3-5um及8-12um量子井紅外線偵測器

Abstract

在本篇論文中，我們研究3-5um和8-12um量子井紅外線偵測器(QWIPs)，內 容包括基本理論，製程技術，雙位障QWIPs以及一維暨二維光柵的耦合效 應。在3-5um紅外線波段，我們製作了兩種雙位障量子井紅外線偵測器( DBQWIPs)，其一是定量研究內部位障厚度對DBQWIP性能的影響，結果顯示 當內部位障的厚度為12A時具有最佳之性能表現；其二是探討應變層砷化 銦鎵/砷化鋁鎵量子井結構，結果顯示其暗電流並未明顯增加。此外，在 一二維光柵的耦合效應研究中，我們採用吸收8um的QWIP作為試片，除了 由實驗結果得到二維光柵的反應度約為一維光柵的兩倍外，並找出最佳之 光柵蝕刻方向是與砷化鎵V型槽相平行，再由吸收波峰對光柵週期之變化 得到在此波段的折射率約等於3。最後，由偏極化分析驗證了光柵耦合的 效應，我們得到若入射光的電場平行於多重量子井，則其並不會被吸收， 這與量子力學中的選擇規則相符。 In this thesis, we have studied 3-5um and 8-12um quantum well infrared photodetectors(QWIPs), including the basic theory, the experimental techniques, the double barrier QWIPs, and effect of coupling using one and two dimensional gratings. In the 3-5um infrared regime, we demonstrated two types of double quantum well infrared photodetectors (DBQWIPs). For the first type DBQWIPs, the effects of the inner barrier thickness on the performance of DBQWIPs were quantitatively studied. From the experimental results, the performance of QWIPs with 12A inner barrier is the best. For the second type DBQWIPs, we studied the straind InGaAs/AlGaAs quantum well structure. The dark currnt did not increse notably. In addition, we studied the effect of coupling with one and two dimensional gratings using 8um QWIPs. The responsivities with two dimensional gratings are nearly twice of those with one dimensional gratings. We found that the best etching direction of gratings is that parallel to GaAs V- groove direction. From the results of the absorption peaks and grating periods, the GaAs index of refraction is very close to 3 in long wavelength (8um) regime. Finally, the effect of grating coupling was verified by polarization analysis.