Apparatus for measuring semiconductor physical characteristics

Reflectometry apparatus for gathering meaningful reflectance data indicative of one or more characteristics of a substance being grown, said apparatus including a reaction chamber which includes a substantially horizontal substrate on which the substance growth occurs, a light source disposed to the outside of said reaction chamber, and a detector also disposed to the outside of the reaction chamber but on the opposite side of the reaction chamber to that at which the light source is disposed, said detector being capable of converting light into electrical signals which are subsequently subjected to computer processing, characterized in that:

• the reaction chamber having a susceptor block atop of which is disposed a substrate suitable for the growing of semiconductor materials, said chamber being elongate and substantially tubular such that gaseous semiconductor precursor material may be caused to flow therethrough along a direction substantially parallel to a longitudinal axis of the chamber from an inlet disposed at an end of the chamber, the chamber having a polygonal cross-section alone a direction parallel to said longitudinal axis, the cross-section having a first vertex and a second vertex with said first vertex having a first aperture and said second vertex having a second aperture;
• the light source being disposed to one side of the reaction chamber with said apertures and vertices being located relative to each other and to said substrate such that light directed into said chamber through said first aperture from said light source impinges on the surface of the substrate, or the surface of the substance being grown thereon, at an acute angle and is reflected away therefrom at a similarly acute angle and exits the chamber through said second aperture after which it is collected by the detector, which is disposed to the alternate side of the reaction chamber from that of the light source when said reaction chamber is viewed in end elevation.

Reflectometry apparatus, comprising:

• an elongate, substantially tubular chamber through which gaseous semiconductor precursor material can flow;
• a susceptor block disposed in said chamber;
• a substrate disposed on top of said susceptor block, said substrate being suitable for the growing of semiconductor materials;
• wherein said chamber has a polygonal cross-sectional that includes a pair of vertices located at upper portions of said chamber above said substrate and being located on one side of a first imaginary line drawn through the geometric centre of the cross-sectional shape, a first of said vertices being disposed to one side of a second imaginary line perpendicular to the first imaginary line, and the second of said vertices being provided to the other side of said second imaginary line;
• wherein said chamber includes a first aperture located at said first vertex and a second aperture located at said second vertex;
• a light source disposed outside said chamber, said light source supplying light into said chamber through said first aperture;
• and
• a detector disposed outside said chamber, said detector being positioned to receive light from said light source that has reflected off the semiconductor material on said substrate and exited said chamber through said second aperture.