Moumita Mukherjee 1*, Soumen Banerjee 2* and J. P. Banerjee 3*
1,3 Centre of Millimeter-wave Semiconductor Devices & Systems, Institute of Radio Physics & Electronics, University of Calcutta
1 Girish Vidya Ratna Lane, Kolkata-700009, West Bengal, India.
2 Hooghly Engineering & Technology College, West Bengal University of Technology, Vivekananda Road, Pipulpati, Hooghly, West Bengal, India.
*1 E-mail: email@example.com, *3 firstname.lastname@example.org, *2 E-mail: email@example.com
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Abstract: High-frequency characteristics of IMPATT Oscillators based on III-V Indium Phosphide (InP), III-V Wurtzite Gallium Nitride (Wz-GaN) and IV-IV Silicon Carbide (3C, 4H and 6H polytypes) are studied and their performances are compared at a frequency of 0.3 THz. A double drift p+ p n n+ structure is chosen for all the materials and investigation has been carried out to obtain maximum conversion efficiency and device negative resistance by optimizing bias current density through modeling and simulation technique. A double iterative computer method based on modified drift-diffusion model has been used to study their performance. The simulation studies reveal that these devices are potential sources for generating high power in the Terahertz regime. The avalanche response time for each of the IMPATT diodes are simulated by a newly developed simulation technique and it has been observed that avalanche response time in InP, GaN and SiC IMPATTs are less than the corresponding transit time of the diodes- which is an essential condition to generate THz oscillation in these devices. The conversion efficiency of III-V InP IMPATT diode is found to be 18.4% at 0.3 THz with an output power of 2.81 W, whereas, III-V Wz-GaN IMPATT is found to generate much higher output power of 6.23 W with a conversion efficiency of 15.47% at 0.3 THz. On the other side, IMPATTs based on IV-IV SiC generate output power of 11.5 W (3C-SiC), 20W (4H-SiC) and 7.5 W (6H-SiC) with corresponding conversion efficiencies of 12.5% (3C-SiC), 15% (4H-SiC) and 12% (6H-SiC) at 0.3 THz. The extensive simulation results reveal that though IMPATT diode based on SiC gives better performance in terms of higher output power in the Terahertz domain compared to other materials, GaN IMPATT has the advantage of higher efficiency. The design data and the proposed fabrication methodology, presented in this paper, will be helpful to realize InP, SiC and GaN based IMPATT oscillators for Terahertz communication.
Keywords: Terahertz frequency, Indium Phosphide, Silicon Carbide, Gallium Nitride, Double Drift Impatt Diode, Wide band gap semiconductors, Avalanche response time, Transit Time limitation, Bias current optimization.
Acknowledgments: The authors wish to acknowledge Institute of Radio Physics & Electronics, University of Calcutta and the Centre of Millimeter wave Semiconductor Devices & Systems (CMSDS) for the support to carry out this research work. The author, M. Mukherjee, is grateful to Defence Research and Development organisation, Ministry of Defence, Govt. of India, for awarding her Research Fellowship to do this work.
Cite this article:
Moumita Mukherjee, Soumen Banerjee, and J. P. Banerjee. Dynamic Characteristics of III-V and IV-IV Semiconductor Based Transit Time Devices in the Terahertz Regime: A Comparative Analysis[J]. International Journal of Terahertz Science and Technology, 2010, Vol.3, No.3: 97-108. DOI:10.11906/TST.097-108.2010.09.10