Following Gummel-Blue approach [1] [H.K. Gummel, J. L. Blue, IEEE Trans. Electron. Devices 14(1967) pp. 569-572.], the effect of undepleted epitaxial layers on the series resistance (Rs) as well as on its microwave properties of single drift region (n+np+) Si IMPATT diodes [2] [M. Mitra, M. Das, S. Kar, S.K. Roy, IEEE Trans. Electron. Devices 40(1993) pp. 1890-1893.] with flat doping profile with capacity 0.2PF at X band under experimental bias current of 25 mA and temperature 373 K have been studied. The computation for series resistance fits well with the device data for flat doping profile [2] [M. Mitra, M. Das, S. Kar, S.K. Roy, IEEE Trans. Electron. Devices 40(1993) pp. 1890-1893.]. The same study has also been simulated on its low-high-low (lhl) doping profile counterpart. The value of Rs increases approximately linearly with the increase of undepleted epi-layer thickness determined by the doping density for both flat and lhl structure. The value of Rs decreases remarkably as the doping profile changes from flat to lhl type. © 2006 Elsevier Ltd. All rights reserved.

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University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Microelectronics Journal

The change of both microwave negative resistance (R) and its parasitic series resistance (Rs) on the rise of junction temperature in the range of 100-220 °C of HP n++np++ Si IMPATT [M. Mitra, M. Das, S. Kar, S.K. Roy, IEEE Trans. Electron. Dev. 40 (1993) 1890] diode at X band (8-12 GHz) have been simulated. The studies followed by Gummel-Blue Technique [H.K. Gummel, J.L. Blue, IEEE Trans. Electron. Dev. 14 (1967) 569] show that for a constant experimental bias current of 25 mA [Mitra et al., 1993], for which the space charge effect is not prominent, the values of negative conductance and negative resistance degrade taking into account the changes in the ionization rates and drift velocities due to rise of temperature. Also observed that the critical series resistance increases with the increase of temperature up to 2.23 Ω, slightly higher than the realistic limit of 2 Ω [Mitra et al., 1993]. © 2006 Elsevier B.V. All rights reserved.

Current Applied Physics

Temperature dependence of microwave resistances of n++np++ Si X band IMPATT diode

The effect of laser radiation on the n+ side of the n +np+ semiconductor junction structure of GaAs and Si IMPATT diode at X band has been studied. Following Gummel-Blue approach [1] and considering the experimental ionization parameters of GaAs [2] and Si [3], the present study predicts that the enhancement of optically induced leakage current increases the value of crucial series resistance with an overall degradation in the microwave negative resistance properties, but with an advantage of wider tuning range at 22 C of the diode. It is also observed that GaAs diode yields lower values of series resistance and higher values of negative conductance than its Si IMPAtT counterpart at X band.

2007 International Conference on Microwave and Millimeter Wave Technology, ICMMT '07

Optically induced series resistance and microwave properties of n +np+ GaAs and Si IMPATT diode

The effect of punch through on the series resistance of n +np+ single drift region Si HP [5082-0432] IMPACT diodes of capacity 0.02 pf around the X band has been studied. The computed result for series resistance fits well with the device data. The analysis shows that for a constant bias current density, when the space charge effect is not prominent, the value of series resistance decreases with the decrease of punch through, determined by the doping density and thickness of the active layer. The decrease of punch through produces an upward shift in the operating frequency of the device. It is also observed that an increase of punch through factor leads to a decrease in negative resistance, conversion efficiency and the susceptance of the device.

Semiconductor Science and Technology

Effect of punch through on the microwave series resistance of n +np+ Si IMPATT diodes around the X band

Pulsed-mode high-power generation in silicon double drift region (DDR) IMPATT devices is briefly reviewed, and current work is presented on the structural parameter dependence of pulsed silicon IMPATTs designed for operation around 94 GHz at a current density of 100 kA cm-2. Computer studies are presented on three DDR structures: (i) flat, (ii) SLHL, i.e. low-high-low structure with single bump on either side of the p-n junction, and (iii) DLHL, i.e. low-high-low structure with double bumps on either side of the p-n junction. The results indicate that the DLHL structures exhibit much higher negative conductance than the other structures. It is seen that the magnitude of the peak negative conductance of the DLHL DDR IMPATT devices decreases appreciably if low-high-low bumps are changed from rectangular to trapezoidal shape. It is also found that the heights of the second bumps produce little variation in the negative conductance of the DLHL device, although the second bumps play a vital role in containing the space-charge effect at high current densities. The heights of the first bumps close to the metallurgical junction, however, produce appreciable changes in the small-signal behaviour of the DLHL diodes. Further, it has been found that the width of the active region, if increased gradually, makes the DLHL diode a narrow band device operating near the avalanche resonance frequency. The effect of variation of bump width and bump location (from the optimized structure) on the high-frequency properties of the device has also been studied and the results are presented in the paper.

Studies on pulsed mm-wave low-high-low silicon IMPATT diodes at high current density and dependence on structural parameters

Spatial variation of negative resistivity has been studied through computer simulation by considering experimental bias current and the device capacitance of single drift (n+ np+) silicon IMPATT diode operating in the X band. From the total device negative resistivity and reactivity, device negative conductance, susceptance and the diode series resistance have been calculated. Computed values of series resistance nearly fit with the experimental results. The present analysis also gives an idea about the load conductance of the circuit in the small signal condition. © 1996 Taylor and Francis Group, LLC.

International Journal of Electronics

Computer simulation of series resistance of an SDR silicon IMPATT diode in the X band

Computer studies have been carried out to study the role of electron and hole saturation currents on the microwave and millimetre-wave performance of a GaAs double drift region (DDR) IMPATT. It has been found that (i) the device negative conductance and (ii) the device negative resistance both decrease with increase of either electron or hole saturation current, i.e. with the decrease in either electron or hole multiplication factor. It has also been observed that the frequency of operation shifts upwards and the device quality factor increases gradually with increasing saturation current. It has further been observed that the upward shift in operating frequency is more when the GaAs DDR IMPATT performance is controlled by the hole saturation current rather than by the electron dominated saturation current. The relative predominance of the hole saturation current over the electron saturation current in inducing the higher frequency shift of the GaAs DDR IMPATT may be explained in terms of the inequality of hole and electron ionization coefficients in GaAs. © 1991 Taylor & Francis, Ltd.

Saturation current induced effects on the microwave and millimetre wave performance of GaAs double drift region IMPATTs

The design and optimization of double drift low-high-low indium phosphide IMPATT diodes have been studied using computer simulation programs for the static and high frequency analyses of the devices. A maximum efficiency of 28% has been obtained with a breakdown voltage of 104.5 V. The device properties have also been studied for various current densities, which involves the effect of mobile space charge in the depletion layer. The admittance characteristics and the spatial distribution of high frequency negative resistivity and reactance in the depletion layer of the optimized low-high-low DDR diode have been studied and compared with those of the flat profile DDR diode. The profiles of negative resistivity in the depletion layers of both low-high-low DDR and flat profile DDR exhibit two peaks in the middle of two drift layers separated by a minimum in the avalanche zone. These profiles provide considerable physical insight regarding the source of microwave power generation in these devices.

Journal	Microelectronics Journal
Publisher	-
ISSN	0026-2692