III-V Epitaxy Chamber Cleaning for In-Situ SiN Passivation
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Solution Overview
Problem
The integration of Group III-V semiconductor materials on silicon substrates is hindered by lattice mismatch and residual material accumulation in the reactor chamber, leading to defects and processing issues during the fabrication of GaN devices, such as increased on-state resistance and Time-Dependent Dielectric Breakdown (TDDB).
Innovation Solution
A two-stage cleaning process using remotely generated plasma with fluorine-based reactive species followed by chlorine-based chemistry is employed to remove SiXNY residual material from the reactor chamber, facilitating the effective cleaning of GaN deposits and enabling the formation of an in-situ silicon nitride (SiN) passivation layer, which reduces interface defectivity and improves device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a single-stage cleaning process is used in the reactor chamber, then the processing time is reduced, but residual materials (SiXNY and GaN) accumulate leading to increased interface defectivity and device failures
Solution Approach 1:
The cleaning process is divided into two distinct stages: first a fluorine-based plasma cleaning to remove SiXNY residual materials, then a chlorine-based chemistry cleaning to remove GaN residual materials. This segmentation allows each cleaning stage to target specific residual materials effectively, preventing interface defectivity and device failures while maintaining reasonable processing time.
2Productivity
If residual materials are not removed from the reactor chamber, then the fabrication process is simpler and faster, but interface defectivity increases leading to TDDB and increased on-state resistance
Solution Approach 1:
The two-stage cleaning process is performed as a preliminary action before growing new epitaxial layers and forming passivation layers. By proactively removing both SiXNY and GaN residual materials before subsequent processing steps, the method prevents interface defectivity, reduces TDDB, and maintains high fabrication throughput without compromising interface quality.
3Device complexity
If an in-situ passivation layer is formed without proper cleaning, then the process complexity is reduced, but the passivation layer quality deteriorates due to residual material contamination
Solution Approach 1:
The two-stage cleaning process using fluorine-based plasma followed by chlorine-based chemistry is performed as a preliminary step before forming the in-situ passivation layer. This removes residual materials that would otherwise contaminate the passivation layer, ensuring high interface quality and low defectivity while maintaining the simplicity of the in-situ formation process.
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 multistage cleaning process enhances the integrity of the epitaxial layers, reducing dynamic on-state resistance and improving TDDB performance by effectively removing residual materials and maintaining a clean reactor environment, thus facilitating the integration of high-quality Group III-V semiconductor devices on silicon substrates.
Implementation Method 1
a cleaning process may involve applying a remotely generated plasma containing fluorine-based reactive species for removing SiXNY residual material
Implementation Method 2
applying a remotely generated plasma containing fluorine-based reactive species for removing SiXNY residual material
Implementation Method 3
a chlorine-based chemistry may be applied in a cleaning process for removing GayNz residual material
Implementation Method 4
forming an in-situ silicon nitride (SiN) passivation layer, which reduces interface defectivity
Data Source
AI summary
A Group III-V semiconductor device and a method of fabricating the same including an in-situ surface passivation layer. A two-stage cleaning process may be effectuated for cleaning a reactor chamber prior to growing one or more epitaxial layers and forming subsequent surface passivation layers, wherein a first cleaning process may involve a remotely generated plasma containing fluorine-based reactive species for removing SiXNY residual material accumulated in the reactor chamber and/or over any components disposed therein.