Crystalline Oxide Layer on III-V Materials for Low-Defect Interfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
III-V materials like InGaAs face challenges in forming stable crystalline oxides due to high density of interface defects and excessive oxidation, limiting their high electron mobility and increasing leakage current in MOSFETs.
Innovation Solution
A method is developed to form a crystalline oxide layer with a (3×2)-O reconstruction on InGaAs surfaces by controlled oxygen exposure and subsequent atomic hydrogen annealing, removing detrimental Ga2O3 while retaining beneficial Ga2O, resulting in a stable and low-defect interface suitable for high-k dielectric deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If III-V materials are used to achieve high electron mobility, then electron mobility is improved, but interface defects increase due to lack of native oxide passivation
Solution Approach 1:
The patent applies parameter changes by controlling oxidation conditions (oxygen exposure time, temperature, pressure) to transform the native oxide from amorphous to crystalline phase, achieving low Dit values of 3E11/cm2-eV while maintaining high electron mobility in III-V materials
Solution Approach 2:
The patent creates a composite interface structure combining crystalline oxide (such as In2O3, Ga2O3) with III-V semiconductor material, forming a passivation layer that simultaneously reduces interface defects and preserves high electron mobility for low-power applications
2Reliability
If native oxides are removed to passivate the interface, then interface quality is improved, but leakage current increases due to excessive oxidation removal
Solution Approach 1:
The patent inverts the conventional approach by intentionally forming and retaining native oxides rather than removing them, using controlled oxidation to create crystalline oxide structures that passivate the interface and reduce leakage current while maintaining low interface defect density
3Reliability
If controlled oxidation is applied to form crystalline oxide, then interface defects are reduced, but process complexity increases due to multiple processing steps
Solution Approach 1:
The patent merges multiple functions into a single controlled oxidation step that simultaneously forms the crystalline oxide structure, provides interface passivation, and reduces interface defects, eliminating the need for separate processing steps while achieving Dit values of 3E11/cm2-eV
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 significantly reduces interface defects and enhances electron mobility, achieving lower leakage currents and improved transistor performance by creating a stable crystalline oxide layer with a (3×2)-O structure, ready for subsequent high-k dielectric deposition.
Implementation Method 1
subjecting the InAs surface to a specific controlled oxidizing environment, e.g., a molecular oxygen beam
Implementation Method 2
annealing the substrate in atomic hydrogen at about 200° C. to about 400° C. for about 1 minute to about 10 minutes
Implementation Method 3
forming a III-V material including three elements on the substrate by epitaxy
Data Source
AI summary
A metal oxide semiconductor field effect transistor (MOSFET) includes a substrate having a source region, a drain region, and a channel region between the source region and the drain region, the substrate having an epitaxial III-V material that includes three elements thereon, a source electrode over the source region, a drain electrode over the drain region, and a crystalline oxide layer including an oxide formed on the epitaxial III-V material in the channel region, the epitaxial III-V material including three elements.