本論文研究主題為以有機金屬化學蒸氣沉積法成長高電子遷移率與低通道電阻之氮化鋁銦/氮化鋁/氮化鎵異質結構於矽基板上，並探討主導氮化鋁銦異質結構電子遷移率之散射機制。為了降低合金散射在氮化鋁銦異質結構中對電子遷移率造成的影響，本研究在氮化鋁銦/氮化鎵之間插入一層氮化鋁二元化合物作為間隔層，阻擋二維電子氣跨入氮化鋁銦位障層。本研究亦探討磊晶條件對氮化鋁銦異質結構電性的影響，在優化磊晶條件之後，試片的表面平坦度可以降低至0.738 nm，在二維電子氣濃度為2.13×1013 cm-2的情況下，載子遷移率可以提升到1360 cm2/V-s，因此成功地達成一個通道片電阻低至215 ohm/sq的氮化鋁銦高電子遷移率電晶體結構。 此外，本研究亦製備了一系列具有不同氮化鎵披覆層厚度與位障層鋁含量的試片，其披覆層厚度與鋁含量分布分別為0 nm 到13 nm與82%到89%。實驗結果顯示，氮化鋁銦異質結構之二維電子氣濃度隨著披覆厚度減少或鋁含量增加而增加，其電子遷移率則隨著電子濃度增加而減少，而界面粗糙的結構，其電子遷移率衰退的幅度較界面平整者顯著。藉由低溫霍爾量測分析推論，具高電子濃度的試片在低溫區其電子遷移率是由界面粗糙散射機制所主導。因此，界面平整度為獲得高二維電子氣濃度氮化鋁銦高電子遷移率電晶體之關鍵要素。 ;This study aims at growing high electron mobility and low channel resistance AlInN/GaN heterostructures on Si substrates by metal-organic chemical vapor deposition, and the investigation of carrier scattering mechanisms in these heterostructures. In order to reduce alloy scattering in AlInN/GaN high electron mobility transistors (HEMTs), a binary spacer layer, i.e. AlN, is inserted between AlInN and GaN so as to prevent electrons in GaN channel from spilling to AlInN barrier layer. By optimizing the growth conditions of AlInN HEMTs, surface roughness of 0.738 nm, electron mobility of 1,360 cm2/V-s with two dimensional electron gas (2DEG) concentration of 2.13×1013 cm-2, leading to a very low sheet resistance of 215 ohm/sq, have been achieved. A series of AlInN HEMTs with GaN cap layer thickness and Al content in AlInN barrier layer ranging from 0 to 13 nm and 82% to 89%, respectively, have also been prepared and characterized. Hall-effect measurements show that 2DEG concentration increases with decreasing GaN cap thickness and increasing Al content in AlInN barrier layer, while electron mobility decreases with increasing 2DEG density. It is also observed that the degradation of electron mobility is more significant for the samples with a rough interface than those with a smooth one. From temperature-dependent Hall-effect measurements, it is concluded that the electron mobility of AlInN HEMTs with high 2DEG density is dominated by interface roughness scattering at low temperature. Reducing interface roughness is an essential task to achieve high 2DEG concentration AlInN HEMTs.
