Abstract: A furnace (100) is provided which aids in the reduction of polysilicon and quartz contaminants during polysilicon deposition on monocrystalline wafers. The wafers are heated for polysilicon deposition within the interior of a quartz tube (102) which is mounted so that the interior sidewalls are vertical and the tube opening is at the top of the furnace. A quartz boat (104) is adapted for carrying the wafers in a spaced apart relationship with a quartz rod (144) maintaining the wafers within the boat when it is suspended vertically from an elevator bar (128). The elevator bar moves the quartz boat vertically into the interior of the quartz tube (102) for heating without contact between the quartz boat and sidewalls of the quartz tube. The level of contamination is therefore less and the yield of certain integrated circuits much improved.