Sierracin Corporation

Roger E Nelson

William E Ward

Clyde L Lucky

A meter for sheet conductance measurements does not touch the conductive surface of a sample. A probe having a resonant tank coil is positioned against a parallel supporting surface of the sample, which may be flat or curved and of unrestricted area. An oscillator incorporating the tank coil is controlled to stabilize oscillator amplitude in response to eddy current loading by the sample. An electrostatic shield in a finger configuration prevents capacitive coupling between the tank coil and the sample without hindering magnetic coupling. A readout of sheet conductance is driven by the oscillator control. Direct current can be coupled to the tank coil for temperature control preventing undesired resistance changes in the tank coil. The oscillator can be controlled by an optically coupled variable gain element. Measurements can be made with the tank coil up to at least 0.75 inch from the conductive surface of the sample.

Apparatus and method for measuring conductance including a temperature

An optical transmission monitor for determining the optical transmissivity and thickness of films deposited on a substrate. A monitor substrate in the form of a rotating disk exposed to the deposition process is used. An optical system for measuring the transmissivity of the disk obstructs a fixed segment of the rotating disk so that the film thickness on the monitor disk is a known fraction of the film on the substrate being processed.

Optical disk transmission monitor for deposited films

A pair of overlapping, normally spaced conductive sheets (16,18) have sufficient flexibility between them to permit electrical contact when touched. One sheet has spaced, approximately parallel electrodes (20,21). The other sheet has spaced approximately parallel electrodes (22,23) transverse to the electrodes of the one sheet. A source of electrical power (10,12) is alternatively connected across the electrodes of one sheet to the exclusion of the other sheet. One electrode of each sheet is coupled to a signal processing circuit (32) having a high impedance differential input.

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Northridge, CA, United States of America

Roger E Nelson