U.S. Philips Corporation

Dirk E Van Dijck

Alan F De Jong

A method of autotuning an electron microscope by producing a series of images of the object to be examined, using a defined tilt of the electron beam in a different direction for each respective image. The images are thereby displaced relative to one another. Each image is then decomposed into a linear and a non-linear component thereof, and the linear image components are separated by Fourier filtering. The relative displacements of a number of the linear image components relative to each other are measured, and the measured displacement values are combined to derive autotuning parameters for the electron microscope.

Method for autotuning of an electron microscope, and an electron

A high-resolution electron microscope (1) comprising a detection system (11), an image processing system (13) and an effective electron source (3) ensuring a comparatively small thermal energy spread of the electrons to be emitted is suitable for executing a method for directly deriving amplitude and phase information of an object (17) in the form of an electron wave function .phi.. To this end, a number of images of an object (17) are recorded by means of a high-resolution electron microscope (1) in image planes (19) with defocus values which differ only slightly. Thus, a substantially continuous series of images is formed as a function of the defocus value, resulting in a substantially three-dimensional image area. A quasi-three-dimensional Fourier transformation is performed thereon in order to separate linear and non-linear image information for the reconstruction of the electron wave function. In practice a two-dimensional Fourier transformation is applied to the recorded images which are subsequently multiplied by a complex weighting factor, followed by summing. As a result, the linear information is concentrated on two spheres in the Fourier space, the non-linear information being uniformly distributed across the Fourier space.

Growing community of inventors

Aartselaar, Belgium

Dirk E Van Dijck