Vapor-Phase Passivation for Selective Deposition on Conductive Surfaces
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Solution Overview
Problem
Current vapor phase deposition processes in semiconductor manufacturing often result in unwanted film buildup on reactor surfaces and dielectric surfaces, leading to contamination, increased processing time, and the need for additional patterning and etch steps, as existing methods for selective deposition are either inefficient or require prolonged exposure to form effective barriers.
Innovation Solution
A method involving the use of smaller vapor-phase passivating agents, such as halogen-containing molecules or halosilanes, to form a passivated conductive surface that prevents unwanted deposition, allowing for selective deposition on dielectric surfaces without blocking the dielectric surface, using processes like atomic layer deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional vapor phase deposition processes are used, then film deposition occurs on all exposed surfaces, but unwanted film buildup on reactor surfaces and dielectric surfaces leads to contamination and increased processing time
Solution Approach 1:
The patent applies preliminary action by forming a self-assembled monolayer (SAM) passivation layer on reactor surfaces and dielectric surfaces before the vapor phase deposition process. This pre-formed protective layer prevents unwanted film deposition during subsequent processing cycles, eliminating the need for post-deposition cleaning and reducing contamination-related rework.
Solution Approach 2:
The patent uses a self-assembled monolayer (SAM) as an intermediary substance between the vapor phase precursors and the surfaces that should remain free of film deposition. This SAM layer acts as a mediator that selectively blocks precursor adsorption on reactor surfaces and dielectric surfaces while allowing controlled deposition on intended substrate surfaces.
2Reliability
If longer exposure to vapor phase passivating agents is used to form effective barriers, then passivation effectiveness improves, but processing time increases
Solution Approach 1:
The patent employs self-service by utilizing self-assembled monolayers (SAMs) that automatically form protective passivation layers on surfaces through spontaneous molecular assembly. This self-organizing process eliminates the need for complex external intervention or prolonged exposure times, as the SAM molecules spontaneously arrange themselves into ordered structures that provide effective passivation.
Solution Approach 2:
The patent applies parameter changes by optimizing the chemical structure and properties of the vapor phase passivating agents to enhance their adsorption kinetics and binding strength. By modifying molecular parameters such as functional group reactivity and chain length, the process achieves effective passivation in shorter exposure times while maintaining high reliability.
3Productivity
If vapor phase deposition is performed without selective passivation, then deposition speed is maintained, but additional patterning and etch steps are required
Solution Approach 1:
The patent applies preliminary action by pre-patterning the reactor surfaces and dielectric surfaces with self-assembled monolayer (SAM) passivation layers before vapor phase deposition. This preliminary selective passivation defines the deposition pattern in advance, allowing direct selective deposition on intended surfaces without requiring subsequent patterning and etch steps to remove unwanted film.
Solution Approach 2:
The patent extracts the patterning function from the deposition process itself by using separate SAM formation steps to pre-defined deposition regions. This separation allows the vapor phase deposition to proceed at full speed on exposed surfaces without needing to slow down for in-process patterning or subsequent corrective etching steps.
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 effectively reduces unwanted film deposition on conductive surfaces while enabling selective deposition on dielectric surfaces, improving processing efficiency and reducing contamination, with the passivation process completed in a shorter time frame compared to traditional methods.
Implementation Method 1
One reactant adsorbs in a self-limiting process on the wafer
Implementation Method 2
A substrate is exposed to one or more volatile precursors which react and/or decompose on the substrate to form a thin film
Data Source
AI summary
Passivation layers to inhibit vapor deposition can be used on reactor surfaces to minimize deposits while depositing on a substrate housed therein, or on particular substrate surfaces, such as metallic surfaces on semiconductor substrates to facilitate selective deposition on adjacent dielectric surfaces. Passivation agents that are smaller than typical self-assembled monolayer precursors can have hydrophobic or non-reactive ends and facilitate more dense passivation layers more quickly than self-assembled monolayers, particularly over complex three-dimensional structures.