Electron Microscope J.M. Yang, NNFC NNFC 분석 / 특성평가범위 업무범위 l NNFC 특성평가 나노단위미세구조분석및표면분석 기술및제품개발참여 불량원인분석 리버스엔지니어링 반도체소자의공정평가 나노단위박막및소재의전기적, 기계적 특성분석및평가 연구, 개발 재료 평가기술개발 평가분석 분석지원업무 생산품 특허 & 신뢰성 리버스엔지니어링분석 Semiconductor Analysis In-line Metrology Structure Analysis Surface Analysis NNFC NNFC NNFC Networking 물질분석 오염분석 특허분석및 Claim 방어 제품신뢰성향상 Chemical Analysis Electrical Characterization Networking NNFC 2 1
NNFC 분석 / 특성평가장비의구성 구조 & 표면분석 Mechanical & Bio 분석 Electrical 특성측정 In-Line 측정 불량분석 RE 분석 FE-(S)TEM Cs-corrected STEM 3D FE-STEM In-situ TEM FE-SEM DB-FIB M-SIMS SPM Nanoindentor FT-IR Microscope Confocal Microscope N-IR Imaging Imaging Ellipsometer Character System Measuring with Manual P/S Character System Measuring with Auto P/S Ellipsometer Reflectometer Surface Profiler Optical Profiler Stress Guage 4-Point Probe X-ray Microscope RIE Wet Station Polisher Auto Microscope 비고 : 표면분석 (XPS, AES, XRD etc.) 은외부기관과 Networking 에의해서비스 3 NNFC 의분석기술 2
3 Atomic Scale Analysis by Cs-corrected STEM HRTEM of Au HAADF-HRSTEM of Si @ 200 kev HAADF-HRSTEM of Si @ 120 kev 0.204 nm 0.1375 nm 0.1375 nm 200 Cd Se Pr 2 O 3 S I-O 0.8 nm Si 150 Intensity [ 10 3 ] 100 50 0 Si-L 1 Si Substrate Si-L 1 Si-L 2,3 Interfacial Oxide Zn S 100 120 140 160 Energy Loss (ev) Atomic Scale Analysis : HRSTEM-EELS spectrum EDS Map of QDs (CdSe/ZnS) 20 nm 5 Dopant Profile Analysis 1D IMP & Diffusion Profiling by SIMS Concentration(atoms/cc) 1E22 1E21 1E20 1E19 1E18 1E17 1 kev Boron as-imp. 1000? 1050? 1100? Xj(@5e17atoms/cc) Concentration(atoms/cc) 1D Dopant(Mg) Profiling by SIMS 10 21 10 20 10 19 10 18 Mg Mg N O In Ga 10 6 10 5 10 4 10 3 10 2 10 1 Intensity(counts/sec) 1E16 0 500 1000 1500 2000 2500 3000 Sputter Depth(angstrom) Depth(angstrom) 10 17 10 0 0 1000 2000 3000 4000 Sputter Depth(angstroms) Sputter Depth(angstrom) 2D Dopant Profiling by Electron Holography Vacuum Gate Gate n + 1.12 µm n + 2D Dopant Profiling by LV-SEM doped B doped gate gate source 0.13 µm drain 0.13 µm P-sub 1μm n-well 0.2 µm 0.2 µm 6
FIB and SPM Analysis Cross-section Analysis Scanning Tunneling Microscopy Magnetic Force Microscopy Au(111) atomic image Magnetic domains of a Co/Pt alloy 2 μm 1 nm 1 μm Patterning & Circuit Modification Scanning Capacitance Microscopy Multi-layered p-n junction profile 2D dopant profiling of a n-mos n + p + n + p + P-Sub. n + p + n + p + SCM Phase P-Sub. Gate n + Gate n + 2 μm 1 um SCM Amplitude P-sub. 2 μm 7 Reverse Engineering Analysis Nondestructive Inspection Process Analysis X-ray Image Computed Tomography Metal 2 Cross Section Metal 1 Capacitor Metal2 Metal1 Bit Line Gate Contact Capacitor Active Bit Line Gate Before Decap Deprocessing Image Stitching Lay-out and Circuit Analysis Layer Photographing Circuit Drawing Circuit Analysis After Hole Decap 8 4
전자현미경분석입문 Beam & Probe A beam : a directed flow of particles or waves that carries energy and information (amplitude, phase, frequency ) l Light - Visible rays : 380 770 nm - Infrared rays - Ultraviolet rays - LASER l Probe - Eextremely sharp tip (3-50 nm radius of curvature) l X-ray - X-rays are electromagnetic radiation - Wavelength : about 100 A to 0.01 A - X-rays by the transitions of inner electrons (light by the transitions of outer electrons) l Ion - Particle formed when a neutral atom gains or loses one or more electrons - Cation : an atom that loses an electron - Anion : an atom that gains an electron l Electron - Negatively charged particle (-1.602 x 10-19 C) - Mass : 9.107 x 10-28 g 10 5
6 Scanning Electron Microscopy Scanning Electron Microscopy (SEM) - 전자발생원 (electron gun) 으로부터방출된전자빔을전자기렌즈를이용하여미소한점으로초점을맞추고, 시료표면위을주사하면이차전자, 후방산란전자, Auger 전자및특성 X 선등의 2 차적인신호가발생 - 이차전자를검출기로미소점에서의변화된신호량의대소를브라운관점의명암으로써영상화시키는방식 Secondary Electrons and Backscattered Electrons 12
7 Scanning Electron Microscopy (SEM) SEM 영역 0.5~5 nm 오제이전자 5~50 nm 이차전자 EDS 영역 450 nm 후방산란전자 ~3 μm 특성 X 선 연속 X 선 연속 X 선과특성 X 선에의한 2 차형광 X 선 13 Scanning Electron Microscopy (SEM) 분석특징및분석기법 표면형상및구조의관찰 SE와 BSE 영상 EDS 원소분석 (Point, Line, Mapping) 분석능 SEM의공간분해능 : ~1 nm EDS 원소분석의검출범위 : C-U SEM 의배율 배율 M = L CRT / L Specimen 표면및단면의 Profile 및 Morphology 관찰 미세 Particle 및오염물질의위치추적및형상분석 EDS 를이용한박막및물질의조성분석 14
Scanning Electron Microscopy (SEM) 15 Scanning Electron Microscopy (SEM) 16 8
9 SEM Imaging and EDS Analysis l Application - Observation of surface topology - SE and BSE imaging - EDS element analysis (Point, Line, Mapping) l Spatial resolution : ~1 nm l Detection element of EDS : C-U Intensity Surface Image 254 nm 57.3 nm Etch Profile Energy ( kev ) EDS Analysis 17 Transmission Electron Microscopy
Transmission Electron Microscopy (TEM) - 고속의입사전자빔을박판시료에조사하면전자는탄성 비탄성산란을일으키며시료를투과하게되는데이때발생하는투과전자와탄성산란전자를이용하여재료의미소영역을확대 관찰하는장치 - 물질의미세구조, 격자결함, 결정구조, 원자배열상태등조사 - 시료와전자빔과의상호작용으로발생하는특성 X선을 EDS로검출하거나, 시료를투과한비탄성산란전자의에너지를 EELS로측정하면미소영역의조성을분석할수있음 SEM Electron Beam Backscattered Electron Secondary Electron 2q Characteristic X-ray EDS Specimen Transmitted Electron Elastically Scattered Electron BF DF Inelastically Scattered Electron EELS HRTEM Pre-field of Objective Lens Specimen Post-field of Objective Lens Objective Aperture Selected Area Aperture Electron Beam q 2q Back-focal Plane Diffracted Beam Transmitted Beam Image Plane FFT IFFT 19 Transmission Electron Microscopy (TEM) l 원자수준분해능에서물질의구조분석 l 물질의결정구조및박막의배향성분석 l EDS 원소분석 (Point, Line, Mapping) l EELS 분석 (Point, Line, Mapping) TEM 의점분해능 : ~0.2 nm EDS 분석의공간분해능 : 나노미터수준 EELS 분석의공간분해능 : 나노미터수준 A level 의분해능에서 device 의단면 profile 관찰및 film 의두께측정 Defect (lattice defect, dislocation 등 ) 관찰에의한 device 불량분석 결정립의크기, 형태등의관찰전자회절을이용한특정영역의미세구조및방위분석결정및계면의원자배열상태관찰 (HRTEM) 박막및 nm scale 미소영역의조성분석 (EDS, EELS) 20 10
TEM Imaging and Electron Diffraction 1 2 200 200 111 111 780A 1 640A 0.204 nm 2 100nm 40A HRTEM of Au Nanoscale EDS Map of the 3 nm Si Fin-FET Silicon fin HfO 2 HRTEM STEM Hf S Poly-si 3nm Buried oxide 3nm 5nm 2 nm 2 nm 21 Analysis of Composition EDS (Energy-dispersive X-ray Spectroscopy) EELS (Electron Energy-Loss Spectroscopy) 차이점 공통점 전체적인조성분석에효율적 Peak 분해능이우수 (~1eV) 하여화학결합상태분석에적합 점분석 (point analysis), 라인프로파일 (line profile), 원소매핑 (elemental mapping) 2 차원적으로 image 와대응하면서원소분포를알수있어불량분석에매우유용 회절 contrast 등의 artifact 가잔상으로남아있는경우가있어해석시주의필요 EDS: E = 0.013 (Z-1) 2 (kev) 내각전자가여기된후원래의위치로천이되는과정에서특성 X 선발생 원소구별의척도 EELS 입사전자가내각전자와충돌하여임계이상의에너지를손실할때 peak 형성 ( 입사전자의비탄성산란이용 ) 원소구별의척도가되며, 피크의 chemical shift 또는형태변화로화학결합상태조사 22 11
Analysis of Composition EDS EELS 비교 검출신호특성 X 선에너지손실전자 EDS : 2 차여기이용 EELS : 입사전자이용 측정효율낮음높음 EELS 의경우측정시간이짧음 분석원소 C U H U EDS : 중원소에유리 EELS : 경원소에유리 검출한계수 wt% 수 at% Energy 분해능 약 150 ev 1 2 ev (Chemical shift 측정 ) EDS 는 background 의강도가낮아정량분석에유리 원소 map STEM ( 각원소동시분석 ) Energy filtering EDS : 다원소 map EELS : energy filtering 23 Analysis of Composition STEM Si Point Analysis Ni Ni SiGe x Si NiSi 에폭시 800 700 600 500 400 300 Line Profile SiK NiK GeK Si-Ge 기판, 계면, NiSi 박막, 에폭시까지의성분분표관찰가능 200 100 0 1 9 17 25 33 41 49 57 65 73 81 89 97 24 12
Focused Ion Beam Focused Ion Beam (FIB) Neutral Atoms Incident Ion (30~50keV) + Ions Detector Electrons Grid bias Displaced Atoms Phonons (heat) Implanted Ions Specimen Focused Ion Beams can image an IC s surface as well as add and remove conductors and insulators. Focused Ion Beam (FIB) technology allows the capability to locally etch materials by milling a sample surface with a highly focused ion beam. This same beam can also be used to locally deposit conductors and insulators. These operations can be made with submicron precision and give rise to a number of useful applications. Typically FIB is utilized in on-chip circuit modification (redesign/repair, device isolation, probe pad formation) and advanced circuit diagnostics for failure analysis (cross-sectioning and TEM / SEM sample preparation). 26 13
Dual Beam FIB System Electron Beam Ion Beam Gas Assisted Etching or Selective Deposition Ga + Ga + Ga + n 0 Ga + Ga + Ga + 27 FIB Techniques l Dual Beam ( 전자 & 이온 ) 을이용한이온밀링 & 물질의영상 l 서브마이크로수준에서의증착, 절단, 연결, 엣치를통한회로수정 l 미세기계가공 (Micro Machining) l 특정위치의 TEM 시편제작 2 um Cross Section Metal Deposition Etch 회로수정 360nm < 30 nm 2 um 500nm 미세 Hole 가공 Step Hole 가공 SPM Tip 가공 TEM 시편제작 28 14
Resolution Source Method Energy Lateral Resolution Depth Resolution Detectable Elements Analyzed Volume X-ray XPS > 1 kev 10 μm 1-10 nm Li-U 10-9 M-SIMS 1-15 kev > 30 μm 2-30 nm All 10-11 Ion Quad.-SIMS 1-15 kev > 30 μm 5 nm All 10-11 TOF-SIMS 1-5 kev 0.1 μm 1-3 monolayers All 10-11 RBS > 1 MeV 2 mm 1-10 nm Li-U 10-8 SEM 0.5-30 kev 6 A TEM 100-400 kev 2 A Electron AES 0.5-10 kev < 15 nm < 2 nm Li-U 10-15 SEM/EDS 0.3-30 kev 4.5nm B-U 10-12 TEM/EDS 100-400 kev 1 nm B-U 10-17 STM < 0.1 nm 0.01 nm Probe (SPM) AFM < 10 nm 0.01 nm MFM < 20 nm 0.01 nm SCM < 20 nm 0.01 nm 29 15