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SEMI C54-1103 © SEMI 2003 1 SEMI C54-1103 SPECIFICATIONS AND GU IDELINES FOR OXYGEN This specification was technically approved b y the Globa l Gases Com mittee and is the direct responsibility of the North American Gase…

SEMI C52-0301 © SEMI 2001 2

Table 1 Classification of Specialty Gases on the

Basis of Shelf Life

Non-

reactive

Reactive Corrosive Unstable

Air

CFH

AsH

GeH

SeH

SiH

BCl

ClF

GeF

HBr

HCl

SiCl

SiF

5.3 Guaranteed Shelf Life Period — The following

guaranteed shelf life periods are recommended as a

minimum.

Table 2 Guaranteed Shelf Life Period

Non-

reactive

Reactive Corrosive Unstable

36 months 24 months 18 months 6 months

5.3.1 When proper packaging materials are chosen and

the container is properly prepared (and passivated),

impurity levels should in theory remain constant over

time for an electronics grade specialty gas with the

exception of the thermally unstable gases. For this

reason, no maximum shelf life periods are

recommended as these will depend on the level of

analytical data collected by the manufacturer or

supplier.

5.4 Mixtures — The shelf life of a mixture is

recommended to be equal to the shelf life of the

component in the mixture with the lowest shelf life. For

example, the minimum shelf life of a reactive gas in a

non-reactive gas matrix would be 24 months. The shelf

life of a mixture should apply both to the impurity

specifications and to the assay of the mixture.

5.4.1 Special attention should be paid to the

preparation of the package for mixtures containing less

than 1,000 ppm of a component. At such levels,

adsorption effects may reduce the shelf life and

minimization of the package internal surface roughness

and/or passivation of the surface may be required.

5.5 Residual Level — The impact of the depletion of a

container on impurity levels is still a matter of debate

among gas suppliers. In general, the impurity levels of

the first gas fraction from a container will differ from

the last gas fraction. In particular moisture levels tend

to rise at lower gas pressures as a result of the relative

increase in importance of the internal container wall

and its adsorbed moisture. In addition, in liquefied

gases the co-existence of both a gas phase and a liquid

phase can have a measurable effect on the distribution

of impurities over the gas fractions. It is argued that at

the point of liquid-dry some impurities, which prefer

solution in the liquid phase over the gas phase, may see

a dramatic rise. It is therefore recommended to always

leave an amount of product in the container and to

avoid a situation of “liquid dry” (i.e., when all of the

liquid phase of a liquefied gas has been used).

NOTICE: SEMI makes no warranties or

representations as to the suitability of the specification

set forth herein for any particular application. The

determination of the suitability of the specification 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 mentioned herein. These

specifications are subject to change without notice.

The user’s attention is called to the possibility that

compliance with this specification may require use of

copyrighted material or of an invention covered by

patent rights. By publication of this specification, SEMI

takes no position respecting the validity of any patent

rights or copyrights asserted in connection with any

item mentioned in this specification. Users of this

specification 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.

International), 3081 Zanker Road, San Jose, CA 95134. Reproduction o

the contents in whole or in part is forbidden without express written

consent of SEMI.

SEMI C54-1103 © SEMI 2003 1

SEMI C54-1103

SPECIFICATIONS AND GUIDELINES FOR OXYGEN

This specification was technically approved 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 July 27, 2003. Initially available at www.semi.org October 2003; to be published November

2003.

1 Purpose

1.1 The purpose of this document is to provide a series

of specifications for different grades of Oxygen (O

)

that are used in the semiconductor industry.

2 Scope

2.1 This document covers requirements for all standard

grades of oxygen used in the semiconductor industry.

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 Description

3.1 Oxygen is an odorless, tasteless, noncombustible

diatomic gas comprising approximately 22% of the

earth’s atmosphere; at cryogenic temperatures it is a

light blue liquid. Noncombustible; a cryogenic gas

derived from liquid air by fractional distillation. Even

though O

is non-combustible, it is a strong oxidizer

that can make other materials combustible depending

on its concentration.

4 Limitations

4.1 None.

5 Referenced Standards

5.1 SEMI Standards

SEMI C1 — Specifications for Reagents

SEMI C3 — Specifications for Gases

NOTICE: Unless otherwise indicated, all documents

cited shall be the latest published versions.

6 Terminology

6.1 Terminology appropriate to this standard is defined

in SEMI C3.

7 Requirements

7.1 Purity and other requirements for the various

grades of oxygen are given in Table 1.

SEMI C54-1103 © SEMI 2003 2

Table 1 Impurity and Other Requirements for Various Grades of Oxygen

Previous SEMI Reference #

C3.22-1000

(Specification)

C3.23-1000

(Specification)

C3.41-0697

(Specification)

Grade 2.5 3.8 5.8

Purity 99.5% 99.98% 99.9998% (See Note

1.)

Impurities Maximum Acceptable Level (ppm) (See Note 2.)

Carbon Dioxide and Carbon Monoxide (CO

+ CO) 5 N/A N/A

Carbon Dioxide (CO

) N/A 1 0.1

Carbon Monoxide (CO) N/A 1 0.1

Hydrogen (H

) N/A N/A 0.1

Nitrogen (N

) 100 30 0.5

Nitrous Oxide (N

O) 2 1 N/A

Argon (Ar) N/A 100 1.0

Krypton (Kr) N/A 10 N/A

Water (H

O) (ppmv) 1 1 0.1

Total Hydrocarbons expressed as Methane (THC) 25 1 0.1

TOTAL IMPURITIES INCLUDING RARE GASES 5000 N/A N/A

TOTAL IMPURITIES N/A 145 2.0

Particles (See Note 3) (See Note 3) (See Note 3)

Note 1: A purifier is allowed to be used to meet this specification.

Note 2: An analysis of significant figures has not been considered. The number of significant figures is based on analytical accuracy and the

precision of the provided procedure.

Note 3: To be determined between supplier and user.

8 Physical Constants

8.1 The physical constants of oxygen are given in

Table 2 (for information only).

Table 2 Physical Constants of Oxygen (for

information only)

Metric Units US Units

Molecular weight 31.999 31.999

Boiling point at 1 atm −183°C −297.4°F

Density of gas at 21.1°C

(70°F) and 1 atm

1.309 kg/m

0.082 lb/ft

Specific gravity of gas at

21.1°C and 1 atm (air = 1)

1.1049 1.1049

Density of liquid at boiling

point

1142 kg/m

71.27 lb/ft

9 Analytical Procedures for Grade 2.5 Oxygen

9.1 Carbon Monoxide, Carbon Dioxide, and Nitrous

Oxide — This procedure is for the determination of

carbon monoxide, carbon dioxide and nitrous oxide

concentration in oxygen using infrared

spectrophotometry.

9.1.1 Detection Limits — 0.5 ppm carbon monoxide,

0.1 ppm carbon dioxide, and 0.2 ppm nitrous oxide.

9.1.2 Instrument Parameters

9.1.2.1 10 meter variable path infrared gas cell.

9.1.2.2 Grating infrared spectrophotometer.

9.1.2.3 Bourdon Vacuum Gauge.

9.1.3 Calibration Standards — 10 ppm carbon

monoxide, 10 ppm carbon dioxide and 10 ppm nitrous

oxide, balance oxygen.

9.1.4 Operating Procedure

9.1.4.1 Pressurize the evacuated gas cell to 50 psia

with the calibration standard. Scan the following wave

numbers for absorbance: carbon monoxide 2172 cm

-1

nitrous oxide 2235 cm

-1

, and carbon dioxide 2360 cm

-1

9.1.4.2 Evacuate the cell and pressurize to 50 psia with

the oxygen sample. Scan the appropriate wave numbers

as in Section 9.1.4.1.

9.1.4.3 Compare the absorbance of the calibration

standard to that of the oxygen sample being tested.

Calculate the concentrations of carbon monoxide,

carbon dioxide and nitrous oxide, using the formula

below. The results may not exceed the specifications in

Section 7 of this standard.

Sample Absorbance

Standard Absorbance

Concentration

of Standard

Concentration

of Sample