Fin-Shaped Structure Enlargement for Region-Specific FinFET Channel Control

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Solution Overview

Problem

Current semiconductor fabrication processes for FinFET devices cannot simultaneously satisfy the demand for greater critical dimension in core regions for increased channel volume and smaller critical dimension in input/output regions to improve short channel effects.

Innovation Solution

A method is developed to fabricate semiconductor devices by forming fin-shaped structures on a substrate with different top surfaces on core and input/output regions, where the critical dimension of the fin-shaped structure on the core region is enlarged through epitaxial growth while maintaining the same critical dimension on the input/output region by using a patterned mask to cover the input/output region during the growth process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the critical dimension of fin-shaped structures is increased in core regions to increase channel volume, then the channel volume and current capability are improved, but the short channel effect control and device reliability deteriorate

Engineering Contradiction:

Improvechannel volumeVSAvoidshort channel effect control

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent applies different critical dimensions to fin-shaped structures in different regions: core regions use larger critical dimensions (e.g., 10-15 nm) to increase channel volume and current capability, while input/output regions use smaller critical dimensions (e.g., 5-10 nm) to maintain excellent short channel effect control. This regional differentiation allows each area to be optimized for its specific functional requirements without compromising overall device performance

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The substrate is divided into distinct core regions and input/output regions, with independently optimized fin-shaped structures in each region. The core region contains fin-shaped structures with larger critical dimensions for high current drive, while the input/output region contains fin-shaped structures with smaller critical dimensions for superior short channel control, allowing simultaneous optimization of both requirements

Inventive Principle:

Principle #1Segmentation

2Reliability

If the critical dimension of fin-shaped structures is decreased in input/output regions to improve short channel effect, then the short channel effect control is improved, but the channel volume and current capability deteriorate

Engineering Contradiction:

Improveshort channel effect controlVSAvoidchannel volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent implements region-specific fin-shaped structure designs where input/output regions utilize smaller critical dimensions (e.g., 5-10 nm) to achieve excellent short channel effect control and device reliability, while core regions employ larger critical dimensions (e.g., 10-15 nm) to maximize channel volume and current driving capability, with each region's structure optimized for its specific functional demands

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If the same critical dimension is used for all fin-shaped structures on the substrate, then the manufacturing process is simplified, but the device performance for different regions cannot be optimized simultaneously

Engineering Contradiction:

Improvefabrication process simplicityVSAvoiddevice performance

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The substrate is segmented into core regions and input/output regions with distinct fin-shaped structure critical dimensions. This segmentation enables independent optimization of each region's performance characteristics while maintaining a relatively streamlined fabrication process through selective processing steps that target specific regions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different critical dimensions are implemented locally in different regions of the substrate. The core region features fin-shaped structures with larger critical dimensions optimized for current drive, while the input/output region features fin-shaped structures with smaller critical dimensions optimized for short channel control, allowing simultaneous optimization of both performance aspects

Inventive Principle:

Principle #3Local quality

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 allows for increased channel width on the core region while maintaining the critical dimension on the input/output region, effectively addressing the demand for both regions and enhancing device performance.

Implementation Method 1

the drain-induced barrier lowering (DIBL) effect and the short channel effect are reduced

Methodology Applied

Scientific EffectDrain-induced barrier lowering effect:

Implementation Method 2

performing a process to enlarge the first fin-shaped structure

Methodology Applied

Scientific EffectEpitaxial growth: Epitaxy

Data Source

PatentUS11876095B2Method for enlarging tip portion of a fin-shaped structure

Publication Date: 2024.01.16 UNITED MICROELECTRONICS CORP

AI summary

A method for fabricating semiconductor device includes the steps of: providing a substrate having a first region and a second region; forming a first fin-shaped structure on the first region and a second fin-shaped structure on the second region; forming a patterned mask on the second region; and performing a process to enlarge the first fin-shaped structure so that the top surfaces of the first fin-shaped structure and the second fin-shaped structure are different.