Polysilicon Substrate Polishing System for Protrusion Removal
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Solution Overview
Problem
The manufacturing of polycrystalline silicon transistors for display devices often results in unintended protrusions at grain boundaries, which negatively affect the active layer characteristics and make it difficult to achieve desired transistor characteristics.
Innovation Solution
A substrate polishing system and method that includes a polishing machine with a lower and upper surface plate, a slurry tank, and a substrate transporter with a sponge, sprayers, and a wiper, which together facilitate chemical mechanical polishing of protrusions on polycrystalline silicon layers, using a slurry with abrasive particles and reactants to smooth the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a substrate polishing system uses a common substrate transporter for both transporting and attaching/separating substrates, then device complexity is reduced, but the ease of operation deteriorates due to the complex multi-directional moving mechanism required
Solution Approach 1:
The substrate transporter is designed to perform multiple functions: transporting substrates between conveyor and polishing machine, attaching substrates to the polishing plate, and separating substrates after polishing. This multi-functional design reduces the need for separate devices for each operation, thereby reducing overall device complexity while maintaining operational capability
Solution Approach 2:
The substrate transporter employs a dynamic moving connector with multi-directional movement capability (first direction for transport, third direction for attachment/separation). This dynamic structure allows the same device to adapt to different operational requirements, resolving the contradiction between using a common device and maintaining ease of operation
2Manufacturing precision
If the upper surface plate has a larger area than the substrate, then polishing coverage and uniformity are improved, but the area of the polishing machine increases
Solution Approach 1:
The upper surface plate is designed with a larger area than the substrate to provide extended polishing coverage. This ensures that the entire substrate surface, including edge regions, receives uniform polishing treatment. The extended area of the upper surface plate creates an overlapping polishing zone that improves polishing uniformity across the substrate
3Adaptability or versatility
If the substrate transporter moves in multiple directions to serve both conveyor and polishing machine, then adaptability is improved, but device complexity increases due to the moving connector mechanism
Solution Approach 1:
The moving connector is designed with dynamic movement capabilities in multiple directions: it can move in the first direction to transport substrates between the conveyor and polishing machine, and in the third direction to perform attachment and separation operations. This dynamic multi-directional movement capability provides the adaptability needed to serve multiple functions with a single device
Solution Approach 2:
The moving connector serves multiple functions through its multi-directional movement: substrate transport, positioning for attachment, and positioning for separation. This universal design allows a single mechanism to handle all substrate handling operations, improving adaptability while the integrated design helps manage the inherent complexity
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
Effectively removes protrusions from polycrystalline silicon layers, improving the characteristics of the active layer and enabling the production of transistors with desired properties by using the substrate polishing system and method.
Implementation Method 1
polishing the substrate in cooperation with the lower surface plate
Implementation Method 2
facilitate chemical mechanical polishing of protrusions on polycrystalline silicon layers, using a slurry with abrasive particles and reactants
Data Source
AI summary
A substrate polishing system includes: a polishing machine and a substrate transporter. The polishing machine includes: a lower surface plate to which a substrate is mounted, and an upper surface plate which faces the lower surface plate and polishes the substrate in cooperation with the lower surface plate, the upper surface plate having a larger area than the substrate mounted on the lower surface plate. The substrate transporter is adjacent to the polishing machine and commonly transports the substrate to and from the polishing machine in a first direction, attaches the substrate to the lower surface plate before polishing thereof, and separates from the lower surface plate the substrate after polishing thereof.