Selective Atomic Layer Deposition With Pinhole-Tolerant Blocking Layers
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Solution Overview
Problem
Current selective deposition methods for semiconductor fabrication require defect-free self-assembled monolayers (SAMs) that take hours to form, leading to reduced throughput and potential defects due to pinholes, and existing methods for depositing HfOx on metal materials but not dielectric materials lack sufficient selectivity.
Innovation Solution
The use of larger metal precursors and specific blocking compounds, such as n-octadecyltris(dimethylamino)silane, combined with larger kinetic diameter metal precursors and less degrading oxidants like alcohols, to form selective blocking layers that allow for faster and more selective deposition of metal-containing layers on specific substrate surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If defect-free self-assembled monolayers (SAMs) are used for selective deposition, then selectivity is improved, but formation time increases to hours and throughput is reduced
Solution Approach 1:
The patent changes the molecular weight parameter of the precursor material from conventional small molecules to large molecules with molecular weights greater than 500 g/mol. This parameter change allows the large molecules to physically block pinholes in the SAM layer, maintaining selectivity while reducing the required SAM formation time from hours to minutes, thereby resolving the contradiction between selectivity and throughput
Solution Approach 2:
The patent introduces large precursor molecules as an intermediary mechanism that addresses the pinhole defect issue. These large molecules act as physical plugs that prevent deposition through SAM defects, serving as a mediator between the SAM layer and the deposition process, allowing selective deposition to proceed without requiring defect-free SAMs
2Speed
If conventional small precursor molecules are used, then deposition speed is fast, but selectivity is lost due to pinholes in the SAM layer
Solution Approach 1:
The patent changes the molecular size parameter of the precursor from conventional small molecules to large molecules with molecular weights greater than 500 g/mol. This parameter change enables the precursors to physically occlude pinholes in the SAM layer, preventing deposition on blocked surfaces while maintaining fast deposition rates on exposed surfaces, thus resolving the contradiction between deposition speed and selectivity
3Manufacturing precision
If rigorous SAM optimization is performed to achieve high selectivity, then selectivity is improved, but process time increases and complexity is increased
Solution Approach 1:
The patent changes the precursor molecular weight parameter to greater than 500 g/mol, which fundamentally alters the deposition mechanism. Instead of requiring rigorous optimization of SAM formation conditions, the large precursor molecules provide physical blocking of pinholes, simplifying the process while maintaining high selectivity, thereby resolving the contradiction between selectivity and process complexity
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 selectivity and reduces defects by enabling deposition on targeted surfaces while minimizing deposition on non-targeted surfaces, thus improving throughput and reducing device failures.
Implementation Method 1
The substrate is exposed to a blocking compound to selectively form a blocking layer on at least a portion of the first surface over the second surface
Implementation Method 2
The substrate is sequentially exposed to a metal precursor and a reactant to selectively form a metal-containing layer on the second surface
Data Source
AI summary
Methods of depositing a film selectively onto a first substrate surface relative to a second substrate surface are described. The methods include exposing the substrate surfaces to a blocking compound to selectively form a blocking layer on at least a portion of the first surface over the second surface. The substrate is sequentially exposed to a metal precursor with a kinetic diameter in excess of 21 angstroms and a reactant to selectively form a metal-containing layer on the second surface over the blocking layer or the first surface. The relatively larger metal precursors of some embodiments allow for the use of blocking layers with gaps or voids without the loss of selectivity.