Changes to base pressure

[Nancy Latta]

Hello Everyone,

One of the things to come out of the Etch Quality Circle is a better 
understanding of why the base pressure for the tool had been set to 
0.5mT.  It seems that when to etcher was purchased it was configured for 
metal etching.  It was never used as a metal etching tool, however.

A major concern with metal etching is moisture and pumping down to very 
low base pressures assured moisture-free etching.  We really do not need 
to pump down to 0.5mT for the processes we run in the amtetcher.

I have changed all the standard recipes (1,2,3,4,5 and 7) and their 
back-up recipes (11,12,13,14,15 and 17) to have a base pressure of 
0.8mT.  I have also reflected that change on the newly laminated Recipes 
and Etch Rates Sheet in the logbook.

This should put an end to the annoyingly long pump downs we have 
recently been experiencing and bring peace back to Etchland.

All comments welcome,

-Nancy