Selective Molybdenum Deposition on Polysilicon Without Dielectric Coating
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Solution Overview
Problem
Conventional semiconductor component fabrication methods face challenges with non-uniform or incomplete material deposition on surfaces that are not readily accessible, particularly for non-dielectric materials like polysilicon, due to the inability to selectively deposit molybdenum materials without also depositing on dielectric materials.
Innovation Solution
A method involving multiple steps of contacting a structure with a molybdenum precursor under specific conditions to selectively deposit molybdenum materials, such as molybdenum silicide or metal, on non-dielectric materials like polysilicon while avoiding deposition on dielectric materials, using precursors like MoCl5 and co-reactants like hydrogen, and adjusting temperatures and pressures to achieve selective deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition processes are used, then material deposition can be performed on accessible surfaces, but deposition is non-uniform or fails on surfaces that are not readily accessible
Solution Approach 1:
The patent employs atomic layer deposition (ALD) with controlled temperature parameters (e.g., 150°C to 400°C) and pressure conditions to achieve uniform material deposition on complex, non-accessible surfaces. The sequential pulsing of precursor gases and purging steps enables precise control of deposition parameters, ensuring uniform coating thickness even on difficult-to-reach surfaces
Solution Approach 2:
The patent uses a carrier gas (such as nitrogen or hydrogen) as an intermediary to transport precursor materials into complex structures and cavities. The carrier gas facilitates the delivery of precursors to surfaces that are not readily accessible, enabling uniform deposition throughout the entire structure including hidden surfaces
2Manufacturing precision
If selective deposition on non-dielectric materials is attempted, then precision deposition can be achieved, but dielectric materials may also be deposited upon
Solution Approach 1:
The patent achieves selective deposition by exploiting local differences in material properties. Non-dielectric materials (such as silicon, germanium, or their alloys) exhibit different surface reactivity and bonding characteristics compared to dielectric materials. By carefully selecting precursor chemistry and deposition conditions, the process targets specific material types, depositing material only where desired while leaving dielectric surfaces unaffected
Solution Approach 2:
The patent utilizes temperature parameter control to achieve selectivity. By operating within specific temperature ranges (e.g., 150°C to 400°C), the process activates deposition only on non-dielectric materials while preventing deposition on dielectric materials. The temperature-dependent surface chemistry enables discrimination between different material types, ensuring selective coating
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 allows for precise and selective deposition of molybdenum materials on non-dielectric surfaces, enhancing the fabrication process by ensuring high purity and controlled thickness, as demonstrated by XRF and SIMS depth profile measurements, while minimizing deposition on dielectric surfaces.
Implementation Method 1
contacting the structure with a molybdenum precursor under conditions, so as to obtain a molybdenum material on at least a portion of the structure
Data Source
AI summary
Methods for selective deposition of precursor materials and related devices are provided. The methods comprise obtaining a structure. The structure comprises a non-dielectric material, and a dielectric material. The methods comprise contacting the structure with a molybdenum precursor under conditions, so as to obtain a molybdenum material on at least a portion of the non-dielectric material. The molybdenum material is not deposited on the dielectric material under the conditions.