Active Matrix Substrate Multi-Tone Photomask Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of active matrix substrates for display devices requires multiple photomasks, increasing costs and processing time, particularly when forming drive circuits or adding functions like in-cell touch panels, as existing methods struggle to reduce the number of photomasks needed while maintaining effective light shielding and high definition.
Innovation Solution
A method involving the use of a multi-tone photomask to form a laminated film with a lower conductive film, insulating film, and semiconductor film, where a resist layer with varying thickness regions is used to pattern the films, allowing for the formation of substructures with overlapping conductive and insulating layers, and a light shielding layer that effectively blocks light without increasing the number of photomasks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple photomasks are used to pattern different metal layers and semiconductor films, then the light shielding efficacy and functional integration are improved, but the manufacturing cost and processing time increase
Solution Approach 1:
The patent combines the light shielding metal layer and the lower electrode layer into a single integrated layer structure. This merging allows both functions to be achieved using one photomask pattern instead of requiring separate photomasks for each layer, thereby reducing the total number of photomasks needed while maintaining effective light shielding and electrode functionality
Solution Approach 2:
The lower conductive layer is designed to serve multiple functions simultaneously: it acts as both a light shielding layer and a lower electrode layer. This multi-functionality eliminates the need for separate dedicated light shielding structures and electrode structures, reducing the number of photomasks required from multiple to just one for this combined layer
2Adaptability or versatility
If additional metal layers are added for light shielding and other functions, then the functional integration is improved, but the number of photomasks and device complexity increase
Solution Approach 1:
The patent merges the light shielding function and the lower electrode function into a single combined layer structure. This reduces the total number of metal layers from multiple separate layers (dedicated light shielding layer + dedicated electrode layer) to one integrated layer, thereby simplifying the device structure while maintaining both functions
Solution Approach 2:
The lower conductive layer is designed with multi-functionality, serving as both the light shielding element and the lower electrode for the TFT. This universal design allows the same layer to fulfill multiple roles, reducing device complexity and the number of photomasks needed compared to having separate dedicated layers for each function
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 reduces the number of photomasks required, enhances light shielding efficacy, and supports the addition of functions while maintaining high definition and reducing processing time and costs.
Implementation Method 1
a step of forming a first resist layer including a first region and a second region thinner than the first region by forming a resist film on the laminated film and exposing and developing the resist film using a multi-tone photomask
Implementation Method 2
a lower conductive layer formed from the lower conductive film... capable of blocking light traveling toward the active layer
Data Source
AI summary
A method for manufacturing an active matrix substrate includes: (A) a step of forming a laminated film including a lower conductive film, a lower insulating film, and a semiconductor film in this order on a substrate; (B) a step of forming a first resist layer; (C) a step of performing a patterning on the laminated film, the step including, in the first formation region, forming the first substructure including a first lower conductive layer, a first lower insulating layer, and a first semiconductor layer respectively formed from the lower conductive film, the lower insulating film, and the semiconductor film, and (D) a step of forming source and drain electrodes electrically connected to the first semiconductor layer.