Browse Prior Art Database

Laser Scanning System

IP.com Disclosure Number: IPCOM000074186D
Original Publication Date: 1971-Mar-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Youlton, FW: AUTHOR

Abstract

A photoresponse of a semiconductor device 10 can be used to study device characteristics and to identify anomalous device behavior.

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Laser Scanning System

A photoresponse of a semiconductor device 10 can be used to study device characteristics and to identify anomalous device behavior.

The topography of the device 10 is displayed in amplifier and display 12 which may include a monitoring oscilloscope sweeping in synchronism with a moving light spot 14 under the control of a control unit 16 as indicated at C. Unit 16 controls the movement of light spot 14 by mechanically rotating a hologram 20 about an axis 22. Unit 16 also provides synchronizing pulses to amplifier and display 12.

Hologram 20 is prepared on a thick emulsion photographic film 24, as shown in A, by varying the angle 9 and alpha or omega and the position of ground glass light aperture in opaque screen 26 in the X-Y plane to produce a series of diagonally arranged light spots or beams 14a, 14b, 14c and 14d in a scanning spot raster area 28 when passing laser light through the hologram 20, as indicated at B. One light spot is produced per exposure at a given angle. The emulsion thickness of film 24 is greater than the fringe pattern.

To scan device 10 with light spot 14, spot 14a is directed to ground glass screen 34 and first and second plane mirrors 30 and 32 are provided to direct the spots 14b, 14c and 14d from hologram 20 to screen 34, from which light is transmitted through microscope 36 to device 10.

The light spots 14a, 14b, 14c and 14d scan sequentially in a horizontal direction across ground glass screen 34 in the followi...