semiconductor industry association worker health project primary prevention initiative: exploring...

Semiconductor Industry Association Worker Semiconductor Industry Association Worker Health Project Health Project

Primary Prevention Initiative: Primary Prevention Initiative: Exploring Opportunities to Further Exploring Opportunities to Further

Minimize Potential Equipment-related Minimize Potential Equipment-related ExposuresExposures

Nick Filipp PhD, CIHPrincipal Consultant

Environmental & Occupational Risk Management, Inc. (EORM)

February 3, 2005

Nick Filipp PhD, CIHPrincipal Consultant

Environmental & Occupational Risk Management, Inc. (EORM)

February 3, 2005

SESHA Presentation~EORM~2/3/05 © 2005 EORM, Inc. 2

Agenda

Background Primary Prevention Initiative Study Team Study Participants Study Approach Results Conclusions Potential Opportunities for

Improvement Acknowledgements


Background In response to negative publicity surrounding

lawsuits, SIA commissioned a Scientific Advisory Committee (SAC) to evaluate potential for increased cancer risks among fab workers– SAC primary objective: conduct an independent,

objective analysis of whether potential semiconductor "clean room" chemical exposures are likely to elevate cancer risk and, based on this analysis, make appropriate recommendations to SIA

SAC concluded: no affirmative evidence of increased risk of cancer for fab population.

SAC also reported: insufficient data exists to conclude whether exposure to chemicals or other hazardous materials has or has not increased cancer risk

SAC provided recommendations for further studies.


Background (cont’d)

SIA outlined various follow-up actions known collectively as the “Worker Health Project”

SIA recommendations included Primary Prevention Initiative (PPI) Tasks

PPI Tasks– Designed to further strengthen ongoing efforts

to ensure a safe workplace– Went beyond the SAC's recommendations– Designed to provide member companies with

a broader base of knowledge to help enhance their existing worker safety programs.


Primary Prevention Initiative: Exploring Opportunities to Further Minimize Potential Equipment-Related Exposures The PPI Committee reviewed the broad spectrum of

chemical operations in the Fab and selected four 200 mm process areas for evaluation: – Etch

• Metal Etch• Polysilicon Etch• Dielectric Etch

– Implant– Thin Films - CVD

• Metal Deposition• Dielectric Deposition• Thermal Oxidation

– Thin Films - Epitaxy• Silicon Epitaxy


Study Objectives:

Identify opportunities for capital equipment suppliers to demonstrate further hazard mitigation through changes to normal operation, preventive and corrective maintenance procedures and tool design

Identify alternatives that might provide opportunities to reduce and/or eliminate the need for administrative controls as the primary means of preventing unsafe exposures


EORM’s Role

PPI Committee retained EORM to perform an assessment of these fab areas to identify further minimization of equipment-related chemical exposures during preventive and corrective maintenance

EORM Project Team:– Nick Filipp, PhD, CIH, Principal Investigator

and Principal Consultant– Andrew McIntyre, CIH, Managing Principal– Andrea Sevier, CIH, Senior EHS Consultant– Patrick Tierney, CIH, Principal Consultant


Study Participants

SIA Member Companies– Participating sites selected based on

availability of equipment included in the study• Four Member Companies provided access

for study objectives

– Site EHS personnel provided access to documentation, technical personnel, and equipment


Study Participants (cont)

Capital Equipment Suppliers– Participant Companies

• Applied Materials• ASM of America• Axcelis Technologies• Novellus Systems• Tokyo Electron America• Varian Semiconductor Equipment Associates

(VSEA)– Two levels of participation

• Provided access to documentation, technical personnel, and equipment at their facilities

• Provided access to documentation only


Study Approach Understand Process and Procedures Identify Potential Chemical Exposures

– Process chemicals– Primary process by-products– Secondary process by-products– Maintenance chemicals

Review maintenance manuals and specifications Review available qualitative and quantitative

exposure data Interview process and maintenance engineering and

EHS staff Observe selected maintenance operations

– Ask a lot of questions– Record data on JHA tool


Data Collection Tool

Microsoft Word Document


Study Results For the processes studied there were common

considerations with regard to potential for chemical exposure

Potential sources of exposure:– Process chemicals– Reactive species formed during process– Byproducts formed from reactions of various

species with:• Each other• Wafer substrate• Materials of construction• Exhaust system components

– Secondary byproducts formed when equipment is opened to atmosphere

– Maintenance chemicals Other considerations:

– Parts cleaning– Preventive maintenance vs. corrective

maintenance


Study Results - Exposure Controls During normal operation chemical exposure is

primarily mitigated by engineering controls supplemented with some administrative controls:– Process contained under reduced pressure– Chambers and process modules equipped for inert

purging– Ventilated enclosures for hazardous chemical

distribution systems– Continuously welded gas delivery lines– Monitored process exhaust to remove emissions– Interlocks to place equipment in “safe state”– Toxic gas monitoring– Small quantities of chemicals used in each batch– Operator training– Detailed SOPs– PPE

Chemical exposure is well controlled during normal operation– Some instances of low level fugitive emissions


Study Results - Exposure Controls During maintenance some of the engineering controls

in effect during normal operation are by passed or shut down. Supplemental engineering controls and additional administrative controls are implemented:– Facility provided maintenance exhaust– Portable toxic gas detection equipment– Parts engineered for facile removal/replacement– Means to seal contaminated parts upon removal– Exhausted disassembly and dirty parts storage facilities– Dedicated facility vacuum systems or portable HEPA

vacuums– Development of detailed procedures for maintenance tasks– Cycle purging of toxic gas lines– Cordoning off and evacuating areas prior to maintenance– Training of maintenance personnel (with regard to chemical

hazards)– PPE to prevent dermal contact and inhalation

Project Team noted that end-users have implemented innovative controls or techniques used to minimize exposures


Conclusions

Existing combinations of engineering, administrative, and personal protective equipment controls were effective at maintaining airborne chemical concentrations below occupational exposure limits during normal production operations and during maintenance.

Opportunities were identified to– Reduce reliance on procedural controls and

PPE– Reduce low level fugitive emissions


Potential Opportunities for Improvement For Semiconductor Company Consideration: Provide additional exhaust ventilation flow through

the tool, or Provide portable exhaust ventilation devices for

emissions from open tool components Introduce air into an enclosed tool to allow chemical

reactions to take place while the process is still contained

Employ comprehensive approach where QEAs, PPE assessments and IH air sampling is used to validate effectiveness of controls

Provide a higher level of EHS guidance in PM procedural documentation (internal), where appropriate

Include LOTO procedures for all sources of energy in maintenance specifications

Expand channels of communication between suppliers and end users to share innovative EHS practices


Potential Opportunities for Improvement For Equipment Supplier Consideration: Evaluate feasibility and advisability of

designing exhaust ventilation through tool Enable the introduction of air into the

reaction chamber prior to it being opened Establish a process for communicating new

supplier maintenance manuals to MC Communicate equipment parts cleaning and

decontamination procedures to MC Provide precautionary courses of action

when normal process clean steps can not be completed


Acknowledgements The EORM Project Team would like to acknowledge the fact

that EHS professionals from the equipment suppliers and member companies participating in this study have been very active in investigating and researching various health and safety issues and frequently share their experiences through publications, presentations, and specialized classes taught at professional meetings.

The EORM Project Team would also like to gratefully acknowledge the Production, Maintenance, Product Safety, and EHS personnel at the participating companies for providing the opportunity to observe maintenance procedures, review documentation, and ask endless questions.

Full EORM Report posted to the SIA Web Page Reference SIA’s President George Scalise Report on Worker

Health and Discussion on PPIhttp://www.sia-online.org/iss_whs.cfm

http://www.sia-online.org/iss_whs.cfm

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