Display Contact Hole Cleaning for Uniform Insulating Layer Etching
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Solution Overview
Problem
Existing methods for manufacturing display apparatuses face challenges in preventing damage to insulating layers during the formation of contact holes, particularly when exposing semiconductor layers, which can lead to uneven etching rates and potential disconnections in the connection electrodes.
Innovation Solution
A method involving a primary cleaning process using a cleaning gas comprising a fluorine-containing gas and a hydrogen-containing gas, such as hydrofluoric acid and ammonia, is employed to etch silicon oxide and silicon nitride layers alternately stacked in the insulating layer, with controlled process conditions to maintain an etch rate difference of 5% or less, followed by a secondary cleaning with pure water to remove the photoresist pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching methods are used to form contact holes, then the insulating layer can be removed to expose the semiconductor layer, but the etching process causes damage to the insulating layer including uneven etching rates of silicon oxide and silicon nitride layers, leading to disconnections and increased contact resistance
Solution Approach 1:
The cleaning process is segmented into multiple stages: first cleaning to remove organic substances, second cleaning to remove inorganic substances, and third cleaning to perform final surface treatment. Each stage uses different cleaning solutions and parameters optimized for specific types of contaminants, preventing damage to the insulating layer while effectively cleaning the contact hole surfaces.
Solution Approach 2:
The cleaning process utilizes controlled changes in chemical parameters (different cleaning solutions with specific compositions), temperature parameters (heating to specific temperatures during cleaning), and time parameters (controlled duration for each cleaning stage) to achieve effective cleaning while maintaining insulating layer integrity and ensuring uniform etching rates.
2Productivity
If the etching process is performed to expose the semiconductor layer, then the contact hole is formed, but the uneven etching rates of different insulating layer materials lead to defects such as disconnections
Solution Approach 1:
Before the final etching process, a preliminary cleaning treatment is performed on the insulating layer surface to remove contaminants and prepare a uniform surface. This preliminary action ensures that subsequent etching proceeds uniformly across different materials (silicon oxide and silicon nitride), preventing dimensional variations and disconnections while maintaining production efficiency.
Solution Approach 2:
A cleaning solution acts as an intermediary substance between the etching process and the insulating layer. This intermediary treatment modifies the surface properties of different insulating materials to achieve uniform etching rates, ensuring dimensional uniformity of contact holes without compromising formation efficiency.
3Ease of manufacture
If aggressive cleaning methods are used to remove photoresist patterns, then complete removal is achieved, but damage to the insulating layer is caused
Solution Approach 1:
The photoresist removal process is segmented into multiple cleaning stages with different mechanisms: first cleaning for organic substance removal, second cleaning for inorganic substance removal, and third cleaning for final surface treatment. This segmentation enables complete photoresist removal while protecting the insulating layer from damage by using progressively milder cleaning approaches.
Solution Approach 2:
The multi-stage cleaning process maintains continuous useful action by seamlessly transitioning between different cleaning mechanisms. Each stage builds upon the previous stage, ensuring complete photoresist removal while continuously protecting the insulating layer through controlled and progressive cleaning actions rather than a single aggressive step.
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 effectively enlarges the contact hole width, removes photoresist residues, and ensures uniform etching, reducing the risk of electrode disconnection and contact resistance, thereby enhancing the manufacturing process efficiency and quality of the display apparatus.
Implementation Method 1
forming, by etching the insulating layer, a contact hole exposing at least a portion of the semiconductor layer
Implementation Method 2
performing a primary cleaning of the insulating layer in which the contact hole is formed, by using a cleaning gas including a fluorine-containing gas and a hydrogen-containing gas
Implementation Method 3
In the primary cleaning, at least a portion of the plurality of silicon oxide layers and at least a portion of the plurality of silicon nitride layers may be etched. In the primary cleaning, a difference between an etch rate of the plurality of silicon oxide layers and an etch rate of the plurality of silicon nitride layers may be about 5 % or less.
Data Source
AI summary
A method of manufacturing a display apparatus includes forming a semiconductor layer on a substrate, forming an insulating layer on the semiconductor layer, forming a photoresist pattern on the insulating layer, forming, by etching the insulating layer, a contact hole exposing at least a portion of the semiconductor layer, and performing a primary cleaning of the insulating layer in which the contact hole is formed using a cleaning gas including a fluorine-containing gas and a hydrogen-containing gas.