Abstract: A pedestal is provided for supporting wafer boats in a process chamber during semiconductor fabrication. The pedestal contains hollow spaces, such as within porous insulating plugs, and gases inside the pedestal may expand during semiconductor processing. The pedestal has an opening for exhausting gases out of its interior and into the process chamber. The opening is provided with a filter, in the form of a sintered ceramic or glass disc sealed within a tube covering the opening, to prevent the passage of particles which may be present inside the pedestal. By filtering the particles, the filter removes a source of contamination, thereby allowing for high quality process results on wafers processed in the process chamber.

Abstract: A pedestal for use in a high temperature vertical furnace for the processing of semiconductor wafers provides a closure and heat insulation for the lower end of the furnace and is a wafer boat support. The pedestal, comprising quartz-enveloped insulation material, supports a wafer boat at a boat support level and is provided with an upper section disposed above the boat support level. The upper section comprises enveloped insulating material. The envelope of the upper section is also formed of quartz and the insulating material in the upper section has a lower thermal conductance than the insulating material in a lower quartz enveloped section.

Abstract: A pedestal for use in a high temperature vertical furnace for the processing of semiconductor wafers provides a closure and heat insulation for the lower end of the furnace and is a wafer boat support. The pedestal, comprising quartz-enveloped insulation material, supports a wafer boat at a boat support level and is provided with an upper section disposed above the boat support level. The upper section comprises enveloped insulating material. The envelope of the upper section is also formed of quartz and the insulating material in the upper section has a lower thermal conductance than the insulating material in a lower quartz enveloped section.