Charging microscopy and cathodoluminescence imaging of semi-insulating gallium arsenide

1986 ◽  
Vol 44 ◽  
pp. 816-817
Author(s):  
T.C. Sheu ◽  
S. Myhajlenko ◽  
D. Davito ◽  
J.L. Edwards ◽  
R. Roedel ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Secondary Electron ◽  
Crystal Defects ◽  
Device Performance ◽  
Gaas Wafer ◽  
Surface Charging ◽  
Gaas Substrates ◽  
Voltage Contrast ◽  
Cathodoluminescence Imaging ◽  
Scanning Electron

Liquid encapsulated Czochralski (LEC) semi-insulating (SI) GaAs has applications in integrated optics and integrated circuits. Yield and device performance is dependent on the homogeniety of the wafers. Therefore, it is important to characterise the uniformity of the GaAs substrates. In this respect, cathodoluminescence (CL) has been used to detect the presence of crystal defects and growth striations. However, when SI GaAs is examined in a scanning electron microscope (SEM), there will be a tendency for the surface to charge up. The surface charging affects the backscattered and secondary electron (SE) yield. Local variations in the surface charge will give rise to contrast (effectively voltage contrast) in the SE image. This may be associated with non-uniformities in the spatial distribution of resistivity. Wakefield et al have made use of “charging microscopy” to reveal resistivity variations across a SI GaAs wafer. In this work we report on CL imaging, the conditions used to obtain “charged” SE images and some aspects of the contrast behaviour.

Linewidth measurement using the low voltage SEM

1986 ◽  
Vol 44 ◽  
pp. 652-653
Author(s):  
M.G. Rosenfield
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Secondary Electron ◽  
Low Voltage ◽  
Fabrication Process ◽  
Critical Dimensions ◽  
Linewidth Measurement ◽  
Threshold Technique ◽  
Scanning Electron

Minimum feature sizes in experimental integrated circuits are approaching 0.5 μm and below. During the fabrication process it is usually necessary to be able to non-destructively measure the critical dimensions in resist and after the various process steps. This can be accomplished using the low voltage SEM. Submicron linewidth measurement is typically done by manually measuring the SEM micrographs. Since it is desirable to make as many measurements as possible in the shortest period of time, it is important that this technique be automated.Linewidth measurement using the scanning electron microscope is not well understood. The basic intent is to measure the size of a structure from the secondary electron signal generated by that structure. Thus, it is important to understand how the actual dimension of the line being measured relates to the secondary electron signal. Since different features generate different signals, the same method of relating linewidth to signal cannot be used. For example, the peak to peak method may be used to accurately measure the linewidth of an isolated resist line; but, a threshold technique may be required for an isolated space in resist.

Circuit Tracing on Integrated Circuit Using FIB Passive Voltage Contrast Effect

2015 ◽  
Author(s):  
Alexander Sorkin ◽  
Chris Pawlowicz ◽  
Alex Krechmer ◽  
Michael W. Phaneuf
Keyword(s):  
Electron Microscope ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Metal Layer ◽  
Database System ◽  
Conventional Procedure ◽  
Sem Imaging ◽  
Voltage Contrast ◽  
Scanning Electron ◽  
Graphic Database

Abstract Competitive circuit analysis of Integrated Circuits (ICs) is one of the most challenging types of analysis. It involves multiple complex IC die de-processing/de-layering steps while keeping precise planarity from metal layer to metal layer. Each step is followed by Scanning Electron Microscope (SEM) imaging together with mosaicking that subsequently passes through an image recognition and Graphic Database System (GDS) conversion process. This conventional procedure is quite time and resource consuming. The current paper discusses and demonstrates a new inventive methodology of circuit tracing on an IC using known FIB Passive Voltage Contrast (PVC) effects [1]. This technique provides significant savings in time and resources.

Failure Analysis of FinFET Circuitry at GHz Speeds Using Voltage-Contrast and Stroboscopic Techniques on a Scanning Electron Microscope

2019 ◽  
Author(s):  
James Vickers ◽  
Seema Somani ◽  
Blake Freeman ◽  
Pete Carleson ◽  
Lubomír Tùma ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Electrical Activity ◽  
Failure Analysis ◽  
Integrated Circuit ◽  
Contrast Mechanism ◽  
Voltage Contrast ◽  
Working Device ◽  
Scanning Electron

Abstract We report on using the voltage-contrast mechanism of a scanning electron microscope to probe electrical waveforms on FinFET transistors that are located within active integrated circuits. The FinFET devices are accessed from the backside of the integrated circuit, enabling electrical activity on any transistor within a working device to be probed. We demonstrate gigahertz-bandwidth probing at 10-nm resolution using a stroboscopic pulsed electron source.

The Morphology and Cathodoluminescence of GaN Thin Films

1996 ◽  
Vol 1 ◽  
Author(s):  
Carol Trager-Cowan ◽  
P. G. Middleton ◽  
K. P. O'Donnell
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Molecular Beam ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Cathodoluminescence Spectroscopy ◽  
Cathodoluminescence Imaging ◽  
Scanning Electron

In this paper we compare gallium nitride (GaN) films grown by molecular beam epitaxy on sapphire (Al2O3), gallium arsenide (GaAs (111)B) and lithium gallate (LiGaO2) substrates. Atomic force microscopy, scanning electron microscopy, cathodoluminescence imaging and cathodoluminescence spectroscopy are used to characterise the films. From growth runs carried out to date, GaN films on GaAs substrates exhibit the best surface uniformity and the cleanest luminescence.

Microchannel plate-based detection systems for Scanning Electron Microscopy

1989 ◽  
Vol 47 ◽  
pp. 726-727
Author(s):  
J. Gray ◽  
D. Corey ◽  
G. Ellis ◽  
R. Sokol
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Integrated Circuits ◽  
Low Voltage ◽  
Microchannel Plate ◽  
Destructive Testing ◽  
Detection Systems ◽  
Voltage Contrast ◽  
Non Destructive ◽  
Scanning Electron

MicroChannel plate (MCP)-based detectors have distinct advantages over scintillator or solid-state types for low voltage applications in scanning electron microscopy. MCPs exhibit excellent detection efficiencies for electrons of energy down to lOOev and are usable at even lower energies, making them ideal detection elements for non-destructive testing and low voltage contrast measurements on integrated circuits. Major advantages of MCP-based detection systems include the following

The Effect of the Indenter Orientation on the Formation of Dislocations and Cracks in (0001) GaN Bulk Crystals

2012 ◽  
Vol 725 ◽  
pp. 67-70
Author(s):  
Ingmar Ratschinski ◽  
Hartmut S. Leipner ◽  
Frank Heyroth ◽  
Wolfgang Fränzel ◽  
Gunnar Leibiger ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Room Temperature ◽  
Secondary Electron ◽  
Orientation Effect ◽  
Bulk Crystals ◽  
Vickers Indenter ◽  
Cathodoluminescence Imaging ◽  
Scanning Electron

(0001) GaN bulk crystals with a thickness of 3.4 mm and a density of in-grown dislocations of 3.5·106cm-2have been deformed at room temperature using a Vickers indenter at two different sample orientations in relation to the indenter. Dislocations and cracks at the indentations were investigated by means of optical microscopy and scanning electron microscopy in secondary electron contrast and cathodoluminescence imaging. The arrangement of indentation-induced dislocations and cracks is described and the orientation effect is discussed.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

Edge Penetration Effects in the Low-Loss Electron Image in the SEM

1988 ◽  
Vol 46 ◽  
pp. 202-203
Author(s):  
Oliver C. Wells
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Beam Energy ◽  
Secondary Electron ◽  
Sharp Edge ◽  
Beam Diameter ◽  
Low Loss ◽  
Additional Information ◽  
Electron Image ◽  
Scanning Electron

The low-loss electron (LLE) image in the scanning electron microscope (SEM) is useful for the study of uncoated photoresist and some other poorly conducting specimens because it is less sensitive to specimen charging than is the secondary electron (SE) image. A second advantage can arise from a significant reduction in the width of the “penetration fringe” close to a sharp edge. Although both of these problems can also be solved by operating with a beam energy of about 1 keV, the LLE image has the advantage that it permits the use of a higher beam energy and therefore (for a given SEM) a smaller beam diameter. It is an additional attraction of the LLE image that it can be obtained simultaneously with the SE image, and this gives additional information in many cases. This paper shows the reduction in penetration effects given by the use of the LLE image.

Failure Analysis With the Scanning Electron Microscope

1972 ◽  
Vol 30 ◽  
pp. 482-483
Author(s):  
John R. Devaney
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
High Reliability ◽  
Military Applications ◽  
Small Structure ◽  
Useful Life ◽  
Insight Into ◽  
Scanning Electron

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.

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