Originally Presented at the 2005 ISMI Symposium on Manufacturing Effectiveness Scott Stewart Sr. Environmental Engineer Intel Corporation

Transcription

1 Reducing Volatile Organic Compound Emissions through Improved Waste Management Originally Presented at the 2005 ISMI Symposium on Manufacturing Effectiveness Scott Stewart Sr. Environmental Engineer Intel Corporation

2 Overview Facility Air Permitting VOC Reduction Toolbox Problem Statement Improved Waste Management Results Remaining Issue 2

3 Facility Air Permitting Intel Policy is that no site be a US Major Source of air emissions 100 tons/year for most criteria pollutants Avoid rigorous requirements that would strangle rapid facility and technology changes Local regulations set more stringent limits 49 tons/year VOCs in Arizona (Title V, non- attainment) 39 tons/year VOCs for Oregon State Minor Source Other local requirements 3

4 Facility Air Permitting, cont d Large, 300mm wafer fabs Increasing process complexity with 18- month technology change cycle Could result in constrained operations as we approach air permit limits VOC limits pose the most likely potential air permit constraint to semiconductor manufacturing 4

5 VOC Reduction Toolbox Wins! Goal setting during Technology Development Point-source emissions are optimized Chemical use minimized Chemical substitution to reduce vapor pressure Thermal oxidizers typically >97% efficient Tool-specific catalytic oxidizers abate >99% 5

6 VOC Reduction Toolbox, cont d Tool maintenance & surface cleaning Use non-voc cleaners where feasible Spec quantity of Isopropyl Alcohol (IPA) at a minimum to achieve needed results Squeeze bottle and pre-saturated wipes Dilute IPA where vapor pressure allows e.g. 6% pre-sat wipes 6

7 Problem VOC Issues Typical Fab VOC Sources 5% is Boiler / Combustion 45% is process tool exhaust abated prior to discharge 50% is Isopropyl Alcohol used on a wipe for surface cleaning Tool skins and chambers, work surfaces, laminated job aids, safety glasses, etc. Based on purchased quantity, assuming 100% is eventually lost to the atmosphere 7

8 VOC Issues, cont d Emissions IPA is the cleanroom solvent of choice Purity, cost, high vapor pressure Tool Uptime! Alternatives are costly, smelly, low vapor pressure, or highly flammable Tool 8

9 VOC Issues, cont d To make matters worse More than half the IPA on a wipe remains on the wipe when discarded This means that >25% of a typical fab VOCs comes from IPA that evaporates from spent IPA wipes Needed a means to capture and quantify IPA in discarded wipes, reducing VOC emissions 9

10 Solution - Improved Waste Management Collected spent 100% IPA wipes in sealable bags from several cleaning operations Chose a bag with easy zip closure and low permeability Weighed bags and performed a percent- volatiles analysis to quantify captured IPA 10

11 Waste Management, cont d Bagged IPA wipes were deemed a suitable cement kiln fuel Keeps IPA out of the air, wipes out of the landfill and offsets other fuel use Air Permitting Agency concurred this is a legitimate VOC reduction and lauded the pollution prevention effort 11

12 Waste Management, cont d Targeted process areas for 100% IPA wipe collection based on usage Pareto Stocked bags, installed collection cans, arranged for transfer and shipping, revised specifications and provided training 12

13 IPA wipes are bagged upon use placed in designated can Resulting in Cleaner Air! and used as fuel shipped to a cement kiln 13 transferred to central location

14 Results Pilot implementation went smoothly Initial IPA capture rate of ~0.3 tons/year Broader implementation capturing >1 ton/year We expect to more than double this at our largest manufacturing / R&D campus Currently emitting a total of ~29 tons/year VOCs Wiper bagging is low risk and cost effective compared to abatement or process changes Plan of Record on newest technology 14

15 The Issue Remains though the Symptom Improved Bagging IPA wipes reduces VOC emissions but does not solve the problem It is a behavioral control on a behavioral practice It is only a short-term bandage We continue to chip-away at the IPA Pareto Environmental constraints will increase We need a break-thru, preserving tool uptime Suitable non-voc solvent alternative to IPA Alternate means to clean tool chambers and other surfaces that doesn t t require solvents 15

16 Many Thanks to: Lacey Badger Stewart Boedecker Roger Churchill Shirley Corbin Kathleen Fiehrer Frank Porter Anne Pritchard Trevor Plaisted Jennifer Shannon 16