Metal Oxide Hardmask for Submicron Pattern Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor manufacturing techniques face challenges in forming submicron patterns due to issues with spacer film selectivity, temperature compatibility, pattern loading, and pattern collapse during space-defined double patterning (SDDP) processes, particularly with conventional SiO and SiN films.
Innovation Solution
A method involving the deposition of a metal oxide hardmask, such as TiO2, using plasma-enhanced atomic layer deposition (PE-ALD) at low temperatures, which provides high mechanical strength, etch selectivity, and reduced capillary forces to prevent pattern collapse, while being compatible with photoresist or amorphous carbon templates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If low-temperature SiO film (LT-SiO) is used as spacer film, then deposition temperature is low (compatible with template), but etch selectivity relative to base film is insufficient
Solution Approach 1:
The patent changes the material composition parameter from conventional SiO to metal oxide (TiO2, HfO2, ZrO2, Al2O3) while maintaining low deposition temperature through ALD process, achieving both low temperature compatibility and high etch selectivity simultaneously
Solution Approach 2:
The patent uses composite material structure with metal oxide as spacer film combined with organic template, where the metal oxide provides etch selectivity while the organic template maintains structural integrity during processing
2Reliability
If Al2O3 is used as spacer material, then etch selectivity relative to base film is high, but dry etch resistance is too high (cannot be etched)
Solution Approach 1:
The patent modifies the oxide material composition from pure Al2O3 to metal oxides like TiO2, HfO2, ZrO2 that have balanced etch properties, enabling both high selectivity against base film and reasonable etchability with fluorine-based chemistries
Solution Approach 2:
The patent applies different material properties at different stages: high etch selectivity during spacer formation, then controlled etchability during spacer removal, achieving stage-specific material performance
3Ease of manufacture
If conventional SiO or SiN films are used, then deposition process is established, but mechanical strength is insufficient causing pattern collapse
Solution Approach 1:
The patent employs metal oxide materials (TiO2, HfO2, ZrO2) that combine the benefits of conventional deposition processes with superior mechanical properties including higher Young's modulus and hardness, preventing pattern collapse
Solution Approach 2:
The patent changes the material system from SiO/SiN to metal oxides, achieving enhanced mechanical strength while maintaining compatibility with existing ALD deposition infrastructure through parameter optimization
4Manufacturing precision
If photoresist template is used, then pattern definition is good, but temperature compatibility is limited (deposition must be below 150°C)
Solution Approach 1:
The patent utilizes ALD process parameters that enable deposition at low temperatures (below 150°C for photoresist, below 300°C for amorphous carbon), maintaining template integrity while achieving conformal spacer formation
Solution Approach 2:
The patent introduces an organic template (photoresist or amorphous carbon) as an intermediary that defines the pattern while protecting the underlying structure, allowing low-temperature metal oxide deposition to proceed
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 metal oxide hardmask ensures precise pattern transfer with minimal critical dimension variations and prevents spacer collapse, maintaining pattern integrity even at submicron scales, with enhanced mechanical properties and etch selectivity compared to conventional SiO and SiN films.
Implementation Method 1
depositing by atomic layer deposition (ALD) a metal oxide hardmask on the template
Implementation Method 2
depositing of a metal oxide hardmask, such as TiO2, using plasma-enhanced atomic layer deposition (PE-ALD)
Data Source
AI summary
A method of forming a metal oxide hardmask on a template includes: providing a template constituted by a photoresist or amorphous carbon formed on a substrate; and depositing by atomic layer deposition (ALD) a metal oxide hardmask on the template constituted by a material having a formula SixM(1-x)Oy wherein M represents at least one metal element, x is less than one including zero, and y is approximately two or a stoichiometrically-determined number.