Offset Axis Showerhead for Semiconductor Processing Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor processing chambers with centrally symmetric showerheads face challenges in achieving uniform gas distribution across substrates due to thermal differentials, leading to uneven deposition or etching reactions, which limits process development, especially in applications involving thin material layers.
Innovation Solution
A semiconductor processing chamber design featuring a moveable susceptor and a showerhead with a vertically extending showerplate axis, where the substrate axis is offset from the showerhead axis, allowing for improved gas distribution control through rotational movement of the susceptor and substrate, maintaining a constant distance between the substrate and showerplate axes during reactant introduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a centrally symmetric showerhead design is used, then the device structure is simple and easy to manufacture, but the gas distribution uniformity across the substrate deteriorates due to thermal differentials
Solution Approach 1:
The patent applies asymmetry by offsetting the substrate axis from the showerhead axis, creating an asymmetric configuration that actively compensates for thermal differential effects. This asymmetric positioning allows the substrate to be treated in a region with more uniform gas distribution, thereby resolving the contradiction between simple symmetric structure and uniform gas distribution.
Solution Approach 2:
The patent implements dynamics by making the susceptor moveable, allowing it to be positioned at different locations relative to the showerhead during the processing cycle. This dynamic positioning enables optimization of gas distribution uniformity while maintaining a relatively simple showerhead structure.
2Device complexity
If the substrate is stationary relative to the showerhead, then the process control is simple, but the deposition or etching uniformity deteriorates due to thermal differentials and residual non-uniformity patterns
Solution Approach 1:
The patent makes the susceptor moveable rather than stationary, allowing dynamic adjustment of substrate position during processing. This dynamic capability enables the system to compensate for thermal differentials and achieve more uniform deposition or etching, while the control system manages the added complexity.
Solution Approach 2:
The patent implements periodic action by rotating the susceptor during the processing cycle. This periodic rotation ensures that all regions of the substrate are exposed to relatively uniform gas distribution over time, compensating for spatial non-uniformities in the showerhead gas flow patterns.
3Device complexity
If the showerhead and substrate are concentrically aligned, then the device structure is symmetric and simple, but the uniformity of substrate treatment deteriorates due to edge effects and non-uniform gas distribution
Solution Approach 1:
The patent deliberately breaks the concentric symmetry by offsetting the substrate axis from the showerhead axis. This asymmetric configuration positions the substrate in a region where gas distribution is more uniform, reducing edge effects and improving overall treatment uniformity, while accepting the increased structural complexity.
Data Source
AI summary
The current disclosure relates to a semiconductor processing chamber comprising a showerhead, the showerhead comprising a showerplate for providing a reactant into the processing chamber. The processing chamber further comprises a moveable susceptor for holding a substrate; wherein the processing chamber has a showerplate axis extending vertically through the showerplate; a substrate axis extending vertically at a position at which the center of the substrate is configured and arranged to be during providing reactant into the processing chamber; and wherein the substrate axis is offset from the showerhead axis. The disclosure further relates to a semiconductor processing assembly and to a method of treating a semiconductor substrate.