Strasbaugh 6DS-SP, Operation Manual

Page: 1246 / 1562

STRASBAUGH, INC.
March 23, 2000 6DS-SP Software Ver 4.33 Page 3
Strasbaugh Confidential Information
Further Throughput Improvement with Short Polish Time for F-B
Configuration:
Version 4.33 starts robot movement to get the next wafers to be polished even earlier than the
version 4.32 improvement. This allows a further approximate 15 second reduction for the
shortest possible polish time before throughput is affected.
Left and Right Force Scaling Effects Now Show on Status Display of
Polish Force:
Version 4.33 makes a change to how polish force is displayed when the left and right force
scaling is not set to 100%. There is no change to actual force due to scaling - only how it is
displayed. This is the force scaling set in Machine Parameters menu page 1. (This change is
associated with the "odd polish force" feature described below.)
Previously, even though the actual force was modified by the scaling factor, the displayed
force value in the status display was inversely adjusted by that same scaling. The displayed
value was therefore the same as the recipe value. This could be confusing since the actual
force could be higher or lower. Now the display will show the actual force. The following
table illustrates the difference assuming a 98% force scaling:
Item Previous values New values
Recipe force 300 lbs 300 lbs
Actual polish force 294 lbs 294 lbs
Displayed polish force 300 lbs 294 lbs
The display will now show the effects of force scaling (as well as the odd force adjustment
described further below).
Left and Right Force Scaling now Affects Ring Force:
Version 4.33 makes a change so that force scaling from the Machine Parameters menu, page
1, modifies both polish and ring force together instead of polish force only.
It was determined that it is best to maintain the ratio of polish to ring force if using force
scaling. Also, any effect on existing process was determined to be negligible. (This change is
associated with the "odd polish force" feature described below.)
Note to technicians:
The scaling factor affects the requested ring force. For example, a ring force recipe value of
2.0 psi with 102% scaling will cause 2.04 psi to be the requested ring force. The change in
counts seen in counters 59 and 60 due to 102% versus 100% may be a different ratio because
the calculation uses calibration variable 198 "Viprr ring offset (lbs)" as an offset. And that
offset is not scaled.