Hybrid Channel NAND Structure Using Flashlamp Monocrystalline Conversion

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Solution Overview

Problem

Current semiconductor devices with three-dimensional memory cell arrays face challenges in enhancing carrier mobility and switching operations due to polycrystalline silicon channel films, which limit the performance of NAND non-volatile storage devices.

Innovation Solution

The implementation of flashlamp annealing to convert polycrystalline silicon channel films into monocrystalline silicon, utilizing a xenon flashlamp to absorb light and increase grain size, thereby reducing carrier scattering and improving mobility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polycrystalline silicon channel films are used in three-dimensional memory cell arrays, then the device structure can be formed, but carrier mobility is limited due to grain boundary scattering

Engineering Contradiction:

Improvecarrier mobilityVSAvoidchannel film structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies flashlamp annealing to change the physical state of the channel film from polycrystalline to monocrystalline. This parameter change in crystal structure eliminates grain boundaries, thereby improving carrier mobility while maintaining the three-dimensional memory cell array structure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition of silicon from polycrystalline state to monocrystalline state through flashlamp annealing. This phase transition transforms the channel film structure to achieve higher carrier mobility by removing grain boundary scattering effects.

Inventive Principle:

Principle #36Phase transitions

2Productivity

If polycrystalline silicon is used for channel films, then manufacturing is simpler, but switching operations are limited due to reduced carrier mobility

Engineering Contradiction:

Improveswitching operation speedVSAvoidcarrier mobility

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the crystalline parameter of the channel film from polycrystalline to monocrystalline through flashlamp annealing. This parameter change directly improves carrier mobility, enabling faster switching operations and better write/erase performance in the memory device.

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

This process enhances the mobility of carriers and improves switching and write/erase operations by transforming polycrystalline silicon channel films into monocrystalline silicon, leading to better performance in semiconductor devices.

Implementation Method 1

utilizing a xenon flashlamp to absorb light and increase grain size

Methodology Applied

Scientific EffectLight absorption and heating: Absorption (EM radiation)

Implementation Method 2

The implementation of flashlamp annealing to convert polycrystalline silicon channel films into monocrystalline silicon

Methodology Applied

Scientific EffectFlashlamp annealing: Annealing

Implementation Method 3

containing a monocrystalline semiconductor... reducing carrier scattering and improving mobility

Methodology Applied

Scientific EffectCarrier transport in semiconductors: Conduction (electrical)

Data Source

PatentUS11791279B2Semiconductor device with hybrid channel

Publication Date: 2023.10.17 KIOXIA CORP

AI summary

A semiconductor device according to an embodiment includes a stacked body having first films and second films that are alternately stacked, a light shielding film provided in a specific layer of the stacked body and having a higher optical absorptivity than that of the second films, and a channel film extending in the stacked body in the stacking direction. The channel film includes a first part located on an upper side than the light shielding film in the stacking direction and containing a monocrystalline semiconductor.