中文摘要：

通过在GaN缓冲层上先生长一层20nm厚的AIN插入层，成功地在此插入层上生长出了200nm厚的AlxGa1-xN（0．22〈x〈0．28）材料。研究并优化了AlxGa1-xN材料上的Ti／Al／Ni／Au欧姆接触和Ni基肖特基接触的形成条件。20nm／150nm／20nm／200nm的Ti／Al／Ni／Au金属层在N2氛围中，700℃下，快速热退火处理120s后，其欧姆接触的比接触电阻率为3．13×10^-5Ω·cm^2。研究表明，当AlxGa1-x，N材料中Al组分x〉0．20时，其上Ni基肖特基势垒高度几乎是不变的。在O2氛围中，300℃下，对AlxGa1-xN材料上10nm厚的金属Ni层氧化90s，得到了此Ni层在314nm的透射率由57．5％提高到78．2％。在器件的光电流谱测量中，得到了器件最短的截止波长为307nm，紫外／可见光达到10^ 以上。

英文摘要：

Followed by depositing 20 nm wide AlN interlayer on the GaN buffer, 200 nm wide AlxGa1-xN （0.22〈x〈0.28） was successfully extended. The conditions of Ohmic contacts formed by Ti/Al/Ni/Au layers and Schottky contacts formed by Ni layer were researched and optimized. The Ohmic resistance of Ti/Al/Ni/Au （20 nm/150 nm/20 nm/200nm） annealed in the N2 ambience,700 ℃ for 120 s is 3. 13 × 10^-5Ω· cm^2. It is demonstrated that when the Al mole fraction of AlxGa1-xN is more than 0.20, the Schottky Barrier Height between metal Ni layer and Al1Ga1-xN is almost the same. When 10 nm wide Ni deposited on the AlxGa1-xN is oxidated in O2 ambience ,300 ℃ for 90 s, the transmission coefficient increases from 57.5% to 78.2% at the wavelength of 314 nm. Consequently, AlxGa1-xN-based UV photodetectors with different cut-off wavelength are obtained. The shortest wavelength of these detectors is 307 nm, and the UV/ visible ratio is 3 orders of magnitude.