Topography-Selective Gap Deposition for Void-Free Semiconductor Filling
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Solution Overview
Problem
Conventional methods face challenges in filling high aspect ratio structures in semiconductor devices without voids, seams, or pinholes, and in achieving topography-selective depositions to form material layers on specific surfaces while avoiding others.
Innovation Solution
A method involving the formation of a material layer on a substrate with a gap, where the gap is partially filled with a gap filling fluid, and the unprotected proximal material layer is selectively etched relative to the gap filling fluid, allowing for the formation of a distal layer on the distal surface without covering the sidewalls or proximal surface, using a cyclical deposition process and plasma treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If flowable gapfill approaches are used to fill high aspect ratio structures, then the structures can be filled voidlessly and seamlessly, but thermal or other treatment is required to obtain high-quality material
Solution Approach 1:
The patent changes the physical state of the gap-fill material from liquid (flowable) to solid (deposited film), eliminating the need for thermal treatment while achieving voidless filling. The deposition parameters (temperature, pressure, gas flow) are optimized to control film formation in high aspect ratio structures without requiring post-deposition annealing or curing steps.
Solution Approach 2:
The patent replaces the mechanical flow process (liquid gapfill flowing into structures) with a vapor-phase deposition process. This substitution eliminates the need for thermal treatment to cure the material, as the solid film forms directly through vapor deposition, simplifying the overall process while maintaining filling quality.
2Manufacturing precision
If conformal deposition approaches are used to fill high aspect ratio structures, then the structures can be filled, but a weak spot or seam is formed which results in defect formation
Solution Approach 1:
The patent employs cyclical deposition processes with multiple pulses of precursor and reactant gases, creating periodic action that builds up the film layer by layer. This periodic deposition ensures complete filling of high aspect ratio structures without forming seams, as each cycle contributes to a continuous, defect-free film that maintains structural integrity.
Solution Approach 2:
The deposition process maintains continuous useful action by ensuring complete film coverage throughout the high aspect ratio structures without interruption or seam formation. The optimized deposition parameters and cyclical process ensure uninterrupted material deposition, eliminating weak spots while achieving complete filling.
3Area of stationary object
If material layers are formed on all surfaces including sidewalls and proximal surfaces, then complete coverage is achieved, but selective deposition on distal surfaces only cannot be accomplished
Solution Approach 1:
The patent applies local quality by making different parts of the substrate receive different treatments. The distal surfaces are selectively coated with gap-fill material while proximal and sidewall regions are protected by sacrificial layers. This local differentiation enables precise spatial control of material deposition, achieving selectivity while maintaining the ability to fill specific regions.
Solution Approach 2:
The patent segments the substrate surfaces into different functional zones: distal surfaces that receive gap-fill material, and proximal/sidewall surfaces covered by sacrificial layers. This segmentation allows independent control of material deposition on different surface types, enabling selective filling of high aspect ratio structures without coating unwanted areas.
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 enables the formation of high-quality material layers within the gap without voids or seams, improving the filling efficiency and selectivity, thereby enhancing the quality and uniformity of semiconductor devices.
Implementation Method 1
removing the gap filling fluid from the substrate
Implementation Method 2
selectively etching the unprotected proximal material layer vis-à-vis the gap filling fluid
Implementation Method 3
forming a material layer overlying the proximal surface, the distal surface, and the sidewalls
Data Source
AI summary
Disclosed are methods and related systems for topography-selective depositions. Embodiments of presently described methods comprise employing a sacrificial gap filling fluid for selectively forming a material on a distal surface of a gap, and not on at least one of sidewalls of the gap and proximal surfaces. Further described are methods for filling a gap with a high quality material by means of a sacrificial gap filling fluid.