以氮化鋁研製金屬-半導體-金屬深紫外光感測器之真空特性研究及探討

Fabrication and Characterization Study of AlN Metal-Semiconductor-Metal DUV Detectors in Vacuum.

李冠緯(Guan-Wei Lee)

指導教授 ： 高慧玲

中原大學/工學院/電子工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200735

摘要

本論文之目的是使用成長於藍寶石（Sapphire）基板上低溫沉積的氮化鋁薄膜（AlN），研製平面式金屬-半導體-金屬（MSM）結構深紫外光偵測器，並在大氣中與真空中量測，探討不同量測環境之下元件所得到之電性。
本實驗利用Helicon迴旋濺鍍系統低溫成長厚度為4000 Å之氮化鋁薄膜，利用晶像結構分析（XRD），分析基板之薄膜特性。金屬-半導體-金屬深紫外光偵測器是利用in situ metallization 製程沉積氮化鋁鋁薄膜後直接濺鍍金屬鋁以得到良好之金屬半導體接面，再由微影蝕刻製程製作元件反應主動面積為250×250μm2指叉鋁金屬電極，本實驗利用兩種光源，150W氘燈與同步輻射光源分別在大氣中與真空環境中使用紫外光源照射元件後量測其光響應。
使用半導體參數分析儀量測結果在偏壓20V下得到其暗電流值約在2.810-13A與4.110-12A，此差異之原因是由於量測系統不同所造成，而使用150W氘燈與波長200nm單光源照射元件後所量測的光電流值分別約在1.1×10-11A與3.1×10-11A。
在波長200nm時得到的光響應頻譜值約介於為1.0~26.9mA/W，與波長240nm時的響應度相比，強度差距將近為兩個order，此結果與文獻上MOCVD沉積AlN製作的MSM元件十分接近，且使用不同的濾光片也有良好的重現性，說明了所製作之氮化鋁金屬-半導體-金屬光偵測器具有良好的波段判別能力，適合深紫外光之偵測。

關鍵字

響應頻譜 ； 氮化鋁 ； 迴旋濺鍍系統 ； 紫外光偵測器

並列摘要

In this thesis, 4000 Å thick AlN thin film was grown on c-sapphire by Helicon sputtering system at 450℃, and was employed to fabricate the AlN metal-semiconductor-metal (MSM) photodetectors. The electrical properties of the devices were measured in the atmosphere and vacuum, respectively.
The semiconductor parameter analyzers were used to measure the I-V characteristics of AlN MSM devices, and demonstrate low dark currents of 2.8´10-13A and 4.1´10-12A in different environments. The dark current of the photodetectors in this work is comparable to that of the AlN MSM devices fabricated by MOCVD in the literatures, indicating the excellent quality of our AlN film. The photo currents measured by 150W D2 lamp and the mono-color light source of 200nm are 1.1×10-11A and 3.1×10-11A, respectively.
The photo responsivity of the devices is ranged between 1.0 and 26.9mA/W at the wavelength of 200nm, and is more than two orders of magnitude larger than that at 240 nm. It is also found to be close to that of the AlN MSM devices fabricated by MOCVD in the reported literatures. Fairly good reproducibility of the devices was also obtained with different filters. The results indicate that AlN MSM devices exhibit good discrimination of UV light and are suitable for the detection of deep ultraviolet.

並列關鍵字

Responsivity spectrum ； AlN ； Helicon sputtering ； UV detector

參考文獻

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