Sono-Tek to show new integrated heat plate option
The SPT200WS combines Sono-Tek’s precision ultrasonic spray-coating technology with automated wafer handling for semiconductor applications, including MEMS and wafers with deep-well or other challenging topographies. The system supports 100, 150 and 200 mm wafers, with a 300 mm configuration available.
The new post-coat heat plate is designed to increase system throughput by separating the photoresist coating and drying processes. After a wafer is coated inside the SPT200 coating module, the automated wafer handler transfers it to the dedicated heat plate for a controlled post-coat bake.
Previously, the coated wafer could remain on the heated chuck inside the coating station for an extended period while the photoresist dried. With the new option, the post-coat soft bake takes place at a separate station, freeing the coating module to begin processing the next wafer sooner. This parallel-processing approach can reduce overall cycle time and increase wafer throughput without sacrificing coating consistency or process control.
The automated process includes:
1. Retrieving a wafer from the cassette
2. Transferring the wafer to the pre-alignment station
3. Loading the aligned wafer into the ultrasonic coating module
4. Applying photoresist while the wafer is positioned on the heated vacuum chuck
5. Transferring the coated wafer to the new post-coat heat plate for a controlled soft bake
6. Returning the completed wafer to the cassette
Sono-Tek’s ultrasonic nozzles produce highly controllable spray patterns at very low flow rates and can reduce photoresist consumption by up to 90% compared with conventional coating methods. The non-clogging nozzle technology is particularly effective for applying uniform coatings over complex three-dimensional features that can be difficult to cover using traditional spin-coating processes.
“The new post-coat soft back heat plate expands the SPT200WS into a more efficient, higher-throughput production platform,” said Brian Booth, VP, Sales & Business at Sono-Tek Corporation. “By moving the drying step outside the coating module, customers can make better use of the coating station and process more wafers in a given period of time. It is a practical automation enhancement designed around the needs of production-scale semiconductor manufacturing.”
