Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Modified Electrostatic Box Deflector for E-Beam Deflection

IP.com Disclosure Number: IPCOM000039208D
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Kern, DP: AUTHOR [+2]

Abstract

Electrostatic deflectors which are simplest to manufacture are deflec- tors using a box design. However, such deflectors cause relatively large electron-optical aberrations. A deflector is described herein which is simple to manufacture as the box deflector but produces aberrations which are an order of magnitude smaller in size, at the expense of increased electronic requirements. Fig. 1 shows an electrostatic deflector in pre-deflection mode. Let P be a point on the optical axis where a (perfect) crossover of the electron beam is located. The electrons are deflected in the transverse electric field produced by the deflector. The exit-side asymptotes of the deflected bundle of rays nearly intersect in a common point P1 in the object plane. P1 is a deflected virtual image of P.

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 53% of the total text.

Page 1 of 2

Modified Electrostatic Box Deflector for E-Beam Deflection

Electrostatic deflectors which are simplest to manufacture are deflec- tors using a box design. However, such deflectors cause relatively large electron-optical aberrations. A deflector is described herein which is simple to manufacture as the box deflector but produces aberrations which are an order of magnitude smaller in size, at the expense of increased electronic requirements. Fig. 1 shows an electrostatic deflector in pre-deflection mode. Let P be a point on the optical axis where a (perfect) crossover of the electron beam is located. The electrons are deflected in the transverse electric field produced by the deflector. The exit-side asymptotes of the deflected bundle of rays nearly intersect in a common point P1 in the object plane. P1 is a deflected virtual image of P. Imaging of P by means of a lens positioned behind the deflector is equivalent to the imaging of P1 by this lens in the absence of any deflector. In this framework, two types of aberrations will result from deflection: distortion and spot blurring. Distortion is the dislocation of the (backtraced asymptote of the) principal ray from its designated position for perfectly linear deflection. (The principal ray is one of an electron initially travelling along the optical axis.) Spot blurring is the dislocation of the deflected position of non-principal rays from the deflected position of the principal ray. Distortion and spot blurring have been investigated theoretically for the proposed deflector in order to compare its imaging quality to that of other deflectors.

(Image Omitted)

Fig. 2 shows a perspective view of the propo...