Papers by Keyword: Bipolar Junction Transistor (BJT)

Abstract: Considering the development of faster power electronic switches, especially silicon carbide (SiC) devices, parasitic elements, such as stray inductances and capacitances, become more and more crucial. Overvoltages caused by stray inductances in combination with fast switching transients can destroy the devices at turn-off. In this paper the implementation of the DVRC circuit for silicon carbide bipolar junction transistors (BJTs) is investigated. The DUT was Fairchild`s FSICBH057A120 (V_CES = 1200 V, R_on = 57 mΩ).

Abstract: I-V-characteristics of an irradiated transistor in many cases should be measured inside the radiation chamber with long cables, which introduces noticeable measurement error. In this paper IV-characteristics of an irradiated bipolar junction transistor measured with the 4-wire and the 2-wire circuits are presented and compared to direct (without cables) measurements. Significant enlargement of measurement error for the 2-wire method in comparison with the 4-wire method is shown for different currents.

Abstract: An efficient methodology of electro-thermal design of smart power semiconductor devices and ICs, based on the combined use of SPICE circuit analysis tool and software tools for 2D/3D thermal simulation of IC chip construction, is presented. The features of low, medium and high power elements, temperature sensors, IC chips simulation are considered.

Abstract: In this work, a 4H-Silicon Carbide (SiC) Bipolar Junction Transistor (BJT) capable of operating at high temperatures up to 673 K is demonstrated. Comprehensive characterization including current gain, early voltage, and intrinsic voltage gain was performed. At elevated temperatures, although the current gain of the device is reduced, the intrinsic voltage gain increases to 5900 at 673 K, suggesting 4H-SiC BJT has the potential to be used as a voltage amplifier at extremely high temperatures.

Abstract: In this work, large area SiC BJTs with good long-term stability in 1000 hrs DC stress tests are demonstrated. It is also illustrated how wafer scanning techniques can be used to reject BJT dies with basal plane dislocations, thereby eliminating the risk for bipolar degradation.

Abstract: Low power Silicon Carbide (SiC) devices and Integrated Circuits (ICs) in conjunction with SiC or Aluminum Nitride (AlN) sensing elements will enable sensing functions in high temperature environments up to 600 °C where no silicon based devices or circuits have been able to survive in that temperature range. In power electronics applications, existence of low power SiC devices and IC technologies will significantly aid the development of high power density power modules in which total weights and cooling systems sizes are reduced. This paper will be evaluating the performances of the fabricated low power SiC device candidates (JFET and BJT) for SiC-based analog ICs design for high temperature and power electronics applications.

Abstract: The aim of this study consists in comparing the effects of temperature on various SiC power devices. Electrical characteristics have been measured for temperatures from 100K to 525K. All devices are suitable for high temperature. However, SiC MOSFETs are not a good choice for cryogenic temperature, while SiC BJTs are less affected by temperature than other components, especially for cryogenic temperature.

Abstract: Performance of 4H-SiC BJTs fabricated on a single 100mm wafer with different SiC etching and sacrificial oxidation procedures is compared in terms of peak current gain in relation to base intrinsic sheet resistance. The best performance was achieved when device mesas were defined by inductively coupled plasma etching and a dry sacrificial oxide was grown at 1100 °C.

Abstract: Electronic device that subjected to various effects by radiations can cause small interferences such as noises in the circuit. These effects are especially critical in operating environment such as outer space, where radiation comes in stronger and more frequent. In this research, analytical study on the effects of ionizing radiation induced by ⁶⁰Co gamma (γ) rays in bipolar junction transistor (BJT) devices had been performed. It was found that the high energy of the radiation allows more valence electrons to be excited to the conduction band in the BJT. This leads to the production of a large number of excited atoms and increases the holes in the valence band. The increase of holes in the base region due to trapping will increase the probability of recombination and reducing the number of electrons that reaches the collector region. This ionizing radiation effect was found to arouse either a permanent or temporarily damage in the devices depending on their current drives and total dose absorbed.

Abstract: Epoxy moulded power modules with a small footprint of 40 mm x 55 mm were fabricated with two switches, each consisting of six parallel 1200 V 50 A rated BJTs and Schottky diodes. The SiC-based power modules have very low on-resistance of 3.3 mΩ and a current gain of 80, both at room temperature. An inverter with specially designed drive circuits was constructed using the power modules and an efficiency of 98.5 % was shown for an output power of 12 kW.