Trench MOSFET Source Wiring Layout Without Mesa Contact Holes
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Solution Overview
Problem
Existing semiconductor apparatus designs face challenges in reducing the dimensions of the mesa region and maintaining high processing accuracy due to the need for contact holes and precise adjustment of the gate electrode and contact hole positions, which complicates the downsizing and voltage withstand of the device.
Innovation Solution
The semiconductor apparatus features a source wiring that contacts both the source contact region on the side wall of the gate trench and the body contact region on the second surface, eliminating the need for a contact hole in the mesa region, allowing for reduced dimensions and simplified processing, while the field plate electrode and insulating layers enhance voltage withstand and switching speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If contact holes are formed in the mesa region to connect source wiring to body region, then electrical connection is achieved, but manufacturing precision requirements increase and device dimensions cannot be reduced
Solution Approach 1:
The invention extracts the contact hole formation step from the manufacturing process by redesigning the source region configuration. The source region is extended to directly contact the body region at the mesa surface, eliminating the need for separate contact holes and their associated high-precision alignment requirements.
Solution Approach 2:
The source region is extended in the vertical dimension (depth direction) to reach the body region, creating a direct contact path that eliminates the need for lateral contact hole alignment. This dimensional approach transforms the connection from a 2D planar alignment problem to a 3D vertical integration solution.
2Reliability
If contact holes and precise position adjustment are used to connect source wiring to body region, then electrical connection is achieved, but device complexity increases
Solution Approach 1:
The source region serves dual functions: it acts as both the active source region for transistor operation and as the contact region connecting to the body region. This merging of functions eliminates separate contact structures and reduces overall device complexity while maintaining reliable electrical connection.
Solution Approach 2:
The extended source region performs multiple functions simultaneously: it provides the source for charge carriers, establishes electrical contact with the body region, and serves as part of the source wiring structure. This multi-functionality reduces the number of discrete components needed.
Data Source
AI summary
Provided is a semiconductor apparatus including a body region formed on a drift region, a body contact region formed on the body region, a gate trench formed to penetrate both the body region and the body contact region and reach the drift region, the gate trench including a side wall and a bottom wall, a source region formed along part of the side wall, the source region being in contact with both the body region and the body contact region, and source wiring arranged across both the gate trench and the body region as viewed in a depth direction of the gate trench. The source region includes a source contact region that is in contact with the source wiring. The source wiring is in contact with both a side surface of the source contact region and a front surface of the body contact region.