Customer SolutionsDesigning a Highly Reliable Electron Beam Control System Using NI LabVIEW FPGA and CompactRIO
Author(s):Chris Tasker, Oregon State University, Department of Electrical and Computer Engineering; Matt Spiegelberg, Oregon State University
Industry:Semiconductor
Product:CompactRIO, LabVIEW, LabVIEW FPGA
The Challenge:Implementing a control and interlock system for a custom electron beam deposition system for use in an advanced semiconductor materials research laboratory.
The Solution:Creating a highly reliable control system with an intuitive user interface while minimizing development time using National Instruments LabVIEW and CompactRIO.
As part of the Advanced Materials Research and Development Program at Our semiconductor processing clean room is an integral part of our development program. The room contains tools such as an RF magnetron sputter system, an ion beam deposition system, thermal evaporators, a chemical vapor deposition (CVD) system, and an electron beam deposition system, as well as other processing-related tools. The electron beam deposition system is a useful development tool because it requires a relatively small amount of material (targets) to be deposited and yields high deposition rates. In late 2004, we needed to replace our aging electron beam deposition system, which had been in use since the early 1980s. We designed a new electron beam deposition system that implements advanced features such as a rasterable electron beam, substrate heating capable of temperatures up to 600°C, and base pressures approaching 1×10-7 Torr. LabVIEW and CompactRIO Reduce Development Time Previous deposition system control systems were built around microcontrollers and desktop computers with digital I/O cards and were programmed in Visual Basic. In planning our new electron beam deposition system, we decided to establish hardware and software standards that would make integration into future processing tools possible. The CompactRIO programmable automation controller (PAC) was an attractive solution for the core control system because of its reconfigurable nature and the ease of programming using LabVIEW. CompactRIO offered the combination of control algorithm hardware implementation in the form of an FPGA and reliable processing with an embedded real-time controller. With the CompactRIO platform, we can accurately interlock and read electron beam conditions in real-time. We also implemented a control program on the host PC so users can access database functionality and real-time system information. Using CompactRIO, we can code completely in LabVIEW, which is much easier than any other platforms we have used. The real-time controller in CompactRIO lets us run our applications in a time-critical manner and provides a high degree of reliability and protection, which is important when monitoring and controlling expensive processing equipment. We developed our control logic entirely in LabVIEW using the LabVIEW FPGA Module. Since LabVIEW was already the standard for our test and measurement applications, coding with the FPGA module in LabVIEW was very straightforward. We wrote, tested, and debugged the FPGA and host code in about one working month – much less time than previous systems that were coded in assembly language or Visual Basic. The result of the project is a control and interlock system that far exceeds what was previously possible. With the system based on CompactRIO, we have a highly reliable, robust, and extremely fast control system. One of the most appealing features of the LabVIEW approach is that we can decide to add functionality, such as PID substrate heat control, with the addition of a parallel while loop and a small amount of code. The new user interface provides information and controls that were not available with the previous system, and we were able to incorporate advanced features such as e-mail notification and database logging to Microsoft Access into the host program.
For more information, contact: Chris Tasker 3031 Tel: (541) 737-2976 Fax: (541) 737-1300 E-mail: chris@eecs.oregonstate.edu
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