Staggered Precursor Dosing in ALD Multi-Station Reactors
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Solution Overview
Problem
Atomic Layer Deposition (ALD) processes are time-consuming due to the need for multiple cycles to achieve substantial film thickness, and existing methods waste precursor and reactants by diverting flow during non-dosing phases, which increases cycle time and costs.
Innovation Solution
Implementing a multi-station substrate processing apparatus with staggered dosing and reaction timing across multiple processing stations, allowing continuous precursor flow and minimizing waste by redirecting reactant flow between stations during ALD cycles, thereby optimizing precursor usage and cycle efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If precursor flow is diverted during non-dosing phases in existing ALD methods, then precursor waste is reduced, but cycle time increases and throughput decreases
Solution Approach 1:
The patent implements continuous precursor flow through the reaction chamber during all ALD cycle phases including dosing, purge, and reaction stages. The precursor flow is never diverted or stopped, eliminating idle time while the excess precursor is removed via exhaust systems. This continuous flow approach eliminates the trade-off between precursor waste and cycle time by making the precursor delivery continuous and useful throughout the entire cycle.
Solution Approach 2:
The system dynamically adjusts the precursor flow rate based on the process stage. During dosing phases, the flow rate is optimized for substrate coverage; during purge and reaction phases, the flow continues but at rates optimized for those specific functions. This dynamic adjustment allows the system to maintain continuous operation while optimizing precursor utilization at each stage, improving both efficiency and throughput.
2Manufacturing precision
If multiple ALD cycles are performed to achieve substantial film thickness, then conformal coating is achieved, but processing time increases significantly
Solution Approach 1:
The patent divides the substrate processing into multiple stations within a single reaction chamber, each capable of independent ALD cycling. While one substrate undergoes dosing, another undergoes purge, and a third undergoes reaction, all simultaneously. This segmentation of the ALD cycle across multiple stations allows continuous processing without waiting for complete cycles to finish sequentially, reducing total processing time while maintaining conformal film quality through controlled dosing at each station.
Solution Approach 2:
The system performs preliminary preparation of substrates at different stations in parallel - some substrates are pre-heated, others are receiving precursor dosing while others are being purged. This preliminary action at multiple stations simultaneously prepares substrates for the next ALD cycle, eliminating idle time between cycles and reducing overall processing time while maintaining the required conformality through controlled dosing sequences.
3Productivity
If precursor flow is continuously maintained without diverting, then cycle time is reduced, but precursor consumption increases
Solution Approach 1:
The patent makes the continuous precursor flow useful throughout the entire ALD cycle by ensuring that precursor is always present in the reaction chamber - during dosing it deposits on substrates, during purge it is removed via exhaust, and during reaction it participates in the ALD reaction. This eliminates waste from stopping and restarting flow while maintaining continuous productive action, reducing cycle time without proportionally increasing precursor consumption.
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 reduces precursor waste and cycle time, enhancing the efficiency and cost-effectiveness of ALD processes by ensuring continuous, stable reactant flow and minimizing the time spent in divert phases, while maintaining consistent layer deposition.
Implementation Method 1
dosing the substrates at the processing stations with a film precursor by introducing the precursor into the one or more reaction chambers and allowing the precursor to adsorb onto the surface of the substrates in an adsorption-limited manner
Implementation Method 2
reacting adsorbed precursor with a plasma, after removing unadsorbed precursor, to form a layer of material on the substrates
Data Source
AI summary
Disclosed herein are methods of depositing layers of material on multiple semiconductor substrates at multiple processing stations within one or more reaction chambers. The methods may include dosing a first substrate with film precursor at a first processing station and dosing a second substrate with film precursor at a second processing station with precursor flowing from a common source, wherein the timing of said dosing is staggered such that the first substrate is dosed during a first dosing phase during which the second substrate is not substantially dosed, and the second substrate is dosed during a second dosing phase during which the first substrate is not substantially dosed. Also disclosed herein are apparatuses having a plurality of processing stations contained within one or more reaction chambers and a controller with machine-readable instructions for staggering the dosing of first and second substrates at first and second processing stations.