TY - JOUR TI - Effect of collector structure on the FBSOA of the dielectrically-isolated LIGBT AU - Nagapudi, V AU - Sunkavalli, R AU - Baliga, BJ T2 - IEEE TRANSACTIONS ON ELECTRON DEVICES AB - In this paper, the dependence of the forward biased safe operating area (FBSOA) on the collector structures of the dielectrically-isolated (DI) lateral insulated gate bipolar transistor (LIGBT) has been analyzed. In addition to the on-state and switching characteristics, pulsed measurements were performed to determine the FBSOA of these devices. Two-dimensional (2-D) numerical simulations were performed to understand the physics behind the operation of devices fabricated with various collector designs. These studies reveal that some of the structures behave like the conventional LIGBT, while others behave like the LDMOSFET with respect to their FBSOA. Some of the structures also exhibit a unique high-voltage blocking ability while carrying current, while having much smaller breakdown voltages. DA - 1998/5// PY - 1998/5// DO - 10.1109/16.669579 VL - 45 IS - 5 SP - 1155-1161 SN - 1557-9646 KW - dielectric isolation KW - lateral IGBT KW - power IC's ER - TY - BOOK TI - Cryogenic operation of silicon power devices AU - Singh, R. AU - Baliga, B. J. AB - The advent of low temperature superconductors in the early 1960's converted what had been a laboratory curiosity with very limited possibilities to a prac tical means of fabricating electrical compone CN - TK7871.92 .S56 1998 DA - 1998/// PY - 1998/// DO - 10.1007/978-1-4615-5751-7 PB - Boston, MA: Kluwer Academic Publishers SN - 0792381572 ER - TY - JOUR TI - Role of defects in producing negative temperature dependence of breakdown voltage in SiC AU - Raghunathan, R AU - Baliga, BJ T2 - APPLIED PHYSICS LETTERS AB - Electron beam induced current (EBIC) techniques were employed in order to understand the role of defects on the breakdown characteristics of SiC. EBIC images revealed that certain defects caused enhanced multiplication leading to the catastrophic failures in SiC diodes. The impact ionization coefficients for holes measured at the defective site (αp,eff) were found to be higher than those measured at a nondefective site. Also, αp,eff measured at the defective site was found to increase with increasing temperature in contrast with a defect free diode where αp decreases with increasing temperature, clearly indicating that the defects produce the observed negative temperature coefficient of breakdown voltage in SiC. DA - 1998/6/15/ PY - 1998/6/15/ DO - 10.1063/1.121591 VL - 72 IS - 24 SP - 3196-3198 SN - 0003-6951 ER - TY - JOUR TI - Lateral N-channel inversion mode 4H-SiC MOSFET's AU - Sridevan, S AU - Baliga, BJ T2 - IEEE ELECTRON DEVICE LETTERS AB - Advances in MOS devices on silicon carbide (SiC) have been greatly hampered by the low inversion layer mobilities. In this paper, the electrical characteristics of lateral n-channel MOSFETs fabricated on 4H-SiC are reported for the first time. Inversion layer electron mobilities of 165 cm/sup 2//V/spl middot/s in 4H-SiC MOSFETs were measured at room temperature. These MOSFETs were fabricated using a low temperature deposited oxide, with subsequent oxidation anneal, as the gate dielectric. DA - 1998/7// PY - 1998/7// DO - 10.1109/55.701425 VL - 19 IS - 7 SP - 228-230 SN - 0741-3106 KW - inversion layer KW - mobility KW - MOSFET KW - silicon carbide ER - TY - JOUR TI - Improved DC-EST structure with diode diverter AU - Sawant, S AU - Baliga, BJ T2 - ELECTRONICS LETTERS AB - A novel emitter switched thyristor (EST) structure with a diode diverter is introduced to obtain superior current saturation characteristics with an excellent forward bias safe operating area, without compromising the on-state voltage drop. The new structure consists of a diode diverter connected to the p-base region of the DC-EST. The saturation current density is lowered significantly, which is desirable to achieve a good saturation current safe operating area. Experimental results are reported to confirm the superior characteristics observed through simulations. DA - 1998/6/25/ PY - 1998/6/25/ DO - 10.1049/el:19980967 VL - 34 IS - 13 SP - 1358-1360 SN - 0013-5194 ER - TY - JOUR TI - Reverse blocking lateral MOS-gated switches for AC power control applications AU - Mehrotra, M AU - Baliga, BJ T2 - SOLID-STATE ELECTRONICS AB - Two new high voltage reverse blocking lateral device structures, called the lateral MOS gated thyristor (LMGT) and lateral IGBT with P+-diverter (LIGBT-D), are presented. Both of these devices are designed to support high reverse voltage suitable for ac power control applications. These devices utilize thyristor current conduction controlled by MOS gate and realize MOS gate controlled switching and current saturation characteristics. The fabricated devices had a bidirectional blocking voltage capability of 600 V. Switching measurements yielded a turn-off time 3 and 5 μs for the LMGT and LIGBT-D devices. DA - 1998/4// PY - 1998/4// DO - 10.1016/S0038-1101(97)00286-4 VL - 42 IS - 4 SP - 573-579 SN - 0038-1101 ER - TY - JOUR TI - Analytical model for the threshold voltage of Accumulation Channel MOS-Gate devices AU - Thapar, N AU - Baliga, BJ T2 - SOLID-STATE ELECTRONICS AB - 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. DA - 1998/11// PY - 1998/11// DO - 10.1016/S0038-1101(98)00179-8 VL - 42 IS - 11 SP - 1975-1979 SN - 0038-1101 ER - TY - JOUR TI - P-type 4H and 6H-SiC high-voltage Schottky barrier diodes AU - Raghunathan, R AU - Baliga, BJ T2 - IEEE ELECTRON DEVICE LETTERS AB - High-voltage Schottky barrier diodes have been successfully fabricated for the first time on p-type 4H- and 6H-SiC using Ti as the barrier metal. Good rectification was confirmed at temperatures as high as 250/spl deg/C. The barrier heights were estimated to be 1.8-2.0 eV for 6H-SiC and 1.1-1.5 eV for 4H-SiC at room temperature using both I-V and C-V measurements. The specific on resistance (R/sub on,sp/) for 4H- and 6H-SiC were found to be 25 m/spl Omega/ cm/sup -2/ and 70 m/spl Omega/ cm/sup -2/ at room temperature. A monotonic decrease in resistance occurs with increasing temperature for both polytypes due to increased ionization of dopants. An analytical model is presented to explain the decrease of R/sub on,sp/ with temperature for both 4H and 6H-SiC which fits the experimental data. Critical electric field strength for breakdown was extracted for the first time in both p-type 4H and 6H-SiC using the breakdown voltage and was found to be 2.9/spl times/10/sup 6/ V/cm and 3.3/spl times/10/sup 6/ V/cm, respectively. The breakdown voltage remained fairly constant with temperature for 4H-SiC while it was found to decrease with temperature for 6H-SiC. DA - 1998/3// PY - 1998/3// DO - 10.1109/55.661168 VL - 19 IS - 3 SP - 71-73 SN - 0741-3106 KW - breakdown KW - electric field KW - silicon carbide KW - Schottky rectifiers ER - TY - JOUR TI - The dV/dt capability of MOS-gated thyristors AU - Venkataraghavan, P AU - Baliga, BJ T2 - IEEE TRANSACTIONS ON POWER ELECTRONICS AB - In this paper, a detailed study of the dV/dt capability of MOS-gated thyristors is performed. It is shown that in addition to the conventional mode of dV/dt-induced turn-on in thyristors, termed the intrinsic mode, there exists another distinct mode of dV/dt-induced turn-on, peculiar to the MOS-gated thyristor structure, which the authors term the extrinsic dV/dt mode. The effective dV/dt capability is determined by both modes and is degraded by the presence of an external gate-cathode resistance and parasitic gate-anode capacitance. The existence of these two modes of dV/dt-induced turn-on is demonstrated experimentally, and the effect of device parameters on the dV/dt capability is studied. DA - 1998/7// PY - 1998/7// DO - 10.1109/63.704134 VL - 13 IS - 4 SP - 660-666 SN - 0885-8993 KW - MOS gate KW - switching KW - thyristors ER - TY - JOUR TI - Analysis and suppression of latch-up during IGBT mode of DG-BRT operation AU - Yamazaki, T AU - Baliga, BJ T2 - SOLID-STATE ELECTRONICS AB - The influence of P-base doping concentration on the saturation characteristics of the dual gate BRT (DG-BRT) structure in the IGBT mode of operation is analyzed in this paper by two dimensional simulation. The common base current gains (αPNP and αNPN) of the inherent PNP and NPN transistors within the DG-BRT structure have been extracted as a function of operating current density. Based upon these values, it is demonstrated that, by using P-base concentration of 5×1018 cm−3, the sum of the current gains (αPNP+αNPN) can be made less than unity in the IGBT mode of operation to suppress latch-up. This results in a significant enhancement of the forward biased safe operating area. DA - 1998/3// PY - 1998/3// DO - 10.1016/S0038-1101(97)00215-3 VL - 42 IS - 3 SP - 393-399 SN - 0038-1101 ER - TY - JOUR TI - An experimental evaluation of the on-state performance of trench IGBT designs AU - Thapar, N AU - Baliga, BJ T2 - SOLID-STATE ELECTRONICS AB - 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. DA - 1998/5// PY - 1998/5// DO - 10.1016/S0038-1101(97)00301-8 VL - 42 IS - 5 SP - 771-776 SN - 1879-2405 ER -