Selective Atomic Layer Deposition Using Large-Precursor Blocking
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Solution Overview
Problem
Current selective deposition methods for metal oxides, such as HfOx, require defect-free self-assembled monolayers (SAMs) which are time-consuming to achieve, leading to limited throughput and selectivity issues due to pinholes and degradation by harsh oxidants, necessitating the development of methods that do not rely on defect-free SAMs and enhance selectivity without extended exposure times.
Innovation Solution
The method involves using larger diameter metal precursors and alcohols as oxidative reagents to form blocking layers on substrates, allowing for selective deposition of metal-containing layers on specific surfaces with reduced SAM exposure times and increased selectivity, thereby avoiding the need for defect-free SAMs and minimizing pinhole-related defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If defect-free self-assembled monolayers (SAMs) are used for selective deposition, then selectivity is improved, but processing time increases significantly
Solution Approach 1:
The patent changes the physical parameters of the metal precursor by using larger diameter precursors (kinetic diameter ≥21 Å). This parameter change allows selective deposition to proceed without requiring defect-free SAMs, thereby reducing processing time while maintaining selectivity. The larger precursor size provides steric protection that prevents deposition through pinholes in the SAM layer.
Solution Approach 2:
The patent introduces a blocking layer as an intermediary between the SAM and the metal precursor. This blocking layer, formed by exposing the substrate to a blocking compound, works in conjunction with the larger diameter metal precursor to achieve selective deposition. The combination of blocking layer and large precursor acts as a mediator system that enables selectivity without requiring perfect SAM coverage.
2Ease of manufacture
If conventional metal precursors are used with SAM-based selective deposition, then processing is simpler, but selectivity is lost due to pinholes and SAM degradation
Solution Approach 1:
The patent modifies the physical parameter of the metal precursor by using larger diameter precursors (kinetic diameter ≥21 Å). This change maintains process simplicity while improving selectivity, as the larger size provides steric protection against deposition through SAM pinholes and reduces sensitivity to SAM degradation.
Solution Approach 2:
The patent introduces a blocking layer formed by exposing the substrate to a blocking compound before the metal precursor deposition. This blocking layer serves as a cushion or protective barrier that compensates for defects in the SAM, preventing unwanted deposition and maintaining selectivity even when the SAM is not perfectly intact.
3Productivity
If smaller diameter metal precursors are used, then deposition efficiency is higher, but selectivity decreases due to pinhole penetration
Solution Approach 1:
The patent changes the physical parameter of the metal precursor by using larger diameter precursors (kinetic diameter ≥21 Å). This parameter change creates an optimal balance where the precursor is still reactive enough for efficient deposition but large enough to be sterically blocked by the SAM blocking layer, thereby maintaining both productivity and selectivity.
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 achieves high selectivity and increased throughput by using larger metal precursors and alcohols, enabling selective deposition of metal oxides like HfOx with improved reliability and reduced defects, even without complete SAM coverage, thus addressing the limitations of existing methods.
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
Implementation Method 3
methods of enhancing selective atomic layer deposition of a metal oxide film using alcohols as oxidative reagents
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.