CAAC Passivation Layer Deposition for Corrosion-Free Metal Surfaces
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving uniformity and stability of passivation layers on metal surfaces during selective deposition, particularly due to the reactivity of carbenes and the use of halogen-metal bonds, which can cause corrosion and uneven deposition.
Innovation Solution
A method involving transmetallation of stable carbene precursors, such as cyclic alkyl amino carbenes (CAACs), is used to form a passivation layer on metal surfaces, avoiding halogen-metal bonds and plasma deposition methods that cause damage, ensuring high conformity and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional carbene deposition methods are used, then deposition can occur on metal surfaces, but the passivation layer lacks thermal and chemical stability
Solution Approach 1:
The patent changes the chemical parameters of the carbene precursor by using stable cyclic alkyl amino carbene (CAAC) ligands with specific molecular structures. This transforms the unstable conventional carbene into a stable form that can form thermally and chemically stable passivation layers on metal surfaces while maintaining high selectivity.
Solution Approach 2:
The patent employs composite molecular structures combining cyclic alkyl groups with amino carbene ligands to create CAAC precursors. This composite structure provides both the stability needed for reliable deposition and the reactivity required for selective metal surface binding, resolving the contradiction between stability and effectiveness.
2Quantity of substance
If halogen-metal bonds are used in deposition, then material can be deposited on metal surfaces, but corrosion occurs on the metal surface
Solution Approach 1:
The patent extracts and eliminates halogen atoms from the precursor molecular structure, replacing them with stable CAAC ligands. This removal of harmful halogen components prevents corrosion while maintaining the ability to deposit stable passivation layers on metal surfaces through alternative bonding mechanisms.
Solution Approach 2:
The patent converts the potential harm of reactive precursor molecules into benefit by designing CAAC precursors that are stable enough to avoid corrosion but reactive enough to form stable passivation layers. The controlled stability of CAAC ligands transforms what would be harmful reactivity into useful selective binding.
3Productivity
If plasma deposition methods are used, then film deposition can occur, but damage is caused to the substrate and narrow features
Solution Approach 1:
The patent replaces the plasma-based deposition mechanism with a thermal decomposition mechanism using stable CAAC precursors. This substitution eliminates the damaging effects of plasma while maintaining effective deposition, particularly in narrow features and high aspect ratio structures where plasma causes damage and poor conformity.
Solution Approach 2:
The patent changes the deposition process parameters by using thermally stable CAAC precursors that decompose at controlled temperatures without requiring plasma activation. This parameter change enables conformal deposition in narrow features while avoiding substrate damage, achieving both productivity and precision.
4Area of stationary object
If selective deposition is attempted on large surface areas, then area coverage increases, but uniformity of layer thickness decreases
Solution Approach 1:
The patent achieves homogeneous deposition across large surface areas by using CAAC precursors with uniform molecular structures and consistent reactivity. The stable ligands ensure uniform decomposition and consistent passivation layer formation throughout the entire substrate area, maintaining thickness uniformity even as coverage increases.
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 method achieves a thermally and chemically stable passivation layer with high selectivity and conformity on metal surfaces, even in narrow features and high aspect ratios, without the drawbacks of conventional methods.
Implementation Method 1
A method involving transmetallation of stable carbene precursors, such as cyclic alkyl amino carbenes (CAACs), is used to form a passivation layer on metal surfaces
Implementation Method 2
exposing a semiconductor substrate having a metal layer thereon to a precursor to form a passivation layer on the metal layer
Data Source
AI summary
Methods of depositing a passivation layer on a semiconductor substrate are described. The methods may include exposing a semiconductor substrate having a metal layer thereon to a precursor to form a passivation layer on the metal layer, the precursor having a general formula (I), where exposing the semiconductor substrate to the precursor may include a transmetallation process. The method may further include purging the semiconductor substrate.