Superlattice Oxygen Monolayers for Charge Carrier Mobility

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Solution Overview

Problem

Current semiconductor devices do not fully leverage advanced materials and processing techniques to achieve optimal performance in terms of charge carrier mobility and energy band engineering.

Innovation Solution

The formation of a semiconductor superlattice with stacked groups of layers, including a base semiconductor portion and an oxygen monolayer constrained within the crystal lattice, which reduces the effective mass of charge carriers and enhances mobility, and can be used to divide semiconductor layers into regions of different conductivity types or dopant concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional semiconductor materials and structures are used, then manufacturing processes are simpler, but charge carrier mobility is limited due to higher effective mass and scattering effects

Engineering Contradiction:

Improvecharge carrier mobilityVSAvoidsuperlattice structure complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The semiconductor layer is segmented into a superlattice structure with alternating thin layers of different semiconductor materials (e.g., SiGe and Si). This segmentation creates multiple interfaces that generate piezoelectric fields, which enhance charge carrier mobility by reducing scattering effects and lowering effective mass, thus resolving the contradiction between mobility improvement and structural complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite semiconductor materials with different band structures and piezoelectric properties arranged in a superlattice. The combination of materials like SiGe and Si creates beneficial strain and piezoelectric effects that improve charge carrier mobility, addressing the limitation of conventional single-material structures while managing complexity through controlled material composition.

Inventive Principle:

Principle #40Composite materials

2Speed

If advanced superlattice structures with multiple materials are implemented, then charge carrier mobility is enhanced through reduced effective mass, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecharge carrier mobilityVSAvoidlayer thickness control

Core Design Contradiction:

SpeedVSManufacturing precision

Solution Approach 1:

The patent optimizes specific parameters of the superlattice structure, including layer thickness ratios, material composition gradients, and interface densities, to achieve enhanced charge carrier mobility. By carefully controlling these parameters within specific ranges, the patent improves mobility while managing manufacturing precision requirements through parameter optimization rather than extreme precision demands.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If dopant diffusion barriers are added to improve device performance, then dopant concentration control is improved, but device complexity and processing steps increase

Engineering Contradiction:

Improvedopant concentration controlVSAvoidprocessing steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The superlattice structure serves multiple functions simultaneously: it acts as both a mobility enhancement layer through piezoelectric effects and a dopant diffusion barrier through its alternating material composition. This multi-functionality improves dopant concentration control and charge carrier mobility without adding separate processing steps, thus resolving the contradiction between reliability improvement and device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 results in higher charge carrier mobility, reduced scattering effects, and improved device performance, including piezoelectric, pyroelectric, and ferroelectric properties, while also acting as a barrier to dopant diffusion and providing high-K dielectric interfaces.

Implementation Method 1

which reduces the effective mass of charge carriers and enhances mobility

Methodology Applied

Scientific EffectEffective mass reduction:

Implementation Method 2

improved device performance, including piezoelectric, pyroelectric, and ferroelectric properties

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

improved device performance, including piezoelectric, pyroelectric, and ferroelectric properties

Methodology Applied

Scientific EffectPyroelectric effect: Pyroelectric Effect

Implementation Method 4

improved device performance, including piezoelectric, pyroelectric, and ferroelectric properties

Methodology Applied

Scientific EffectFerroelectric effect:

Implementation Method 5

acting as a barrier to dopant diffusion

Methodology Applied

Scientific EffectDiffusion barrier: Diffusion Barrier

Data Source

PatentUS11682712B2Method for making semiconductor device including superlattice with O18 enriched monolayers

Publication Date: 2023.06.20 ATOMERA INC

AI summary

A method for making a semiconductor device may include forming a semiconductor layer, and forming a superlattice adjacent the semiconductor layer and including stacked groups of layers. Each group of layers may include stacked base semiconductor monolayers defining a base semiconductor portion, and at least one oxygen monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The at least one oxygen monolayer of a given group of layers may comprise an atomic percentage of 18O greater than 10 percent.