Generation of THz Oscillations by Diodes with Resonant Tunneling Boundaries

Abstract

Diodes with a resonant tunneling border are studied as possible sources of THz range. The diodes represent planar two-terminal structures containing a conductive channel and an active lateral border. The lateral border is an AlGaAs/GaAs-based double barrier resonant tunneling structure sandwiched between the channel and metal electrode. It electrically connects to an ohmic contact forming the anode. The operating principle of diodes is based on the use of transfer electron effect in the channel and electron transport throw the lateral border that can result in an increase in the oscillation frequency and extension of operating frequency range. The analysis was performed using ensemble Monte Carlo technique. Oscillation efficiency and frequency properties of the diode are determined. The relation between the maximum efficiency at a specific frequency and the magnitude of the applied bias is shown. It is found that the maximum efficiencies for lower operating frequencies correspond to large bias voltages, while ones at high frequencies are obtained for low bias voltages. Thus, it is possible to create a voltage-controlled oscillation source. The influence of a position of RTB and impurity doping on the generation efficiency of the diode has been investigated. The position of the active lateral border closer to the cathode contact results in a decrease in the generation efficiency and the rise in the oscillation frequency is demonstrated. The possibility to obtain generation in the range from 50 to 550 GHz is shown. The maximum oscillation efficiency is close to 10 % and corresponds to 110 GHz.

Energy and Frequency Properties of Planar n+-n-n+ Diodes with Active Side Boundary

“…This allows us to determine the influence of the side boundary element on operation of the considered structures. 4), metal contacts (5,6), side boundary element (7), metal jumper (8) 2D diode model of the diode is used. Basic elements and calculating peculiarities of simulation correspond to [7].…”

“…The analysis of the operation of diodes in the generation mode is carried out similarly to [6,7]. The diode is assumed to be located in a resonator.…”

“…Another feature of planar diodes is the current flow between contacts along the semiconductor/surrounding material interface. Taking into account the fact that in submicron structures the motion of electrons is close to ballistic, the introduction of additional elements on the surface or change in the electrode shape can significantly change the frequency and energy characteristics of devices [5,6]. In [5,6], the authors consider a number of planar structures with additional semiconductor elements located on the diode side boundary and electrically connected to the diode anode.…”

“…Taking into account the fact that in submicron structures the motion of electrons is close to ballistic, the introduction of additional elements on the surface or change in the electrode shape can significantly change the frequency and energy characteristics of devices [5,6]. In [5,6], the authors consider a number of planar structures with additional semiconductor elements located on the diode side boundary and electrically connected to the diode anode. The elements represent complex structures in the form of a graded-gap layer [5] and double-barrier resonant tunneling structures [6].…”

“…In [5,6], the authors consider a number of planar structures with additional semiconductor elements located on the diode side boundary and electrically connected to the diode anode. The elements represent complex structures in the form of a graded-gap layer [5] and double-barrier resonant tunneling structures [6]. The possibility to obtain generation in a wide frequency range of the millimeter and terahertz ranges is shown.…”