Area-Selective Hardmask Deposition for Edge Placement Control
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Solution Overview
Problem
Current semiconductor manufacturing techniques face challenges in achieving selective deposition of hardmask materials on SiN versus SiO2, which is crucial for reducing edge placement errors and minimizing the number of mask steps required.
Innovation Solution
The method involves exploiting differences in surface fluorination, etch-rate, reactivity with aminosilane inhibitors, and electrostatic repulsion using halide precursors to achieve high selectivity in the deposition of metal oxides or metal oxynitrides on SiN versus SiO2 surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithography with DUV light sources is used, then manufacturing reliability is maintained, but edge placement errors increase and critical dimensions cannot be reduced below sub-10 nm scale
Solution Approach 1:
The patent changes the fundamental parameter of patterning methodology from top-down photolithography to bottom-up area-selective deposition. By using ALD with controlled surface chemistry reactions, the process achieves atomic-level precision in depositing hardmask materials only on desired surfaces, enabling critical dimension control at 5 nm and below while maintaining manufacturing reliability through self-aligned processes
Solution Approach 2:
The patent replaces the optical/mechanical photolithography system with a chemical deposition system. Instead of using light exposure and mechanical mask alignment, the process uses area-selective atomic layer deposition where chemical reactions occur only on specific surface types (SiN vs SiO2), eliminating edge placement errors associated with mechanical alignment
2Manufacturing precision
If multiple masks and complex fabrication processes are used to shrink critical dimensions, then manufacturing precision improves, but device complexity and processing steps increase
Solution Approach 1:
The patent implements self-aligned patterning where the hardmask deposition automatically occurs only on the intended surfaces (e.g., SiN) while excluding others (e.g., SiO2). This self-selectivity eliminates the need for multiple alignment steps and masks, reducing process complexity while maintaining precision
Solution Approach 2:
The patent applies different surface properties to different areas of the substrate. By functionalizing SiN surfaces with specific groups (e.g., NH2) that promote ALD reactions while SiO2 surfaces remain inert or are passivated, the process achieves spatially selective deposition without requiring multiple masks or complex fabrication sequences
3Manufacturing precision
If area-selective deposition is implemented to reduce edge placement errors, then manufacturing precision improves, but process complexity increases due to surface functionalization requirements
Solution Approach 1:
The patent performs preliminary surface functionalization before the ALD process. By pre-treating surfaces with specific chemical groups (e.g., silane coupling agents on SiN, or passivation layers on SiO2), the process establishes the selectivity needed for precise hardmask deposition, enabling edge placement error control while managing complexity through advance preparation
4Productivity
If selective hardmask deposition on SiN vs SiO2 is achieved, then the number of mask steps is reduced, but deposition selectivity control becomes more difficult
Solution Approach 1:
The patent exploits the fundamental chemical difference between SiN and SiO2 surfaces. By using precursors that react selectively with SiN surface groups (e.g., NH2-terminated SiN) while SiO2 surfaces are passivated or unreactive, the process achieves high deposition selectivity. This chemical parameter differentiation enables reducing mask steps while managing selectivity control through chemistry rather than complexity
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 selective deposition of hardmask materials with high precision, reducing the number of processing steps and improving the control of edge placement errors, thereby enhancing the efficiency of semiconductor fabrication.
Implementation Method 1
pretreating the surface with a plasma, wherein the plasma removes a native oxide layer on the nitride layer portion
Implementation Method 2
functionalizing the surface of the substrate with at least one cycle of exposing the surface to an aminosilane small molecule inhibitor
Implementation Method 3
exposing the surface to a metal precursor; and exposing the surface to a co-reactant, to provide a metal oxide or metal oxynitride layer selectively deposited on the nitride layer portion
Data Source
AI summary
The present inventive concept relates to area-selective deposition (ASD) area-selective atomic layer deposition (AS-ALD) processes, and applications thereof. Methods of selectively depositing metal oxides and metal oxynitrides, such as TiO2 and TiON, on nitride (SiN) as a growth area vs. oxide (SiO2) as a nongrowth area, and applications thereof in, for example, self-aligned block (SAB) patterning and self-aligned multiple patterning (SAMP) processes are described.