System and method for edge termination of super-junction (SJ) devices

Abstract

The subject matter disclosed herein relates to super-junction (SJ) power devices and, more specifically, to edge termination techniques for SJ power devices. A semiconductor super-junction (SJ) device includes one or more epitaxial (epi) layers having a termination region disposed adjacent to an active region. The termination region includes a plurality of vertical pillars of a first and a second conductivity-type, wherein, moving outward from the active region, a respective width of each successive vertical pillar is the same or smaller. The termination region also includes a plurality of compensated regions having a low doping concentration disposed directly between a first side of each vertical pillar of the first conductivity-type and a first side of each vertical pillar of the second conductivity-type, wherein, moving outward from the active region, a respective width of each successive compensated region is the same or greater.

Description

BACKGROUND[0001]The subject matter disclosed herein relates to super-junction (SJ) power devices and, more specifically, to edge termination techniques for SJ power devices.[0002]For semiconductor power devices, super-junction (SJ) (also referred to as vertical charge-balance) designs offer several advantages. For example, SJ devices demonstrate reduced on-resistance and reduced conduction losses relative to conventionally designed unipolar power devices. Additionally, SJ drift layers can be applied to a variety of power devices, such as metal-oxide-semiconductor field-effect transistors (MOSFETs), junction field effect transistors (JFETs), bipolar junction transistors (BJTs), diodes, as well as other devices that may be useful for medium-voltage (e.g., 2 kV-10 kV) and high-voltage (e.g., greater than or equal to 10 kV) power conversion related applications.[0003]For high-voltage and / or high-current applications, devices fabricated using wide bandgap semiconductors (e.g., silicon ca...

AI Technical Summary

Benefits of technology

This patent is about a new method for making semiconductor devices called SJ devices. The method uses a special edge termination design that allows the devices to have a lower blocking voltage, while still being fast and using minimal process steps. This design also allows for the formation of small pillars in the termination region, which results in a smaller device size and higher device cell density. Overall, this invention provides a more efficient and effective way to make SJ devices.

Problems solved by technology

However, there are also significantly higher electric fields present in wide bandgap semiconductors devices under reverse bias.

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