Field service update ....

[John Shott]

STSetch2 community:

Frank Monano from STS Field Service arrived mid afternoon.  He had time 
to adjust the rotational alignment of the carousel so that wafers are 
now well aligned on the chuck as determined both by the mark on the 
backside of the wafer from the lip seal as well as based on the shadow 
of the clamp fingers on the top side.  That alignment looks good and 
well matched in both carousel position #1 and in position #2.

During the course of the afternoon, we loaded approximately 6 wafers 
from each of the two carousel positions and did not see the situation 
that others have reported where a wafer does not actually end up on the 
chuck but comes back out on the carousel.  Others have reported that 
this happens when the wafer is mounted in carousel slot #1 but not when 
in slot #2 (the number is stamped in the carousel at the 9 o-clock 
position of the wafer nearest you when the load door is up and you are 
standing at the end of the machine).

We have cleared the wafer loading shutdown so that some may be able to 
get some useful etching overnight.  To be conservative, I suggest that 
you load your wafers in carousel slot #2.

Note: Frank believes that we may still  have to adjust the reed switch 
that determines when the pins are fully lifted during the wafer 
loading.  If that switch engages too soon while the pins are still 
lifting, the carousel arm will begin to retract before the wafer is 
fully lifted.  This will result in the failure to load a wafer and it 
will still be sitting on the carousel arm ... although offset towards 
the chamber.

In any event, we are hopeful that some of you may be able to get some 
useful etching done this evening.

Tomorrow morning we hope to look at the "clearable" RF error and look in 
detail at the positioning of the lift pins relative to the switch that 
senses the wafer up position.

Happy etching,

John