US 4,526,468 AGranted

Method for determining the phase of phase transformable light scattering material

AssigneeRCA Corporation

InventorsEdgar F. Steigmeier, Heinrich Auderset

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Abstract

A method of determining the crystalline or structural quality of phase transformable material such as silicon uses light scattering. The material is exposed to a beam of light of a selected wavelength. Scattered light having an intensity above a threshold is detected to provide a signal which is used to control the intensity of a display beam of a visual display device. The threshold is varied to thereby vary the display beam intensity so as to provide the minimum intensity of display beam which yields a full display. The value of the thusly adjusted threshold intensity is used as a direct measure of the structural quality of the material. The light scattering process is used to determine the phase of deposited material. A layer of silicon material annealed from as-deposited amorphous phase material is easily and quickly distinguished from material as-deposited crystalline phase material and subsequently annealed.

Claims10

Dependent claims

A method for determining the phase of a deposited material having a property of absorbing light to a given penetration depth, said material being capable of being deposited in either of two predetermined phases, comprising the steps of:

(a) depositing one of said two phases of said material on a surface;
(b) exposing one or more regions of said material to a beam of light of a selected wavelength;
(c) detecting light having an intensity greater than a threshold intensity scattered from the exposed material to provide an electrical signal proportional to the intensity of scattered light detected above said threshold intensity;
(d) applying the electrical signal to a visual display device to control the intensity of the display beam of the device;
and
(e) varying said threshold intensity to thereby vary the intensity of the display beam so as to provide the minimum intensity of display beam which yields a full display of the exposed material, wherein the value of the threshold intensity is a direct measure of the phase in which said material was deposited.

3 more elements

Dependencies are inferred from the claim text.