Trench Contact Layout for Semiconductor Breakdown and Latch-Up Control

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Solution Overview

Problem

Conventional semiconductor devices face challenges in effectively reducing the resistance of the base region and improving the extraction of minority carriers, which affects the breaking withstand capability and latch-up prevention.

Innovation Solution

The semiconductor device incorporates trench contacts with a contact layer of higher doping concentration, formed by ion implantation, that extends into the emitter region and is in contact with the emitter region and contact layer, facilitating the extraction of minority carriers and preventing carrier injection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If ion implantation is used to form the contact layer, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improvecontact layer doping concentration controlVSAvoidfabrication process steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing ion implantation to form the high-doping contact layer before forming the trench contact structure. The contact layer is prepared in advance with controlled doping concentration and depth, and then the trench contact is formed by etching through the emitter region down to this pre-prepared contact layer. This sequence improves manufacturing precision by establishing the doping profile beforehand, while the standardization of this preliminary step reduces overall process complexity.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enhances the breaking withstand capability and stabilizes the potential of the base region, improving the extraction efficiency of minority carriers and preventing latch-up.

Implementation Method 1

improving the extraction efficiency of minority carriers

Methodology Applied

Scientific EffectCarrier diffusion: Diffusion

Implementation Method 2

formed by ion implantation

Methodology Applied

Scientific EffectIon implantation: Ion Implantation

Data Source

PatentUS12199162B2Semiconductor device and fabrication method of semiconductor device having improved breaking withstand capability

Publication Date: 2025.01.14 FUJI ELECTRIC CO LTD

AI summary

There is provided a semiconductor device including: a drift region of a first conductivity type disposed in a semiconductor substrate; a base region of a second conductivity type disposed above the drift region; an emitter region of the first conductivity type disposed above the base region; a plurality of trench portions arrayed in a predetermined array direction on a front surface side of the semiconductor substrate; a trench contact disposed on the front surface side of the semiconductor substrate between two adjacent trench portions; and a contact layer of the second conductivity type disposed under the trench contact and having a higher doping concentration than the base region, wherein a lower end of the trench contact is deeper than a lower end of the emitter region, and the emitter region and the contact layer are in contact with each other at a side wall of the trench contact.