Angled Gas Inlet Epitaxy for Uniform Wafer Edge Deposition
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Solution Overview
Problem
Existing epitaxial chemical vapor deposition (CVD) processes struggle to achieve an ultra-flat epitaxial surface on semiconductor wafers, particularly at the wafer edge, due to uneven deposition profiles and limited useable edge area.
Innovation Solution
A reaction apparatus with angled gas inlets for channeling process gases into a reaction chamber at specific angles (45° to 75°) to control the deposition profile, using a combination of silicon-containing gases and hydrogen chloride to enhance uniformity and increase the usable edge area of semiconductor wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional epitaxial CVD processes are used with standard gas inlet configurations, then the deposition process can be performed, but the deposition profile is uneven and the usable edge area is limited
Solution Approach 1:
The patent introduces a second gas inlet positioned at an angle (45°-75°) relative to the first gas inlet, creating an asymmetric gas delivery configuration. This asymmetric arrangement allows differential gas flow distribution across the wafer surface, enabling independent control of deposition rates at different radial positions, particularly enhancing the usable edge area while maintaining overall uniformity
Solution Approach 2:
The angled second gas inlet enables localized control of deposition conditions. By directing gas flow at specific angles, the system can optimize deposition uniformity in different regions of the wafer, particularly addressing the edge region requirements without compromising the overall deposition profile
2Manufacturing precision
If the epitaxial deposition rate is carefully controlled to achieve flatness specifications, then the ultra-flat epitaxial surface can be achieved, but the deposition process becomes more complex and time-consuming
Solution Approach 1:
The patent employs parameter changes by introducing a second gas inlet with specific angular positioning (45°-75°) and adjusting gas flow rates through different inlets. This allows dynamic control of the deposition profile to achieve ultra-flat surfaces while managing process complexity through systematic parameter optimization
3Manufacturing precision
If the epitaxial deposition rate is carefully controlled to achieve flatness specifications, then the ultra-flat epitaxial surface can be achieved, but the processing time increases
Solution Approach 1:
By introducing the second gas inlet and optimizing gas flow parameters, the system achieves better deposition uniformity that allows for higher deposition rates while maintaining flatness specifications, thereby improving productivity without sacrificing manufacturing precision
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 apparatus achieves a more uniform radial deposition profile and increases the usable edge area of semiconductor wafers by controlling the silicon deposition slope near the edge, aligning with customer specifications for integrated circuit substrates.
Implementation Method 1
Epitaxial chemical vapor deposition (CVD) is a process for growing a thin layer of material on a semiconductor structure
Implementation Method 2
The upper liner and the lower liner define a first gas inlet for channeling a first process gas into the reaction chamber in a first direction
Data Source
AI summary
A reaction apparatus for depositing an epitaxial layer on a semiconductor structure. The reaction apparatus includes a first gas inlet for channeling a first process gas into the reaction chamber in a first direction. The reaction apparatus includes a second gas inlet for channeling a second process gas into the reaction chamber in a second direction. The first direction and second direction form an angle of between 45° and 75°.