Patent ID: 7314526
Filing Date: 2008-01-01
Classification: C30B

Abstract:
1. An improved reaction chamber for an epitaxial reactor comprising a belljar having a shoulder and made of insulating and transparent material, a susceptor provided with disk-shaped cavities for receiving wafers of materials to be treated and having an insulating and chemically resistant flat plate arranged above it, comprising: a diffuser formed by a cap supplied by a central dome-piece connected to a symmetrical annular distribution chamber having a plurality of pipes of the same length which connect said annular chamber of the cap to a dome zone of the belljar situated just underneath a neck connecting an upper flange to the dome, said plurality of pipes ensuring a uniform distribution of flow at a lower speed; a cylindrical zone of the belljar extended above the flat plate supported above the susceptor so as to eliminate any interference between the flat plate and shoulder; a minimum internal diameter of the belljar for sufficiently spacing the belljar from the susceptor; and on the corners of the susceptor, in its upper zone, projecting baffles inserted into recesses formed in the body of the susceptor, said baffles extending longitudinally at half the height of the susceptor; wherein the cap of the diffuser is fixed to an annular flange which is in turn fixed to an upper thickened flange of the belljar by means of a pair of two half counter-flanges gripping the annular flange against the upper thickened flange of the belljar; and wherein the fixing of the cap of the diffuser to the annular flange is performed by means of a plurality of spring-loaded tie-rods which push in an elastic manner the cap against the annular flange.