Interdisciplinary Resource Center for Nanotechnology

...going for nano

Scanning ion helium microscope Zeiss ORION

Print

Low beam convergence provides high focus depth.

Helium ion beam shows very little diffraction influence because of He ions mass. Since the helium ion beam is much less affected by diffraction, than the electron beam, it can be focused to a smaller probe, enabling sub-nanometer resolution. Features of ions scattering result in high material contrast.

Another feature of helium ion microscope is low beam current, three orders of magnitude lower than typical SEM beam current. It allows to prevent destruction of sample caused by ion beam and  to reduce charging of non-conductive specimen surface.

Flood gun charge compensation system allows to work with insulator samples without resolution deterioration.

Parameters of scanning ion microscope Zeiss ORION:

Acceleration voltage 10-40 kV.

Ion beam current: 0,1-100 pA.

Sharpness edge resolution : 0,6 nm.

Backscattered ions detector.

Ion source is tungsten tip which field ionithation of helium atoms takes place on. Scanning field ion microscopy mode allows to observe sourse with atomic resolution to form a trimer and to adjust it mechanically. One of trimers atoms (in the centre of frame) is used as source for beam formation.

Backscattered ions detection (right image) allows to get high material contrast and to observe grains orientation.

Low beam convergence provides high focus depth, higher than typical SEM focus depth.

Images, obtained in IRC for Nanotechnology.