Chemical vapour deposition appts. for pure semiconductor - with silver or silver plated steel bell to withstand pressure differential

摘要

Equipment for the deposition of pure semiconductor material, esp. Si, by the thermal decompsn. of a gaseous cpd. on a substrate heated to the decompsn. temp. of the cpd. concerned by the passage of an electric current, consists of a metal base plate with gas inlet and outlet nozzles, a holder for the substrate and electric leads, covered by a coolable bell having a gas tight seal with the edge of the base plate. The novel feature is that the reaction chamber, including the surface of the bell, consists of Ag or Ag-plated steel. Deposn. can be carried out under pressure without the need to apply an equal pressure to the outside of the bell, as in the case of a quartz bell.