Lift-off Circuit Pattern Formation via Resist Eaves Geometry
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Solution Overview
Problem
The existing photolithography etching process for forming circuit patterns on substrates is costly and environmentally unfriendly due to its high number of steps, low yield, and significant chemical usage, and it struggles with precision issues such as film peeling and incomplete protective layer coverage, leading to potential circuit disconnections.
Innovation Solution
A method is developed to form a circuit pattern on a substrate using a resist layer with an eaves-type opening shape, where the height and width of the opening are specifically determined to prevent the thin film layer from peeling off and ensure precise pattern formation, including the use of a protective layer to cover the thin film layer effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography etching process is used to form circuit patterns, then pattern formation precision is good and mass productivity is achieved, but manufacturing cost becomes very high and environmental load increases due to large amount of chemical solutions used
Solution Approach 1:
The patent extracts and eliminates the etching step from the conventional photolithography process by using the lift-off method. Instead of etching away material to create patterns, the invention forms complete thin film layers and then selectively removes unwanted portions through resist peeling, thereby simplifying the manufacturing process while maintaining pattern precision
Solution Approach 2:
The patent inverts the conventional approach by forming patterns through material addition and selective removal rather than material subtraction through etching. The lift-off method forms complete films first and then removes excess material by peeling off the resist layer, which is the reverse of the traditional etching sequence
2Manufacturing precision
If conventional photolithography etching process is used, then circuit patterns can be formed with good precision, but film peeling and incomplete protective layer coverage occur leading to potential circuit disconnections
Solution Approach 1:
The patent applies preliminary action by forming the complete thin film layer structure before pattern definition. The resist layer is applied over the entire substrate surface, complete thin film layers are deposited, and then the resist is peeled off to reveal patterns. This sequence ensures that all films are fully formed and adherent before any removal occurs, preventing film peeling issues
Solution Approach 2:
The resist layer serves as an intermediary that protects the thin film layers during the formation process. By maintaining the resist layer throughout the thin film deposition process and then selectively removing it through peeling, the invention ensures complete protective layer coverage while achieving precise pattern formation without film adhesion problems
3Device complexity
If lift-off method is used to reduce manufacturing steps and environmental load, then number of steps is reduced and chemical usage decreases, but pattern precision and reliability are compromised due to film peeling issues
Solution Approach 1:
The patent applies parameter changes by optimizing the resist layer thickness and the thin film layer thickness to specific ranges. By controlling these parameters, the invention ensures that the thin film layers form completely and uniformly before resist peeling, thereby achieving high pattern precision while maintaining the simplified lift-off process structure
4Manufacturing precision
If multiple manufacturing steps are performed in photolithography etching process, then desired circuit patterns can be formed, but manufacturing cost increases and yield decreases
Solution Approach 1:
The patent merges multiple separate manufacturing steps into a single integrated lift-off process. Instead of performing separate etching, cleaning, and protective layer formation steps, the invention combines these operations into one process sequence where the resist layer serves multiple functions: pattern definition, film formation mask, and protective layer. This merging significantly improves manufacturing yield and cost efficiency
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 enhances pattern precision and reliability, reduces the risk of film peeling and disconnections, and lowers environmental impact by minimizing chemical usage and steps, resulting in a more cost-effective and efficient manufacturing process.
Implementation Method 1
by exposing the resist layer via a mask and developing it, a pattern (inverse circuit pattern) which is inverse to the circuit pattern is formed
Data Source
AI summary
A method for manufacturing a circuit pattern-provided substrate including forming a resist layer on a substrate, forming an opening corresponding to a circuit pattern and having an eaves cross-sectional shape in the resist layer, forming a thin film layer having a portion formed on the substrate in the opening and a portion formed on the resist layer, and removing the resist layer such that the resist layer and the portion of the thin film layer formed on the resist layer are removed from the substrate. The forming of the opening comprises exposing the resist layer with a mask device which changes an exposure amount of the resist layer such that the eaves cross-sectional shape has a space at a boundary between the resist layer and the substrate.