Cyclic Silicon Nitride Deposition for Plasma-Free Surface Selectivity
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in selectively depositing materials comprising silicon and nitrogen, such as silicon nitride, without using plasma, which is necessary for achieving desired properties like etch resistance, and existing methods are limited in scalability and industrial application.
Innovation Solution
A cyclic deposition process involving a silicon precursor and a nitrogen precursor in a vapor phase is used to selectively deposit materials comprising silicon and nitrogen on a substrate, with the silicon precursor being a halosilane and the nitrogen precursor being ammonia or hydrazine, allowing for precise control over the deposition on specific surfaces and avoiding metal-containing reactants to minimize defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma is used to deposit silicon nitride, then etch resistance is achieved, but process complexity and cost increase
Solution Approach 1:
The patent replaces plasma-based deposition with a thermal vapor-phase deposition process. Instead of using plasma energy to drive the chemical reactions, the invention uses thermal energy alone to decompose the halosilane precursor and form silicon nitride. This substitution eliminates the need for plasma generation equipment and associated process complexity while achieving the desired etch resistance through controlled thermal decomposition and reaction.
Solution Approach 2:
The invention changes the deposition parameters by operating in a thermal regime rather than a plasma regime. By carefully controlling temperature, precursor flow rates, and reaction chamber conditions, the process achieves silicon nitride deposition with equivalent or superior etch resistance compared to plasma methods, but with simplified process equipment and operation.
2Manufacturing precision
If conventional patterning is used to deposit different materials, then material selectivity is achieved, but the number of processing steps increases
Solution Approach 1:
The patent applies preliminary surface treatment or passivation to specific regions of the substrate before deposition. By pre-modifying the surface properties of areas where silicon nitride should not deposit (such as applying a blocking layer or passivation agent), the process enables selective deposition in a single step rather than requiring multiple patterning and deposition cycles. This preliminary action reduces the total number of processing steps while maintaining high material selectivity.
Solution Approach 2:
The invention creates local quality differences on the substrate surface through selective passivation or blocking treatments. Different regions of the substrate are prepared with different surface properties, allowing the vapor-phase precursor to react only on desired areas. This local differentiation enables precise spatial control of deposition without requiring complex conventional patterning sequences.
3Productivity
If selective deposition is implemented, then the number of patterning steps decreases, but deposition selectivity control becomes more difficult
Solution Approach 1:
The patent introduces an intermediary blocking layer or passivation agent that mediates between the vapor-phase precursor and the substrate surface. This intermediary substance selectively prevents deposition on certain areas while allowing it on others. By controlling the distribution and properties of this intermediary layer, the process achieves high deposition selectivity with simplified patterning, as the intermediary acts as a controllable gatekeeper that directs material deposition to desired locations.
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 method achieves selective deposition with high selectivity (>50%) and controlled composition, enabling the formation of layers with desired properties like etch resistance without plasma exposure, enhancing the scalability and industrial applicability of silicon nitride deposition.
Implementation Method 1
providing a silicon precursor comprising silicon and halogen into the reaction chamber in a vapor phase; and providing a nitrogen precursor into the reaction chamber in a vapor phase to form material comprising silicon and nitrogen on the first surface
Data Source
AI summary
The disclosure relates to methods and deposition assemblies for selectively depositing material including silicon and nitrogen on a first surface of a substrate relative to the second surface of the same substrate. In the disclosure, material including silicon and nitrogen is selectively deposited on a first surface of a substrate relative to a second surface of the same substrate by a cyclic deposition process by providing a substrate in a reaction chamber, providing a silicon precursor comprising silicon and halogen into the reaction chamber in a vapor phase and providing a nitrogen precursor into the reaction chamber in a vapor phase to form the material including silicon and nitrogen on the first surface.