DC-CVD Diamond Reactor with In-Situ Outgrowth Removal
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Solution Overview
Problem
Conventional DC-CVD methods face challenges in growing high-quality single crystal diamond over large areas due to low growth rates, plasma instability, arcing, and carbonaceous outgrowths, which disrupt uniformity and prolong the growth process, especially at low pressures and high power densities.
Innovation Solution
A DC-CVD reactor with a defect removal system and controlled electrode temperatures, using a sweeper mechanism to remove carbonaceous outgrowths and maintain plasma stability, along with high DC power densities and methane concentration, to enhance growth rates and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If DC-CVD is used to grow single crystal diamond over large areas, then the deposition area is increased, but the growth rate decreases and plasma stability deteriorates
Solution Approach 1:
The patent implements a movable sweeper rod that can dynamically adjust its position and contact pressure against the substrate holder. This dynamic mechanism allows the system to adapt to plasma instabilities and carbonaceous outgrowths in real-time, maintaining optimal cleaning action across large deposition areas while preserving high growth rates through controlled mechanical intervention during the deposition process
Solution Approach 2:
The sweeper rod system operates autonomously to remove carbonaceous outgrowths and maintain plasma stability without requiring external intervention. The mechanism self-regulates through its mechanical contact with the substrate holder, continuously cleaning the deposition surface and preventing plasma disruptions that would otherwise reduce growth rate, thereby enabling sustained high-productivity operation over large areas
2Productivity
If DC power density is increased to enhance growth rate, then productivity improves, but plasma instability and arcing increase
Solution Approach 1:
The sweeper rod proactively removes carbonaceous outgrowths before they can disrupt plasma stability or cause arcing. By continuously cleaning the substrate holder surface during deposition, the system prevents plasma instabilities from developing, allowing high DC power densities to be maintained safely and reliably throughout the growth process
Solution Approach 2:
The mechanical contact between the sweeper rod and substrate holder provides real-time feedback on plasma conditions and surface quality. When carbonaceous outgrowths begin to form and threaten plasma stability, the sweeper mechanism responds immediately by removing them, creating a feedback loop that maintains plasma reliability even at high power densities that would otherwise cause arcing
3Area of stationary object
If deposition area is enlarged, then manufacturing capacity increases, but carbonaceous outgrowths and plasma uniformity decrease
Solution Approach 1:
The sweeper rod system divides the large deposition area into zones that can be individually monitored and cleaned. By making contact with the substrate holder at multiple points along the deposition surface, the mechanism ensures uniform plasma distribution and removes carbonaceous outgrowths across the entire large area, maintaining manufacturing precision throughout the expanded deposition zone
Solution Approach 2:
The movable sweeper rod dynamically adapts to variations in plasma uniformity across different regions of the large deposition area. By adjusting its position and contact pressure in real-time, the system maintains consistent cleaning action and plasma distribution throughout the entire substrate holder surface, ensuring uniform diamond growth even over expanded areas
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 system achieves high-quality single crystal diamond growth with increased rates and uniformity over large areas by stabilizing plasma and preventing arcing, ensuring consistent diamond deposition.
Implementation Method 1
applying a DC voltage to the first electrode and second electrode, wherein the DC voltage is higher than 900 V, and generating a plasma between the first electrode and second electrode
Implementation Method 2
chemical vapor deposition process... introducing process gases in the CVD reactor... generating a plasma between the first electrode and second electrode
Data Source
AI summary
Disclosed herein are methods for producing a diamond material, and preferably a single crystalline diamond material. Also disclosed is a DC chemical vapor deposition (DC-CVD) reactor for depositing diamond materials comprising a defect removal system incorporated within the CVD reactor, configured to remove carbonaceous outgrowth defects during a diamond deposition process, without interfering with or stopping the deposition process.