Processing Chamber Boundary Layer Disruption via Mechanical Vibration
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Solution Overview
Problem
Conventional deposition processes face reduced chemical utilization efficiency due to the formation of a boundary layer near the substrate surface, where reaction products and byproducts accumulate, hindering access of reactive species and slowing down reactions.
Innovation Solution
The implementation of a processing chamber with a showerhead and substrate support configured to disrupt the boundary layer through mechanical pulsing, agitation, and controlled flow characteristics, including pulsing flow control valves, pressure control valves, and vibratory motion, to enhance the removal of reaction products and byproducts and improve chemical utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fluid is flowed across the substrate surface from a showerhead, then deposition occurs on the substrate, but a boundary layer forms adjacent the substrate surface where reaction products and byproducts accumulate, reducing chemical utilization rate
Solution Approach 1:
The showerhead or substrate support is subjected to mechanical vibration to disrupt the boundary layer adjacent to the substrate surface. This vibration causes the boundary layer to oscillate and thin out, preventing accumulation of reaction products and byproducts, thereby maintaining high chemical utilization rates while continuing the deposition process
Solution Approach 2:
Periodic pulsing of the fluid flow through the showerhead is implemented to disrupt the boundary layer. The periodic variation in flow rate creates corresponding oscillations in the boundary layer thickness, preventing stagnant accumulation of reaction products and continuously refreshing the reactive species supply to the substrate surface
2Stability of the object's composition
If the boundary layer is allowed to form naturally, then a stable flow regime is maintained, but the diffusion of reactive species to the substrate surface is slowed by accumulated reaction products
Solution Approach 1:
The system transitions from a static boundary layer to a dynamic one by introducing controlled vibrations or flow pulsations. The boundary layer thickness and velocity profile are made time-dependent, creating periodic disruption that enhances reactive species diffusion while maintaining overall process stability through controlled parameters
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 effectively disrupts the boundary layer, increasing the diffusion rate of reactive species to the substrate, improving chemical adsorption, purging residual chemicals, and enhancing the overall chemical utilization efficiency and byproduct removal during deposition processes.
Implementation Method 1
The fluid from the showerhead flows across the substrate surface due to, in part, the pressure of flow rate of the fluid
Implementation Method 2
The boundary layer is a region of space adjacent the substrate surface in which the movement of reactive species is diffusion limited rather than based on the developed flow rate
Implementation Method 3
The implementation of a processing chamber with a showerhead and substrate support configured to disrupt the boundary layer through mechanical pulsing, agitation, and controlled flow characteristics, including pulsing flow control valves, pressure control valves, and vibratory motion
Data Source
AI summary
Processing chambers and methods to disrupt the boundary layer are described. The processing chamber includes a showerhead and a substrate support therein. The showerhead and the substrate support are spaced to have a process gap between them. In use, a boundary layer is formed adjacent to the substrate support or wafer surface. As the reaction occurs at the wafer surface, reaction products and byproduct are produced, resulting in reduced chemical utilization rate. The processing chamber and methods described disrupt the boundary layer by changing one or more process parameters (e.g., pressure, flow rate, time, process gap or temperature of fluid passing through the showerhead).