Abstract: A reflectometry method and apparatus for gathering meaningful reflectance data indicative of one or more characteristics of a substance being grown on a horizontal substrate within a reaction chamber. The apparatus includes an external light source which shines light into the chamber through an opening having a shutter for selectively permitting or preventing the light from passing in and out of the chamber through the opening. A detector receives light that reflects off the substance and exits the chamber through the opening. During operation, the substrate is rotated about an axis substantially normal to the growing plane within the reaction chamber to ensure uniform deposition of the substance thereon. The shutter momentarily opens in synchronicity with the speed of revolution of the substrate such that substantially the same discrete area of the growing substance is illuminated so as to eliminate the effects of precession on the measurements.

Abstract: A reflectometry method and apparatus for gathering reflectance data indicative of one or more characteristics of a semiconductor substance being grown on a substrate within a reaction chamber. The method includes directing light of known characteristics from a light source into the reaction chamber towards the surface of the semiconductor at an acute angle, preferably 46°, and collecting the light reflected from the surface at a detector located on the other side of the chamber. The received light is then converted into electrical signals which are subsequently subjected to computer processing. The reaction chamber can have a rectangular cross-sectional shape with apertures cut in the two vertices of the reaction chamber located above the substance to thereby allow the light to pass into the reaction chamber at the acute angle and out again after having been reflected from the surface of the semiconductor.

Abstract: A reflectometry method and apparatus for gathering meaningful reflectance data indicative of one or more characteristics of a substance being grown on a horizontal substrate within a reaction chamber. The apparatus includes an external light source which shines light into the chamber through an opening having a shutter for selectively permitting or preventing the light from passing in and out of the chamber through the opening. A detector receives light that reflects off the substance and exits the chamber through the opening. During operation, the substrate is rotated about an axis substantially normal to the growing plane within the reaction chamber to ensure uniform deposition of the substance thereon. The shutter momentarily opens in synchronicity with the speed of revolution of the substrate such that substantially the same discrete area of the growing substance is illuminated so as to eliminate the effects of precession on the measurements.

Abstract: A reflectometry method and apparatus for gathering reflectance data indicative of one or more characteristics of a semiconductor substance being grown on a substrate within a reaction chamber. The method includes directing light of known characteristics from a light source into the reaction chamber towards the surface of the semiconductor at an acute angle, preferably 46°, and collecting the light reflected from the surface at a detector located on the other side of the chamber. The received light is then converted into electrical signals which are subsequently subjected to computer processing. The reaction chamber can have a rectangular cross-sectional shape with apertures cut in the two vertices of the reaction chamber located above the substance to thereby allow the light to pass into the reaction chamber at the acute angle and out again after having been reflected from the surface of the semiconductor.