Zigzag Substrate Transport for Uniform Gas Distribution in ALD
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Solution Overview
Problem
In atomic layer deposition, non-uniform gas distribution in the chamber leads to inadequate precursor adsorption across the substrate surface, resulting in varying film thicknesses depending on the substrate sites.
Innovation Solution
A film formation apparatus with a chamber divided into zones, featuring adjustable discharge ports and a zigzag substrate transportation path, ensures homogeneous gas distribution by positioning supply and discharge ports on opposite sides of the substrate's width direction, allowing for precise control of gas flow and concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas is supplied into zones in a space-divided type ALD process, then film formation speed is improved, but gas distribution uniformity deteriorates
Solution Approach 1:
The chamber is divided into multiple zones (first zone, second zone, third zone) with separate supply and discharge ports for each zone. This segmentation allows independent control of gas flow in each zone, enabling uniform gas distribution across the substrate surface while maintaining high film formation speed through parallel processing in multiple zones.
Solution Approach 2:
Each zone is equipped with individually adjustable discharge ports that can control gas discharge量 independently. This local quality control ensures that gas is uniformly distributed to all areas of the substrate, preventing the non-uniform gas distribution that would otherwise occur in a space-divided system, thereby achieving both high productivity and uniform film thickness.
2Device complexity
If substrate is transported linearly through zones, then apparatus complexity is reduced, but gas distribution uniformity deteriorates
Solution Approach 1:
The substrate transportation path is designed as a zigzag shape rather than a straight line, causing the substrate to reciprocate among the zones multiple times. This curved/reciprocating path ensures that all areas of the substrate surface are uniformly exposed to the gas supply in each zone, achieving uniform gas distribution and film thickness while maintaining relatively simple apparatus structure.
3Device complexity
If discharge ports have fixed opening state, then device complexity is reduced, but gas concentration control precision deteriorates
Solution Approach 1:
The discharge ports are designed with individually adjustable opening states, allowing dynamic control of gas discharge量 from each zone. This dynamic adjustment capability enables precise control of gas concentration and distribution uniformity across the substrate, optimizing film formation quality while the control system manages the complexity of multiple adjustable ports.
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 enhances film formation precision by preventing insufficient precursor supply, optimizing raw material usage, reducing waste, and minimizing unintended chemical vapor deposition growth, while maintaining efficient gas distribution and apparatus size.
Implementation Method 1
by using a self-limiting effect in surface adsorption that prohibits a certain type of gas from being adsorbed onto a surface after the surface is covered by the gas, only one layer of precursor is adsorbed onto the surface
Implementation Method 2
the reactive gas is introduced to oxidize or reduce the above precursor to thereby obtain one thin layer having a desired composition
Data Source
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AI summary
A film formation apparatus and a film formation method that can homogenize the distribution of gas in each zone in a chamber and improve film formation precision is provided. A film formation apparatus according to one embodiment is characterized in that the film formation apparatus includes: a chamber which includes a plurality of zones into which gas is introduced, and a plurality of discharge ports that discharge the gas located in at least any of the zones and that can individually adjust an opening state; and a transportation unit that transports a substrate so as to pass through the plurality of the zones in the chamber.