p型氮化鋁鎵之歐姆接觸研究

Abstract

氮化物半導體材料已成功應用在光電元件，例如發光二極體, 雷射二極體。藍光可應用在顯示和資料儲存上。高品質的歐姆接觸可以改善元件的電性和光性.但在氮化物材料上要形成高品質的歐姆接觸卻有各式個樣的挑戰。然而，一般來說在缺乏高功函數的金屬和表面電洞濃度難提高的情況下，要做低電阻的歐姆接觸是相當困難。 研究下一世代的發光二極體和高功率雷射二極體光電元件在紫外波段(350nm以下)引起大家的興趣。在本論文中，我們探討利用具應變的接觸層在p-型氮化鋁鎵的歐姆接觸特性。在這次實驗中,我們使用鎂掺雜的GaN和InGaN來當作接觸層。

Gallium nitride (GaN)-based semiconductor materials have been successfully applied to optoelectronic devices such as light-emitting diodes (LEDs) and laser diodes (LDs) for display and data storage in the blue wavelength region. There are numerous challenges in forming high-quality ohmic contacts to GaN-based materials, which are crucial for improving the electrical and optical performances in the devices. In general, however, fabricating low-resistance ohmic contacts is difficult in the case of p-type GaN due to the absence of metals having a work function larger than that of p-GaN and the difficulty in increasing near-surface hole concentrations.

The research on next-generation LED and high-power LD optoelectronic devices in the ultraviolet (UV) wavelength region below 350 nm has become interesting. In this study, we demonstrated Ohmic contacts to p-type AlGaN using Mg-doped GaN and InGaN as a contact layer. Hope to Utilizing a strained-contact layer to bend band at the surface to enhanced tunneling transport.