http plasma hanyang ac kr Plasma Electronics Lab

플라즈마 소스 및 응용 정진욱 한양대학교 전기공학과 http: //plasma. hanyang. ac. kr Plasma Electronics Lab Hanyang University, SEOUL, KOREA

추천도서 • 플라즈마 전자공학 (네이버 카페) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

22 nm Transistor Technology • Intel Technology Roadmap • Transistor history Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Electronics & Plasma • Plasma Etching – Dry etching (gas phase) EXTRAORDINARY CAPABILITIES !! • Core i 7 Sandy Bridge – Feature size ~ 32 nm ! • Core i 7 Ivy Bridge (2012) – Feature size ~ 22 nm !!! Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Background • 원자론의 역사 – 고대 그리스 – 데모크리토스 – 19세기 초 – 돌턴 – 아인슈타인 1905년 볼츠만 http: //navercast. naver. com/contents. nhn? contents_id=133 아인슈타인 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Background • 기체의 분자/원자 모형 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma ? • 4 th State of Matter • Plasmas in nature: 99 % of the matter in universe – 사하(Saha) 방정식 (amount of ionization in thermal equilibrium) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasmas in Nature • 지구 전리층 – 지구 자기권과 오로라 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

History of Plasma • Plasma 발견의 역사 – 최초의 plasma 발생 실험: Faraday 1835 – 4 th state of matter : Crookes 1879 – 최초의 명명자 : Langmuir 1928 • Plasma oscillation 발견 : Langmuir 1929 • Plasma의 어원(고대 그리스어: (a thing formed or molded) – 생물학: 1893년 Purkynie, proto-plasma(원형질) – 의학: plasma (혈장, 림프액) – 물리학: 1928년 Langmuir plasma Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Classification of Plasma • 이온화 정도에 따른 플라즈마 – Weakly(partially) ionized(process plasma) – Highly(fully) ionized plasmas(fusion plasma) • 이온 온도에 따른 플라즈마 – Low temperature plasma (cold plasma) – High temperature plasma(fusion) • 용도에 따른 플라즈마 – Process (RF, ECR, ICP, Helicon, . . . ) – Fusion (Tokamak, Tandem mirror, . . . ) • 평형 정도에 따른 플라즈마 – Non LTE – cold plasma – Local Thermal Equilibrium - thermal plasma – Complete Thermal Equilibrium – stars Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Classification of Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Generation • 전기장으로 전자 가속 – 1 e. V = 11, 600 K 해당 에너지 Neutrals (radical) 전기장 (DC, RF, …) + electron Hot electron Electron Heating Neutral Positive ion Electrons Ionization Plasma = electrons + ions + neutrals (ground + excited) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Applications Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Applications –Tokamak (Fusion) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Applications –Tokamak (Fusion) • The main plasma current is induced in the plasma by the action of a large transformer Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Applications –Tokamak (Fusion) • Getting close to fusion Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Applications –Tokamak (Fusion) KSTAR: Korea Superconducting Tokamak Advanced Research Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Applications – 행성 탐사 우주선 • 플라즈마 추진체 – 100배의 분출 속도 – 오랜 기간 가속 – 화성까지 약 50일 http: //www. youtube. com/watch? v=GIg 6 p. Wwez. EU Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Electronics & Plasma • Moore’s law Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

What is plasma etching ? A simple MOS transistor Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

What is plasma etching ? wafer Another example : Si + 4 F Si. F 4 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Etch process in Plasma etching • Example of ion-assisted etching Reactive radical gas (F) Ion beam (Ar+) Byproduct (Si. F 4) Si wafer Coburn et. al. Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Etch Processes 다뉴세문경(多紐細紋鏡). 국보 141호 초기 철기시대의 청동거울 0. 3 mm간격으로 13. 000개의 가는 선 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Etch Processes Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Etch Gallery Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma 구조 • Plasma bulk & Sheath – 플라즈마와 reactor가 닿는 표면에 생기는 부분 – The non-neutral region between the plasma and the wall Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma 구조 • • The characteristic length scale of a plasma Low voltages sheaths ~ few Debye lengths Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma 구조 • PIC-MCC – potential, N(t) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Bohm’s Speed Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

RF 플라즈마 소스 Plasma Electronics Lab Hanyang University, SEOUL, KOREA

RF & Microwave discharges • Capacitive Coupled Plasma(CCP) – Voltage coupling • Inductive Coupled Plasma(ICP) – Current coupling – Helicon plasma (magnetic field) • Microwave plasma(~2. 45 GHz) – Surface Wave plasma, Electron Cyclotron Plasma(ECR) 코일(Coil) Antenna I. M. B B Blocking capacitor CCP E Substrate 전자석 RF Microwave 2. 45 GHz Quartz window RF Vacuum Pump RF ICP ECR Helicon Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Plasma Sources in Processing • RF Power + antenna or electrode Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

플라즈마 소스 • RF 플라즈마 소스 및 마이크로파 플라즈마 소스 – Capacitive Coupled Plasma(CCP) • Capacitive electric field – Inductive Coupled Plasma (ICP) • Inductive electric field – Microwave plasma(~2. 45 GHz) • Surface Wave plasma, Electron Cyclotron Plasma(ECR) Antenna I. M. B B E RF Substrate Blocking capacitor RF CCP Vacuum Pump ICP Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Electron heating • Heating zone – In CCP, rf sheath ~ mm – In ICP, skin layer ~ cm Antenna I. M. B Sheath Skin layer E RF CCP ICP Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr RF

Impedance matching • RF Generator의 Impedance와 Chamber Impedance 의 값을 일치시 켜 주는 것 • 반사파 없이 최대 파워 전달 • 장비의 안정성 ZL=1 – j 100 or 1 + j 100 ZL=50 + j 0 ZT = 50 RF Generator Matching Network Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Impedance matching • Maximum power transfer in DC when R 0 = RL • Averaged transfer power in AC Vrf RT ZL = RL + j XL Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Impedance matching • Find CL and CT for impedance matching Load impedance ZL = R + j XL ZL Zin RT CT Vrf CL XL R Impedance matcher Matching condition : Re(Zin) =RT, Im(Zin)=0 CL and CT =? Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Smith chart • Graphical plot of normalized resistance and reactance functions in the reflection-coefficient plane Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Z and Y Charts add series inductance Z add series capacitance add shunt inductance Y add shunt capacitance Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Impedance matching example RF out RF In 2 Generator 3 1 Load 3 +j 50 j 20 j 100 Load ZL = 200 - j 70 2 0 10 20 50 100 oo -j 100 -j 20 -j 50 1 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

RF discharges • Electrodeless lamp (Inductive discharge) • 수명 100, 000 시간, 최대 150 W (GE QL ) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Power deposition in RF discharges • RF Power deposition mechanisms – Joule heating (α discharge) – Secondary electron emission ( discharge) – Fermi acceleration by sheath oscillation Surfing (Wave-particle interaction, Landau damping) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Capacitive Coupled Plasma(CCP) Potential(voltage) distribution Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Capacitive Coupled Plasma (CCP) • 평행 평판형 RF 방전의 구조와 등가 회로 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Inductively Coupled Plasma (ICP) u Discharge by the induced electric field inside the RF coil current Inductive discharge and Faraday's law u Plasma generation mechanism RF current → Time-varying axial B-field →Time-varying azimuthal E-field →Electrons are accelerated → Ionization → Plasma Generation u ICP ▶ non-capacitive discharge ▶ High density discharge ▶ electrodeless discharge Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Inductively Coupled Plasma (ICP) u Planer type – – 안테나의 구조에 따라 플라즈마 균일도가 조절됨 오른쪽 그림의 경우 직경 200 mm에서 약 ± 10 %의 균일 도를 가짐 2 k. W power source -> 폭 2 mm 리본형 안테나 사용 (밀도: 1011 cm-3) Antenna I. M. B B E Substrate Plasma RF Vacuum Pump Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Inductively Coupled Plasma (ICP) • Cylindrical type Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Inductively Coupled Plasma (ICP) • Capacitive coupling (E- field) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Inductively Coupled Plasma (ICP) • Faraday shields Cylindrical ICP Planar ICP Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Cares in designing the ICP Source u High antenna Voltage (high inductance) u Radial Uniformity u Azimuthal symmetry u Dielectric window damage (sputtering) E Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Azumuthal Symmetry • Double stack antenna type (DOSA) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Power Feeding • 일반 ICP의 Power Feeding의 문제 – Stray Cap으로 인해 Input current 와 out current 같지 않음 – Capacitive power coupling으로 밀도 저감, sputtering 이슈 – Balanced feeding이 바람직함. • Terminal capacitor 장착 Iin Iout Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

RF Power Feeding • 플라즈마 발생 효율 개선 • Balun transformer in ICP : Experiment results ( Ar 50 [sccm] ) 20 m. Torr Power [W] I 1 [A] I 2 [A] 30 3. 57 3. 51 30 6. 08 5. 53 40 3. 96 3. 93 40 6. 83 6. 15 50 4. 26 4. 23 50 7. 33 6. 62 60 4. 63 4. 6 60 7. 87 7. 11 70 4. 79 4. 76 70 8. 25 7. 41 Balun None Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Power Feeding • Transformer를 이용해서 Balance Feeding으로 변환 • ICP 모드에서 확실한 효과 • 약 50% 밀도 개선 Iin Iout Argon @ 50 m. Torr Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Power Feeding • Electron Temperature & Plasma Potential – 전자온도 저감 (2. 6 2. 0) – 플라즈마 전위 약 50% 감소 • 이온 에너지 손실 50% 저감 • 플라즈마 데미지 감소 예상 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

ICP with Ferromagnetic cores • Strong inductive E fields current Ferrite current Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

ICP with Ferromagnetic cores • Electrodless lamp (Inductive discharge) • 수명 100, 000 시간, 최대 150 W (GE QL ) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

ICP with Ferromagnetic cores • 강자성체 이용 ICP – 저압, 고밀도, 고균일 플라즈마 K. H Lee et. al. , PSST 2009 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

ICP with Ferromagnetic cores • 강자성체 이용 ICP – 저압, 고밀도, 고균일 플라즈마 Non uniformity (<3%) Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

ICP with Ferromagnetic cores • 강자성체 이용 ICP – 저압, 고밀도, 고균일 플라즈마 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

플라즈마 진단 Plasma Electronics Lab Hanyang University, SEOUL, KOREA

Plasma parameters Parameter Symbol Related Information 플라즈마 밀도 (plasma density) np, ne, ni Etch rate, sputter rate 전자온도 (electron temperature) Te Ionization rate, dissociation rate, selectivity 이온 flux (ion flux) Jis = ni u. B Etch rate, sputter rate 생산성(Throughput) 플라즈마 전위 (plasma potential) Vp Incident ion energy onto substrate 부유 전위 (floating potential) Vf Indicator of plasma potential 전자 에너지 분포 함수 (electron energy distribution function) EEDF Electron heating mechanism Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Single Langmuir Probe • Ideal I-V curve – Probe area << ground area A : ion saturation current region, B : Electron collection region C : Electron saturation region Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Single Langmuir Probe • Real I-V curve in cylindrical probe Sheath expansion increase in the collection area Ip VB Vp VB Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Commercial Single Probe • Wise Langmuir probe (HYU) EEPF Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Floating Harmonics Probe • Wise Probe - HYU • 플라즈마 sheath의 비선형성 이용 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Floating Harmonics Probe • Plasma parameters @ 20 m. Torr Electron Temperature Ion density Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

OES – Optical Emission Spectroscopy HR-4000 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

OES – Optical Emission Spectroscopy Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

OES – Argon Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

플라즈마 전자공학 연구실 연구 주제 • Plasma sources – Next generation plasma source development (high density plasma) – Improvement of plasma sources by rf power feeding modification, rf power transfer monitoring, etc. – Electron heating & transport mechanism (physics) • Plasma diagnostics & monitoring – Electron energy distribution function (EEDF) measurement – Real time plasma diagnostics • Harmonics analysis method (HYU patent) • 2 D Plasma profile measurement • Plasma monitoring in plasma reactors • monitoring of chamber wall – Optical emission spectroscopy (OES) • Gas temperature (rotational), electron temperature, excited species Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

플라즈마 진단 및 모니터링 • Stand alone 형 – 10 k. Hz, ~1 V – 내장 MPU, 외부 PC 필요 X – Small footprint • 양산 챔버에 장착 가능 Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

2 D Plasma Profile measurement • 2 D Plasma Profile on wafer level – Based on Harmonics analysis method – Identical 29 probes – 2 r =5 mm, 2 R =300 mm Biasing to all probes through MUXs within 1 sec • A A 0 A 1 A 2 EN 1 EN 2 EN 3 EN 4 B Digital port for line selection C 8 data lines Mux 8 data lines `` Gas injection Mux Shielded 29 data cable 8 data lines Sweep voltage FFT 2 D interpolation Mux 5 data lines Mux probe Pumping port Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr

Wafer 형 진단 기술 • Wireless 2 D 진단 d = 3. 3 mm Plasma Electronics Lab, Hanyang University, KOREA http: //plasma. hanyang. ac. kr