semi合集-English.pdf - 第7070页
SEMI S18-1102 © SEMI 2002 8 10.4.3 Perform appropriate leak tests to confirm that the affected system is safe be fore allowing silan e family gas back into the system . 10.4.4 Check the reliability of installed detector …
SEMI S18-1102 © SEMI 2002
7
8.5.2 The system should be calibrated at intervals
specified by the detection system manufacturer.
8.5.3 Calibration should be performed frequently
enough to meet the accuracy criteria.
8.6 The gas leak detection system should have back up
power (e.g., UPS, emergency power, etc.) to maintain
its function during short-term power interruption or be
fail-safe. The back up power should be periodically
tested or inspected and the test or inspection
documented.
NOTE 16: The testing, the inspection, and the documentation
must be in accordance with any applicable regulations.
8.7 There may be a need for gas detection in some
exhaust treatment systems to detect breakthrough. See
the Exhaust Treatment System section for details.
NOTE 17: Gas detector monitoring in ducts may be required
by regulation or permits.
9 Fire Detection, Suppression, and Alarm
Systems
9.1 Alarms should connect to the facility under the
guidelines of SEMI S2.
9.2 Fire Detection and suppression system(s) where
used should be operational at all times, including when
equipment or facilities are shut down or in maintenance
modes. See SEMI S14 for guidelines for determining
whether such systems are appropriate and for designing
them.
EXCEPTION 1: Maintenance of the fire detection system.
EXCEPTION 2: Activation of the fire detection system
should not remove power from fire detection system and
safety systems.
9.3 Fire Detection and Suppression for Bulk Silane
Systems
9.3.1 An automatic fixed water spray system should be
provided for any bulk silane system for purposes of
cooling the system only.
9.3.1.1 The regulator station and control panel areas
should also be protected by a water spray system for
purposes of cooling the system only.
NOTE 18: Design density, area and duration should be
calculated appropriate to the surface area of the container
using a method such as the one provided in NFPA 318.
9.3.2 Activation of the optical flame detectors, manual
activation, or heat-link activators should initiate the
water spray system and should close emergency shutoff
valves (ESOVs). ESOVs should be located directly on
the source or on the piping, as close to the container as
possible.
9.4 Fire Detection and Suppression
9.4.1 Fires within valve manifold boxes (VMBs) may
impinge on other lines within the VMBs. If this is
assessed as an unacceptable risk, there may be a need
for fire protection.
9.4.2 When fire protection is installed, it should remain
active during all conditions such as maintenance and
service.
EXCEPTION: Maintenance of the fire protection system.
10 Emergency Response
10.1 Exhaust and abatement systems should be left
running during any emergency event, including fire in
the facility.
10.2 Evacuation of Personnel
10.2.1 Procedures for evacuation, as a result of a gas
leak, should be developed based on a hazard analysis
and should be appropriate to the level of hazard.
10.2.2 After an evacuation, no one should re-enter the
area until the exposure risk has been reduced to an
acceptable level.
10.2.3 All personnel in the facility should be trained
regarding proper evacuation procedures.
10.3 Leak Identification and Isolation
10.3.1 If the appropriate method of achieving a safe
situation is for a response team to enter, only authorized
and trained response personnel may enter to locate and
fix the leak.
10.3.2 If the leak location can be accurately
determined, the specific source supplying silane family
gases to the leak location should be automatically shut
down.
10.3.3 If the leak location cannot be accurately
determined, all of the systems supplying the area where
the leak was detected should be shut down.
10.3.4 Do not enclose a silane installation where
adequate exhaust flow can not remain during a leak.
This could lead to an explosion.
10.4 Recovery from Leaks
10.4.1 Trained personnel should investigate the
incident until the original or root cause is determined.
Systems should not be restarted until the safety of the
entire system is confirmed.
10.4.2 Sufficiently purge all affected systems with an
inert gas.
SEMI S18-1102 © SEMI 2002
8
10.4.3 Perform appropriate leak tests to confirm that
the affected system is safe before allowing silane family
gas back into the system.
10.4.4 Check the reliability of installed detectors.
Change the detectors if necessary.
10.4.5 Confirm that the system (from the silane family
gas, source systems to the gas abatement systems) is not
damaged. Perform corrective actions if necessary.
10.5 Fire and Explosion
10.5.1 The only safe way to extinguish a gas fire is to
shut off the source.
NOTE 19: Do not attempt to extinguish any gas fire except
by shutting off the source. Many countries require fire
extinguishers at gas storage areas, but these should be used
for extinguishing things other than the gas, or for escape.
10.5.2 Water spray or deluge systems should be used
only to cool the container or adjacent containers to
prevent other cylinders from heating or over-
pressurizing.
10.5.3 Accidental extinguishing of a gas fire without
shutting off the gas presents an unacceptable risk of
explosion.
10.5.4 When fire is suspected, contact the emergency
responders.
NOTE 20: Local fire departments may not be trained in
silane family gas fires. The emergency responders should
include plant emergency response teams or public hazard
response teams, as well as fire departments.
10.5.5 Only trained personnel should enter an area
affected by a silane family gas fire.
10.5.5.1 Trained responders to a fire event should be
wearing appropriate protective equipment before
entering the area.
10.5.5.2 After a fire event, check the reliability of
installed fire detectors. Change the detectors if
necessary.
11 Materials, Components, and Constructions
for Silane Family Gas Handling Equipment and
Facilities
11.1 Material Material used for piping and
components for silane family gas should be suitable for
maintaining structural integrity.
11.1.1 Combustible materials (as defined in SEMI S2)
should not be used in constructing assemblies that
contact, support or make up structural components of
silane family gas handling equipment, unless
specifically designed as safety devices.
11.1.2 Materials such as SUS304, SUS316, SUS316L,
Monel, Hastelloy or XM-27 may be needed to provide
adequate protection from corrosion related to
chlorosilanes.
11.1.3 Dust caps for chlorosilanes, plastic gaskets or
O-rings for secondary seals should be made of
chemically stable and heat-resistive materials (e.g.,
PTFE) of a suitable size to fit the cap.
11.2 Components
11.2.1 Components should be nationally approved,
conform to national standards, or be accompanied by
data that demonstrates safety and compatibility.
11.2.2 When cylinder connection gaskets are used they
should be single-use metal-surface compression gaskets
(unless incompatible) that do not provide a source of
additional fuel.
11.2.3 Components used in the piping should be
selected with structures that minimize dead leg sections.
11.2.4 Gas cabinet or equipment suppliers should
provide the user with reliability data for repeated
operations, so the user can schedule replacement of the
components within their expected lifetimes.
11.2.5 If a pneumatic valve is used, the operating gas
should be nitrogen (N
2
) or another inert gas.
11.3 Construction
11.3.1 Equipment, facilities and piping should be
protected from electrostatic discharge.
11.3.2 Assembly of stainless steel components should
be by welding wherever possible to reduce the need for
exhausted enclosures.
11.3.3 Fittings — Fittings should be welded,
(preferably orbital-butt-welded) wherever possible.
Mechanical joints (metal-gasket face-seal fittings)
should be used when disassembly will be required.
NOTE 21: Compression fittings lead to increased risk of
leaks, especially when subjected to expansion and contraction
by temperature changes.
11.3.4 Only cylinder connections approved by a
recognized authority such as the Compressed Gas
Association (CGA) should be used on gas cylinders, to
prevent connection of a cylinder containing an
incompatible gas.
NOTE 22: Special style connections such as CGA-DISS can
provide added protection by their use of “keyed”
differentiation between gas types.
12 Pressurization and Leak Testing
12.1 Each supply piping system should be both
pressure-tested and leak tested.
SEMI S18-1102 © SEMI 2002
9
NOTE 23: Leak testing alone (as in SEMI F1 purity testing)
will not detect potential increased-pressure failures.
12.2 Pressurization Testing
12.2.1 Pressurization testing should be performed to
determine the integrity of the assembled piping.
12.2.2 Pressurization testing should be performed at
150% of the pressure to which the piping section can
be exposed if a single component fails.
NOTE 24: There may be pressure requirements to higher
levels under some regulations.
12.2.3 Procedure Seal the test target with the test
gas and pressurize to the test pressure. Maintain the
test condition for 24 hours. Read the pressure gauge
and confirm that the pressure deviation (with
temperature correction) is within the error of the gauge.
12.3 Leak Testing
12.3.1 Use one of the following two methods:
NOTE 25: Leak testing should be performed with a gas such
as Helium or Helium/balance Nitrogen.
12.3.2 Inboard Leak Testing
12.3.2.1 Generate a vacuum within the test section with
a leak check system. Expose the exterior of the piping,
its joints and fittings to a tracer gas source. While
exposing the exterior of the piping to the tracer gas
watch the leak detection system for detection of the
tracer gas.
12.3.2.2 Detection of any tracer gas indicates a leak.
12.3.3 Outboard Leak Testing
12.3.3.1 Pressurize the test section with the test gas to
150% of the pressure expected during normal operation
at room temperature. Use a leak detection system to
search the exterior of the piping for presence of the
tracer gas.
NOTE 26: Authorities Having Jurisdiction (AHJs) may
require higher pressures.
12.3.4 Corrective Actions — If any pressure or tracer
gas gauge change is detected, repair the leak and retest.
12.4 Exhaust Piping
NOTE 27: Pressurized exhaust piping does not include
facility exhaust ducts.
12.4.1 Pressurized Exhaust Pipe Leak Testing
Exhaust and treatment system piping should be pressure
tested to 100% of what could be the expected pressure
within the piping during a catastrophic reaction within
the piping. The expected pressure is determined by
evaluation of the foreseen operating pressure and
exhaust piping contents.
13 Storage
13.1 General Considerations
13.1.1 Storage area construction materials should be
non-combustible and compatible with the hazards
presented by the silane family gases present.
NOTE 28: For certain gases, it may be necessary to consider
multiple hazards, such as in the case of dichlorosilane, which
is both pyrophoric and corrosive.
13.1.2 Silane family gases should be separated from
other gases per SEMI S4.
13.1.3 The recommended storage temperature is less
than 40°C.
13.1.4 A water deluge or sprinkler system should be
installed over storage area for silane family gases to
cool the gas containers during a fire event and reduce
the effect of impingement of flame from one container
on another.
EXCEPTION: Cylinders of volume of 1 liter or less may be
exempt from this criterion.
NOTE 29: Many jurisdictions require sensors, detectors, and
lighting fixtures all to be of electrical construction meeting
hazardous location requirements (e.g., not less than NEC
Class 1 Div. 2.) in rooms classified as flammable rooms.
13.1.4.1 Access to a source of fire protection water
should be provided.
13.2 Cylinder Storage
13.2.1 Cylinders of silane family gases in storage
should maintain cylinder valve plug securely tightened
and cylinder valve protective cap in-place.
13.2.2 Cylinders should be stored in an area adequately
designed to protect the building from reasonably
foreseeable incidents in the cylinder storage area.
13.2.2.1 Cylinders not located in bunkers should be
provided with a security open chain-link fence. The
cylinders should be separated from adjacent structures
and the fence by a minimum distance of 2.7m (9ft) as
shown in Figure 2. [NFPA 318]
13.2.2.2 If cylinders which contain silane family gases
are stored in a structure independent from occupied
building, mechanical or natural ventilation at a
minimum of
0.005 meter/second (about 1cfm/square
foot) should be provided for the structure in which the
cylinders are stored.
NOTE 30: Refer to standards such as NFPA 318 or High
Pressure Gas Safety Law for more details.
13.2.3 The construction or location of the cylinder
storage should not inhibit safe cylinder transfer.