May 14, 2004 7AF Software Version 6.06.0 Features
STRASBAUGH CONFIDENTIAL INFORMATION
1
7AF Version “6.06” Features
05/14/2004 Steven Jacobson
Purpose
Version 6.06.0 allows alignment of round wafers to detect both major and minor flats. Detection of the minor
flat in the expected position means that the wafer is not upside-down. If the minor flat is not detected, the wafer
is flipped over and is again examined for the minor flat. This prevents grinding the wrong side of the wafer if the
operator placed it into the cassette incorrectly.
Another new feature adds decimal numbers to Ind Wafer grind measurement files.
Minor Flat Detection
Two hardware modifications are required for detection of the minor flat and for flipping the wafer. An optical
sensor must be attached to the pre-aligner. It must be located precisely where the minor flat will be once the
wafer has been aligned. This sensor will be valid for one and only one wafer diameter. That is, if you use it with
4-inch wafers, you need to have it moved before it can be used with a different diameter wafer. In addition a
small platform must be attached to the pre-aligner as a temporary holding location to enable flipping the wafer if
it is found to be upside-down. The robot must be trained to get and put a wafer at this location. The platform
has two station id’s. As station M, the robot puts a wafer on the platform with the wafer above the end-effector.
As station m, the robot gets a wafer from the platform with the end-effector above the wafer.
With these modifications, you may select this special alignment as align mode “Minor Flat” in your grinding
recipe. If the minor flat is not found at the expected position on either side of the wafer, grinding is prevented,
and the Prealigner Error alarm is displayed. Also note that the Defaulto recipe is used for Home and Reference.
You are advised NOT to select Minor Flat alignment in Defaulto. If you select it, and then use wafers that do
not have a minor flat, Reference will be prevented and the Prealigner Error alarm will be displayed.
For additional control, it is possible to specify an angle to which the aligned wafer must be rotated before trying
to detect the minor flat. If, for example, it is not possible to place the sensor at the location of the minor flat but
it is possible to place it at some other point along the circumference of the wafer, this will allow detection of the
minor flat. The aligned wafer will be rotated to the correct angle and will be rotated back to the aligned position
after reading the sensor. The angle, if needed, will be in Coordinate Special Item number 4 for station c, the pre-
aligner. This value is given in hundredths of a degree, clockwise. To rotate thirteen and a half degrees
counterclockwise from the aligned position, set the value as SCSI c, 4, -1350 in the robot coordinate file.
If you do not need to rotate, leave the value as zero.
Ind Wafer Grind with Decimals
Ind Wafer Grind now allows its input measurement file to contain either integer data or decimal data or a
mixture of both. It will calculate grind targets using up to one decimal place, i.e., a tenth of a micron. The
thikness program has also been changed to allow decimal numbers to be input. If decimal data is used, the file
created by thikness will be slightly larger than the original size. Gem is also changed to allow this additional size
file to be transferred. (File size is an issue only if Gem is used. Without Gem, any size file is allowed.)
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