Patent ID: 7705610
Filing Date: 2010-04-27
Classification: G01B

Abstract:
1. An apparatus for determining the thickness of a film on a substrate comprising: a first sensor including a microwave transmitter for producing a primary microwave energy, a waveguide for directing said primary microwave energy towards a target, a reflected energy separator to separate microwave energy reflected from the target and direct the reflected energy along a different path, and a detector for receiving only separated microwave energy reflected off said target; an analyzer for determining the thickness of the film on a substrate, the analyzer programmed to carry out the steps of (i) measuring the in-phase and quadrature components of the reflected microwave energy; (ii) comparing the measured components to stored data; and (iii) determining a thickness value of the film; (iv) determining the phase angle of the reflected wave from the in-phase and quadrature components of the reflected microwave energy; and an indicator for providing results of the determination.