From rcrane at snf.stanford.edu  Thu Mar  6 10:17:39 2003
From: rcrane at snf.stanford.edu (Dick Crane)
Date: Thu, 06 Mar 2003 10:17:39 -0800
Subject: HEPA air shutdown in litho area on Saturday, 3/8
Message-ID: <3E6790C3.D0E4B523@snf.stanford.edu>

A kind reminder concerning Saturday working affecting the litho area.

Litho users,

On Saturday, March 8, the HEPA air shut down in the Nikon aisle will
affect local temperature and humidity control, which will affect the PR
quality from the SVG coater and resolution on the Nikon body 4, the
Ultratechs, and the EVG aligner. See details below.

Facilities will be upgrading the HEPA fan drive control units. This
upgrade will affect the quantity of air blowing through the HEPA filter
which will affect the airborne, particle count in the fab. Local area
volume of air will drop to 20% of normal flow. I would estimate that our

class 100 cleanroom will become a class 1000 room for a few hours. The
air is clean, but the room's ability to deal with particle assaults is
reduced. Processing which is very sensitive to particle contamination or
temp/humidity control
should be avoided in the affected areas during the upgrade work.

Photo area: On Saturday, March 8, from 0700 to 1100, L102, the Nikon
aisle (Nikon body 4, Ultratechs, EVG aligner and bonder, SVG coat and
develop tracks) will have reduce air flow. This loss may be critical to
your process. Track exhaust flow will not be affected.

Mask making area: On Saturday, March 8, from 1200 to 1600, L106, the
mask making room (Micronic, AFMs) will have reduce air flow. This loss
should not affect your process. Wet bench exhaust will be unaffected.

Thanks for your patience,

Dick





From rcrane at snf.stanford.edu  Mon Mar 10 17:48:10 2003
From: rcrane at snf.stanford.edu (Dick Crane)
Date: Mon, 10 Mar 2003 17:48:10 -0800
Subject: HEPA air shutdown in litho area week of 3/16
Message-ID: <3E6D405A.179B7781@snf.stanford.edu>

Litho users,

I have just learned that the cooling tower at the co-gen plant which
services our humidity control system for litho will shutdown for an
annual, week long maintenance starting Monday, 3/16 at midnight and
continuing through Friday, 3/21 until  noon. This shutdown will affect
our dehumidifying abilities. Recently the the humidity controls have
been calling for more water to be added to reach the 45% set point. If
the outside air remains dry, then we will have humidity control during
this shutdown. If the outside air turns humid, then the lab air humidity
will increase. This increase will affect  the PR quality from the SVG
coater and resolution on the Nikon body 4, the Ultratechs, the Susses,
and the EVG aligner.

Sorry about the shutdown and thanks for your patience,

Dick