FPD 세정공정 2006 년 5 월 3 일 배재흠수원대학교화공생명공학과
디스플레이분류 Electronic Display CRT FPD Projection 비발광 자발광 LCD PDP 유기 EL FED AM TFT PM TN STN PDLC CRT: Cathode Ray Tube FPD: Flat Panel Display LCD: Liquid Crystal Display PDP: Plasma Display Panel 유기 EL: Organic Electro Luminescence FED: Field Emission Display TFT: Thin Film Transistor A(P)M: Active (Passive) Matrix (S)TN: (Super) Twisted Nematic PDLC: Polymer Dispersed Liquid Crystal
FPD Process Overview TFT LCD Glass GATE Electrode Insulator & a-si DATA Electrode Passivation Pixel Electrode Patterning Patterning Patterning Patterning Patterning Deposition & Patterning Process in Detail Cleaning Deposition Cleaning PR Coating Exposure Develop Etching PR Strip Inspection PECVD R F Wet Etch H H H SiH H N H H H H H SiNSiN Si N DC TARGET SPUTTER Ar+ Al Al Al Al Al Al Ar+ SUBSTRATE Dry Etch F O Si Gas PLASMA Si RF SiF 4
FPD Cleaning Process Process Sequence Loading UV or O 3 BRUSH Scrub (W/Detergent) DI SHOWER BUBBLE JET F/RINSE UDG (Ultra dry Gate) Unloading Organic Removal Large Particle Small Particle Small Particle Preventing Particle Re-adhesion Dry Option Organic Removal : O 3 Water (Better Wet ability), UV BUBBLE JET, CAVITATION JET, HIGH PRESSURE JET, MEGA SONIC SHOWER, PULSE JET Heated Air Hot DIW Dry Air Knife Dry Marangoni Dry Spin Dry IPA Dry Vacuum Dry UDG
FPD Cleaning Technology Trend* Cleaning Method 94~96 97~99 Trend 00 ~ Target Chemical Cleaning Brush U/S M/S DI Shower Bubble Jet High Pressure Jet Cavitation Jet Pulse jet HPM/SJ VUV One Chamber / Multi Cleaning Dry Cleaning Function Water - O₃Water : Oxidative - H₂water : Reductive -ElctrolyzedWater Floor-Space-effective Environment-friendly Performance Enhancement Yield-up Scalability UV Cleaner : Excimer, DUV LASER, Plasma Running-cost-effective Investment-cost-effective CO 2 Cleaning Ice Particle Cleaning Dry system Hot Air Hot DI Spin Dry IPA Dry Air knife UDG * 박영순, 태화일렉트론
Example of Semiconductor Cleaning Process H 2 SO 4 /H 2 O 2 (SPM) 4:1 유기물 120~150 C 온초순수 Rinse 80~90 C 초순수 Rinse 실온 초순수 Rinse 실온 DHF 0.5% Chemical Oxide HCl/H 2 O 2 /H 2 O (HPM) 1:1:6 금속 80~90 C 초순수 Rinse 실온 초순수 Rinse 실온 NH 4 OH/H 2 O 2 /H 2 O (APM) 0.05:1:5 입자 80~90 C DHF 0.5% Chemical Oxide 초순수 Rinse 실온 초순수 Rinse 실온
Conventional Wet Cleaning Process 분류 Cleaning Methods Cleaning 목적및 Mechanism Comments APM, SC-1 (NH 4 OH/H 2 O 2 /H 2 O) Light Organics, I/II 족 Metals, Particle 제거 2H 2 O 2 + C --> CO 2 +2H 2 O Metal Re-Adsorption (Alkali 계 Metal) due to low Redox potential 75~90 ºC M + H 2 O 2 -->MO +H 2 O, MO+4NH 4 OH -->M(NH 4 ) 4+ Si- wafer micro-roughness 화학적 세정 HPM, SC-2 (HCl/H 2 O 2 /H 2 O) 75~85 ºC SPM (H 2 SO 4 /H 2 O 2 /H 2 O) 90~130 ºC Metal( 알칼리이온, 중금속 ) 제거 Ion Exchange : Na + +HCl --> NaCl + H + Complex : M + H 2 O 2 --> MO + H 2 O MO +2HCl -->MCl 2 +H 2 O Heavy Organic, Metal 제거 H 2 SO 4 +H 2 O 2 --> H 2 SO 5 (CARO'S ACID) + H 2 O H 2 SO 5 + Hydrocarbon --> CO 2 + H 2 O +H 2 SO 4 Formation of thin hydrophilic chemical oxide film Difficult in maintenance of hardware due to high corrosiveness Formation of thin hydrophilic chemical oxide film Generation of SO 2-4 Residue on the substrate Dilute HF (HF/H 2 O) Natural Oxide Film, Metal 제거 6HF +SiO 2 --> H 2 SiF 6 + 2H 2 O 3HF + M --> MF3 +3H + Removal of surface oxide and metal in the metal oxide film by dilute HF solution Removal of noble metal by H 2 O 2 BOE (HF/NH 4 Cl/H 2 O/ Oxide Film 제거 계면활성제 ) Buffered oxide etchant HF/NH 4 F=1:7
FPD 와 Semiconductor 의세정비교 * Classification Semiconductor Process Flat Panel Display Process 1. 세정의대상 2. 세정제 3. 세정목적 4. 반송단위 Wafer. ~ 300 mm dia. SC1, SC 2, SPM.. RCA cleaning.. Acid & Base Mixture Organics, Metal, Particle, Oxide 약 25 매 /lot, Carrier 300*400mm(1 st G) Glass, ~ 1870*2200 mm (7 th G) 1000(3G) 12,000m 3 /day(6g) Detergent, THAM**, 電解水 Organics, Particle, Water Marks, Metal, Oxide 1 매, 연속반송 5. 세정방식 Dip, Bath Shower, Spray 6. 세정시간 7. 기타 about 10 min/each bath Below 1 min /1 매, chamber 연속반송 1000 ~ 8000 mm/min 얼룩 (Water Marks) * 권정현, 삼성 SDI ** tetra methyl ammonium hydroxide
Mechanism of Organic Removal 1. PRINCIPLE Remove an electron from organic molecules to oxidize and decompose them to CO 2, H 2 O, and etc. 2. HOW TO REMOVE AN ELECTRON? To remove an electron by high ORP solutions such as H 2 SO 4, HCI, HNO 3, etc. have been used. 3. WHY OZONIZED WATER? ORP of ozonized water(diw with a few ppm of ozone) is higher than those of H 2 SO 4, HCI, HNO 3. 4. O 3 and OH - (hydroxyl ion) in water generates OH * (hydroxyl radical) which promotes oxidation of organics. 5. Initiators such as high ph or UV radiation may be necessary for OH * reaction.
Mechanism of Particle Removal 1. 1 ST Step.lift off Substrate Substrate 1. 2 ND Step.Prevention of re-adhesion * Mechanical lift off - Ultra sonic (MHz) - Brush scrub Chemical lift off - Substrate etching with alkaline and HF -Use of H 2 Water : H radical generation inactivation of soil or detachment of soil - Particles are dissolved with HF or decomposed with O 3 - - -- - - Change of surface potential charge of particle and substrate Substrate -Alkaline ph - Negative potential may help the enhancement of negative charge. Same polarity of Zeta potential between particle and substrate
Mechanism of Metal Removal 1. Metals in SiO₂film MOx SiO₂ Substrate M+ Substrate SiO₂ * Metals are removed together with SiO₂by etching with HF. 2. Metals on bare Si MOx Substrate M+ Substrate * Metals are ionized by acidic and oxidative solutions. acidic and oxidative solutions. Conventional : Acid & oxidizer at Hot temp & High conc. Activated UPW : Diluted acidic oxidative solutions(hf/o 3 or HCl/ O 3 solution) ORP of Ozonized water is higher than those of H 2 SO 4, HCl, HNO 3 etc.
Cleaning Principles Contaminants to be removed Necessary Conditions Methods to be done Cleaning solutions Organic Contaminants To be oxidized and decomposed Into solution Increase ORP of the solution than organics Ozonized Water (O 3 Water) Particle Contaminants Separate particles from surface Equalize Zeta potential of particle and substrate Alkallic, Hydrogen Water (NH 4 + - H 2 Water) Metallic Contaminants Metals to be ionized and decomposed into solution Increase ORP of the solution than metal Acidic Ozonized Water (HCl-O 3 Water)
Functional Water Indirect DIW Electrolysis (Separation of Gas / liquid) Ultra pure Water(DIW) Direct DIW Electrolysis O 3 Water Generator H 2 Water Generator Ion Water Generator O₃Water H₂Water Anode Water + HCl Cathode Water + NH 4 OH ph ORP(mV) 7 +1,350 7-350 ph ORP(mV) 5~7 +400 1~5 +1,100 6~8-350 9~13-750
Electrolyzed water (EW) The controlled water in terms of ph and oxidation-reduction potential (ORP) by the electrolysis Easy to control ph/orp in wide range with only current /voltage changes Oxidation-reduction potential (ORP, E) O x + ne = R ed (1) E = E o RT/(nF) log (C red /C ox ) (2) at C red > C ox, ORP is negative value (reductive water) at C red < C ox, ORP is positive value (oxidative water)
Principle of EW Generation Electrode Membrane Electrode Membrane CW AW OH - H + H 2 OH - H + O 2 or O 3 H + H + OH - OH - CW AW H + OH - OH - H + H 2 NH + 4 NH + 4 OH - O 2 or O 3 OH - H 2 O NH 4 OH Electrode Membrane Electrode Membrane CW AW CW AW OH - H + OH - H + H + OH - OH - H + H 2 H + H + O 2 or O 3 Cl - Cl - H 2 O 2 or O 3 NH + 4 NH + 4 Cl - Cl - HCl NH 4 Cl
EW Cleaning Procedure for Generating Electrolyzed Water Supply electrolyte Such as UPW, NH 4 OH, HCl, and NH 4 Cl Supply electrolysis power 7.0~9.0 A, 10~12 V Anode water, Cathode water Anode and cathode water generation Measurement of EW properties ORP, ph and lifetime, FT-IR Surface cleaning Particle counter, TRXFA, AFM
EW Cleaning ORP (V) 2.0 1.5 1.0 0.5 0-0.5-1.0 EW Properties -1.5 0 2 4 6 8 10 12 14 ph A : Anode water with electrolyte B : Anode water by UPW ~ Effective for removal of metal ions Oxidative water, High H + Conc. Similar to properties of O 3 water C : Cathode water by UPW D : Cathode water with electrolyte ~ Effective for removal of particles Reductive water, High OH - Conc. Similar to properties of H 2 water Normally used with NH 4 OH
국내전해이온수공급업체 1. 마이크로뱅크 (http://www.micro-bank.co.kr ; 031-905-3420) 산업자원부의청정생산기술과제수행 (Hynix와공동수행 ) 반도체 /LCD 세정용 3조식전해장치제조기술개발및응용 ( 금속오염물, 유기물, SiO 2 미립자, SO 2-4 이온제거 ) Redox를이용한산업공정에서의일반세정기술개발및응용 ( 하드디스크, PCB, 광학렌즈등 ) 전해산성수에의한살균소독시스템개발 음용이온수기개발 : 한국세라스톤에알카리성이온수기공급 2. 맥스산업 (02-716-6883~4) 직류전원에의하여산성 / 알칼리성전해수 (ph 2.0~12.0, ORP±1000mV이상 ) 응용 : 반도체, LCD 및 PCB 기판세정 각종배관라인의세정및살균 3. 서양에이아이 (http://www.seoyang.co.kr ; 02-488-8444)
일본전해이온수공급업체 1. REIKEN, INC. (http://www.reikeninc.co.jp) - Dynakleen.D 고주파 (30~34 khz) 전기분해 : 부식예방및스케일제거, 화학물질미사용 3조시스템 (+, -, earth) : 이물질이전극에미부착 전극유지용이, 자체세정효과 활성수 : 살균및악취제거, 유지비저렴 (ROI = 1~1.5 year) 2. Nissin seiki Co., Ltd. (http://www.nissin-seiki.co.jp) - 강알칼리이온세정수생성시스템 (NEWSEW-01-RO) 강알칼리이온수생성 (ph 12~12.5) 순수세정장치가있어알칼리수와순수를별도로생산가능 전해질로 CaCO 3 사용 피세정물의산화및부식방지, 악취제거및살균효과 3. NITTO KOSHIN CO., Ltd. - 전해수생성 unit 본체에수돗물을직접연결하여연수와알칼리성전해수생성 ( 전해질사용 ) 연수기의재생은완전자동 응용사례 : ⅰ) 액정유리의최종세정 ⅱ) Al 가공유세정에서탄화수소계세정제대체
Applications of Functional Water Classification FPD Semicon Wafer O 3 Water Organic Removal 1. Pre-Cleaning 2. Pre-Deposition 3. Post-Deposition 1. Post-SPM Rinse 2. Pre/Post-CMP 3. Post-Ashing 1. Growth of Protective Oxide 4. P/R Strip 4. P/R Strip H 2 Water Particle Removal 1. Clean bare glass 2. Rinse after etching 1. Post-CMP 1.Rinse after Chemical Bath 1.Removal of Metal, Electrolyzed Water Removal of Metal & Particle 1. Post-CMP Particle & Organics 2. SO 2-4 removal after SPM cleaning
Bubble Jet Technology* 1) Principle Uniform Flow Jet Nozzle Liquid + Gas Flow W/Higher Energy Remove 노즐 Fine Particle Higher Velocity 2) Performance Nozzle Particle Removal Ratio(%) Particle Removal Ratio(%) Liquid Gas S M L T High Pressure Jet Bubble Jet S M L T (Initial Particle : 1000-3000ea 3) TEST : BM Pre-deposition S 1~3 μm, M 3~5 μm, L 5 μm, T 1 μm ) NO Item O₃Water Roll Brush Bubble Jet Shower(M/S) Di Shower Aqua knife Air knife Avg. Particle Residue 1 2 W / BJ 66EA W/O BJ 170.3EA Note : 1. Avg. Initial Particle : 2166EA 2. Sample Size(N) : 3Pcs, Each 3. Particle Counter : 1μm (Hitachi : GI-4700) 4. Glass Size : 590 * 670 * 박영순, 태화일렉트론 Removal Ratio(%) 97 % 92 % 1 2
Dry Systems* Heated Air Hot DI Spin Dry Heated @ 80 ~ 200 Water mark Surface Oxidation Cleaning Performance Degradation Higher Running cost Heated @ 80 Water mark Surface Oxidation Cleaning Performance Degradation Higher Running cost Room Temp. Mechanical Damage Poor Scalability Lower Running cost IPA Dry Air knife UDG(Ultra Dry Gate) Heated @ 250 Fire Issue Fire Extinguisher necessary Single Process impossible Higher Running cost Room Temp. Water mark Additional De-humidifier necessary Cleaning Performance Degradation Lower Running cost CDA (Room Temp.) Ultra Dry Air (Water content : <0.5ppm) Evaporation of surface water trace Lowest Running cost * 박영순, 태화일렉트론