Planar n+-n-n+ Diode with Active Side Boundary on InP Substrate

Authors O.V. Botsula , V.O. Zozulia , K.H. Prykhodko

V.N. Karazin Kharkiv National University, 4, Svoboda Sq., 61077 Kharkiv, Ukraine

Issue Volume 15, Year 2023, Number 1
Dates Received 30 December 2022; revised manuscript received 17 February 2023; published online 24 February 2023
Citation O.V. Botsula, V.O. Zozulia, K.H. Prykhodko, J. Nano- Electron. Phys. 15 No 1, 01011 (2023)
PACS Number(s) 85.30.Fg, 73.40.Kp, 73.40. – c
Keywords Active side boundary, Electric field strength, Negative differential conductivity, Doping level, Current oscillation, Frequency range, Generation efficiency (2) .

We have studied generation of electromagnetic oscillations in the long-wavelength part of the terahertz range by diode structures with active side border. Diodes represent planar structures 1.28 (m long, 0.32 (m wide. They include a conductive channel placed on a semi-insulating InP substrate, two contacts, and an active side boundary (ASB) in the form of an n-type region located between the InP channel and the metal electrode connected to the ohmic contact of the anode. Donor concentration in a channel is 6·1022 m – 3. The article considers two different ASB on the bases of InP and InGaAs and analyses generation efficiency of diodes. We carried out a simulation by the Ensemble Monte Carlo technique. The characteristics of the diode are compared with the characteristics of common InP diodes with the same parameters. We found out that the I-V characteristic of diodes does not contain a region with negative differential conductivity. However, there are high frequency current oscillations. The operation regime is close to trapped domain mode. In the course of the research, we determined the efficiency and frequency properties of the diode. The frequency range of diodes is established to be in the range from 100 to 350 GHz. Maximum generation efficiency of diodes with InP-based ASB is about 2.5 % at a frequency of 160-180 GHz. The article highlights the effect of increase in cutoff frequency in the case of using ASB to compare with a common InP diode. In particular, using InP-based ASB, gives current oscillation in the range from 300 to 350 GHz when ASB position is near the anode contact. Nevertheless, this effect is absent if InGaAs-based ASB is applied. Thus, we assume that frequency properties can be improved due to enhanced energy relaxation in ASB.

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