Diodes Inc.

Peter Hugh Blair

Lee Spencer Riley

This application provides a process for making a circuit of a bipolar junction transistor (BJT). The switchable short in one implementation of the invention is formed in a semiconductor wafer. A collector region is formed in the semiconductor wafer and inside of the collector region, a first base region is formed. An emitter region is formed inside the base region to form the BJT. A drain region is also formed inside the base region adjacent to the emitter region. A gate is formed over a portion of the base region adjacent to the drain region and the emitter region. The gate is connected to the collection region.

Method for making a bipolar junction transistor having an integrated switchable short

The invention solves the problem of depressed SOA of a bipolar junction transistor (BJT) when operated in an open base configuration by integrating in the same semiconductor chip a switchable short between the base and the emitter of the BJT. The switchable short switches between a high resistive value when the collector voltage of the BJT is lower than the base voltage. and a lower resistive value when the collector voltage is higher than the voltage base to effectively lower the BJT current gain (h). The switchable short in one implementation of the invention is in the form of a MOSFET with its gate connected to the BJT collector. The invention further teaches disposing in the integrated circuit chip a junction diode with a breakdown voltage lower than the BVCBO of the BJT. The addition of the junction diode provides a measure of maintaining the effectiveness of the MOSFET as switchable short at a reduced size.

Bipolar junction transistor having an integrated switchable short

A trenched MOS gate controlled rectifier has an asymmetric trench structure between the active area of active trenches and the termination area of termination trenches. The asymmetric trench structure has a gate electrode on one side of the trench to turn on and off the channel of the MOS structure effectively and a field plate structure on the other side with field dielectric sufficiently thick in order to sustain the high electric field during the reverse bias condition.

Growing community of inventors

Manchester, United Kingdom

Peter Hugh Blair