Planar Motor Substrate Transfer With Sensor-Based Position Correction
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Solution Overview
Problem
Conventional substrate transfer robots in semiconductor manufacturing face issues such as gas intrusion and limited movement, which affect positioning accuracy, especially with the demand for miniaturization and precise placement of substrates during high-temperature and low-temperature processing.
Innovation Solution
A substrate transfer apparatus utilizing a planar motor with electromagnetic coils and a magnetically levitated base, combined with a substrate detection sensor and transfer controller, enables high-precision positioning by calculating and correcting the transfer position of substrates based on detection data, overcoming the limitations of traditional robots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transfer robot with articulated arm structure is used, then substrate transfer can be achieved, but positioning accuracy deteriorates due to gas intrusion and movement limitations
Solution Approach 1:
The patent replaces the articulated arm mechanical structure with a planar motor system that uses electromagnetic fields for substrate transfer. The planar motor includes a mover with permanent magnets and a stator with electromagnetic coils, eliminating mechanical contact and articulation points that cause positioning errors and gas leakage.
Solution Approach 2:
The patent introduces a vacuum cushion mechanism where a vacuum state is created between the substrate and the holder to prevent substrate displacement during transfer. This vacuum cushioning effect compensates for any residual positioning deviations and prevents gas intrusion issues.
2Reliability
If conventional transfer robots are used, then substrate transfer is possible, but positioning accuracy deteriorates due to gas intrusion from vacuum seals
Solution Approach 1:
The patent eliminates mechanical vacuum seals by using a planar motor system that operates with magnetic fields and a vacuum cushion. The vacuum cushion creates a gas barrier without requiring physical sealing components that can leak or degrade, thereby maintaining both transfer reliability and positioning accuracy.
3Adaptability or versatility
If planar motor is used for substrate transfer, then movement limitations are overcome, but positioning accuracy may be affected without correction mechanisms
Solution Approach 1:
The patent incorporates a position detection sensor that detects the substrate position during transfer. The transfer controller uses this detection signal to calculate the actual position and generates correction values to adjust the transfer position, ensuring high positioning accuracy while maintaining the versatility of the planar motor system.
Solution Approach 2:
The transfer controller calculates correction values in advance based on the detected substrate position and pre-calculates the corrected transfer position. This preliminary correction ensures that the substrate is accurately positioned at the target location without requiring post-transfer adjustment.
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 solution ensures high positioning accuracy of substrates during transfer, reducing misalignment and improving processing uniformity and characteristics by accurately placing substrates in processing chambers.
Implementation Method 1
a planar motor including a main body, a plurality of electromagnetic coils disposed in the main body, and a linear driver configured to supply a current to the electromagnetic coils, and magnetically levitate and linearly drive the base
Implementation Method 2
a planar motor including a main body, a plurality of electromagnetic coils disposed in the main body, and a linear driver configured to supply a current to the electromagnetic coils
Data Source
AI summary
A substrate transfer apparatus for transferring a substrate is disclosed. The apparatus comprises: a transfer unit including a substrate holder configured to hold a substrate, and a base having therein a magnet and configured to move the substrate holder; a planar motor including a main body, a plurality of electromagnetic coils disposed in the main body, and a linear driver configured to supply a current to the electromagnetic coils, and magnetically levitate and linearly drive the base; a substrate detection sensor configured to detect the substrate when the substrate held by the substrate holder passes by; and a transfer controller configured to calculate an actual position of the substrate held by the substrate holder based on detection data of the substrate detection sensor, calculate correction values for a logical position that has been set, and correct a transfer position of the substrate based on the correction values.