Title:
The phase plate for TEM
Document Type and Number:
Japanese Patent JP6027942
Kind Code:
B2
Abstract:
The invention relates to a phase plate for use in an electron microscope, more specifically to a Zernike type phase plate. Such a phase plate comprises a central hole, and a thin film causing a phase shift of the electrons passing through said film. This phase shift causes the CTF to change from a sine-like function to a cosine-like function. A disadvantage of this prior art type phase plate is that many electrons are scattered from the beam by the phase plate. Another disadvantage of this prior art phase plate is that for a range of frequencies, where the cosine-like function shows a minimum, the use of a phase plate actually degrades the CTF as the sine-like function would show a maximum. The phase plate according to the invention is therefore equipped with a film in the form of an annulus (32), carried by a much thinner film (30). As a result only in a small spatial frequency range (for low frequencies) the phase is changed (and thus the CTF), and for other spatial frequencies the phase shift is negligible, and thus the CTF 300 remains unchanged. Due to the much smaller thickness of the carrier film 30 the scattering is negligible as well.
Inventors:
Bart buies
Application Number:
JP2013102688A
Publication Date:
November 16, 2016
Filing Date:
May 15, 2013
Export Citation:
Assignee:
FEI COMPANY
International Classes:
H01J37/295; H01J37/26
Domestic Patent References:
| JP2003217498A | ||||
| JP2009506485A | ||||
| JP2006162805A |
Other References:
Mueller K,Phase plates for electron microscopes,OPTIK,1976年 1月,vol.45, no.1 January 1976,pages 73-85
Danev R. et. al,Practical factors affecting the performance of a thin-film phase plate for transmission electron microscopy,Ultramicroscopy,2009年 3月,vol. 109, no.4, March 2009,pages 312-325
Kuniaki Nagayama,Development of phase plates for electron microscopes and their biological application,European Biophysics Journal,2008年 2月,vol. 37,no. 4, February 2008,pages 345-358
Lentzen M.,The turning of a Zernike phase plate with defocus and variable spherical aberration and its use in HRTEM imaging,Ultramicroscopy,2004年 1月,vol.99, January 2004,pages 211-220
Danev R. et. al,Practical factors affecting the performance of a thin-film phase plate for transmission electron microscopy,Ultramicroscopy,2009年 3月,vol. 109, no.4, March 2009,pages 312-325
Kuniaki Nagayama,Development of phase plates for electron microscopes and their biological application,European Biophysics Journal,2008年 2月,vol. 37,no. 4, February 2008,pages 345-358
Lentzen M.,The turning of a Zernike phase plate with defocus and variable spherical aberration and its use in HRTEM imaging,Ultramicroscopy,2004年 1月,vol.99, January 2004,pages 211-220
Attorney, Agent or Firm:
Tadashige Ito
Tadahiko Ito
Shinsuke Onuki
Tadahiko Ito
Shinsuke Onuki
Previous Patent: A metal joined part article and the jointing material for metal
Next Patent: JPS6027943
Next Patent: JPS6027943