semi合集-English.pdf - 第3886页
SEMI F27-0997 © SEMI 1997, 2003 1 SEMI F27-0997 (Reapproved 1103) TEST METHOD FOR MOISTURE INTERACTION AND CONTENT OF GAS DISTRIBUTION SYSTEMS AND COMPONENTS BY ATMOSPHERIC PRESSURE IONI ZATION MASS SPECTROMETRY (APIMS) …
SEMI F26-0697 © SEMI 1997, 2003 5
NOTICE: SEMI makes no warranties or
representations as to the suitability of the standards set
forth herein for any particular application. The
determination of the suitability of the standard is solely
the responsibility of the user. Users are cautioned to
refer to manufacturer's instructions, product labels,
product data sheets, and other relevant literature,
respecting any materials or equipment mentioned
herein. These standards are subject to change without
notice.
By publication of this standard, Semiconductor
Equipment and Materials International (SEMI) takes no
position respecting the validity of any patent rights or
copyrights asserted in connection with any items
mentioned in this standard. Users of this standard are
expressly advised that determination of any such patent
rights or copyrights, and the risk of infringement of
such rights are entirely their own responsibility.
Copyright by SEMI® (Semiconductor Equipment and Materials
International), 3081 Zanker Road, San Jose, CA 95134. Reproduction o
f
the contents in whole or in part is forbidden without express written
consent of SEMI.
SEMI F27-0997 © SEMI 1997, 2003 1
SEMI F27-0997 (Reapproved 1103)
TEST METHOD FOR MOISTURE INTERACTION AND CONTENT OF
GAS DISTRIBUTION SYSTEMS AND COMPONENTS BY
ATMOSPHERIC PRESSURE IONIZATION MASS SPECTROMETRY
(APIMS)
This test method was technically reapproved by the Global Gases Committee and is the direct responsibility
of the North American Gases Committee. Current edition approved by the North American Regional
Standards Committee on September 16, 2003. Initially available at www.semi.org October 2003; to be
published November 2003. Originally published September 1997.
1 Purpose
1.1 This test will determine the quantity of removable
moisture and the degree of interaction with trace
concentrations of gas phase moisture, of gas
distribution systems and components. APIMS is
currently the technique of choice for such tests because
it is essentially the only commercially available method
capable of ppt moisture analysis and because of its
superior response time. This method may provide
guidelines for the application of other techniques with
similar detection limits and response time to APIMS
which are not commercially available at this time.
1.2 The results of this test can be used for qualitative
ranking of systems and components and can also be
used, by a sufficiently sophisticated user, as input for
numerical simulation of distribution system behavior.
2 Scope
2.1 System and Component Types — This procedure
applies to in-line components to be used to contain
electronics grade materials in semiconductor gas
distribution systems. The following components are
expected to yield meaningful results when tested
according to the present method: tubing, connectors
(fittings), particle filters, valves (check, relief, shut-off,
and metering), regulators, flow-through
transducers/sensors, mass flow controllers and meters.
Components with dead volumes, such as pressure
gauges, can be tested according to this method, but the
results will be difficult to interpret. Additional criteria
besides those considered here need to be developed for
testing components with dead volumes.
2.1.1 As gas phase moisture levels are dominated by
desorption from surfaces, the procedure is expected to
be most useful for components of large surface area
such as particle filters and tubing. Components with
very small wetted surface areas may have moisture
interactions which are too small to measure using this
test. Check valves and relief valves can be tested only if
their operating parameters are consistent with the test
conditions.
2.1.2 Tubing samples must be rather long (3–4 m) to
yield useful results, but they can be bent into a U shape
in order to be accommodated into a practical test bench.
Radii of curvature should be no less than 6 times the
internal diameter of the tube and the minimum number
of bends should be used. Most ultra-high purity
components are currently supplied with metal gasket
connectors, so the test bench employed should be fitted
with mating connectors. This type of fitting is usually
welded to tubing, which is not recommended as it
introduces a potential source of uncontrolled variability
to the experiments. Instead, a compression fitting on the
tube and a suitable adapter should be used. The
compression fitting should not be disconnected after
initial connection until the test series is over. In this
way, deterioration in integrity of the connection can be
avoided. The same type of gasket to compression fitting
adapter should be used for all tubing samples.
2.1.3 Purifiers require special test procedures and are
not addressed here.
2.1.4 Simple systems consisting of components
connected in line can be tested by the present method.
Complex systems (i.e., those with more than one
potential inlet and/or outlet) will show performance
which varies depending on the test configuration
(which inlets and outlets are chosen). Testing of such
systems is not addressed by the current document.
2.2 Gases — The procedure will be carried out in
nitrogen. The results will provide a ranking with respect
to moisture contribution which may be applied with due
caution to components intended for use in other gas
streams. Other “inert” gases will have different purging
characteristics and may dry a component more quickly
or slowly. Reactive gases may react chemically with
moisture. Considerations relating to corrosion
resistance are outside the scope of the present
document, although the test procedure may prove useful
in corrosion studies.
2.3 Operating Situations — Moisture contribution from
a component may be the result of contamination arising
in its manufacture, or from subsequent exposure to
SEMI F27-0997 © SEMI 1997, 2003 2
ambient air or non-dry gas. Thus, it is necessary to
consider two main situations:
1. The “initial dry-down” situation, which is
determined by the moisture content of the
component as received with the effects of
manufacturing process and design, surface quality,
pretreatment and packaging convoluted together.
2. The “Response to upset” situation, which is
determined by the amount of moisture taken up by
the component and subsequently released in any
exposure after receipt.
NOTICE: This standard does not purport to address
safety issues, if any, associated with its use. It is the
responsibility of the users of this standard to establish
appropriate safety and health practices and determine
the applicability of regulatory or other limitations prior
to use.
3 Limitations
3.1 This test method allows the determination of
moisture interactions which can be used, for example,
to rank components in order of decreasing moisture
interaction. Because different degrees of moisture
interaction are desirable in different situations, selecting
the “best” components requires consideration of how
they will be used in a given distribution system, either
qualitatively or through numerical simulation of
distribution system behavior.
4 Referenced Standard
4.1 SEMI Standard
SEMI C15 — Test Method for ppm and ppb Humidity
Standards
NOTICE: Unless otherwise indicated, all documents
cited shall be the latest published versions.
5 Terminology
5.1 Acronyms and Abbreviations
5.1.1 APIMS — Atmospheric Pressure Ionization Mass
Spectrometry
5.1.2 EPSS — Electropolished Stainless Steel
5.1.3 MFC — Mass Flow Controller
5.1.4 ppm — molar parts per million (µmole/mole).
The same as ppmv.
5.1.5 ppb — molar parts per billion (nmole/mole). The
same as ppbv.
5.1.6 ppt — molar parts per trillion (pimole/mole). The
same as pptv.
5.2 Definitions
5.2.1 induction time — the elapsed time between when
humidified gas is input to the test component and when
moisture is detected at the moisture analyzer. For a
component and test system which are perfectly
transparent to moisture the induction time is equal to
the residence time of the gas in the system.
5.2.2 peak height — the maximum moisture
concentration recorded when a moisture input of
predefined length and concentration is introduced to a
test component.
6 Required Equipment
6.1 APIMS — The APIMS used for moisture detection
can be of any type. In order to be considered valid, any
series of moisture tests shall reference two single point
calibrations, one at the beginning and one at the end of
the series. These calibrations shall both be made under
the same analytical conditions (flow, pressures, plate
voltages, etc.) as the tests and the results shall be within
5% of each other. Provided this condition is met, the
interval between calibrations may be left to the
discretion of the operator; however, it is suggested that
calibration should be carried out whenever the
equipment is moved and/or every two weeks of
operation.
6.2 Dry Gas and Moisture Generator — A source of
extremely dry nitrogen (less than 100 ppt moisture) and
a moisture generator capable of delivering up to 13 slm
nitrogen doped with 50 ppb moisture is required. This
generator may be the same as used to calibrate the
APIMS. The output of the generator shall be verified
according to SEMI C15.
6.2.1 Most ultra-high purity components are currently
fitted with metal gasket type connectors. The same type
of connector should, therefore, be incorporated into the
test bench for connection to the test components.
6.3 Test Blank — Any series of tests shall include the
results of testing a blank. The blank shall be the shortest
convenient length (no more than 1 m) of 1/4"
electropolished stainless steel (EPSS) tubing with
suitable fittings and/or adapters at either end to enable it
to be inserted in place of the test specimen.