Scanning tunneling/atomic force microscope

Scanning electron microscope Scanning tunneling/atomic force microscopes 3-6nm <0.2nm 10-250,000X Surfaces Surfaces... 

The most recent developments in determining the surface structure are the scanning tunneling microscope (STM) and the scanning or atomic force microscope (SFM or AFM) [36, 37]. These techniques are capable of imaging the local surface... 

Newer techniques that are responding to the need for atomic level imaging and chemical analysis include scanning tunneling microscopes (STMs), atomic force microscopes (AFMs) (52), and focused ion beams (FIBs). These are expected to quickly pass from laboratory-scale use to in-line monitoring apphcations for 200-mm wafers (32). 

Three scanning probe techniques are described in more detail below the scanning tunneling microscope, the atomic force microscope, and the friction force microscope. 

Our laboratories are currently equipped with three UHV Omicron microscopes, a variable-temperature scanning tunneling microscope (STM), a room-temperature atomic force microscope (AFM)/STM, and a low-temperature liquid helium bath cryostat STM, all of which are currently driven by Omicron Scala software and electronics. 

However, the transition from nanoscience to nanotechnology had to come from yet a concnrrent innovation in tools used by scientists. This was the invention of the first scanning tunneling microscope (STM) in 1981 [60], followed by the invention of the atomic force microscope (ATM) in 1986 [61]. 

STM (scanning tunneling microscope) and AFM (atomic force microscope)... 

The field ion microscope is perhaps the simplest of all atomic resolution microscopes as far as mechanical and electrical designs are concerned. The atomic resolution microscopes, at the present time, include also different types of electron microscopes,1 the scanning tunneling microscope (STM)2 and the atomic force microscope (AFM)2 Before we discuss the general design features of the field ion microscope it is perhaps worthwhile to describe the first field ion microscope,3 and a very simple FIM4 which can be constructed in almost any laboratory. The first field ion microscope, shown in Fig. 3.1, is essentially a field emission microscope5 except that it is now equipped with a palladium tube with... 

The resolution of the atomic force microscope depends on the radius of curvature of the tip and its chemical condition. Solid crystal surfaces can often be imaged with atomic resolution. At this point, however, we need to specify what Atomic resolution is. Periodicities of atomic spacing are, in fact, reproduced. To resolve atomic defects is much more difficult and usually it is not achieved with the atomic force microscope. When it comes to steps and defects the scanning tunneling microscope has a higher resolution. On soft, deformable samples, e.g. on many biological materials, the resolution is reduced due to mechanical deformation. Practically, a real resolution of a few nm is achieved. 

Surface diffraction experiments have to be done in UHV. Otherwise the surfaces are covered with a monolayer of adsorbed molecules. At this point the reader might ask why do we not have to use UHV in scanning tunneling or the atomic force microscope In both techniques the tip penetrates through the surface contamination layer. In the scanning tunneling microscope it is often just invisible because contamination layers are usually not good conductors. In... 

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