Self Aligned Fin Formation via Mandrel Removal
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Solution Overview
Problem
The manufacturing of FinFET structures with high aspect ratios for sub-10 nm nodes is challenging due to limitations in current patterning and lithography processes, which are time-consuming and do not provide reliable patterning, especially for forming dense circuits with small pitch sizes.
Innovation Solution
A method involving the formation of mandrel structures, conformal deposition of fin materials, and selective etching processes to create FinFET structures without the need for multiple patterning processes, allowing for transition from silicon to III-V materials while maintaining crystal lattice orientations, using a processing system with various chambers for deposition and etching operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional multiple patterning processes (SADP, SAQP) are used to form sub-10 nm node FinFET structures, then patterning reliability is improved, but manufacturing complexity and processing time increase significantly
Solution Approach 1:
The patent extracts and removes the mandrel structures after fin formation, eliminating the need for complex multiple patterning processes. The mandrels serve only as temporary placeholders that define the fin pitch, and their removal simplifies the overall manufacturing process while maintaining patterning reliability.
Solution Approach 2:
The mandrel structures are formed in advance before the actual fin structures. This preliminary action establishes the pitch pattern that will be replicated in the fins, allowing subsequent conformal deposition to automatically achieve the desired pitch without requiring additional patterning steps.
2Manufacturing precision
If multiple patterning processes are used to achieve small pitch sizes, then manufacturing precision is improved, but productivity decreases due to increased processing time
Solution Approach 1:
The manufacturing process is segmented into distinct stages: mandrel formation, conformal fin deposition, and mandrel removal. This segmentation allows each stage to be optimized independently and enables parallel processing of multiple fins simultaneously through conformal deposition, significantly improving throughput compared to sequential patterning methods.
Solution Approach 2:
The conformal deposition process automatically replicates the mandrel pitch pattern across the entire substrate without requiring additional lithography or patterning steps. The process is self-aligning and self-replicating, achieving high precision pitch control while maintaining high productivity.
3Quantity of substance
If high aspect ratio fin structures are formed, then current density is improved, but manufacturing difficulty increases due to reduced critical dimensions
Solution Approach 1:
The mandrel structures serve as intermediary elements that enable the formation of high aspect ratio fins. By using mandrels as temporary templates, the process achieves precise control over fin dimensions and pitch without requiring direct patterning at the critical fin dimensions, thereby simplifying manufacturing while achieving high current density.
Solution Approach 2:
The patent transitions from planar patterning to three-dimensional conformal deposition. The fin structures are formed by depositing material conformally on the sidewalls of mandrels, effectively using the vertical dimension to achieve precise pitch control and high aspect ratios without being constrained by two-dimensional lithography resolution limits.
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 efficient formation of FinFET structures with reduced complexity and increased throughput, maintaining acceptable crystal lattice orientations and allowing for the transition to III-V materials, thus overcoming the limitations of existing methods.
Implementation Method 1
a first fin material layer may be conformally deposited within the recess
Data Source
AI summary
Methods and apparatus for forming FinFET structures are provided. Selective etching and deposition processes described herein may provide for FinFET manufacturing without the utilization of multiple patterning processes. Embodiments described herein also provide for fin material manufacturing methods for transitioning from silicon to III-V materials while maintaining acceptable crystal lattice orientations of the various materials utilized. Further embodiments provide etching apparatus which may be utilized to perform the methods described herein.