Multi-Inject ALD Chamber Lid for Uniform Gas Flow
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Solution Overview
Problem
Conventional atomic layer deposition (ALD) processes face challenges in achieving uniform gas flow, leading to localized thin spots on substrate surfaces, particularly when dealing with high aspect ratio features, which complicates the formation of void-free and seam-free submicron interconnects essential for advanced semiconductor technologies.
Innovation Solution
The proposed solution involves a chamber lid assembly with a gas dispersing channel and multiple annular channels, coupled with an insert that provides a truncated coupling lid, allowing for the controlled flow of process gases through apertures, ensuring a uniform circular gas flow around the central axis and into the reaction zone above the substrate, thereby enhancing gas distribution and deposition uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional ALD chamber injection process is used, then the structure is simple, but the gas flow is not uniform resulting in localized thin spots on the substrate surface
Solution Approach 1:
The gas injection system is segmented into multiple annular channels (first annular channel, second annular channel, third annular channel) that are stacked vertically and independently可控. Each annular channel delivers gas to different radial zones of the substrate, enabling precise control of gas flow distribution and eliminating localized thin spots through coordinated injection from multiple segments.
Solution Approach 2:
The invention transitions from a conventional single-plane gas injection system to a three-dimensional stacked annular channel structure. The annular channels are arranged at different heights (vertical dimension) and different radial positions, creating a multi-dimensional gas delivery network that achieves uniform deposition across the entire substrate surface by controlling gas flow from multiple spatial dimensions.
2Productivity
If gas flow is increased to improve deposition rate, then productivity increases, but gas phase reactions increase due to excess reactants remaining in the chamber
Solution Approach 1:
The reactant delivery is segmented into separate pulses through independently controlled annular channels. The first annular channel delivers the first reactant, followed by a purge phase, then the second annular channel delivers the second reactant. This temporal and spatial segmentation prevents excess reactants from remaining in the chamber simultaneously, eliminating gas phase reactions while maintaining high deposition rates through efficient sequential processing.
Solution Approach 2:
The gas injection system employs periodic pulsing through the stacked annular channels, where each channel operates in sequence rather than continuously. The first annular channel pulses the first reactant, then purges, then the second annular channel pulses the second reactant. This periodic action ensures complete reaction of each reactant before the next is introduced, preventing harmful gas phase reactions while maximizing deposition 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 results in more uniform gas flow and deposition, reducing the risk of localized thin spots and improving the uniformity of film thickness across the substrate, particularly at the edges, while also minimizing back diffusion and allowing independent control of gas flow, thus enhancing the quality of submicron features in semiconductor manufacturing.
Implementation Method 1
flowing the two or more process gases from the two or more annular channels through apertures of an insert disposed in the inner region and into an upper portion of a channel in the chamber lid assembly
Implementation Method 2
a tapered bottom surface extending from the bottom portion of the channel to a peripheral portion of the chamber lid assembly
Implementation Method 3
flowing the one or more process gases through the channel and into a reaction zone above a substrate disposed on a substrate support
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Embodiments of the invention relate to apparatus and methods for depositing materials on substrates during atomic layer deposition processes. In one embodiment, a chamber lid assembly comprises a channel having an upper portion and a lower portion, wherein the channel extends along a central axis, a housing having an inner region and at least partially defining two or more annular channels, an insert disposed in the inner region and defining the upper portion, the upper portion fluidly coupled with the two or more annular channels, and a tapered bottom surface extending from the bottom portion of the channel to a peripheral portion of the chamber lid assembly.