Scanning Helium Ion Microscope
Encyclopedia
A Scanning Helium Ion Microscope (SHIM or HeIM) is a new imaging technology based on a scanning helium
ion beam. This technology has several advantages over the traditional scanning electron microscope
(SEM). Due to the very high source brightness, and the short De Broglie wavelength of the helium ions, which is inversely proportional their momentum, it is possible to obtain qualitative data not achievable with conventional microscopes which use photons or electrons as the emitting source. As the helium ion beam interacts with the sample, it does not suffer from a large excitation volume, and hence provides sharp images on a wide range of materials. Compared to a SEM, the secondary electron yield is quite high, allowing for imaging with currents as low as 1 femtoamp. The detectors provide information-rich images which offer topographic, material, crystallographic, and electrical properties of the sample. In contrast to other ion beams, there is no discernible sample damage due to relatively light mass of the helium ion.
Since 2007 this technology is commercialized and instruments have been shipped to customers. A surface resolution of 0.24 nanometers has been demonstrated.
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
ion beam. This technology has several advantages over the traditional scanning electron microscope
Scanning electron microscope
A scanning electron microscope is a type of electron microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern...
(SEM). Due to the very high source brightness, and the short De Broglie wavelength of the helium ions, which is inversely proportional their momentum, it is possible to obtain qualitative data not achievable with conventional microscopes which use photons or electrons as the emitting source. As the helium ion beam interacts with the sample, it does not suffer from a large excitation volume, and hence provides sharp images on a wide range of materials. Compared to a SEM, the secondary electron yield is quite high, allowing for imaging with currents as low as 1 femtoamp. The detectors provide information-rich images which offer topographic, material, crystallographic, and electrical properties of the sample. In contrast to other ion beams, there is no discernible sample damage due to relatively light mass of the helium ion.
Since 2007 this technology is commercialized and instruments have been shipped to customers. A surface resolution of 0.24 nanometers has been demonstrated.
External links
- Carl Zeiss SMT – Nano Technology Systems Division: ORION He-Ion microscope
- Microscopy Today, Volume 14, Number 14, July 2006: An Introduction to the Helium Ion Microscope
- How New Helium Ion Microscope Measures Up - ScienceDaily