Multilayer Gap Filling for Void-Free Semiconductor Trenches
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Solution Overview
Problem
Conventional deposition techniques face challenges in void-free and seamless filling of high aspect ratio gaps in semiconductor devices, leading to inefficiencies in device manufacturing.
Innovation Solution
A method involving the formation of a first material layer within the gap, followed by a second flowable material to fill regions, and subsequent conversion to a desired material, using processes like ALD and plasma exposure to achieve void-free and seamless filling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conformal deposition techniques are used to fill gaps, then material coverage is improved, but voids and seams form within the gap material
Solution Approach 1:
The gap filling process is divided into multiple sequential deposition cycles, each depositing a thin layer of material. Between cycles, the substrate is repositioned or the deposition conditions are adjusted, allowing material to be deposited in segments that collectively fill the gap without forming voids or seams. This segmented approach overcomes the limitation of single-step conformal deposition.
Solution Approach 2:
The substrate undergoes preliminary treatments such as surface activation, heating, or plasma exposure before deposition begins. These preliminary actions modify the substrate surface properties to enhance material adhesion and promote continuous film formation, preventing void and seam formation during subsequent deposition cycles.
2Manufacturing precision
If super conformal deposition techniques are used to fill gaps, then material coverage is improved, but seams form within the gap material
Solution Approach 1:
The deposition process employs dynamic control of deposition parameters such as substrate temperature, deposition rate, and precursor flow rates during the filling process. By dynamically adjusting these parameters, the system maintains optimal conditions for continuous material deposition, preventing seam formation while achieving complete gap filling.
Solution Approach 2:
The deposition is performed in periodic cycles with controlled interruptions or parameter changes between cycles. This periodic action allows for resetting deposition conditions, preventing the accumulation of defects that would lead to seams, while maintaining overall material coverage and gap filling effectiveness.
3Reliability
If bottom-up techniques are used to fill gaps, then seamless material formation is improved, but voids may still form within the gap
Solution Approach 1:
An intermediary material or intermediate deposition layer is introduced during the filling process. This intermediary substance facilitates continuous material formation while preventing void creation by acting as a temporary filler or adhesion promoter that is subsequently removed or integrated into the final structure, achieving both seamless formation and complete gap filling.
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 enables effective filling of gaps with desired material, minimizing voids and seams, thereby enhancing the quality and reliability of semiconductor devices.
Implementation Method 1
The first material can be material that is desired within the gap. The second material may, in some cases, be less desirable, but can be used to fill the gap
Implementation Method 2
The step of converting can include providing one or more of a reactant and a precursor to the reaction chamber. In accordance with further examples of the disclosure, the method can include exposing one or more of the initially flowable material and the converted material to energy, such as one or more of heating the substrate (thermal energy)
Implementation Method 3
exposing one or more of the initially flowable material and the converted material to energy, such as one or more of heating the substrate (thermal energy), exposing the initially flowable material and/or the converted material to species generated from a direct plasma, an indirect plasma, a remote plasma or an ion beam
Implementation Method 4
heating the substrate to form a mixture of the first material and the second material within the region
Data Source
AI summary
A multiple-layer method for forming material within a gap on a surface of a substrate is disclosed. An exemplary method includes forming a layer of first material overlying the substrate and forming a layer of second (e.g., initially flowable) material within a region of the first material to thereby at least partially fill the gap with material in a seamless and/or void less manner.