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SEMI F13-1101 © SEMI 199 3, 2001 2 5 Terminology 5.1 automatic shut-of f (ASO ) — A remotely actuated valve, pref erabl y the cylinder valv e, but possibly a valve located close to the cylinder valve, which can isolate t…

SEMI F13-1101 © SEMI 1993, 20011

SEMI F13-1101

GUIDE FOR GAS SOURCE CONTROL EQUIPMENT

This guide was technically approved by the Global Facilities Committee and is the direct responsibility of the

North American Facilities Committee. Current edition approved by the North American Regional Standards

Committee on August 27, 2001. Initially available at www.semi.org September 2001; to be published

November 2001. Originally published in 1993.

1 Purpose

1.1 The purpose of this document is to provide a guide

for the design and operational requirements of gas

source control equipment which is used to control

pressure and flow from a gas cylinder to the point of

use.

2 Scope

2.1 This document describes the components and

minimum performance criteria for gas source control

equipment used with hazardous production material

(HPM) semiconductor gases. This guide also includes

recommended component functions and operating

requirements.

2.2 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 health practices and determine the

applicability or regulatory limitations prior to use.

3 Related Documents

3.1 These documents should be used in the design,

fabrication, installation, and operation of gas source

control equipment.

3.2 SEMI Standards and Safety Guidelines

SEMI F1 — Specification for Leak Integrity of High-

Purity Gas Piping Systems and Components

SEMI F2 — Specification for 316L Stainless Steel

Tubing for General Purpose Semiconductor

Manufacturing Applications

SEMI F3 — Guide for Welding Stainless Steel Tubing

for Semiconductor Manufacturing Applications

SEMI F4 — Guide for Remotely Actuated Cylinder

Valves

SEMI F6 — Guide for Secondary Containment of

Hazardous Gas Piping Systems

SEMI F14 — Guide for the Design of Gas Source

Equipment Enclosures

SEMI S2 — Environmental, Health, and Safety

Guideline for Semiconductor Manufacturing Equipment

SEMI S4 — Safety Guideline for the Segregation/

Separation of Gas Cylinders Contained in Cabinets

SEMI S5 — Safety Guideline for Flow Limiting

Devices

3.3 Compressed Gas Association Documents

Pamphlet P-1 — Safe Handling of Compressed Gases

in Containers

Standard V-1 — Compressed Gas Cylinder Valve

Outlet and Inlet Connections

3.4 National Fire Protection Association Document

NFPA 704 — Identification of the Hazards of Materials

for Emergency Response

NOTE 1: Unless otherwise indicated, all documents cited

shall be the latest published versions.

4 Referenced Standards

4.1 Various codes and ordinances apply in different

municipalities. These documents must be followed for

the installation and operation of these systems. These

codes may include:

Applicable Occupancy Codes — Uniform Building

Code (UBC)

Article 51 — Uniform Fire Code (companion document

to above UBC)

Article 80 — Uniform Fire Code (companion document

to above UBC)

Applicable Occupancy Codes — BOCA National

Building Code

, BOCA National Fire Prevention Code

Local Ordinances — As applicable.

NOTE 2: Unless otherwise indicated, all documents cited

shall be the latest published versions.

1 Compressed Gas Association, Inc. (CGA), 1725 Jefferson Davis

Highway, Suite 1004, Arlington, VA 22202

2 National Fire Protection Association, 1 Batterymarch Park, Quincy,

MA 02269

3 International Conference of Building Officials (OCBO), 5360

Workman Mill Road, Whitter, CA 90601

4 Building Officials and Code Administrators International, Inc.

(BOCA), 4051 W. Flossmoor Road, Country Club Hills, IL 60478

SEMI F13-1101 © SEMI 1993, 2001 2

5 Terminology

5.1 automatic shut-off (ASO) — A remotely actuated

valve, preferably the cylinder valve, but possibly a

valve located close to the cylinder valve, which can

isolate the product as close to the cylinder valve as

possible. It may also be a device which attaches to the

cylinder valve stem or handle to close the valve.

5.2 compressed gas association (CGA) —

Organization that sets standards for the handling and

safe use of gases. Used in this document to refer to the

cylinder valve outlet connection for each product as

designated by the CGA.

5.3 cylinder — A pressure vessel designed for

pressures higher than 276 kPa (40 pounds per square

inch absolute) and having a circular cross section. It

does not include a portable tank, multi-unit tank car

tank, cargo tank, or tank car. It also refers to non-DOT

low pressure containers used for liquid product having

low vapor pressure.

5.4 gas source control equipment (GSCE) — Refers to

the equipment assembly beginning at the product exit

from the cylinder valve to the beginning of the

distribution piping leading to the point of use (POU).

These assemblies are usually mounted on panels and

are sometimes referred to as process panel systems.

5.5 hazardous production material (HPM) — A solid,

liquid, or gas that has a degree-of-hazard rating in

health, flammability, or reactivity of Class 3 or 4 as

ranked by NFPA 704 and which is used directly in

research, laboratory, or production processes which

have, as their end product, materials which are not

hazardous.

5.6 high pressure isolation (HPI) valve — A shut-off

valve located on the high-pressure side of a gas piping

system that, when closed, isolates the purged volume

from the pressure regulator and other downstream

components.

5.7 low pressure isolation (LPI) valve — A shut-off

valve located on the low-pressure side of a gas system

that, when closed, isolates the purged volume from the

distribution piping and all other downstream

components.

5.8 point of use (POU) — Refers to the manufacturing

tool which uses the product. Point of use is

distinguished from the GSCE by having its own design

criteria, separate function, and physical separation from

the GSCE.

5.9 product — Refers to the gas phase in the cylinder.

6 Configuration

6.1 Manual/Auto Operation

6.1.1 Manual equipment without automation is

adequate if it includes an ASO plus excess flow device.

(Where required, per UFC articles 51 and 80.)

Automated purging is generally more efficient than

manual purging and is, therefore, recommended. The

ASO function is achieved if the ASO valve

automatically defaults to a closed position via a

pneumatically actuated valve, or separate actuator that

will close a manual cylinder valve. Either method

should be fail-safe (default to a closed position on loss

of power and/or pneumatics). This could also be

initiated by any number of abnormal circumstances.

6.1.2 Fully Automatic — This is a broad category of

designs using any number of transducers, remotely

operated valves, and logic to accomplish safeguarding,

monitoring, and automatic purging. Extension of this

approach to central data collection, analysis, and

reporting via computers and special programs offers the

capability of further reducing hazards and enhancing

safety.

6.2 Cylinder Connections

6.2.1 Compressed gas cylinders are connected to the

panel equipment using the connection on the outlet of

the cylinder valve. The appropriate regulatory agency

has designated one or more connections for each

product gas.

6.2.2 Other containers for liquid or low vapor pressure

materials may require the connection of two fittings.

One of these is used to admit gas, which either

pressurizes the product, allowing liquid withdrawal, or

absorbs the product, allowing withdrawal of a gas-

phase mixture of the product and the gas. The other

fitting is used for withdrawal. The types and labeling of

the connections vary among suppliers.

6.2.3 High Pressure Pigtail — A semi-flexible

assembly of piping, subjected to cylinder pressure,

which is used to connect the cylinder to the rigidly

mounted components on the panel. The intent of this

flexible assembly is to accommodate the location of the

cylinder outlet.

6.2.4 No Pigtail — An alternate acceptable method

allows cylinders to be elevated or lowered to match the

fixed height of the connection point on fixed panel

equipment.

6.3 Cross Contamination

6.3.1 Purge Gas Cylinder Contamination by Process

Gas — Purge gas is supplied from cylinders, with each

purge gas cylinder limited to a single process gas panel

or several panels using the same process gas class or

different mixture ratios of the same process gas class. A

check valve should be installed in each line connecting

the purge gas to the process panel equipment.

6.3.2 Process Gas Cylinder Contamination by Purge

Gas — The purpose of purging is to remove air or

residual process gas from the panel equipment (or part

of it) back to the internal cavity of the closed cylinder

valve.

WARNING: Check valves are not acceptable in this

part of the process gas system because purging would

be defeated. Cross contamination can only be prevented

by safeguards which assure complete cylinder valve

closure and process gas venting, before purging begins.

6.4 Materials — All materials furnished should be

manufactured to nationally recognized standards.

Metals used for the wetted surfaces should be type 3l6L

stainless steel, or other materials that provide equal or

improved compatibility with the gas in service.

Nonmetallic seals that are used in valve or regulator

seats must also be compatible with the product in

service.

6.5 Joints — All welded joints should be butt welded

(no socket welds) and should comply with SEMI F3.

Connection fittings should be face seal type.

6.6 Particle Control — Particle contamination is

controlled through the proper selection of components

and system hardware, good design practices, clean

fabrication methods, and proper operation of the

system.

6.7 Internal Volume — The internal cavities should be

configured for minimum surface area and internal

volume to enhance purging. Dead end legs should be

eliminated or kept to a minimum volume and length.

6.8 Maintainability — Planned maintenance or forced

repair is facilitated or inhibited by specific design

concepts and features. From a safety point of view, it is

mandatory to be able to purge the entire GSCE (all

cavities) and to have a downstream shutoff (low

pressure isolation valve) and disconnect fitting.

7 Performance Recommendations

7.1 Functional Recommendations

7.1.1 The ASO should be designed to close based on

an alarm or fail signal from an auxiliary component. It

should be designed to fail closed and should have a

working pressure at least 1.1 times the product cylinder

pressure. If a pressure sensor is located between the

ASO and the cylinder valve, as depicted in Figure 1, it

should also have a working pressure at least 1.1 times

the product cylinder pressure.

7.1.2 Pressure Reduction — Gases are most

commonly required at POU at less than 100 psig.

Cylinder pressure is reduced to the lower pressure by a

gas pressure regulator, when necessary.

CONNECTION

Figure 1

Typical Gas Source Control System