Researchers at the University of California, Santa Barbara have created both surface and buried p-type regions without the need for doping the materials with an acceptor.
Vertical GaN power devices have gained increased attention, due to their potential to provide higher breakdown voltage without increasing specific on-resistance. As a result, numerous vertical GaN power devices and transistors have been demonstrated in recent years. However, these devices suffer from the inefficiency of dopant based p-type doping in buried p-GaN layers. For example, the p-type doped concentration cannot be increased sufficiently in U-MOSFET type devices, because p-type GaN layer is located close to the channel. The design of these devices, their growth, and fabrication space is severely impeded.
Researchers at the University of California, Santa Barbara have created both surface and buried p-type regions without the need for doping the materials with an acceptor. A III-Nitride active region on a polar substrate comprises graded polar materials and has a polar orientation. Holes in a hole supply region above the active region are driven into the active region by a piezoelectric and/or spontaneous polarization field generated by the composition and grading of the active region. Devices enabled include LEDs without acceptor doping in the active p-type region (p-region) and buried active p-regions and devices based on this availability, such as tunnel junction based LEDs and lasers, and vertical electronic devices that need buried p-regions, such as CAVETs, MOSFETs and super-junction devices.
|United States Of America||Published Application||19-0181329||06/13/2019||2016-770|