In-Line OLED Metrology for Layer Thickness and Dopant Concentration
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Solution Overview
Problem
Existing end-of-line metrology systems for OLED production suffer from significant delays in providing feedback on dopant concentrations and layer thicknesses, leading to suboptimal deposition processes and reduced yield.
Innovation Solution
An in-line process monitoring and control system is implemented, featuring a metrology head with reflectometry and photoluminescence capabilities, positioned within a transfer chamber to provide real-time measurements of layer thickness and dopant concentration during the OLED deposition process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If end-of-line metrology systems are used to monitor OLED layers, then manufacturing completeness is ensured, but significant delays occur in providing feedback on dopant concentrations and layer thicknesses
Solution Approach 1:
The patent implements in-line metrology measurements during the deposition process itself, performing thickness and dopant concentration measurements before the deposition is complete. This preliminary action eliminates the inherent delay of end-of-line measurement systems, providing real-time feedback that enables immediate process adjustments while maintaining comprehensive monitoring of all critical parameters.
Solution Approach 2:
The system incorporates real-time feedback loops where in-line measurements of layer thickness and dopant concentration are continuously monitored and fed back to the deposition control system. This enables dynamic adjustment of deposition parameters during the process, resolving the contradiction by providing both comprehensive monitoring and immediate feedback without the time delays characteristic of end-of-line systems.
2Loss of time
If in-line process monitoring is implemented, then real-time feedback is achieved, but device complexity increases
Solution Approach 1:
The patent employs a multi-functional metrology system that performs multiple measurement types (thickness measurement via reflectometry, dopant concentration via photoluminescence) using an integrated in-line measurement platform. This universal approach consolidates what would otherwise require multiple separate measurement systems, achieving real-time feedback while limiting the increase in overall system complexity through functional integration.
Solution Approach 2:
The system uses optical intermediaries (light sources, detectors, and optical paths) as mediators to perform non-contact measurements during deposition. These optical intermediaries enable real-time monitoring without physically interfering with the deposition process or requiring complex direct sampling systems, thus achieving real-time feedback with controlled complexity increase.
3Manufacturing precision
If sequential deposition using multiple chambers is used, then layer quality is maintained, but production efficiency decreases
Solution Approach 1:
The patent implements continuous in-line measurements throughout the sequential deposition process in multiple chambers, eliminating idle measurement time between chambers. By maintaining continuous monitoring and feedback across the entire multi-chamber process, the system enables real-time optimization that maintains layer quality while improving production efficiency through reduced cycle times and minimized non-productive intervals.
Solution Approach 2:
The system dynamically adjusts deposition parameters in real-time based on in-line measurements taken during the sequential chamber process. This dynamic control allows each chamber to operate at optimized conditions while maintaining overall process coordination, resolving the contradiction by enabling both precise layer quality control and improved production efficiency through adaptive, real-time parameter optimization across multiple chambers.
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 enables rapid in-line monitoring and control, allowing for immediate adjustments to the deposition process, thereby improving device performance, tightening yields, and reducing production costs.
Implementation Method 1
At least one of the one or more sensors is positioned to receive reflections of the first light beam from the workpiece within the transfer chamber to perform reflectometry measurements and generate a thickness measurement of a layer on the workpiece from the reflectometry measurement
Implementation Method 2
a second light source to generate a second light beam to induce photoluminescence in the layer on the workpiece in the transfer chamber
Data Source
AI summary
An organic light-emitting diode (OLED) deposition system includes two deposition chambers, a transfer chamber between the two deposition chambers, a metrology system having one or more sensors to perform measurements of the workpiece within the transfer chamber, and a control system to cause the system to form an organic light-emitting diode layer stack on the workpiece. Vacuum is maintained around the workpiece while the workpiece is transferred between the two deposition chambers and while retaining the workpiece within the transfer chamber. The control system is configured to cause the two deposition chambers to deposit two layers of organic material onto the workpiece, and to receive a first plurality of measurements of the workpiece in the transfer chamber from the metrology system.