Variable Volume Reactor for Pulsed Deposition Purging
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Solution Overview
Problem
The semiconductor industry faces challenges in depositing conformal thin films in small-diameter holes or high aspect ratio features, as existing methods like CVD are not extendable beyond 120 nm, and pulsed layer deposition (PLD) requires high precursor exposure and purging while minimizing precursor usage and reaction time for commercial viability.
Innovation Solution
A reactor with a variable volume reaction chamber and a movable pedestal allows for controlled precursor exposure and efficient purging by switching between a small and large volume, enabling high exposure and rapid reaction while reducing precursor and byproduct amounts through precise volume adjustments and gas purging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the precursor is allowed to remain for a long period above the surface or if the concentration of the precursor above the wafer is high, then the deposition reaction goes to completion, but the process time increases and precursor usage increases
Solution Approach 1:
The reactor chamber volume is dynamically changed between a first volume during precursor exposure and a second larger volume during purging. This dynamic volume adjustment allows high precursor concentration in a small volume for rapid deposition, then rapidly expands the volume for efficient purging, resolving the contradiction between reaction completion and process time
Solution Approach 2:
The patent changes the physical parameter of chamber volume to control precursor exposure. By adjusting the chamber volume, the precursor concentration above the wafer is controlled - high concentration in small volume for deposition, low concentration in large volume for purging - enabling both complete reaction and rapid process cycling
2Manufacturing precision
If the precursor is allowed to remain for a long period above the surface or if the concentration of the precursor above the wafer is high, then the deposition reaction goes to completion, but the amount of precursor used increases
Solution Approach 1:
The dynamic chamber volume allows concentrating the precursor in a small volume during exposure, ensuring complete surface saturation with minimal precursor. After deposition, the volume expands to disperse and remove excess precursor, reducing overall precursor consumption while maintaining reaction completion
Solution Approach 2:
By changing the chamber volume parameter, the system achieves high precursor concentration in a confined space during exposure (ensuring complete reaction) then rapidly dilutes and removes excess precursor by expanding the volume, minimizing precursor loss
3Manufacturing precision
If the purging steps are sufficient to remove unreacted precursor and byproducts, then the film quality is improved, but the process time increases
Solution Approach 1:
The chamber volume is dynamically expanded during purging to create a large volume for efficient removal of unreacted precursor and byproducts. This large volume allows sufficient purging to occur rapidly, maintaining film quality while minimizing purging time
Solution Approach 2:
The chamber volume parameter is changed to a large value during purging, enabling rapid removal of contaminants. The large volume facilitates efficient gas flow and contaminant removal, achieving sufficient purging in minimal time while preserving film quality
4Productivity
If each step is made as short as possible to form the thin film quickly, then the productivity increases, but the deposition reaction may not go to completion
Solution Approach 1:
The chamber volume is dynamically reduced to a small first volume during precursor exposure, concentrating the precursor to achieve high reaction rates and complete surface saturation in minimal time. This dynamic volume control enables both rapid processing and complete reaction
Solution Approach 2:
The chamber volume parameter is optimized to a small value during exposure, creating high precursor concentration that drives rapid and complete deposition reactions. This parameter optimization enables short exposure times while ensuring reaction completion, maximizing productivity
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 enables efficient pulsed layer deposition with reduced precursor usage and fast processing times, making it suitable for ultra-large scale integration (ULSI) and minimizing environmental impact.
Implementation Method 1
contacting a surface of a substrate in the reaction chamber with a first precursor at the first chamber volume to react with and deposit a first layer on the substrate
Implementation Method 2
contacting the first layer in the reaction chamber with a second precursor at the first chamber volume to react with and deposit a second layer on the first layer
Implementation Method 3
removing undeposited first precursor and any excess reaction product by purging the reaction chamber at the second volume with a gas
Data Source
AI summary
A method of depositing material on a substrate comprises providing a reactor with a reaction chamber having a first volume, and contacting a surface of a substrate in the reaction chamber with a first precursor at the first chamber volume to react with and deposit a first layer on the substrate. The method further includes enlarging the reaction chamber to a second, larger volume and removing undeposited first precursor and any excess reaction product to end reaction of the first precursor with the substrate.