Browse Prior Art Database

Electron Beam Scanning Velocity Detection Method

IP.com Disclosure Number: IPCOM000079904D
Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Das, G: AUTHOR [+2]

Abstract

A semiconductor diode is often used to detect an electron beam in electron optical systems. The diode in such systems amplifies the beam current. However, at beam intensities required for photolithographic applications and with scanning speeds in excess of 100 inches/sec, the diode characteristics deteriorate in terms of gain and speed. Consequently, the scanning speed of the beam cannot be determined accurately and, therefore, is inadequate for monitoring electron beams.

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 100% of the total text.

Page 1 of 2

Electron Beam Scanning Velocity Detection Method

A semiconductor diode is often used to detect an electron beam in electron optical systems. The diode in such systems amplifies the beam current. However, at beam intensities required for photolithographic applications and with scanning speeds in excess of 100 inches/sec, the diode characteristics deteriorate in terms of gain and speed. Consequently, the scanning speed of the beam cannot be determined accurately and, therefore, is inadequate for monitoring electron beams.

A thin film of amorphous carbon or similar material is placed between the beam and the diode. This amorphous film has the effect of diffusing the beam,
i.e., as if it were defocused, over a large area. The diode then detects the E- beam with fast response, enabling measurement of the scan rate of the beam.

The drawing illustrates diagrammatically the principle involved, where 1 is a metal calibration grid and 2 is the thin amorphous carbon film superimposed between the electron beam E and the diode 3. The diode is biased, as shown, and connected to an appropriate oscilloscope.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]