STRASBAUGH, INC.
5-26 February 19, 2002 7AF SECS/GEM Interface Ver. 1.9
Strasbaugh Confidential
should send a S2F41 message to the 7AF containing the remote command, “PP-SELECT”, the Lot Id to be used and the
recipe name to be used. The Lot Id is up to 12 ASCII characters. The recipe name must be a valid DOS file name and
present on the 7AF. The 7AF will respond with a S2F42 message. If the S2F41 message is successful, S2F42 will have a
HCACK (Host Command Acknowledge) = 0. However, if the message is not successful, S2F42 will have a HCACK
equal to a non-zero value which explains why the command was rejected. If an invalid parameter was specified in the
S2F41 message, the S2F42 response will list the invalid parameter(s) name and the reason that each parameter was
considered to be invalid.
The operator can confirm that the message was accepted by looking at the GEM status line in the upper right corner of the
screen. If the S2F41 message was successful, the line will read “PPID SET.” If the S2F41 message was not successful,
the line will read “PPID NOT SET.” Another confirmation would be to check the variables, “Next Lot ID” (VID #25)
and “Next Recipe (PP) to Use” (VID #26) by generating a report through GEM.
Limitations: There are some limitations in setting the PP and Lot Ids. First, once a grind cycle has been started, the host
cannot change the PP. If an attempt is made to change the PP during a grind cycle, the request will be denied, the send
turrets will be locked to prevent material being presented to the robot and a notice will be presented to the operator
notifying them that the turrets have been locked due to an attempted change.
Before a grind cycle is started, the PP can be freely changed. This means that care must be taken to not change the PP once
material has been set onto the send turret. This could result in material being processed with the wrong recipe (PP).
Operators could be trained to note if the PP changes when presenting material to the machine and not start the grind cycle
until the discrepancy is resolved. See below for other ideas on how to use GEM to check this.
Once a cassette is placed on a send turret, it must not be removed and replaced. If this happens, the 7AF will assume that
new material has been presented and attach the “Next Lot ID” to all material in the cassette. This may not be the correct
Lot Id. The host can monitor the “material received” (CE ID #24 and #26) collection events for spurious, unexpected
events. Note that sending a PP change to a different recipe during a grind cycle will lock the send cassettes and keep the
material from being processed. This could be used as a strategy to avoid material with the wrong Lot Id from being
presented to the robot.
Error Detection and Recovery Strategies: Some steps will be discussed that can be used to confirm that procedures are
being followed properly and that information has been transmitted correctly. Simple steps will be discussed first, with
increasingly sophisticated strategies later. There are a wealth of tools available through GEM and you may derive other
strategies to suit your process.
First, operator training should include double checking the PP (recipe). Also, the operator can check the GEM status line
to confirm that the command was accepted. The operator can be assisted in this effort by the host. If an error or problem is
detected in setting the PP, the host can send a message to the operator through the S10F3/S10F4 Terminal Display
feature.
The host can check that the proper sequence is followed by insuring that no material is presented to the machine by
monitoring the “material received” (CE ID #24 and #26) collection events before the recipe is requested from the host
at a terminal. If this occurs, check the appropriate “Turret Status” variable (VID #29 and #31) to see if a cassette is
present. If so, use through the S10F3/S10F4 Terminal Display feature to tell the operator to remove the material and
request that the host set up the PP and Lot Id. Likewise, the host can check that the operator does indeed present material
immediately after requesting that the PP and Lot Id are set up.
Check if the operator did not comply before starting the machine by monitoring the “Process State Changed” (CE ID
#31) or “Start Wafer Grind Cycle” (CE ID #41) collection events, and the “Process State” variable (VID #15). If the
operator has not complied and the turret is not already turned, the turrets can be locked by sending a different PP, stopping
the material from being presented to the robot. If material has already been presented, send a message to the operator to
immediately stop the cycle. Material may need to be cleared from the machine, but wafers will not be ground with an
incorrect PP.
5.8 Material Movement
Material movement on the 7AF consists of three components: 1) The input cassette; 2) the output cassette; and 3) The
Equipment. In order for processing to begin, a cassette of wafers must be placed on the input port and an empty cassette
on the output port. The 7AF then takes wafers from the input cassette, processes them and then places them in the output
cassette. Before a new lot can be started, these cassettes must be removed and replaced with empty/full cassettes. The
following diagrams depict the state transitions for the input and output ports on the 7AF. Any state transition which
occurs for the input ports, (CEIDs 23, 24, 25, 26) will be sent to the Host if enabled. Any state transition which occurs
for the output ports will trigger the appropriate collection events (CEID 27, 28, 29, 30).
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