CO2 Plasma ALD SiO2 Deposition Minimizing Hardmask Carbon Loss
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Solution Overview
Problem
Conventional atomic layer deposition (ALD) processes using strong oxidizers like Nitrous Oxide or Oxygen result in high carbon consumption from hardmask layers, leading to non-uniform feature profiles and critical dimension loss, which becomes increasingly problematic as device sizes shrink.
Innovation Solution
Employing carbon-dioxide (CO2) as a weak oxidizer in the ALD process for low-temperature deposition of silicon-dioxide (SiO2) films, which releases a lower concentration of reactive Oxygen radicals, minimizing carbon consumption and achieving a highly planar etch profile without the need for new process chamber configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If strong oxidizers like Nitrous Oxide or Oxygen are used in ALD processes, then deposition efficiency is improved, but carbon consumption from hardmask layers increases significantly
Solution Approach 1:
The patent changes the chemical parameter of the oxidizer from strong oxidizers (O2, N2O) to a weak oxidizer (CO2). This parameter change reduces the reactivity toward carbon in hardmask layers while still enabling oxide film deposition through controlled plasma activation, thereby reducing carbon consumption while maintaining deposition functionality
Solution Approach 2:
The patent inverts the conventional approach by using a weak oxidizer (CO2) instead of strong oxidants. The CO2 plasma provides sufficient oxygen for oxide deposition at low temperatures without the excessive carbon consumption associated with strong oxidizers, achieving a balance between deposition efficiency and hardmask preservation
2Manufacturing precision
If strong oxidizers are used to achieve complete oxide film coverage, then film uniformity is improved, but feature profile planarity deteriorates due to carbon loss
Solution Approach 1:
By changing the oxidizer parameter from strong to weak (CO2), the patent achieves film uniformity through controlled deposition while preserving feature profile planarity. The CO2 plasma provides sufficient oxygen for complete oxide coverage without the carbon erosion that causes profile non-uniformity
Solution Approach 2:
The patent converts the typically harmful effect of plasma reactivity into a benefit by using CO2 plasma. The plasma provides the necessary activation for uniform film deposition while the weak oxidizing nature of CO2 prevents the harmful carbon consumption that would otherwise degrade feature profiles
3Quantity of substance
If conventional ALD processes are used, then deposition is achieved, but critical dimension loss occurs due to carbon consumption
Solution Approach 1:
The patent changes the chemical composition parameter of the oxidizer to CO2, which provides sufficient oxygen for oxide film deposition while having lower affinity for carbon compared to conventional oxidizers. This parameter change enables simultaneous achievement of complete film coverage and critical dimension preservation
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
The use of CO2 as an oxidant in ALD processes significantly reduces carbon-based hardmask consumption, preserves critical dimensions, and achieves a uniform, planar feature profile, addressing the limitations of conventional ALD methods while maintaining similar deposition cycle times.
Implementation Method 1
processing the substrate to expose the surface of the substrate and the surfaces of the SOH to a second precursor via a second plasma. The second precursor is different from the first precursor and includes a mixture of carbon-dioxide gas and an inert gas
Implementation Method 2
The processing causes Oxygen radicals to be released and react with the silicon-hydrogen bonds formed on the surface of the substrate and the surfaces of the SOH to form an oxide film layer
Implementation Method 3
The second precursor includes a mixture of carbon-dioxide gas and an inert gas, and the processing causes Oxygen radicals to be released and react with the silicon-hydrogen bonds
Data Source
AI summary
A method for defining thin film layers on a surface of a substrate includes exposing the surface of the substrate to a first precursor via a first plasma to allow the first precursor to be absorbed by the surface of the substrate. A second precursor that is different from the first precursor is applied to the surface of the substrate via a second plasma. The second precursor is a Carbon dioxide precursor that releases sufficient oxygen radicals to react with the first precursor to form an oxide film layer on the surface of the substrate.