A GaAs/AlGaAs based Asymmetrical DBS (ADBS) RTD

Abstract

To explore the application prospect of GaAs/AIGaAs based Asymmetric DBS (double barriers) (ADBS) RTD (resonate tunneling diode), its transfer coefficient and RT (resonate tunneling) current density were modeled through solving of its Schrodinger equation with the method of Airy functions. Then the influences of higher barrier height on its DC characteristic and operation principles at positive and negative bias conditions were comparatively studied through simulation experiments with TCAD. The experimental results and analyses indicate that its current-voltage characteristic at negative bias is distinctively different from that at positive bias. The former appears obviously lower valley current and voltage hence lower function voltage, bigger PVCR (ratio between peak and valley currents) and broader valley bottom with similar peak current and voltage to the latter. Therefore, negative biased GaAs/AIGaAs based ADBS RTD might be more suitable for low power loss and high speed MVL (multi-valued logic) applications.The characteristic dimension (CD) of integrated semiconductor devices has been decreasing in exponential trend according to Moors law. As the CD is scaled down to nanometer, the physical limit of semiconductor devices is approached and many quantum effects appear in the traditional devices, which lead to their abnormal operations. To surmount this severe obstacle, novel devices based on quantum effects of electrons in nanostructures has been being explored and nanometer quantum devices have been being put forward little by little [1], among which RTD (Resonant Tunneling Diode) is one of the most attractive hits and became one of the nanometer devices produced in advance with the development of advanced epitaxial growing technologies such as MBE (Molecular Beam Epitaxy), MOCVD (Metal Organic Chemical Vapor Deposition)/Metal Organic Vapor-Phase Epitaxy (MOVPE) [2-6]. Its physical structure and the negative differential resistance (NDR) of RTD determine its feasibility and robustness in design of multiple-valued logic (MVL) circuits. The ultra-high-integration density characteristic of RTD is capable of greatly reducing the size of the system, the numbers of circuit interconnections and nodes. R TO is very beneficial to further improve the system performance due to its 978-1-4673-7005-9 /15/$31.00 ©2015 IEEE 380 ultra-high-speed and self-latch characteristics. The latter will lead to reduced number of devices, chip size and power consumption of a given circuit or system and all kinds of parasitic effects caused by interconnection wires can also be cut down. With the applications of MVL, more complicated logic function can be realized on a smaller chip with less pins and inter connections in between the systems, which appears remarkable merits in the high speed signal processing, transmission and storage. Therefore, combining RTD with MVL will be capable of improving the circuits' performance from many aspects, and have broad application prospects in the field of circuit design. Applied RTDs into MVL circuit d...

A novel quantum well RTD with intensive and continuous current oscillation in the bias voltage range higher than 3.15 V

“…As for the quantum devices for pure electron applications, dimensions of quantum well and barrier layers are much thinner than those of quantum devices for optical applications [1][2][3][4][5][6], which leads to much more significant quantum size effect since the dimensions of quantum well and barrier layers are much more closer to their de Broglie wavelengthes respectively on one hand and inner band carrier transportation mechanism dominants when sub-band energy level split occurs on the other hand.…”