Evaluation of the long-term stability of critical-dimension measurement scanning electron microscopes using a calibration standard

1997 ◽  
Vol 15 (6) ◽  
pp. 2177 ◽  
Author(s):  
Fumio Mizuno
Keyword(s):  
Critical Dimension ◽  
Calibration Standard ◽  
Term Stability ◽  
Long Term Stability ◽  
Dimension Measurement ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

A study of robust critical dimension measurement algorithm for use in differing scanning electron microscope configurations in the measurement of submicron semiconductor geometries

1991 ◽  
Vol 49 ◽  
pp. 882-883
Author(s):  
Terrence W. Reilly ◽  
Louis G. Dawang
Keyword(s):  
Critical Dimension ◽  
Confocal Laser ◽  
Measurement Instruments ◽  
Dimension Measurement ◽  
Measurement Algorithm ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Two Machines ◽  
Development Group ◽  
Scanning Electron

Within semiconductor companies, there can be many different critical dimension (CD) measurement instruments. They could be optical, electrical, confocal laser, or scanning electron microscopes (SEM). Often times, they are not only different configurations, but different brands as well. There is a great need for a measurement algorithm that has the ability to deliver the same measurement between two machines. It is possible the development group within a semiconductor company would use an SEM with expanded capabilities when compared to the production group's SEM. If this is the case, the ability to use a measurement algorithm that is impervious to the influence different microscope designs have on the signal output used for measurement would enhance system matching. One would believe that two identical CD systems should produce nearly the same measurement. However, when two totally different systems are compared, only a robust algorithm would give good machine to machine matching of measurements.

Current State of Biological High-Resolution Scanning Electron Microscopy

1988 ◽  
Vol 46 ◽  
pp. 180-181 ◽  
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Performance ◽  
Low Voltage ◽  
Backscattered Electrons ◽  
Lens Position ◽  
Low Voltage Operation ◽  
Signal Collection ◽  
Probe Size ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

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).

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

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 ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

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.

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