@article{thapar_baliga_1999, title={Enhancing the maximum controllable current density of the accumulation channel driven bipolar transistor}, volume={43}, ISSN={["0038-1101"]}, DOI={10.1016/S0038-1101(98)00255-X}, abstractNote={The phenomenon of potential barrier lowering in the N-base region limits the maximum controllable current density (Jmcc) of the accumulation channel bipolar transistor (ACBT). The barrier lowering occurs when the hole current flowing into the P/N-base collector junction of the ACBT creates a bias opposing the built-in potential of the P/N-base junction. A significant improvement in the Jmcc of the ACBT has been obtained after electron radiation because the hole current flowing into the P/N-base junction is decreased as a result of the reduction in minority carrier lifetime. Furthermore, the Jmcc of the ACBT is shown to increase significantly by ramping the gate electrode to negative voltages during turn-off. The enhancement in the Jmcc brought about by this method is limited by the channel density of the PMOSFET created along the deep trench sidewall on application of a negative gate bias. A new dual gate ACBT structure, integrating a high channel density PMOSFET within its unit cell, is proposed and demonstrated to be superior to the conventional ACBT structure.}, number={2}, journal={SOLID-STATE ELECTRONICS}, author={Thapar, N and Baliga, BJ}, year={1999}, month={Feb}, pages={395–402} }
 @article{thapar_baliga_1998, title={An experimental evaluation of the on-state performance of trench IGBT designs}, volume={42}, ISSN={["1879-2405"]}, DOI={10.1016/S0038-1101(97)00301-8}, abstractNote={The on-state performance of non-self aligned and self aligned trench IGBT designs is experimentally evaluated and compared for the first time in this paper. In contrast to previous reports based only on numerical simulations, experimental results presented in this paper demonstrate that the non-self aligned trench IGBT designs are superior to the self-aligned trench IGBT designs. Furthermore, the variation in the on-state voltage drop with the unit cell parameters of the non-self trench IGBT obtained through numerical simulations show trends that are opposite to those observed experimentally. Our analysis indicates that the disagreement between the experimental and numerical simulation results arises due to the assumption of an ideal ohmic contact to the N+ emitter of the TIGBT designs made in previous numerical simulations.}, number={5}, journal={SOLID-STATE ELECTRONICS}, author={Thapar, N and Baliga, BJ}, year={1998}, month={May}, pages={771–776} }
 @article{thapar_baliga_1998, title={Analytical model for the threshold voltage of Accumulation Channel MOS-Gate devices}, volume={42}, ISSN={["0038-1101"]}, DOI={10.1016/S0038-1101(98)00179-8}, abstractNote={An analytical model for the threshold voltage of Accumulation Channel MOS-Gate devices is developed for the first time in this paper. Using the model, an equation for the threshold voltage is derived in terms of the design and fabrication process parameters. The values of the threshold voltage predicted by the analytical equation are found to be in excellent agreement with those extracted from numerical simulations and experimental measurements on both silicon and silicon carbide devices. The analysis in this paper is therefore useful in choosing the design and fabrication process parameters required to tailor the threshold voltage of Accumulation Channel MOS-Gate bipolar and unipolar devices.}, number={11}, journal={SOLID-STATE ELECTRONICS}, author={Thapar, N and Baliga, BJ}, year={1998}, month={Nov}, pages={1975–1979} }
 @article{thapar_baliga_1998, title={Influence of the collector resistance on the performance of accumulation channel driven bipolar transistor}, volume={42}, ISSN={["0038-1101"]}, DOI={10.1016/S0038-1101(98)00127-0}, abstractNote={In this paper, the physical mechanism limiting the maximum controllable current density (Jmcc) and safe operating area (SOA) of the accumulation channel driven bipolar transistor (ACBT) is identified and analyzed for the first time. According to our analysis, the hole current flowing into the P+ collector at the shallow trench creates a bias opposing the built-in potential of the P+ collector/N-drift junction due to a finite resistance associated with the contact to the diffused P+ collector region. This lowers the potential barrier established in the narrow mesa region (in between the self-aligned trenches) by the built-in potential of the P+ collector/N-drift junction and the control gate potential and promotes electron injection from the N+ emitter into the N-drift region over the potential barrier. At the onset of electron injection over the potential barrier, gate control over the base drive of the vertical wide base PNP transistor in the ACBT is lost. This hypothesis has been verified through numerical simulations and confirmed by experimental measurements which indicated an increase of over 300% in Jmcc due to a reduction in the contact resistance to the P+ collector region after a post metallization anneal of the fabricated ACBT designs. Based upon these observations, a new ACBT structure with a Schottky collector junction is proposed. It is demonstrated that the proposed ACBT structure has a higher Jmcc and wider SOA in comparison to the ACBT structure with P+ collector region.}, number={9}, journal={SOLID-STATE ELECTRONICS}, author={Thapar, N and Baliga, BJ}, year={1998}, month={Sep}, pages={1697–1703} }
 @misc{thapar_shenoy_baliga_1998, title={Static-induction transistors having heterojunction gates and methods of forming same}, volume={5,753,938}, number={1998 May 19}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Thapar, N. I. and Shenoy, P. M. and Baliga, B. J.}, year={1998}, month={May} }
 @misc{baliga_thapar_1997, title={Depleted base transistor with high forward voltage blocking capability}, volume={5,679,966}, number={1997 Oct. 21}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Baliga, B. J. and Thapar, Naresh I.}, year={1997}, month={Oct} }
 @article{thapar_baliga_1997, title={The accumulation channel driven bipolar transistor (ACBT)}, volume={18}, ISSN={["1558-0563"]}, DOI={10.1109/55.568754}, abstractNote={A new three-terminal power switch called the Accumulation Channel driven Bipolar Transistor (ACBT) is proposed and experimentally demonstrated. In the on-state, the characteristics of the ACBT have been found to approach those of a P-I-N rectifier with a MOSFET in series for regulating its current, an equivalent circuit considered to be an ideal for MOS/Bipolar power devices. Unlike previous devices, the high off-state voltage is supported by the formation of a potential barrier to the flow of electrons from the N/sup +/ emitter into the N-drift region within a depletion region. The absence of the P-base region within the ACBT cells eliminates the parasitic four layer PNPN thyristor which had limited the performance of previous MOS/Bipolar transistor structures. Consequently, the ACBT structure has large maximum controllable and surge current densities in addition to low on-state voltage drop and high-voltage current saturation capability.}, number={5}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Thapar, N and Baliga, BJ}, year={1997}, month={May}, pages={178–180} }