Browse Prior Art Database

In Line Ion Beam Monitor

IP.com Disclosure Number: IPCOM000089224D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Geipel, H: AUTHOR [+2]

Abstract

An in-line ion-beam monitor having Faraday plates 10, 12, 14 and 16 for detection of an ion-beam overscan is provided with circuits for detecting low beam currents used for doses below 10/13/ ions/cm/2/, which may be used for surface tailoring of field-effect transistors formed in semiconductor wafers.

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In Line Ion Beam Monitor

An in-line ion-beam monitor having Faraday plates 10, 12, 14 and 16 for detection of an ion-beam overscan is provided with circuits for detecting low beam currents used for doses below 10/13/ ions/cm/2/, which may be used for surface tailoring of field-effect transistors formed in semiconductor wafers.

The plates 10, 12, 14 and 16 are connected to amplifiers 18, 20, 22 and 24, respectively. Independent gain selections of 1, 10, 100 and 1000 may be provided for each of the amplifiers 18, 20, 22 and 24. Filters 26, 28, 30 and 32 are coupled to the outputs of the respective amplifiers 18, 20, 22 and 24, respectively, to eliminate high and low frequency noises which may have been produced on the ion beam in the monitor or ion source. Buffer circuits 34, 36, 38 and 40 are coupled to the inputs of an analog adder 42 to electrically isolate, from an impedance standpoint, the analog adder from the filters 26, 28, 30 and
32. The output, which is a composite signal, from the analog adder 42 is applied to the Z-axis blanking of an oscilloscope 44 for controlling the intensity of the electron beam to produce the ion-beam scan patterns on the oscilloscope screen. An appropriate synchronization generator or scanner 46 provides required pulses to the horizontal and vertical deflection plates of the oscilloscope
44.

Since it has been found that the charges or signals developed on Faraday plates 12 and 16 are approximately ten times the intensity of those...