Semiconductor device and method for manufacturing the same

Abstract

A semiconductor device which solves the following problem of a super junction structure: due to a relatively high concentration in the body cell region (active region), in peripheral areas (peripheral regions or junction end regions), it is difficult to achieve a breakdown voltage equivalent to or higher than in the cell region through a conventional junction edge terminal structure or resurf structure. The semiconductor device includes a power MOSFET having a super junction structure formed in the cell region by a trench fill technique. Also, super junction structures having orientations parallel to the sides of the cell region are provided in a drift region around the cell region.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The disclosure of Japanese Patent Application No. 2009-263600 filed on Nov. 19, 2009 including the specification, drawings and abstract is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]The present invention relates to semiconductor devices (or semiconductor integrated circuit devices) and a cell peripheral layout technique or a breakdown voltage enhancement technique in a method for manufacturing a semiconductor device (or semiconductor integrated circuit device).[0003]Japanese Unexamined Patent Publication No. 2007-116190 and US Patent Publication 2005-098826 disclose various structures relating to layout of the vicinity of a cell region in a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) with a super junction structure which is manufactured by a multi-epitaxial technique or a trench insulating film filling technique (implantation of ions into trenches). These structures include P− re...

AI Technical Summary

Benefits of technology

[0004]Regarding drift regions of power MOSFETs or the like, an important issue is to develop a high breakdown voltage FET with low on-resistance or the like beyond the traditional silicon limit. In this direction, various methods for introducing a super junction structure have been developed, in which the super junction structure has slab-shaped N type columns and P type columns arranged alternately in a drift region with a relatively high doping concentration. The techniques for introducing a super junction structure are roughly divided into three categories: multi-epitaxial technique, trench insulating film filling technique, and trench fill technique (trench filling or trench epitaxial filling). Among them, the multi-epitaxial technique, in which epitaxial growth and ion implantation are repeated many times, allows wide latitude in process and design but requires high cost because it involves a complicated process. The trench insulating film filling technique, in which ions are obliquely implanted in a trench and the trench is then filled with insulating film by CVD (Chemical Vapor Deposition), is simpler but disadvantageous in terms of size because it requires a trench area.

[0007]An object of the present invention is to provide a semiconductor device as a solid active device or the like with high breakdown voltage and low on-resistance.

[0012]Since in a semiconductor device including a power MOSFET having a super junction structure formed in a cell region by a trench fill technique, a drift region around the cell region has a super junction structure having an orientation parallel to each side of the cell region, a drop in breakdown voltage around the cell region can be effectively prevented.

Problems solved by technology

Regarding drift regions of power MOSFETs or the like, an important issue is to develop a high breakdown voltage FET with low on-resistance or the like beyond the traditional silicon limit.

Among them, the multi-epitaxial technique, in which epitaxial growth and ion implantation are repeated many times, allows wide latitude in process and design but requires high cost because it involves a complicated process.

The trench insulating film filling technique, in which ions are obliquely implanted in a trench and the trench is then filled with insulating film by CVD (Chemical Vapor Deposition), is simpler but disadvantageous in terms of size because it requires a trench area.

In a super junction structure, because the body cell region (active region) has a relatively high doping concentration, it is difficult to achieve, in peripheral areas (peripheral regions and junction end regions), a breakdown voltage equivalent to or higher than that in the cell region through a conventional junction edge termination structure or resurf (reduced surface field) structure.

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