A brief introduction to tunneling scanning microscopes. This slides was provided by Alireza Sohrabi at Bu-Ali Sina University.

1. In the name of God
Scanning Tunneling Microscopy
(STM)
Alireza Sohrabi
Ali Shoghi
November 2020

2. Outline
Introduction
Type of microscopy
Image of an STM
Components of STM
Principle
Two Methods of Scanning
Application
Advantages & Disadvantages
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3. introduction
 instrument for imaging surfaces.
 development in 1981(IBM Research-Zurich).
 Gerd Binning and Heinrich Rohrer.
 Earned Nobel Prize in Physics 1986.
 Use not only in vacuum but also in air and liquid various.
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4. Type of microscopy
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5. Image of an STM
First STM
(Nobel Prize Winning)
Current example
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6. Components of STM
 Scanning Tip
 Piezoelectric Scanner
 Distance Control and Scanning Unit
 Data Processing Unit(Computer)
 Vibration Isolation System
Components
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7. Principle
 Scanned by a very fine Metallic Tip.
 XYZ Position.
 The Sample is Positively or Negatively.
 The Tip is a Short Distance from the Surface.
 Applied a Bias Voltage.
 Electrons Tunnel from Surface.
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8. Two Methods of Scanning
 Constant Height Mode
 Constant Current Mode
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9. Interesting Images from STM
Pt Surface By STM (5000 A) Cu Surface By STM (5000 A)
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10. Application
 Discern about the surface of a material:
Such as: friction, roughness, defects & …
rotate individual Atoms.
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11. Advantages
 Analysis 0 K temperature
 No damage to the sample
 Vertical resolution superior to SEM
 rotate of individual atoms
 Use not only in vacuum
 3D image production
Disadvantages
 Samples limited to conductors and
semiconductors
 Requires initial surface preparation
 Very low speed
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12. Any Question?
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