Bipolar Mode Static Induction Transistor Research Articles

An analytical model for the saturation characteristics of bipolar-mode static induction transistors

This paper presents an analytical model of bipolar-mode static induction transistor (BSIT) aiming to elaborate the saturation behavior of its device characteristics. Based on new ideas and analyses, it is pointed out that the saturation behavior is due to the shrinking of the plasma, which is composed of large magnitude of holes and electrons resulting from carrier injection. The density and profile of the plasma are mainly governed by the gate biasing voltage. A transition voltage and a saturation voltage are defined, respectively, where the saturation voltage is expressed as a function of the gate voltage. It is also shown that the transconductance changes nearly exponentially with the gate voltage in the saturated segment of current. The analytical results are shown in good accordance with experiments.

High-power rectifier using the BSIT operation

A novel high-power rectifier using the BSIT (Bipolar mode Static Induction Transistor) operation has been demonstrated. In order to improve the reverse blocking capability of this diode, an ion implanted P-type channel structure is introduced. Device simulations have revealed that, as the tradeoff relationships between reverse blocking voltage, forward voltage drop, and reverse recovery time are considered, there exists an optimum set of the channel dosage and the channel width.

Low loss static induction devices (transistors and thyristors)

To decrease the power loss, a current gain of a bipolar mode Static Induction Transistor (BSIT) is examined with quasi-one-dimensional analysis. The current gain dependence on source contact area is presented with experimental, analyzed and simulated results. Concerning Static Induction Thyristor (SIThy), the switching speed improvement methods are presented to reduce the switching loss of device. A proton irradiation, or a shorting method is a useful technique to decrease the switching time and switching loss of SIThy.

Rectifier characteristics based on bipolar-mode SIT operation

A novel rectifier concept based on bipolar-mode static induction transistor (BSIT) operation is proposed. A numerical simulation has revealed that the turn-on mechanism of this rectifier, owing to a combination of static induction effects and minority carrier injection, can make its forward-voltage drop and reverse recovery time smaller than those of the conventional p-i-n rectifier. As an example of the design methods, the simulation has clarified the effects of decreasing the doping concentration in the channel between p/sup +/ regions on improvement in the tradeoff between a forward voltage drop and leakage current.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Effects of the doping profile on current characteristics in BSITs

Proposed are two doping profiles of the conducting channel in bipolar-mode static induction transistors (BSITs) that improve the current handling capability. By using the results obtained from two-dimensional device simulations, it is shown that BSITs with the proposed profiles exhibit higher drain current density and DC current gain than conventional BSITs. Also discussed is the tradeoff between the current and voltage capabilities. >

Bipolar-mode static induction transistor: experiment and two-dimensional analysis

A bipolar-mode static induction transistor (BSIT) with a simple planar structure as an experimental device has been fabricated. Two-dimensional numerical simulation has been used to investigate the operational principle for the BSIT with the pentode-like shape revealed by the output characteristics. Using the simulation, the variation of the potential barrier as a function of the bias voltages has been explained. The results show that the potential barrier is varied uniquely according to the physical condition of the conduction channel determined by the external bias voltages. This variation can be explained easily with the DC circuit models originating from the physical conditions of the conduction channel. The analysis shows that the current in the BSIT is controlled in a complex manner by the voltages. >

Punching through device and its integration—Static induction transistor

Static induction transistor (SIT) having a short-channel structure is characterized by small gate capacitance, high transconductance, and nonsaturation current-voltage characteristic. The major mechanism of current transport in SIT is majority-carrier injection due to barrier height control at the intrinsic gate in the channel. When the channel is completely pinched off due to the gate-to-channel built-in voltage in a junction-gate SIT (JSIT), there appears a normally-off SIT. In the forward gate bias operation of JSIT, which is called bipolar mode SIT (BSIT), the switching speed is far more improved from the conventional JSIT. BSIT exhibits saturation current-voltage characteristic. In BSIT, the drain voltage for the onset of current saturation is lower than that of the bipolar transistor and the current density is very high, leading to characteristics of low impedance, high transconductance, and high current gain. Applications of SIT in LSI are discussed especially concentrating on the BSIT. SIT logic circuit (SITL) containing BSIT exhibits short propagation delay time and low power dissipation and is very promising in the future development of VLSI.