Method and apparatus for preventing contamination in a hot plate oven

A hot plate oven for curing a coating layer on a wafer without contamination problem comprising:

• an oven body of elongated shape having an open top and a cavity defined by two side panels, two end panels and a bottom panel, said two end panels having slot openings therein for a pair of wafer carrying blades to pass therethrough;
• a plurality of metal heating blocks situated in said oven body arranged in a matrix form with a preset spacing therein-between, said plurality of metal heating blocks having a planar top surface adapted for intimately engaging a wafer positioned thereon;
• a pair of metal wafer carrying blades positioned in said preset spacing between said plurality of metal heating blocks adapted to move both in a longitudinal direction of said oven body to traverse a wafer and in a vertical direction to load or unload said wafer from said planar top surface of said plurality of metal heating blocks;
• and
• an interlocking circuit for detecting an electrical short between said pair of metal wafer carrying blades and said plurality of metal heating blocks and for stopping the movement of said pair of metal wafer carrying blades.