Browse Prior Art Database

Collector for Secondary Emitted in an SEM of Reduced Energy

IP.com Disclosure Number: IPCOM000099181D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Jenkins, KA: AUTHOR [+2]

Abstract

Disclosed is a method for obtaining a high electron collection efficiency in a scanning microscope which has the primary electron landing reduced by biasing the specimen.

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This is the abbreviated version, containing approximately 58% of the total text.

Collector for Secondary Emitted in an SEM of Reduced Energy

       Disclosed is a method for obtaining a high electron
collection efficiency in a scanning microscope which has the primary
electron landing reduced by biasing the specimen.

      Electron microscopes do not achieve good resolution when energy
of the primary electron beam is low, say, below 2  It is also known
that there are many instances in it is desirable to examine a
specimen with a low beam  However, the resolution achievable with low
energy may not be adequate.

      It has been shown that it is possible to achieve the of high
energy electron beams with low energy by biasing the specimen such
that the landing energy the beam is reduced, while rest of the system
is passed by a high energy beam [*]. the resolution is not much
affected is due to the fact at low energy, the electron probe
diameter is affected by chromatic aberrations in the lens.

      However, collecting the secondary electrons produced by biased
specimen is difficult.  This is because the electrons are accelerated
away from the specimen the lens, missing the detector.  Many
detectors have proposed to solve this problem, but none of them are
efficient. This article describes a method of these electrons with
high efficiency.

      The invention is drawn schematically in the figure.  An is
equipped with a photomultiplier tube detector (PMT) the objective
lens.  In addition, a pair of retarding 10 is placed in the...