Super-junction device

Abstract

The invention discloses a super-junction device. The super-junction device comprises a super-junction structure, channel regions, a buffer layer, source regions and a drift region; first conductive type columns and second conductive type columns are alternately arranged so as to form the super-junction structure; a drain region is formed by a semiconductor substrate at the bottom of the buffer layer; the source regions are formed at the surfaces of the channel regions; the drift region, the channel regions and the second conductive type columns form a parasitic body diode; the first buffer sub-layer and a second sub-layer are stacked together to form the buffer layer; the doping concentration of the second sub-layer is lower than the doping concentration of the first conductivity type columns; the softness factor of the reverse recovery of the super-junction device can be increased by adjusting the doping concentration of the second buffer sub-layer; the doping concentration of the first buffer sub-layer is higher than the doping concentration of the second buffer sub-layer; and the specific on-resistance of the super-junction device can be maintained or decreased by adjusting thedoping concentration of the first buffer sub-layer. With the super-junction device of the invention adopted, the softness factor of the reverse recovery can be improved, the cost of the device and thespecific on-resistance of the device can be reduced, and the breakdown voltage of the device can be improved.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a super junction device. Background technique [0002] The super junction structure is composed of alternately arranged N-type pillars and P-type pillars. If the superjunction structure is used to replace the N-type drift region in the vertical double-diffused MOS transistor (Vertical Double-diffused Metal-Oxide-Semiconductor, VDMOS) device, the conduction path is provided through the N-type column in the conduction state, and when the conduction The P-type column does not provide a conduction path; in the off state, the PN column jointly bears the reverse bias voltage, forming a super-junction metal-oxide-semiconductor field-effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET). Such as figure 1 Shown is a structural diagram of an existing super-junction device. The super-junction device is a super-junction power device. Here, an N-type super-juncti...

AI Technical Summary

Problems solved by technology

Therefore, in the prior art, the softness factor can be improved by increasing the thickness of the buffer layer. However, since the buffer layer is formed by an epitaxial process, the thicker the buffer layer, the longer the time of the epitaxial process, and the higher the cost of the epitaxial process. This will increase the cost of the device; at the same time, the increase in the buffer layer will also increase the specific on-resistance of the device

Images