Beam shaping techniques in scanning electron lithography systems

A variety of beam shaping techniques are described which we have developed to overcome writing speed limitations inherent to the serial exposure of scanning electron beam lithography systems. We will present experimental results demonstrating the technical feasibility of the various shaping techniques. Figure 1 illustrates E-beam pattern generation by a Gaussian round beam and various shaped beam configurations. The SEM-type, Gaussian round beam exposes one image point at a time. The size of the beam spot is identical with the spatial resolution of the system and is typically 4 to 5 times smaller than the minimum pattern features. For shaped-beam systems, the spatial resolution given by the edge slope of the beam profile is decoupled from the size and shape of the beam spot. Consequently, a plurality of image points can be projected in parallel without loss of resolution. This combination of scanning and projection techniques provides a fast exposure rate without sacrificing the flexibility of computer-controlled pattern generation.

Download Full-text

Micropatterning of Permalloy Films by Electron Lithography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092207 ◽

1976 ◽

Vol 34 ◽

pp. 448-449

Author(s):

J. K. Maurin

Keyword(s):

Electron Beam ◽

Subsequent Development ◽

Electron Optical System ◽

Microelectronic Device ◽

Magnetic Bubble ◽

Control Beam ◽

Photosensitive Material ◽

Direct Exposure ◽

Electron Lithography ◽

Scanning Electron

Conductor, resistor, and dielectric patterns of microelectronic device are usually defined by exposure of a photosensitive material through a mask onto the device with subsequent development of the photoresist and chemical removal of the undesired materials. Standard optical techniques are limited and electron lithography provides several important advantages, including the ability to expose features as small as 1,000 Å, and direct exposure on the wafer with no intermediate mask. This presentation is intended to report how electron lithography was used to define the permalloy patterns which are used to manipulate domains in magnetic bubble memory devices.The electron optical system used in our experiment as shown in Fig. 1 consisted of a high resolution scanning electron microscope, a computer, and a high precision motorized specimen stage. The computer is appropriately interfaced to address the electron beam, control beam exposure, and move the specimen stage.

Download Full-text

Formalism for the determination of intermediate stress gradients using X-ray diffraction

Journal of Applied Crystallography ◽

10.1107/s0021889809004300 ◽

2009 ◽

Vol 42 (2) ◽

pp. 192-197 ◽

Cited By ~ 3

Author(s):

Thomas Gnäupel-Herold

Keyword(s):

Lattice Strain ◽

Narrow Line ◽

X Ray Diffraction ◽

Beam Spot ◽

Strain Measurements ◽

One Dimensional ◽

X Ray ◽

Stress Gradients ◽

Shaped Beam

A method is outlined that allows the determination of one-dimensional stress gradients at length scales greater than 0.2 mm. By using standard four-circle X-ray diffractometer equipment and simple aperture components, length resolutions down to 0.05 mm in one direction can be achieved through constant orientation of a narrow, line-shaped beam spot. Angle calculations are given for the adjustment of goniometer angles, and for the effective azimuth and tilt of the scattering vector for general angle settings in a four-circle goniometer. The latter is necessary for the computation of stresses from lattice strain measurements.

Download Full-text

High-Spatial-Resolution Cathodoluminescence Measurement of InGaN

MRS Proceedings ◽

10.1557/proc-743-l3.52 ◽

2002 ◽

Vol 743 ◽

Author(s):

Hisashi Kanie ◽

Hiroaki Okado ◽

Takaya Yoshimura

Keyword(s):

Electron Microscope ◽

Energy Level ◽

Spatial Resolution ◽

Diffusion Length ◽

High Spatial Resolution ◽

Lower State ◽

Measuring Apparatus ◽

Bulk Crystals ◽

Recombination Centers ◽

Scanning Electron

ABSTRACTThis paper described observation of cathodoluminescence (CL) of microcrystalline InGaN bulk crystals under a scanning electron microscope (SEM) with a high-spatial-resolution (HR) CL measuring apparatus. HR-CL spectra from facets of InGaN crystals vary from facet to facet and are single peaked. Histogram analysis of the CL peak positions of HR spectra from the facets of the crystals in the area scanned during a low-resolution CL measurement shows a two-peaked form with comparable peak wavelengths. The diffusion length of a generated electron- ho le pair or an exciton from the recombination centers with a higher-energy-level state to that with a lower state is estimated to be 500 nm at the longest by the comparison of two monochromatic HR-CL images of adjoining facets.

Download Full-text

Enhanced method for High Spatial Resolution surface imaging and analysis of fungal spores using Scanning Electron Microscopy

Scientific Reports ◽

10.1038/s41598-018-34629-8 ◽

2018 ◽

Vol 8 (1) ◽

Author(s):

Gopal Venkatesh Babu ◽

Palani Perumal ◽

Sakthivel Muthu ◽

Sridhar Pichai ◽

Karthik Sankar Narayan ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Spatial Resolution ◽

High Spatial Resolution ◽

Fungal Spores ◽

Surface Imaging ◽

Scanning Electron

Download Full-text

Computer Controlled Scanning Electron Microscopy (CCSEM) Analysis of Straw Ash

Impact of Mineral Impurities in Solid Fuel Combustion ◽

10.1007/0-306-46920-0_33 ◽

2005 ◽

pp. 441-453

Author(s):

Henning Sund Sørensen

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Computer Controlled ◽

Straw Ash ◽

Scanning Electron

Download Full-text

Evaluation of computer-controlled SEM in the study of metal-contaminated soils

Mineralogical Magazine ◽

10.1180/0026461036720096 ◽

2003 ◽

Vol 67 (2) ◽

pp. 219-231 ◽

Cited By ~ 10

Author(s):

H. W. Langmi ◽

J. Watt

Keyword(s):

Electron Microscopy ◽

Heavy Metals ◽

Contaminated Soils ◽

X Ray ◽

Computer Controlled ◽

Weathering Crusts ◽

Individual Particles ◽

Element Mapping ◽

Scanning Electron

Computer-controlled scanning electron microscopy (CCSEM) has been assessed for the determination of form and size distribution of heavy metals in urban contaminated soils. Metal distributions within individual particles were determined using X-ray element mapping. The sites selected for study were (1) around a landfill site, previously a colliery in Wolverhampton, UK and (2) a private garden adjacent to a railway in Nottingham, UK. Backscattered thresholding techniques were used to isolate the Pb-containing categories. The classification results for both Wolverhampton and Nottingham soils were generally similar but more Pb-containing classes were observed for the Nottingham samples when a comparison was made between results of the same size fractions. However, difficulties with the technique arose when particles showing chemically similar weathering crusts were assigned to the same class, despite having different internal compositions. The CCSEM data therefore need to be interpreted with caution and their application limited to situations in which particle internal complexity is not an issue.

Download Full-text