Novel AlAs-InGaAs-AlAs Resonant Tunnelling Diodes for THz

双势垒量子阱(DBQW)RTD被认为是在室温下制作高速功能器件和THz振荡器的最有前途的候选材料。对于太赫兹振荡器，最近(2016年)报道的室温下电子单器件的最高频率为1.9太赫兹，这为实现紧凑和高效的电子学太赫兹振荡器带来了很大的希望DBQW-RTD的最简单形式，由几个单分子层组成，中间夹着两层厚度为3单分子层的非掺杂势垒。发射极和集电极接触区是重掺杂的。实现这一成果的关键技术之一是对超薄半导体异质结外延生长的精确控制。振荡器的结构设计和微加工技术也是至关重要的。为了在太赫兹区域实现振荡，本计划将研究一种新型的RTD结构设计，该结构采用超薄AlAs张拉势垒和高度压缩的InGaAs量子阱，有效地降低了收集极耗尽区的工作偏置电压和电子渡越时间。本文研究了具有0.9 nm厚势垒的InGaAs/AlAs RTD振荡器在室温下的基频振荡。该计划将研究RTD与射频电路的集成，以形成太赫兹区域的完整箭头波段发射器，用作连续太赫兹成像系统中的高功率发射器。

The Double-Barrier Quantum Well(DBQW) RTD is considered as the most promising candidate for high-speed functionaldevices and THz oscillators at room temperature. For THz oscillators, the highestfrequency of electronic single devices at room temperature reported recently (2016)is 1.9THz holding much promise for the realisation of compact and efficient electronicTHz oscillatorsThe DBQW-RTD in its simplest form, consists of a few monolayers undoped quantumwell sandwiched between two undoped layer of barriers of thickness 3 monolayers.The emitter and collector contact regions are heavily doped. One of the keytechnologies for this achievement is the precise control of epitaxial growth of ultrathinsemiconductor heterostructures. The structural design of oscillators andmicrofabrication technology are also crucial. To achieve oscillations in the terahertzregime, this programme will examine a novel RTD structure designs with ultra thinAlAs tensile barriers and highly compressive InGaAs quantum wells, which effectivelyreduces both the operating bias voltage and electron transit time in the collectordepletion region. InGaAs/AlAs RTD oscillator with 0.9-nm-thick barriers will bestudied for fundamental oscillations at frequencies > 1 THz at room temperature. Thisprogramme will examine the integration of RTDs with RF circuits to form completenarrow band emitters in the THz region for use as high power emitters in CW THzimaging systems.