The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
An arrangement is described for compensating for backscatter current variation, due mainly to plate-to-plate variations in material thickness, in E-beam mask inspection tools.
English (United States)
This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately
67% of the total text.
Page 1 of 2
Technique To Improve Subfield Registration
An arrangement is described for compensating for backscatter current
variation, due mainly to plate-to-plate variations in material thickness, in E-beam
mask inspection tools.
In E-beam mask inspection tools, an electron beam shaped spot may be
scanned along two edges of a metal pattern, shown at 1 in Fig. 1 on glass mask 4. As can be seen, the scan areas 2 and 3, respectively, partially cover the
edges of the metal. When properly aligned, the proportion of each scan area
which overlaps metal and overlaps glass will be equal; i.e., Alpha of one scan
equals Beta of the other. Alpha and Beta are determined by integrating the
backscattered signal as the beam scans along the edge. The displacement in
the X direction (Delta X) of the scans with respect to the metal pattern is
proportional to the difference of the signals during the two scans.
However, if the backscatter signal varies a significant amount,
for example, as caused by a change in density of the target metal
pattern due to thickness variations in the pattern or due to a change
in the intensity of the illuminating beam, it can be shown that this
change in backscatter signal will be falsely interpreted as a change
in Delta X.
Integration of the signal along two edges equals displacement in
where Sc equals backscatter signal from clear area
So equals backscatter signal from opaque area
This article proposes that the variation in Delta x be