Substrate Motion Control in Horizontal CVD Reactors
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Solution Overview
Problem
Conventional chemical vapor deposition (CVD) processes face challenges in controlling deposition rate and uniformity due to sensitivity to process conditions, and the use of static substrates leads to excessive recirculation loops detrimental to film quality and yield.
Innovation Solution
A processor-implemented method for real-time optimization and control of substrate in motion CVD, involving a CVD reactor with crucibles and inlets for specific flow rates and temperatures, where the substrate is given a reciprocating motion. This method includes determining optimal operating conditions through Design of Experiments, Computational Fluid Dynamics modeling, and multi-objective optimization to enhance deposition rate and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a static substrate is used in the CVD reactor, then the reactor configuration is simple, but excessive recirculation loops occur around the substrate which are detrimental to film quality and yield
Solution Approach 1:
The substrate is transformed from a static configuration to a dynamic one by implementing reciprocating motion. The substrate moves back and forth along the reactor axis, which eliminates excessive recirculation loops and improves film quality and yield while maintaining relatively simple reactor configuration.
2Manufacturing precision
If process conditions are tightly controlled to achieve uniform deposition, then film uniformity is improved, but the deposition rate decreases due to sensitivity to process conditions
Solution Approach 1:
The substrate motion dynamically exposes different regions of the substrate to the precursor flow over time. This temporal variation in exposure compensates for spatial non-uniformities in the reactor, achieving uniform deposition without requiring extremely tight control of process conditions, thus maintaining higher deposition rates.
Solution Approach 2:
The reciprocating motion of the substrate creates a periodic action where different zones of the substrate are alternately exposed to the precursor flow. This periodic exposure pattern ensures uniform deposition across the substrate surface while allowing more lenient process control, preserving deposition rate.
3Manufacturing precision
If the substrate is given reciprocating motion to reduce recirculation loops, then film quality and yield are improved, but the device complexity increases
Solution Approach 1:
A reciprocating motion mechanism is implemented to move the substrate back and forth along the reactor axis. This dynamic configuration reduces excessive recirculation loops and improves film quality and yield. The complexity is managed by using a relatively simple linear reciprocating mechanism rather than complex multi-axis motion systems.
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 method achieves improved deposition rate and uniformity by optimizing substrate motion and process conditions, thereby enhancing film quality and yield in real-time, while minimizing recirculation loops and improving quantitative yield.
Implementation Method 1
a substrate positioned at a specific location inside the CVD reactor that is given a reciprocating motion
Implementation Method 2
Chemical vapor deposition (CVD) is a process of depositing a compound on a substrate, by a series of gas phase reactions and surface reactions occurring near the substrate
Implementation Method 3
performing Computational Fluid Dynamics (CFD) modelling on the DoE
Data Source
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AI summary
There is a challenge with limited quantitative yield and uniformity of film being deposited by a chemical vapor deposition (CVD) process. The present disclosure provide methods and systems for real-time optimization and control of substrate in motion CVD. In the present disclosure, solution for improving KPIs of chemical vapor deposition process of transition metal dichalcogenides (TMDs) in a horizontal CVD reactor is provided. A provision of substrates in motion CVD reactor is provided that makes substrate to reciprocate, rotate, revolve, or oscillate in horizontal and vertical direction to improve deposition rates. The present disclosure increases deposition rate by providing more surface area to precursors flowing into the CVD reactor. An effect of process parameters is investigated using computational fluid dynamics (CFD), machine learning and optimization process. This leads to optimization of the CVD reactor and optimized recommendation settings for the CVD reactor are obtained.