015 cm−2, and hole mobility at 48~54 cm2/V⋅s, showing the two-dimensional hole gas (2DHG) behavior. The result is not attainable with the holes by acceptor doping, which exhibiting strong temperature dependence. To explore the possibility in device applications, the BN-based p-channel HFETs were fabricated and characterized by DC measurements. The device exhibited the depletion-mode characteristics and demonstrated limited gate modulation capability. The result indicates that the 2DHG at BN/Si can be controlled by gate voltage, showing a potential for wide-bandgap CMOS logic circuits.
