<100> Channel Orientation in Charge Trap Memory

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Solution Overview

Problem

Conventional nonvolatile charge trap memory devices with channel regions oriented along the crystal plane may not be optimal, leading to suboptimal performance due to stress from isolation structures and non-uniform tunnel oxide growth, affecting drive current and reliability.

Innovation Solution

A nonvolatile charge trap memory device with a channel region oriented along the crystal plane, featuring a uniform liner oxide layer in the isolation structure and uniform tunnel oxide growth on both the top surface and sidewalls, reducing stress and improving reliability and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If channel region is oriented along the <100> crystal plane, then drive current and reliability are improved, but manufacturing complexity increases due to requiring specific crystal orientation control

Engineering Contradiction:

Improvedevice reliabilityVSAvoidcrystal orientation control

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the crystal orientation parameter from conventional <110> to <100> for the channel region, which fundamentally alters the stress characteristics and oxide growth behavior, thereby improving reliability while managing the complexity through systematic process design

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional <110> crystal plane orientation is used, then manufacturing process is simpler, but stress from isolation structures degrades device performance

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoiddevice performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

3Productivity

If channel region has <110> crystal plane orientation, then tunnel oxide growth is faster, but non-uniform growth reduces manufacturing precision

Engineering Contradiction:

Improveoxide growth rateVSAvoidoxide uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the crystal orientation parameter from <110> to <100>, which modifies the oxide growth kinetics to achieve uniform growth rates on different crystal planes, thereby simultaneously improving manufacturing precision and maintaining acceptable productivity

Inventive Principle:

Principle #35Parameter changes

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

The device demonstrates increased drive current and improved reliability by mitigating stress and ensuring uniform growth, enhancing the overall performance compared to devices with channel regions oriented along different crystal planes.

Implementation Method 1

uniform tunnel oxide growth on both the top surface and sidewalls

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS7880219B2Nonvolatile charge trap memory device having <100> crystal plane channel orientation

Publication Date: 2011.02.01 LONGITUDE FLASH MEMORY SOLUTIONS LTD

AI summary

A nonvolatile charge trap memory device and a method to form the same are described. The device includes a channel region having a channel length with <100> crystal plane orientation. The channel region is between a pair of source and drain regions and a gate stack is disposed above the channel region.