The Sirius™ control system comprises a HOST PC
and a controller for each tube, mounted at tube level in the load station.
Associated temperature I/O modules are mounted in the gas cabinet base. The
system provides local recipe management and data acquisition.
All
parameters of each process run, as well as operator identification, are data
logged and stored in Microsoft Access™ data tables and may be recalled on
the monitor, sent to a remote location or printed out. Data may be reviewed
with Microsoft Access™.
Each process is archived when it is
downloaded and other parameters (gas flow, temperatures, valve positions, etc.)
are monitored at least every 15 seconds and data logged.
The system
automatically captures process control information during all runs which may be
displayed in an easy-to-read graph, either during capture or from a history
file.
The graph shows absolute engineering values versus time
and two plots can be shown simultaneously so that you may compare a run with a
recipe or two runs with each other. Axis can be magnified to study specific
process problems, such as furnace recovery after product loading.
An event
log, maintained in both a rolling and a permanent file, keeps track of all
processes and user events. You can sort the log by as many as ten criteria to
display information in the most useful way.
Real-time data (gas flow,
temperatures, valve positions, etc.) is displayed on the HOST monitor in a
graph form and may be printed out.
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12-bit D/A and A/D converters are located within
two feet of each MFC, minimizing cable length and number of connections for
optimum reliability. The D/A and A/D converters and MFC's use a common power
supply, eliminating reference voltage problems associated with multiple power
supplies. The result is exceptionally precise MFC control.
The
temperature I/O modules provide high-resolution (0.05C), 1500-volt isolation
between thermocouples plus individual cold-junction compensation for each TC.
Each module also contains local digital conversion and optical isolation. This
entirely solid-state temperature and power driver package provides accurate and
dependable temperature control.
The HOST computer displays a plumbing schematic
for the gas control system, with status lights for each pneumatic valve and
alarm condition.
A network option lets you connect one or more furnaces to
remote engineering terminals. Equipment and process engineers can then access
tube status, recipes, data capture files and event logs from PCs in their
offices. Local recipe edits can be backed up automatically on remote terminals.
The
Sirius™ HOST PC can interface with your production control system using a
bridge PC with appropriate communications software. As a batch of wafers enters
a furnace step the production control system sends a message to the bridge PC
to download the recipe to the selected tube. |
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