Block Copolymer Self-Assembly for Nanoscale Air Gap Etch Masks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing nanoscale air gap structures in integrated circuits are complex and require multi-step lithographic exposure, etching, and high-pressure chemical vapor deposition, necessitating a simpler approach for reduced complexity and improved efficiency.
Innovation Solution
A method involving a block copolymer with a first and second polymer block, where nanostructures self-assemble and align perpendicular to a substrate surface, and are etched at a lower rate than the surrounding layers, allowing for the formation of nanoscale features and masking during etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multi-step lithographic exposure, developing, and etching methods are used to produce nanoscale air gap structures, then manufacturing precision can be achieved, but device complexity increases significantly
Solution Approach 1:
The block copolymer system performs self-assembly to automatically form the nanoscale patterned structures without requiring external lithographic exposure and developing steps. The immiscible polymer blocks spontaneously organize into periodic domains, creating the desired air gap patterns through self-service rather than complex external processing
Solution Approach 2:
The patent combines multiple functions into a single material system: the block copolymer simultaneously serves as the self-assembling pattern-forming agent, the etch mask (due to differential etch rates between blocks), and the structural template for air gap formation, eliminating the need for separate lithography, etching, and deposition processes
2Manufacturing precision
If sacrificial organic polymer removal methods are used to form air gaps, then air gap structures can be produced, but the process requires additional high pressure chemical vapor deposition steps increasing complexity
Solution Approach 1:
The patent extracts and eliminates the sacrificial polymer removal step and high pressure CVD capping step from the process sequence. Instead of forming air gaps by removing sacrificial material and then capping with deposited layers, the block copolymer method directly forms the gap structures through self-assembly with the low-etch-rate blocks serving as the final mask
Solution Approach 2:
The patent uses standard pressure CVD or spin-coating processes instead of expensive high pressure CVD equipment, and employs the block copolymer as a disposable self-assembling template that is eventually removed, replacing complex expensive processes with simpler, more accessible techniques
3Manufacturing precision
If conventional multi-layered structures with multi-step lithographic exposure are used, then nanoscale features can be formed, but productivity decreases due to multiple processing steps
Solution Approach 1:
The block copolymer performs preliminary self-assembly to pre-form the complete nanoscale patterned structure before any etching or deposition steps. This preliminary action of self-organization eliminates the need for sequential lithographic exposure and developing steps, accelerating the overall process
Solution Approach 2:
The patent establishes continuity by having the block copolymer self-assembled structure continuously serve as the etch mask throughout the etching process, and the low-etch-rate blocks continuously protect the underlying layers, eliminating interruptions between pattern formation and etching operations
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 method simplifies the production of nanoscale air gap structures by enabling self-assembly and selective etching, reducing complexity and improving the efficiency of feature formation in integrated circuits.
Implementation Method 1
nanostructures of the additional material self-assemble within the first polymer block, the nanostructures self-aligning perpendicular to the surface of the first layer
Implementation Method 2
etching the film of the combination and the first layer, the nanostructures having an etch rate lower than an etch rate of the block copolymer, the nanostructures having an etch rate lower than an etch rate of the first layer
Data Source
AI summary
A method for producing surface features and an etch masking method. A combination is provided of a block copolymer and additional material. The block copolymer includes a first block of a first polymer covalently bonded to a second block of a second polymer. The additional material is miscible with the first polymer. A film is formed of the combination directly onto a surface of a first layer. Nanostructures of the additional material self-assemble within the first polymer block. The film of the combination and the first layer are etched. The nanostructures have an etch rate lower than an etch rate of the block copolymer and lower than an etch rate of the first layer. The film is removed and features remain on the surface of the first layer. Also included is an etch masking method where the nanostructures mask portions of the first layer from said etchant.