Atomic Layer Deposition via Simultaneous Precursor Introduction
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Solution Overview
Problem
Conventional atomic layer deposition (ALD) methods are limited by the need for sequential introduction of precursor species and the requirement of purge periods, which can slow down the deposition process and are not suitable for heat-sensitive applications.
Innovation Solution
The method introduces a first and second precursor species simultaneously in the reaction chamber, with alternating activation and regeneration periods, where photon energy is used to excite the precursor species, allowing for self-saturating surface reactions and potentially skipping purge periods, thereby enhancing the deposition rate and allowing for lower temperature processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sequential precursor introduction with purge periods is used, then reaction by-products are removed effectively, but deposition rate is reduced and process time increases
Solution Approach 1:
The patent combines the removal of reaction by-products with the introduction of the next precursor species by using a common gas flow path. The same gas flow that removes by-products during the purge period also serves as the carrier for the next precursor, eliminating the need for separate purge and precursor introduction steps. This merging of functions directly increases deposition rate by reducing idle time.
Solution Approach 2:
The patent maintains continuous gas flow through the reaction chamber throughout the deposition cycle, ensuring that the removal of reaction by-products is a continuous process rather than an intermittent one. This continuous action prevents by-product accumulation and maintains optimal reaction conditions throughout the deposition process, thereby improving overall productivity without requiring additional purge periods.
2Reliability
If high temperature processing is used, then precursor decomposition is prevented and film quality is maintained, but heat-sensitive substrates are damaged
Solution Approach 1:
The patent introduces photon energy (electromagnetic radiation) as an additional parameter to activate precursor species and drive surface reactions. By changing the energy input mode from purely thermal to include photonic activation, the process can achieve effective precursor decomposition and film formation at lower temperatures, making it suitable for heat-sensitive substrates while maintaining film quality.
Solution Approach 2:
The patent uses photon energy as an intermediary to facilitate the decomposition of precursor species and drive surface reactions. Instead of relying solely on thermal energy, photons act as a mediator that provides the necessary activation energy for chemical reactions at lower temperatures, thereby protecting heat-sensitive substrates while ensuring complete precursor decomposition and high-quality film formation.
3Temperature
If photon energy activation is used, then lower processing temperatures are achieved, but process complexity increases
Solution Approach 1:
The patent designs the reaction chamber to serve multiple functions: it acts as both the reaction vessel and the photon source housing. The photon source is integrated into the chamber structure, allowing the same component to provide both containment and activation functions. This multi-functionality reduces the number of separate components needed, thereby minimizing the increase in device complexity while enabling lower temperature processing.
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 a faster ALD growth rate and allows for low-temperature passivation of heat-sensitive materials by optimizing the interaction between precursor species, resulting in a more efficient and versatile deposition process.
Implementation Method 1
during the activation period the first precursor species adsorbed to the substrate surface in a preceding regeneration period is excited by photon energy, whereby the adsorbed first precursor species reacts on the surface with the second precursor species which is in gas phase
Implementation Method 2
ALD utilizes chemisorption and eliminates physisorption during the deposition process. During chemisorption a strong chemical bond is formed between atom(s) of a solid phase surface and a molecule that is arriving from the gas phase
Implementation Method 3
Second precursor vapor is then introduced into the reaction space. Second precursor molecules react with the adsorbed species of the first precursor molecules, thereby forming the desired thin film material
Data Source
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AI summary
A method that comprises performing an atomic layer deposition sequence comprising at least one deposition cycle, each cycle producing a monolayer of deposited material, the deposition cycle comprising introducing at least a first precursor species and a second precursor species to a substrate surface in a reaction chamber, wherein both of said first and second precursor species are present in gas phase in said reaction chamber simultaneously. The invention also relates to an apparatus with a reaction chamber (210), a metal precursor source (41 ) and a processing gas source (40). Objects of the invention are to achieve a fast atomic layer deposition and a lowered required processing temperature.