A Study on odor reduction for Semiconductor Industry. Cheong-Ju ESH TEAM Administration Division, Hynix Semiconductor Inc.

Transcription

1 A Study on odor reduction for Semiconductor Industry. Cheong-Ju ESH TEAM Administration Division, Hynix Semiconductor Inc.

2 Index Features of Odor Research for Odor Management Indicator Odor Reduction Case in Cheongju Business Suggestions of Odor Management in Semiconductor Industry Further Study

3 1. Features of Odor Odor : One or more volatilized chemical compounds that human beings perceive by the sense of olfacti on and can feel unpleasant and disgusted. 1) One kind of sensory pollution that results in public grievance, 2)Main control target with PFC Gas Mgt. in air quality Theoretical Featrues of Odor Odor in Semiconductor 1. Individual Variation of Odor 2. Diversity of Odor-causing Substance 3. Odor doesn t reduce corresponding to reduction of its concentration Odor research and measures establishment to improve the odor control in semiconductor industry should be required

4 2. Research for Odor Management Indicator Exhaust HF Concentration at Outlet Odor Ion Analysis for Singular Substance of Ou tside Air in the Business Place HF Concentration of pollutants Olfactory Results

5 3. Odor Reduction Case in Cheongju Business Average Odor 66% Reduction 8 월 9 월 10 월 11 월 12 월 1 월 2 월 3 월 4 월 5 월 6 월 7 월 8 월 9 월 10 월 11 월

6 3-1. Operation Optimazation for 2 nd Wet Scrubber Experimental Results of Exhaust Odor in Circulating Water at 2 nd Scrubber Conduc.(mS/m) 300 Odor 250 Conductivity[µs/m] ph * Optimal Standard : C-W 1) : PH 7~8 & Conductivity: 40~50 ph ) Circulating Water PH - Equilibrium Constant at Specific Temp. decrease PH increase H3O+ decrease concentration of F- ion increase concentration of HF(aq) decrease the solubility of HF(gas) increase of sources of odor 2. Conductivity - Dissociated ion in solution Increase conductivity at concentration decrease gas solubility Increase odor

7 3-2. L/G Improvement for 2 nd Wet Scrubber Target Gas Solubility Gas HF(g) Solubility to water miscible NH 3 (g) 31% NF 3 (g) 2.1% N 2 O(g) 7.6% L/G Improvement Cas in Cheongju Business - Change to Multistage Treatment Structure of 2 nd Wet-Scrubber (L/G Improvement : 300% Up) Before Improvement After Improvement Increase 30.2% Odor Reduction Efficiency

8 3-3. Odor Treatment System Basic Concept for Odor Treatment Odor Analysis Results at Each Bay Odor * 1 st Step : Gas Decomposition/Absorption at High Temp. 2 nd Step : Fianl Absoprtion after 1 st Treatment 1 st Scrubber Inlet 1 st Scrubber Outlet 2 nd Scrubber Inlet 2 nd Scrubber Outlet Equip st Scrubber Sub Duct 2 nd Scrubb er 1 2

9 System Analysis Results for Odor Treatment in Thin Film Process Efficency Equipment 2nd Scrubber Middle Scrubber 3 Step Absorption Stage System 1 차 Scrubber 90% Odor Reduction after Addition to High Cons. Gas Step in T/F Process

10 3-4. Alkali Gas Treatment System Basic Concept for Alkali Scrubber - Introduction of H2SO4 Neutralization System after Separation of NH3 Gas Main Exhaust as NH3 Application Result of Alkali Scrubber - Achievement of 95% NH3 Removal Rate after Constitution of Alkali System [NH3 Conc. Before/After Process] Diff(Nitride) Wet Station Main Duct 2 nd Scrubber Neutralized Chemical H2SO4 % [NH3 Removal Rate] Sub Duct CMP (SC-1) NH3 + H2SO4 (NH4)HSO4 Equipment Before

11 4. Suggestions of Odor Mgt. of Semiconductor Industry Suggestion 1 : Consititution of Alkali Exhaust System in Process (Consititution of Dual Type: Acid & Alkali Wet-Scrubber) :F :Cl :NH3 : VOC(Volatile Organic Compounds) Wet (NaOH Neutral.) Wet (H2SO4 Neutral.) Adsorption Or Incineration HF Wastwat er Drain Acid Gas (F & Cl ) Solvent Wastwater Drain Alkali Gas (NH3) Organic Gas (IPA, PR hume)

12 Suggestion 2 : System Constitiution of Multiple Absorption System for High Conc. Odor Exhaust Process (Requirement for L/G Enlargement in T/F Process) 1 st Degradation of PFCs Gas Combustion L/G Improvement Final Soluble Gas Removal Equipment Middle Scrubber (Wet) 1 st Scrubber 2st Scrubber

13 Suggestion 3 : VOC Process is Suitable for Organic Odor of hereafter Fab. Enlarged (High Efficiency of Condensation / Oxidation for IPA) Organic Compounds Used by Semiconductor Process - IPA[Isopropyl Alcohol], CH 3 OCH 3 [Acetone], C 3 H 8 hydrophobic : electroneutral & be not soluble in water Organic Gas must be treated for oxidation or absorption Gas Process Mechanism of VOC Scrubber System - Maintain about 820 inside RTO(Regenerative Thermal Oxidizer) of VOC Scr Maintain Enough Ignition Temp. for Inflow Organic Gas [Ignition Temp. IPA : 399, Acetone : 465, Propane : 540 ] Generation of CO2 & H2O after Reformation of Organic Molecule

14 5. Further Study Backgroud Limitation of Subjective Odor Analysis Sense of smell varies from person and is tired easily Measurement(Olfactory Result) error of Up to 30% can be possible depending on test conditions Objective indicators of odor that can quantify is necessary Further Plan Development of Real-Time Odor Measurement System Currently on Testing of complex odor detector based on semiconductor Building real-time measurement system to manage odor from the source to the emmission Using monitoring Indicator of prevention facilites & unusual situations of Fab

15 Thank You