TSV Liner Formation Using Spin-On Coating
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Solution Overview
Problem
The formation of conformal through-silicon via (TSV) liners in high aspect ratio openings is challenging due to uneven thickness profiles, leading to inadequate sidewall coverage and increased manufacturing costs, especially with existing chemical vapor deposition (CVD) methods that struggle with low-k dielectric layers.
Innovation Solution
A novel spin-on coating process using a flowable chemical, such as tetra-ethyl-ortho-silicate (TEOS) or methyltriethoxysilane (MTES), is employed to form TSV liners, where the solvent evaporation rate and spinning parameters are controlled to achieve uniform thickness across the sidewalls and bottom of the TSV opening, ensuring better conformity and adjustable k-values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If chemical vapor deposition (CVD) is used to form TSV liners in high aspect ratio openings, then the liner formation process is simple, but the liner thickness is uneven with poor sidewall coverage
Solution Approach 1:
The patent changes the deposition parameters by using spin-on coating with controlled solvent evaporation rate and spinning parameters, transforming the process from CVD to a solution-based approach that achieves uniform thickness in high aspect ratio openings
Solution Approach 2:
The patent replaces the chemical vapor deposition mechanism with a spin-on coating mechanism, using mechanical spinning and controlled evaporation to achieve uniform liner formation instead of chemical deposition
2Manufacturing precision
If sub-atmospheric chemical vapor deposition (SACVD) is used to deposit TSV liners, then the liner profile is improved, but the manufacturing cost increases and low-k dielectric layers cannot be formed
Solution Approach 1:
The patent changes the material deposition approach by using spin-on coating with controlled solvent evaporation, enabling the formation of low-k dielectric materials that cannot be deposited by SACVD, while maintaining cost-effectiveness
Solution Approach 2:
The patent enables the use of low-k dielectric materials in TSV liner formation, expanding material options beyond what SACVD can provide and achieving both cost-effectiveness and functional requirements
3Manufacturing precision
If repeated etch-back and deposition cycles are performed to improve TSV liner conformity, then the liner uniformity increases, but the manufacturing complexity and time increase
Solution Approach 1:
The patent performs preliminary action by optimizing the spin-on coating parameters and solvent evaporation rate to achieve uniform liner thickness in a single deposition step, eliminating the need for repeated etch-back and deposition cycles
Solution Approach 2:
The patent extracts the problematic repeated etch-back and deposition cycles from the process, achieving liner conformity through a single optimized spin-on coating step with controlled evaporation
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 process results in TSV liners with improved conformity and sidewall coverage, reducing manufacturing costs and enabling the formation of low-k dielectric layers, while maintaining efficient filling of metallic materials and integration with diffusion barrier layers.
Implementation Method 1
A novel spin-on coating process using a flowable chemical, such as tetra-ethyl-ortho-silicate (TEOS) or methyltriethoxysilane (MTES), is employed to form TSV liners
Implementation Method 2
where the solvent evaporation rate and spinning parameters are controlled to achieve uniform thickness across the sidewalls and bottom of the TSV opening
Data Source
AI summary
An integrated circuit structure includes a semiconductor substrate; a through-semiconductor via (TSV) opening extending into the semiconductor substrate; and a TSV liner in the TSV opening. The TSV liner includes a sidewall portion on a sidewall of the TSV opening and a bottom portion at a bottom of the TSV opening. The bottom portion of the TSV liner has a bottom height greater than a middle thickness of the sidewall portion of the TSV liner.