原子層沉積成長氧化物發光二極體之研製

Abstract

本研究論文在探討利用自組小球微影技術與原子層沉積系統製作氧化鋅/氮化鎵或矽發光二極體元件與特性量測，分成三部分論述第一部分是自組小球微影技術之原理與步驟介紹，且介紹原子層沉積系統原理與材料分析，第二部分是氧化鋅/氮化鎵發光二極體製作與量測，第三部分為氧化鋅/矽發光二極體製作與量測。 首先，本文敘述利用原子層沉積系統成長氧化鋅，並且使用PL、XRD等量測技術，分析氧化鋅之成分。從PL結果得知晶體激發出中心位置在383 nm，半高寬為25 nm之紫外光，而由XRD材料分析得知晶體為多晶結構。 吾人以上述之自組小球微影技術與原子層沉積系統製作氧化鋅/氮化鎵發光二極體元件，並量測其電壓-電流特性、電激發光頻譜，並發現該元件在正負偏壓下皆有可見光及紫外光發光特徵。吾人利用自組小球微影技術與原子層沉積製作氧化鋅/矽發光二極體元件，發現該原件具整流特徵，導通電壓為6伏特，在正偏壓產生連續可見光頻譜，且不因注入電流之增加而光譜明顯藍移。吾人改用平面型發光二極體元件結構，成長於(001)與(111)面向之矽基板，發現以6 nm厚度ZnO/Si LED 其發光強度較3 nm ZnO/Si 結構提升五倍且亮度均勻。

In this thesis, we present the fabrication and characterization of ZnO/GaN and ZnO/Si light-emitting diode (LED) using self-assembled nanosphere lithography and atomic layer deposition (ALD). First, we discuss the theory and process of self-assemble nanosphere lithography, and present the theory of ALD system followed by material analysis. Second, we fabricate and measure the ZnO/GaN LED devices. Third part, we fabricate and measure the ZnO/Si LED devices. From the PL analysis pumped by a 266nm Nd:YAG solid-state laser, we observed a peak emission wavelength at 383nm with a full width at half maximum (FWHM) of 25nm. Data from the XRD analysis suggest the ZnO film grown by the ALD system to be poly crystalline. For fabricated the ZnO/GaN LED devices from the current-voltage and the electroluminescence (EL) data, these devices exhibit non-ideal electrical characteristic. The devices emit ultraviolet and visible light under both forwarded and reversed bias, respectively. For the ZnO/Si LED devices, they exhibit current rectification characterization and have a turn-on voltage of 6V and the devices emit continuous visible light under forward bias. In addition, we fabricated planar type for ZnO LED on (001) and (111) P-Si substrates. We detect five-fold increase in the emission intensity for a 6nm-thick ZnO/Si LED compared with a 3nm-thick ZnO/Si LED.