SEM Equipment Capabilities Evaluated for Sub-Half Micron Semiconductor Applications

Abstract Evaluation of Scanning Electron Microscopes (SEMs) was initiated for the purpose of purchasing a SEM that would improve the productivity of scanning electron microscopy during the cycle of analysis and deprocessing of semiconductor devices in a failure analysis lab. In addition to the need for high image resolution at low electron acceleration voltages, an accurate motorized stage is a major evaluation factor. It is necessary for the analyst to drive directly to a known location such as a memory cell with a high assurance that the site of interest was found. There are two main areas of focus in this paper. First, our SEM evaluation methodology will be presented along with the results of our evaluation. Second, the technology associated with motorized stages will be discussed in light of our requirements for a motorized, highly accurate stage. As a byproduct of this evaluation, this paper is presented so as to push the SEM industry to offer a SEM with an accurate stage for subhalfmicron products at reasonable cost.

Microscopy in the Real World - Instrumentation Requirements

Microscopy and Microanalysis ◽

10.1017/s1431927600028695 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 524-525

Author(s):

Brian Cunningham

Keyword(s):

Electron Microscopy ◽

High Performance ◽

Ease Of Use ◽

User Requirements ◽

End User ◽

Transmission Electron ◽

Reasonable Cost ◽

Electron Microscopes ◽

In the last two decades, microscopy, in particular transmission electron microscopy, has moved from the research environment into industry. As such, the user requirements of the microscopes have changed. Previously, users required the highest performance in all aspects of microscopy e.g. imaging, analytical capabilities, with little regard to other factors. Today, additional requirements are being placed on areas such as ease of use, reliability, high throughput, expanded sample requirements, and networking capabilities. However, the “high performance” aspects of the instrumentation are still a high priority to the end user. These user requirements cause microscope manufacturers a dilemma in many instances. It is not always possible to provide the “new” requirements while still maintaining the high performance of the instruments, at a “reasonable” cost. An example is the large sample requirements in scanning electron microscopes. Large stages are inherently more prone to vibration than smaller stages, and therefore adversely affect resolution.

Field of View and Image Distortion : A Review of Low Magnification Imaging In the Environmental and Conventional Scanning Electron Microscopes (SEM)

Microscopy and Microanalysis ◽

10.1017/s143192760001285x ◽

1997 ◽

Vol 3 (S2) ◽

pp. 1193-1194

Author(s):

Brendan J. Griffin

Keyword(s):

Electron Microscopy ◽

Field Of View ◽

Depth Of Field ◽

Aperture Size ◽

Sem Image ◽

Electron Microscopes ◽

Working Distance ◽

Most scanning electron microscopy is performed at low magnification; applications utilising the large depth of field nature of the SEM image rather than the high resolution aspect. Some environmental SEMs have a particular limitation in that the field of view is restricted by a pressure limiting aperture (PLA) at the beam entry point of the specimen chamber. With the original ElectroScan design, the E-3 model ESEM utilised a 500 urn aperture which gave a very limited field of view (∼550um diameter at a 10mm working distance [WD]). An increase of aperture size to ∼lmm provided an improved but still unsatisfactory field of view. The simplest option to increase the field of view in an ESEM was noted to be a movement of the pressure and field, limiting aperture back towards the scan coils1. This approach increased the field of view to ∼2mm, at a 10mm WD. A commercial low magnification device extended this concept and indicated the attainment of conventional fields of view.

Series in Microscopy in Materials Science: Electron Microscopy in Heterogeneous Catalysis. P.L. Gai and E.D. Boyes. Series Editors: B. Cantor, M.J. Goringe, and J.A Eades. Institute of Physics Publishing, Bristol, England; 2003, 233 pages (Hardback). ISBN 0-7503-0809-5

Microscopy and Microanalysis ◽

10.1017/s1431927603030526 ◽

2003 ◽

Vol 9 (4) ◽

pp. 368-368

Author(s):

Hiroyasu Saka

Keyword(s):

Electron Microscopy ◽

Heterogeneous Catalysis ◽

Materials Science ◽

The Past ◽

Dynamic Observation ◽

Electron Microscopes ◽

This book deals with in situ dynamic observation and analysis of heterogeneous catalysis using environmental cells (EC) in transmission (TEM) and scanning electron microscopes (SEM). In general, it is based on outstanding and unique works carried out by the authors themselves over the past three decades, who pioneered this key enabling area of materials science.

Scanning Electron Microscopic Studies on the Tegument of Trematodes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050925 ◽

1974 ◽

Vol 32 ◽

pp. 182-183

Author(s):

J. E. Ubelaker ◽

R. D. Specian ◽

V. F. Allison

Keyword(s):

Electron Microscopy ◽

Host Response ◽

Electron Microscopic ◽

Scanning Electron Microscopic ◽

Microscopic Studies ◽

Physiological Demands ◽

Electron Microscopes ◽

Among the parasitic flatworms, only members of the trematoda have exploited nearly every conceivable niche. Since physiological demands in each habitat present special problems in eluding the host response as well as obtaining nourishment the surface epithelia of such organisms warrant special attention. To gain an appreciation of tegumental diversity in the trematoda, representative trematodes from numerous habitats in their respective hosts were examined by scanning electron microscopySpecimens were collected from natural infections, fixed in paraformaldehyde and dehydrated in alcohol. Ethanol was exchanged with amyl acetate prior to CO2 drying in a Denton DCP-1 critical point dryer. The dried specimens were mounted on metal holders, outgassed and rotary coated with gold-palladium. These were then examined with the ISI Mini-SEM and AMR 1000 scanning electron microscopes.

An Innovative Method for Imaging and Chemical Analysis of Wet Samples in Scanning Electron Microscopes

Microscopy Today ◽

10.1017/s1551929500053591 ◽

2005 ◽

Vol 13 (4) ◽

pp. 10-15 ◽

Cited By ~ 2

Author(s):

Irit Ruach-Nir

Keyword(s):

Biological Sciences ◽

Electron Microscopy ◽

High Resolution ◽

Chemical Analysis ◽

Sample Processing ◽

Innovative Method ◽

Electron Microscopes ◽

Electron microscopy (EM) of fully wet samples is a valuable tool for studies in the material, medical and biological sciences. In order to appreciate the natural structures of tissues or materials they should be examined in their native wet state, as opposed to a dry form that incorporates artifacts of sample processing. Viewing and analyzing wet samples at high resolution has undergone a significant improvement only recently due to the innovative WETSEMTM technology developed by QuantomiX.

Use of the Cryoscan apparatus for observation of freeze-fractured planes of a sensitive Quebec clay in scanning electron microscopy

Canadian Geotechnical Journal ◽

10.1139/t82-011 ◽

1982 ◽

Vol 19 (1) ◽

pp. 111-114 ◽

Cited By ~ 56

Author(s):

Pierre Delage ◽

Daniel Tessier ◽

Martine Marcel-Audiguier

Keyword(s):

Electron Microscopy ◽

Freeze Fracture ◽

Fracture Planes ◽

Sensitive Clay ◽

Electron Microscopes ◽

The cryoscan is an apparatus equipping the JEOL scanning electron microscopes, and allowing the observation of freeze-fracture planes of samples whose temperature is maintained below −100 °C. The application of this method to a sensitive clay from Quebec shows an aggregated structure, the aggregates being separated by 1 μm size voids.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081279 ◽

1978 ◽

Vol 36 (2) ◽

pp. 82-83 ◽

Cited By ~ 1

Author(s):

Nakazo Watari ◽

Yasuaki Hotta ◽

Yoshio Mabuchi

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Fine Structure ◽

Light Microscopy ◽

Thin Sections ◽

Transmission Electron ◽

Identical Cell ◽

Electron Microscopes ◽

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Current State of Biological High-Resolution Scanning Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102985 ◽

1988 ◽

Vol 46 ◽

pp. 180-181 ◽

Cited By ~ 1

Author(s):

Klaus-Ruediger Peters

Keyword(s):

High Performance ◽

Low Voltage ◽

Backscattered Electrons ◽

Lens Position ◽

Low Voltage Operation ◽

Signal Collection ◽

Probe Size ◽

Electron Microscopes ◽

A new generation of high performance field emission scanning electron microscopes (FSEM) is now commercially available (JEOL 890, Hitachi S 900, ISI OS 130-F) characterized by an "in lens" position of the specimen where probe diameters are reduced and signal collection improved. Additionally, low voltage operation is extended to 1 kV. Compared to the first generation of FSEM (JE0L JSM 30, Hitachi S 800), which utilized a specimen position below the final lens, specimen size had to be reduced but useful magnification could be impressively increased in both low (1-4 kV) and high (5-40 kV) voltage operation, i.e. from 50,000 to 200,000 and 250,000 to 1,000,000 x respectively.At high accelerating voltage and magnification, contrasts on biological specimens are well characterized1 and are produced by the entering probe electrons in the outmost surface layer within -vl nm depth. Backscattered electrons produce only a background signal. Under these conditions (FIG. 1) image quality is similar to conventional TEM (FIG. 2) and only limited at magnifications >1,000,000 x by probe size (0.5 nm) or non-localization effects (%0.5 nm).

Low-voltage, high-resolution scanning electron microscopy of polymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127037 ◽

1987 ◽

Vol 45 ◽

pp. 466-467 ◽

Cited By ~ 1

Author(s):

S. J. Krause ◽

W.W. Adams ◽

S. Kumar ◽

T. Reilly ◽

T. Suziki

Keyword(s):

Electron Microscopy ◽

Low Voltage ◽

Chromatic Aberration ◽

Image Resolution ◽

Resolution Limit ◽

Crossover Point ◽

New Generation ◽

Beam Damage ◽

Scanning electron microscopy (SEM) of polymers at routine operating voltages of 15 to 25 keV can lead to beam damage and sample image distortion due to charging. Imaging polymer samples with low accelerating voltages (0.1 to 2.0 keV), at or near the “crossover point”, can reduce beam damage, eliminate charging, and improve contrast of surface detail. However, at low voltage, beam brightness is reduced and image resolution is degraded due to chromatic aberration. A new generation of instruments has improved brightness at low voltages, but a typical SEM with a tungsten hairpin filament will have a resolution limit of about 100nm at 1keV. Recently, a new field emission gun (FEG) SEM, the Hitachi S900, was introduced with a reported resolution of 0.8nm at 30keV and 5nm at 1keV. In this research we are reporting the results of imaging coated and uncoated polymer samples at accelerating voltages between 1keV and 30keV in a tungsten hairpin SEM and in the Hitachi S900 FEG SEM.

Observation of GaAs/AlAs Superlattice Structures in both Secondary and Backscattcred Electron Imaging Modes with an Ultrahigh Resolution Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010018077x ◽

1990 ◽

Vol 48 (1) ◽

pp. 404-405

Author(s):

K. Ogura ◽

A. Ono ◽

S. Franchi ◽

P.G. Merli ◽

A. Migliori

Keyword(s):

Gaas Layer ◽

Objective Lens ◽

Superlattice Structure ◽

Backscattered Electron ◽

Instrumental Resolution ◽

Electron Microscopes ◽

Superlattice Structures ◽

Electron Imaging ◽

In the last few years the development of Scanning Electron Microscopes (SEM), equipped with a Field Emission Gun (FEG) and using in-lens specimen position, has allowed a significant improvement of the instrumental resolution . This is a result of the fine and bright probe provided by the FEG and by the reduced aberration coefficients of the strongly excited objective lens. The smaller specimen size required by in-lens instruments (about 1 cm, in comparison to 15 or 20 cm of a conventional SEM) doesn’t represent a serious limitation in the evaluation of semiconductor process techniques, where the demand of high resolution is continuosly increasing. In this field one of the more interesting applications, already described (1), is the observation of superlattice structures.In this note we report a comparison between secondary electron (SE) and backscattered electron (BSE) images of a GaAs / AlAs superlattice structure, whose cross section is reported in fig. 1. The structure consist of a 3 nm GaAs layer and 10 pairs of 7 nm GaAs / 15 nm AlAs layers grown on GaAs substrate. Fig. 2, 3 and 4 are SE images of this structure made with a JEOL JSM 890 SEM operating at an accelerating voltage of 3, 15 and 25 kV respectively. Fig. 5 is a 25 kV BSE image of the same specimen. It can be noticed that the 3nm layer is always visible and that the 3 kV SE image, in spite of the poorer resolution, shows the same contrast of the BSE image. In the SE mode, an increase of the accelerating voltage produces a contrast inversion. On the contrary, when observed with BSE, the layers of GaAs are always brighter than the AlAs ones , independently of the beam energy.