Prospects of 4H-SiC Double Drift Region IMPATT Device as a Photo-Sensitive High-Power Source at 0.7 Terahertz Frequency Regime

Moumita Mukherjee,Nilratan Mazumder,Sitesh Kumar Roy

doi:10.1155/2008/275357

Moumita Mukherjee, Nilratan Mazumder + Show 1 more

Open Access

https://doi.org/10.1155/2008/275357

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Abstract

The dynamic performance of wide-bandgap 4H-SiC based double drift region (p++ p n n++) IMPATT diode is simulated for the first time at terahertz frequency (0.7 Terahertz) region. The simulation experiment establishes the potential of SiC based IMPATT diode as a high power (2.5×1011 Wm−2) terahertz source. The parasitic series resistance in the device is found to reduce the RF power output by 10.7%. The effects of external radiation on the simulated diode are also studied. It is found that (i) the negative conductance and (ii) the negative resistance of the diode decrease, while, the frequency of operation and the quality factor shift upward under photoillumination. Holes in 4H-SiC based IMPATT are found to dominate the modulation activities. The inequality in the magnitude of electron and hole ionization rates in the semiconductors may be correlated with these findings.

Highlights

Terahertz (THz) science and technology are rapidly developing all over the world
The authors in this paper have reported for the first time the potential of 4H-silicon carbide (SiC) as a suitable base material for THz Impact avalanche transit time (IMPATT) device
The optimized design parameters of the unilluminated SiC DDR IMPATT diode for which Mn and Mp are both large (= 106) are mentioned in the last section

Summary

INTRODUCTION

Terahertz (THz) science and technology are rapidly developing all over the world. There is strong interest in the exploitation of the THz frequency range in virtually all fields of basic natural science (physics, chemistry, and biology) as well as medicine [1]. The possibility of generating high power from an IMPATT has been investigated by studying the DC and small-signal properties of WBG 4H-SiC-based flat profile DDR (double drift region, p++ p n n++) IMPATT diode simulated for operation at THz regime. A recent report on the effect of ionizing radiation on Si IMPATT diode characteristics establishes that control of IMPATT performance by any external radiation is an emerging technique that is currently being explored for important application possibilities [8] These interesting results for photoilluminated IMPATTs have prompted the authors to investigate theoretically the role of external radiation in modulating the dynamic properties of the 4H-SiC DDR THz IMPATT. A modified simulation scheme has been used for this purpose

THEORY OF SIMULATION TECHNIQUE

RESULTS AND DISCUSSIONS

THz c ab

CONCLUSION