雙能障超晶格紅外線偵測器

Superlattice Infrared Photodetector with Double Barriers

吳坤政(Kun-Jheng Wu)

指導教授 ： 管傑雄

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01863

摘要

超晶格結構已經被廣泛地應用在紅外線偵測器上。本篇論文的目的，就是在研究具有高偵測率的超晶格紅外線偵測器。
首先，我們提出一種新的結構是在十五週期的超晶格兩側加入不同厚度的電流阻擋層。藉由簡單的製程步驟，以及量測儀器的架設，我們對元件做了一些光電特性的量測。我們發現這顆偵測器在不同的外加偏壓極性會有不對稱的電流電壓特性曲線及不同的光電流頻譜響應。
為了更深入地研究其成因，我們藉由改變不同的蝕刻深度，製作出兩顆不同的偵測器，分別命名為Sample A和Sample B。偵測器Sample A 是我們原始的結構；偵測器Sample B則是蝕刻至超晶格層，並將電極沈積於此。
實驗結果顯示，偵測器Sample B比起原始結構的偵測器Sample A有較佳的響應度及偵測率。經由比較這兩顆偵測器的光電特性，如光譜響應、電流電壓特性等，我們對Sample A的電流操作機制及其電流電壓特性曲線的不對稱性有更進一步的了解。同時我們也提出Sample B的製程概念，用以提升偵測器的偵測率。這些結果將作為日後我們在偵測器結構設計上的重要參考。

關鍵字

超晶格紅外線偵測器

並列摘要

The superlattice structure has been used extensively in the infrared photodetectors. In this thesis, our purpose is to fabricate a superlattice infrared photodetector (SLIP) with high detectivity.
First, we propose a novel structure for the superlattice infrared photodetector. The structure is composed of a 15-period superlattice sandwiched between two asymmetric blocking layers. By the simple fabrication process and the measurement setup, we can measure the electrical and optical properties of our devices.
This structure shows asymmetric current-voltage characteristic and different photoresponse when we switch the bias polarity. To obtain more information, we change the etching depth and fabricate two detectors Sample A and Sample B. Sample A is with the original structure and Sample B is the detector with only one barrier.
The experiment data reveals that the responsivity and detectivity of Sample B are better than that of Sample A. By the comparison of these two detectors, we propose the operational mechanism and have further understanding of the asymmetric current-voltage characteristic. Furthermore, Sample B shows the promising detectivity in comparison with Sample A. This result is helpful for us to improve the performance of our detectors.

並列關鍵字

Superlattice

參考文獻

[1] C. H. Kuan, W. H. Hsieh, S. Y. Lin, C. C. Chen, J. M. Chen,“Investigation of superlattice infrared photodetectors to reach the background limited performance at high temperature,”Photodetector: Materials and Devices VI,” edited by Gail J. Brown and M. Razeghi, 2001

[2] The Physics of Quantum Well Infrared Photodetectors, edited by K. K. Choi (1997)

[3] C. C. Chen, H. C. Chen, M. C. Hsu, W. H. Hsieh, C. H. Kuan, S. Y. Wang, and C. P. Lee, J. Appl. Phys. 91,3,943 (2001)