InGaAs/AlAsSb/InGaAs 單能障結構穿隧電流之研究

Abstract

在此計劃中，我們以MOCVD磊晶法完成InGaAs/AlAsSb/InGaAs單能障穿隧 二極體之試製，AlAsSb能障厚度為130A、理論模擬有效能障厚度約為105A 。室溫下的電性量測中，我們首度在這材料中發現了微分負電阻(Negtive Differential Resistance, NDR)，峰谷值電流比(Peak-to-valley current ratio, PVR)為1.2、峰值電流密度(peak-current density, Jp) 為158A/cm^2;100K的量測中，峰谷值電流比則為4.2、峰值電流密度為54 A/cm^2。這是目前為止，單能障結構研究中所量測到具有最大峰谷值電流 比的文獻報告，亦是截至目前為止，第一份有關InGaAs/AlAsSb/InGaAs單 能障穿隧結構的文獻報告。 In this project, we made a series of experiment in studying the tunneling phenomena of InGaAs/AlAsSb/InGaAs single barrier tunneling diodes grown by MOCVD system. For example, from the room temperature electrical measurements, we attained negtive differential resistance (NDR) in a 130-A-thick AlAsSb barrier diode with peak-to-valley current ratio(PVR) of 1.2 and peak current density of 158A/cm^2. Further, a measurement of this diode with peak-to-valley current ratio of 4.2 and peak current density of 54A/cm ^2 is also attained at a temperature of 100K. It is interesting to note that the PVR value 4.2 at 100K is substantially higher than what has previously been reported for any single-barrier structure, such as InAs/GaSb and InAs/AlGaSb series. To the best of our knowledge, our current study is the first observation on NDR phenomena in AlAsSb series single barrier structure.