以三族氮化物之表面聲波元件與金屬-半導體-金屬元件研製新型紫外光感測器

Fabrication study of novel UV detector using III-Nitrides thin films

徐振瑋(Chen-Wei Hsu)

指導教授 ： 高慧玲

中原大學/工學院/電子工程研究所/碩士(2008年)

https://doi.org/10.6840/CYCU.2008.00079

摘要

由於紫光偵測器的應用範圍日漸廣泛，包含國防、工業、科學研究，以及醫學方面都有對紫外光偵測器的需求性。而光偵測器的種類繁多，隨需求的不同，所要求的精確性也有差異。以較短波長之紫外光偵測來說，目前以光電倍增管(PMT)的量測最為精準，但其缺點為價格昂貴且元件易碎。Silicon UV偵測器則因其能隙關係，對於短波長的光偵測較無效率。
而三族氮化物材料因其優異的壓電特性以及寬能隙(3.4~6.2eV)使之具有無視可見光的特性，在光偵測器的應用上又具有減少輻射傷害、較低的暗電流及高響應度等特性，故適合用來製作紫外光偵測器之材料。
本論文利用三族氮化物的優點及特性以AlN/GaN/Sapphire、GaN/Sapphire兩種三族氮化物基板製作新型紫外光偵測器。此偵測器整合了兩種類型的光偵測器，包含了直流形式的金屬-半導體-金屬元件及以交流形式的表面聲波元件製作成之振盪器。此新型紫外光偵測器因包含接收及產生RF訊號之元件，使得在應用上具有可以遠端遙控之優勢，另一方面，亦可藉由此兩種三族氮化物材料能隙的不同，使得元件具有分辨入射光波段的功能。經由實驗，驗證了兩種光偵測元件整合後量測UV光的可行性，而新型UV光偵測器之交、直流兩元件所量測之數據顯示其輸出訊號變化皆對光源強度呈線性關係，驗證了此新型元件在紫外光偵測器上之適用性。

關鍵字

氮化鎵 ； 表面聲波元件 ； 氮化鋁 ； 金屬-半導體-金屬元件 ； 紫外光偵測器 ； 表面聲波振盪器

並列摘要

Recently, the demands of UV detectors for the military, industry and scientific needs have become more and more extensive. The required sensitivity of UV detectors depends on the various applications. UV detectors are traditionally made of photomultiplier tubes (PMTs) and the Si photodiodes. Although PMTs have the highest accuracy, the high price and the fragility prevent it from being widely used for UV sensing. Silicon photodiode is used for its lower cost, but the small band gap results in the inefficiency for UV sensors.
The III-Nitrides are suitable for UV sensors application because they possess superior piezoelectricity and wide bandgap as well as radiative attack、low dark current and high responsivity.
In this thesis, novel UV detectors were fabricated using III-Nitrides based on AlN/GaN/Sapphire and GaN/Sapphire. The detectors combine a surface acoustic wave (SAW) device and metal-semiconductor-metal (MSM) device. The detectors can be remotely controlled by using RF signals of SAW, and also have the feasibility to distinguish the wavelength range of the incident light through the different bandgaps of AlN and GaN. The results of illuminating experiments demonstrated the possibility of combining two devices to form the new type of UV detectors. The experimental data also revealed that the output frequency shift of the SAW oscillator and the photocurrent of the MSM are both linearly dependent on the radiation power. It indicates the potential to obtain sensitive and accurate UV detectors using this novel III- nitride devices.

並列關鍵字

surface acoustic wave(SAW) devices ； Metal-Semiconductor-Metal(MSM) devices ； AlN ； GaN ； SAW oscillators ； UV detectors

參考文獻

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