Scanning Electron Microscope (SEM)

Slides:

Advertisements

Similar presentations

Ge 116 Module 1: Scanning Electron Microscopy

Advertisements

Basic Electron Microscopy

SEM & TEM in Polymer Characterization

BY Assistant Professor Dr. Akram R. Jabur Department of Materials Eng. University Of Technology.

Lecture 11. Microscopy. Optical or light microscopy involves passing visible light transmitted through or reflected from the sample through a single or.

Electron Optics.

Scanning Electron Microscope (SEM)

Groups: WA 2,4,5,7. History  The electron microscope was first invented by a team of German engineers headed by Max Knoll and physicist Ernst Ruska in.

Hong Koh Yiin -CAMTEC Image from:

Introduction Secondary electron secondary electron detector The electron beam interaction with near surface specimen atoms will make a signal which results.

Components of Initial Eprobe Startup Electron Gun –turning on beam, setting beam current, acceleration, saturation level Focusing lenses –Permit focussed.

Electron Beam Source Temescal SFIH – 270 – 2 Fernando Lloret Vieira

Electron Optics Two essential components: 1)Electron source (gun) 2)Focusing system (lenses) Add scanning apparatus for imaging Electron gun Cathode Anode.

Electron-Specimen Interactions

Electron Microscope. Light Resolution  The resolution of a microscope is limited by the diffraction of light. Single diffractionSingle diffraction 

Scanning Electron Microscope Jamie Goings. Theory Conventional microscopes use light and glass lenses SEM uses electrons and magnetic lenses to create.

Scanning Electron Microscope د. عمر عبد القادر.

FYSZ460 Electron Beam Lithography Electron Beam Lithography FYSZ460 Advanced Laboratory Exercise Mikko Palosaari

Introduction to scanning electron microscopy

Transmission Electron Microscopy

Microscopes are used to increase the magnification and resolving power of the unaided eye MICROSCOPES.

SEM microscope By: Doug, Holly & Oleg. Scanning Electron Microscope vs. Optical Microscope Advantages Continuously variable magnification High resolution.

BY SANTANU PRAMANIK(09369) HITESH KUMAR GUPTA(09320) CHANDAN SINGH(09260) SCANNING ELECTRON MICROSCOPE MATERIAL SCIENCE ASSIGNMENT.

Do it with electrons !. Microscopy Structure determines properties We have discussed crystal structure (x-ray diffraction) But consider now different.

EBL: Focus & height rev 0, 6/6/08. Electron gun ZrO/W emitter Suppressor First anode Second anode Acceleration electrodes Ground anode First alignment.

Factors affecting the depth of field for SEM Afshin Jooshesh.

Electron Microscopy.

Scanning Electron Microscopy

Introduction to transmission electron microscopy

Forensic Instrumentation

B. Spatial coherancy & source size Spetial coherancy is related to the size of the source. Source size governs spatial coherancy and maller source sizes.

SEM (SCANNING ELECTRON MICROSCOPE) Özgen Buğdaycı Elif Topçuoğlu Yavuz Duran Hacettepe University

Notre Dame extended Research Community NANOWeek: The Power of Microscopes Optics Visible light Optical microscopes and telescopes Scanning electron microscope.

Electron Microscopes Used to count individual atoms What can electron microscopes tell us? Morphology – Size and shape Topography – Surface features (roughness,

Scanning Electron Microscope (SEM)

Electron Probe Microanalysis EPMA Electron Optical Column UW- Madison Geology 777.

Scanning Electron Microscope

Introduction to Graphical Hardware Display Technologies

NANO 225 Micro/NanoFabrication Electron Microscopes 1.

NANO 230 Micro/Nano Characterization

Scanning capacitance microscopy

Conventional SEM Specimen at high vacuum – requires sample fixation and dehydration or freezing. Charging is minimized by coating sample with metal or.

SEM- Schematic Overview. Electron Detection Tungsten Filament Electron Source.

08/03/09 SEM signal generation

SEM Scanning Electron Microscope

The Microscopes. The Microscope 1. The microscope is an optical instrument that uses a lens or combination of lenses to magnify and resolve the fine details.

Comparison b/w light and electron microscopes LIGHT MICROSCOPE ELECTRON MICROSCOPE Magnification can be done upto 2000 times Resolving power is less.

Types of Electron Microscopes Electron microscopes use a beam of electrons rather than visible light to illuminate the sample. They focus the electron.

Scanning Transmission Electron Microscope

Do it with electrons !. Microscopy Structure determines properties We have discussed crystal structure (x-ray diffraction) But consider now different.

3 July July July Conventional X-rays Generator Basic components of an X-ray machine:  Electron source.  Vacuum where electrons were.

SEM Imaging - Magnification and Deflection System

Scanning Electron Microscope Eee-Jay Rodriguez. The Structure of the Microscope Inside Outside.

Introduction to scanning electron microscopy

Presentation on SEM (Scanning of Electron Microscope) Represented by:-Ravi Kumar Roll:- (BT/ME/1601/006)

Introduction to scanning electron microscopy

TRANSMISSION ELECTRON MICROSCOPy (TEM).

Laboratory equipment Lecture (3).

Introduction to Scanning Electron Microscope by Sameer S

METALLURGICAL MICROSCOPE

Electron Microscope Dr. Laxmi Kant Pandey.

X-ray Production Sharif Qatarneh Medical Physics Division

NANO 230 Micro/NanoFabrication

Topic 1: Introduction to Histology

The Microscopes.

Do it with electrons !.

Electronics and Instrumentation Vidnyan Mahavidyalaya, Sangola.

SEM Imaging - Magnification and Deflection System

Computed Tomography (C.T)

Presentation transcript:

Scanning Electron Microscope (SEM) Major components: Vacuum system Electron beam generation system Electron beam manipulation system Beam specimen interaction system Detection system Signal processing system Display and recording system SEM operation principles: http://www.youtube.com/watch?v=PNHn4YM7yfc&feature=related SEM introduction http://www.youtube.com/watch?v=c7EVTnVHN-s&feature=related

Vacuum system Low vacuum pump (<10-3 Torr) (remove 99.99% of air), high vacuum pump(>10-3 Torr) SEM operation need 10-4 to 10-6 Torr

E beam generation Three components: 1) cathode (filament or field emission) 2) grid cap that control the flow of electrons 3) anode that attracts and accelerates electrons Voltage ranges from 0.1 to 40 Kv, (10kV the most common for biological specimen) the higher the voltage the better the resoution (but greater heat will be generated on the specimen) On/off switch for high voltage (HV) Beam current (the flow of electrons that hit a sample), controlled by bias voltage between filament and grip cap, Increasing beam current results in deeper penetration of electron and a larger diameter spot) Filament current control (adjustment of current filament, providing necessary heating current to filament) Filed emission: advantages: cool cathode, emitted beam is smaller in diameter (better resolution), longer life time disadvantages: higher vacuum need (~10-7 Torr), cleaner microscope needed, not many x-rays generated (due to low beam currents and small beam diameters)

E beam manipulation E-gun is controlled by electrostatic field, while the rest of SEM is controlled by magnetic lenses. Electromagnetic lenses: - condenser lenses: reduce spot size spherical aberration limit resolution - correct astigmatism (non-circular beam spot), due to beam formed by filament is elliptical, dirt in column, beam distorted on the aperture using stigmator (control strength and azimuth) - correct alignment - two sets of magnetic coils (raster coils) that move the seam scanning in the X and Y direction - magnification: ratio of dimension of CRT to dimension of the area being scanned two ways of magnification adjustments: 1) change scanned area of the specimen 2) adjust focal point of the beam and working distance (move Z-axis to bring sample to focal point) Aperture: a round hole that control the passing through of scattered electrons - small aperture for high resolution - big aperture for low resolution with more electrons needed

Beam interaction Backscattered electrons Secondary electrons X-rays Cathode Luminescence Specimen current Transmitted electrons