CVD reactor

CVD reactor comprising:

• a reactor casing with a casing cover,
• a heated susceptor for one wafer or several wafers, which is disposed in the reactor casing,
• a fluid inlet unit including a plurality of openings facing said wafer or wafers through which heated CVD media enter the reactor, and
• a fluid outlet disposed on the periphery of the reactor casing, through which the introduced media are discharged again,
• the reactor characterized in that:
• said fluid inlet unit comprises a hollow body spaced from said casing cover having an underside, in which said openings are provided, which is heated by said susceptor substantially by thermal radiation and/or thermal conduction,
• a flushing gas inlet means is provided which introduces a flushing gas into a space between an upper side of said hollow body and said casing cover in such a way that the upper side will dissipate heat into an environment outside the CVD reactor through the flushing gas, and
• that conditions of heat supply and dissipation to or from said hollow body, respectively, are so controlled as to heat said CVD media, without any supply of a medium for heating from outside of a gas supply system of the CVD reactor, and that a positive temperature gradient exists between the upper side and the underside of said hollow body.