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...

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Benefits of technology

[0005]In an embodiment, a semiconductor super-junction (SJ) device includes a substrate layer having a first conductivity-type and one or more epitaxial (epi) layers disposed on the substrate layer and including a termination region disposed adjacent to an active region. The active region includes vertical charge-balance pillars of the first conductivity-type, each having a first width, and vertical charge-balance pillars of a second conductivity-type, each having a second width. The termination region includes a plurality of vertical pillars of the first and second conductivity-type, wherein, moving outward from the active region, a respective width of each successive vertical pillar of the plurality of vertical pillars 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 of the plurality of compensated regions is the same or greater.

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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