Bizen, a new disruptive wafer process technology, has been verified by physical wafer results and calibration to produce the same voltage levels, switching speeds and power handling performance of wide bandgap devices, the developers Search For The Next (SFN) claim. The first devices to use the technology are members of the QJT (Quantum Junction Transistor) family which includes three parts rated at 1200V/75A, 900V/75A and 650V/32A, offered in the industry-standard TO247 or TO263 power MOSFET packages. Of high significance is these devices can be created using standard silicon substrates on established, larger-geometry silicon processing lines.
Explains David Summerland, CEO and founder of Nottingham-based Search For The Next, which invented the Bizen technology: “To get this level of performance from traditional silicon-based MOSFETs, the device size must be much bigger. 1200V/75A in a TO247 housing can be achieved using wide bandgap materials like silicon carbide, but this approach has other well-known issues. SiC, for example, takes much longer to process and has a significant manufacturing carbon footprint. Also, regardless of the roadmaps, SiC does not scale like silicon, and the economic argument that SiC can match silicon does not take into account the advances made possible by Bizen. By contrast, the data we have obtained from physical wafer tests proves that by using Bizen on silicon substrates, our QJTs deliver the same performance as SiC or GaN. Yet the production equipment required to make a QJT is exactly the same as for a standard silicon MOSFET, and the Bizen process adds no extra manufacturing complexity.”
Bizen applies quantum mechanics to a conventional bipolar wafer process. The result is an extremely rugged and dependable device with the heritage and pedigree of conventional bipolar silicon technology. The technology also reduces lead times from 15 weeks – typical for incorporating MOS to create large scale integration CMOS – to less than two weeks, and halves the number of process layers; the new QJTs employ these same eight layers and wafer process.