ABSTRACT

Abstract. GalnP/GaAs triple barrier resonant tunneling diodes (TBRTDs) were fabricated and nonlinear variable capacitance characteristic was estimated on the basis of S-parameter analysis. Comparing the results with theoretical simulation, peaks in DC bias dependence of capacitance in the TBRTD is observed. It is found that the peak is due to electron accumulation in the emitter side of quantum well that is not the case of double barrier resonant tunnelling diodes which is unique to the TBRTDs. 1

1. Introduction Resonant tunnelling diodes (RTDs) are expected to be one of key devices for ultra high frequency operation up to THz order due to negative differential resistance (NDR) characteristics on the basis of resonant tunnelling. As parasitic components including an actual structure determine upper limits of the device performance for RF operation, several reports concerning parasitic components such as quantum capacitance and equivalent circuit analysis have been reported for double barrier RTDs [1-6]. However, there are no reports on an estimation of parasitic components in triple barrier resonant tunnelling diodes (TBRTDs) although TBRTDs have advance of large NDR conductance compare to DBTRDs due to energy filter action for electrons [7-8]. Since mechanism of NDR characteristics is determined by alignment and misalignment of two quantum levels of two quantum wells in TBRTDs, trend of parasitic components especially capacitance components are likely to be nonlinear and different from those of DBRTDs.