氮化物半導體與表面金屬之間的位能障礙研究

Study on the Potential Barriers between Nitride Semiconductors and Surface Metal

吳秉修(Ping-Hsiu Wu)

指導教授 ： 楊志忠

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202102755

摘要

我們使用X射線光電子能譜(XPS)和紫外光電子能譜(UPS)技術來量測氮化鋁鎵和表面銀之間的位能障。經UPS測量，我們也可以計算氮化鋁鎵的功函數。我們研究兩種類型的氮化鋁鎵樣品，包括固定鋁含量的氮化鋁鎵層和沿c軸連續降低鋁含量的氮化鋁鎵層。在氮化鋁鎵樣品研究之前，我們首先確定適合XPS測量的銀沉積厚度(7 nm)，並使用不同摻雜條件的氮化鎵樣品測試量測與數據處理過程。我們的結果顯示任一類型的氮化鋁鎵樣品中氮化鋁鎵和銀之間的位能障隨著鋁含量而增加。由於鋁含量梯度的結構導致p型行為，這種氮化鋁鎵樣品上的位能障通常高於固定鋁含量的氮化鋁鎵。p型氮化鋁鎵的功函數也明顯高於本質氮化鋁鎵。然而，功函數隨鋁含量的變化較難確定，這可能是由於UPS測量結果難以準確判讀擬合。

關鍵字

氮化物半導體 ； 位能障礙

並列摘要

The techniques of X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) are used for calibrating the potential barrier between AlGaN and surface Ag. With UPS measurement, the work function of AlGaN can also be calibrated. Two types of AlGaN samples are studied, including AlGaN layers of fixed Al contents and decreasing-Al contents along the c-axis. Before AlGaN sample study, we first determine a suitable Ag deposition thickness (7 nm) for XPS measurement and test the measurement techniques with un-doped GaN of different doping conditions. Generally, the potential barrier between AlGaN and Ag increases with Al content in either type of AlGaN sample. Because the Al-decreasing structure results in p-type behavior, the potential barriers on AlGaN of Al-decreasing contents are generally higher than those on AlGaN of fixed Al contents. The work function of p-type AlGaN is significantly higher than that of intrinsic AlGaN. However, the dependence of work function on Al content is not very clear, likely due to the difficulty of accurate calibration in UPS measurement.

並列關鍵字

Nitride Semiconductors ； Potential Barriers

參考文獻

1. Yao, Y. F.; Yang, S.; Teng, C. C.; Chou, K. P.; Liu, C. W.; Kuo, Y.; Kiang, Y. W.; Yang, C. C. Formation of Surface Silver Nano-Nnetwork Structures through Hot Electron Regulated Diffusion-Limited Aggregation. Sci. Rep. 2019, 9, 6997.

2. Kneissl M, Kolbe T, Chua C, Kueller V, Lobo N, Stellmach J, Knauer A, Rodriguez H, Einfeldt S and Yang Z 2011 Advances in group III-nitride-based deep UV light-emitting diode technology Semicond. Sci. Technol. 26 014036

3. Kent T F, Carnevale S D, Sarwar A T M, Phillips P J, Klie R F and Myers R C 2014 Deep ultraviolet emitting polarization induced nanowire light emitting diodes with AlxGa1-xN active regions Nanotechnology 25 455201

4. Shatalov M, Sun W, Lunev A, Hu X, Dobrinsky A, Bilenko Y, Yang J, Shur M, Gaska R, Moe C, Garrett G and Wraback M 2012 AlGaN deep-ultraviolet light-emitting diodes with external quantum efficiency above 10% Appl. Phys. Express 5 082101

5. Takano T, Mino T, Sakai J, Noguchi N, Tsubaki K and Hirayama H 2017 Deep-ultraviolet light-emitting diodes with external quantum efficiency higher than 20% at 275 nm achieved by improving light-extraction efficiency Appl. Phys. Express 10 031002