LDMOS FinFET Integration via Offset Drain Contact

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Solution Overview

Problem

The integration of laterally diffused metal oxide semiconductor (LDMOS) with FinFET devices has proven challenging due to compatibility issues, as existing methods struggle to effectively combine the two technologies.

Innovation Solution

The process involves forming a FinFET transistor with a fin of semiconductor material, a transistor gate electrode, raised source and drain regions of epitaxial growth material, and offsetting the drain contact region to create a laterally diffused metal oxide semiconductor configuration, allowing for the integration of LDMOS with FinFET devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional FinFET manufacturing processes are used, then standard FinFET performance is achieved, but LDMOS integration is not possible

Engineering Contradiction:

ImproveLDMOS integration capabilityVSAvoidprocess compatibility

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The manufacturing process is divided into distinct stages: initial FinFET formation, selective epitaxial growth for raised source/drain regions, and subsequent LDMOS-specific modifications. This segmentation allows each stage to be optimized independently, enabling LDMOS integration without compromising FinFET performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the device are given different properties through selective epitaxial growth. The raised source and drain regions are grown with specific doping and orientation to create high-resistivity drain regions characteristic of LDMOS, while maintaining standard FinFET characteristics in other areas.

Inventive Principle:

Principle #3Local quality

2Power

If LDMOS structure is integrated into FinFET, then high power and RF performance is achieved, but manufacturing complexity increases

Engineering Contradiction:

Improvehigh power and RF performanceVSAvoidmanufacturing process complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The LDMOS raised source/drain structure is merged with the FinFET fabrication sequence by performing selective epitaxial growth after gate formation but before contact opening. This combines what would traditionally be separate process flows into a unified manufacturing sequence, reducing overall complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The raised source and drain regions are formed preliminarily during the FinFET fabrication process itself, before final contact formation. This preliminary action establishes the LDMOS structure early in the process, avoiding the need for additional complex steps later.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If raised source and drain regions are formed through epitaxial growth, then LDMOS configuration is achieved, but manufacturing precision requirements increase

Engineering Contradiction:

ImproveLDMOS configurationVSAvoidepitaxial growth control

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The epitaxial growth process utilizes parameter changes including selective doping during growth, control of growth rate and temperature, and post-growth thermal processing to achieve the desired LDMOS structure. These parameter adjustments enable precise control over the raised source/drain region properties.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The epitaxial growth process acts as an intermediary step that transforms the standard FinFET structure into an LDMOS-compatible structure. This intermediary process enables the transition between the two device types while maintaining control over the final device characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach enables the successful integration of LDMOS with FinFET transistors, enhancing compatibility and performance for high power and radio frequency applications by providing a high resistivity drain region.

Implementation Method 1

epitaxially growing first epitaxial growth material on a top of said fin on a first side and second side of the transistor gate electrode to form a raised source region and a raised drain region, respectively

Methodology Applied

Scientific EffectEpitaxial growth: Epitaxy

Data Source

PatentUS9660083B2LDMOS finFET device and method of manufacture using a trench confined epitaxial growth process

Publication Date: 2017.05.23 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A FinFET transistor includes a fin of semiconductor material with a transistor gate electrode extending over a channel region. Raised source and drain regions of first epitaxial growth material extending from the fin on either side of the transistor gate electrode. Source and drain contact openings extend through a pre-metallization dielectric material to reach the raised source and drain regions. Source and drain contact regions of second epitaxial growth material extend from the first epitaxial growth material at the bottom of the source and drain contact openings. A metal material fills the source and drain contact openings to form source and drain contacts, respectively, with the source and drain contact regions. The drain contact region may be offset from the transistor gate electrode by an offset distance sufficient to provide a laterally diffused metal oxide semiconductor (LDMOS) configuration within the raised source region of first epitaxial growth material.