| 摘要 |
The deposition controller controls a coating machine used in the deposition of the thin film coatings. The deposition controller is particularly useful for the deposition of multiple layers or co-deposition of multiple materials. The integrated system is a single hardware unit controlled by the software residing on the local computer. The single unit combines the functionality of a deposition controller, mass flow controller, quartz crystal controller, optical monitor chip change controller, and an optical monitor signal analyzer. The integrated system utilizes a Programmable Logic Controller (PLC) for the purpose of controlling the deposition process. A run sheet file is used by the system to create a set of process parameters. The system also examines a run sheet file at the time of its opening for its integrity with respect to the minimum layer optical thickness requirement expressed in terms of QWOT (quarter wave optical thickness). The controller utilizes an optimized polynomial regression function technique for the accurate layer termination while monitoring the reflection or transmission function and calculating its first and second derivatives to eliminate false termination points. |
