Automating an Ion-Beam Deposition System with LabVIEW

Author(s):
Richard Brueggman - Data Science Automation, Inc.

Industry:
Energy/Power

Products:
LabVIEW,

The Challenge:
Automating a complex ion-beam deposition system to make it easy to operate.

The Solution:
Using new features in LabVIEW 6 ito fully automate the deposition system so that we can now control it using a simple script.

The Naval Research Laboratory expressed a desire to automate an ion-beam deposition system. Because of the manual nature of every control, operating the system required the presence of highly qualified personnel during the entire deposition process. Using LabVIEW to control the ion-beam power supplies, the Kepco power supply, the gas controllers, and all of the valves while monitoring the pressures and flows in the system, we were able to fully automate the system and control it using a script language.

The Ion-Beam Deposition System
Before we automated the system, personnel had to control the power supplies to the two ion-beam sources for each of the targets as well as a third ion-beam source for cleaning and assisting during deposition as well as the shutters for both targets and the substrate. There was no PID setup to control the substrate temperature. Additionally, the operator had to manually monitor the deposition rate using the two Inficon Crystal Monitors - one for each target. There was no feedback mechanism in place and the deposition process did not have logging capabilities. Furthermore, any inadvertent errors, such as depositing for too long or too short went unnoticed, invalidating any further research performed on the sample deposited.
The Naval Research Laboratory contracted Data Science Automation to provide a turnkey solution to operate the ion-beam deposition system using a simple script, so that personnel with a minimal technical background could operate the system.

Data Science Automation installed a Pentium III PC running Windows 2000 with a National Instruments GPIB card, an 8-port serial card, and an NI-DAQ card. The serial ports and GPIB controller communicate with the ion beam and heater power supplies as well as the crystal oscillator controller. The DAQ card controls the SCXI chassis using the SCXI-1124, SCXI-1125, SCXI-1161, and SCXI-1180 modules. The modules provide the analog and digital I/O to control four pneumatic valves, four electromagnetic valves, four flow controllers, and the substrate temperature to monitor the gas flows and pressures at various locations in the system.

Using new features of LabVIEW 6i, such as the tab-control, Data Socket connections, and control references, we developed an application that only requires user interaction during script creation, and little or none during script execution, significantly reducing the risk of operator error. An additional benefit is the system’s ability to log all operations, so we can verify the exact deposition procedure as long as we keep the log files. With this program, we can also use and execute the script multiple times, enabling the operator to repeat the same procedure, and remove the variability inherent in manual operation of the equipment.
We developed the application using a complex queued-state machine that executed the script and provided user interaction. We implemented 20 different commands in the script language, including variables and the ability to execute a "for-next" loop.

Four additional loops execute in the background, each of which can access several front-panel controls using control references. The first loops communicate over the RS-232 with the gauge controller and continuously updates the pressure readings from the ion gauge, the baratron manometer gauge and the two convectron gauges on the front panel. The second loop monitors all of the ion gun controls and communicates any changes to one of the three ion-beam power supplies over the RS-232. The third loop monitors the substrate temperature and controls a Kepco power supply over GPIB using PID. The last loop monitors the system for any errors and logs all relevant parameters to a file each time a step is executed in the script.

Not only can the system now run automatically with little user intervention, the operator can also monitor and control the system from his or her desk, requiring far fewer entries into the clean room. Using the NI-DAQ OPC server and VISA, we were able to easily connect to the hardware. LabVIEW provided an easy-to-use development environment that made it easy for us to develop high-level instrument drivers for each of the 10 instruments the system controls.

For more information, contact:
Richard Brueggman

Data Science Automation, Inc.

400 Southpointe Blvd., Suite 210

Canonsburg, PA 15317

Tel: (724) 745-8400

Fax: (724) 745-8461

E-mail: rmb@dsautomation.com

Browse All Case Studies »