Transparent Electrode Contact Structure for High-Definition Displays
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Solution Overview
Problem
High-definition liquid crystal display devices face manufacturing yield reduction due to connection failures of small contact holes in pixels, particularly in virtual reality applications where high precision is required.
Innovation Solution
The display device incorporates a specific layered structure with silicon oxide and silicon nitride insulating layers to ensure reliable electrical connections between semiconductor, source, and transparent electrodes, preventing contact hole discontinuities and maintaining display quality even with misalignment of substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high definition is achieved with small pixels, then display quality is improved, but connection reliability of contact holes deteriorates
Solution Approach 1:
The patent employs a composite insulating layer structure combining silicon oxide layers (first and second insulating layers) with a silicon nitride layer (third insulating layer). This composite material approach leverages the complementary properties of different materials: silicon oxide provides good insulation and etch selectivity, while silicon nitride offers high density, moisture barrier properties, and mechanical strength. The combination creates a robust multi-layer structure that maintains connection reliability even with small contact hole dimensions required for high definition displays.
Solution Approach 2:
The insulating structure is segmented into multiple distinct layers rather than using a single homogeneous layer. The first insulating layer (silicon oxide), second insulating layer (silicon oxide), and third insulating layer (silicon nitride) are separately formed with different thicknesses and properties. This segmentation allows each layer to perform its specific function optimally: the lower silicon oxide layers provide insulation and etch stopping, while the upper silicon nitride layer provides a dense barrier and mechanical support, collectively ensuring connection reliability in miniaturized pixels.
2Manufacturing precision
If contact hole size is reduced for high definition, then pixel density is improved, but manufacturing yield deteriorates
Solution Approach 1:
The patent implements a cushioning structure by forming the third insulating layer (silicon nitride) over the second insulating layer (silicon oxide) before forming contact holes through them. This pre-formed multi-layer structure provides mechanical cushioning and stress distribution that prevents contact hole discontinuities and connection failures during subsequent manufacturing processes. The different material properties and thicknesses of the layers create a buffered structure that absorbs manufacturing variations, thereby maintaining high manufacturing yield even with reduced contact hole sizes for high pixel density.
3Length of moving object
If insulating layers are made thinner for small pixels, then pixel size is reduced, but connection stability deteriorates
Solution Approach 1:
The patent applies local quality by assigning different thicknesses and material properties to different insulating layers based on their specific functional requirements. The first and second insulating layers (silicon oxide) have different thicknesses optimized for their respective positions and functions, while the third insulating layer (silicon nitride) has thickness and material properties specifically tailored for providing mechanical strength and moisture barrier at the contact hole region. This localized optimization ensures connection stability is maintained even when overall pixel dimensions are reduced.
Data Source
AI summary
According to one embodiment, a display device includes a transparent semiconductor, a first insulating layer, a gate electrode, a second insulating layer, a source electrode, a third insulating layer, a transparent electrode which is in contact with the semiconductor in a second contact hole penetrating the first insulating layer, the second insulating layer and the third insulating layer, a fourth insulating layer, a color filter, and a pixel electrode electrically connected to the transparent electrode. The first insulating layer and the second insulating layer are silicon oxide layers. At least one of the third insulating layer and the fourth insulating layer is a silicon nitride layer.