Wafer transfer apparatus

Apparatus for placing a semiconductor wafer in a precise slot location on a second element, there being at said precise slot location a known variation in the shape of said second element, said apparatus comprising

• a support member for supporting said semiconductor wafer while said member is translated toward said second element along a placement direction,
• a first transport means for moving said support member or said second element along a direction transverse to said placement direction, and
• sensing means located on said support member for sensing the relative alignment along said transverse direction of said support member and said variation in shape,
• said sensing means comprising
• an energy-beam source adapted and positioned to direct an energy beam along a path that intersects said slot at least when said support member and slot are aligned so that more of said beam is transmitted along said path when said member and slot are aligned than when said member and slot are not aligned, and
• an energy-beam sensor adapted and positioned to detect the difference in the amount of said beam transmitted along said path.

Apparatus for inserting semiconductor wafers in a holding boat of the type having at least two slots in which each said wafer is received, comprising

• a wafer support member or paddle for supporting said wafers,
• rotation means for rotating said support member by the angle necessary to cause edges of said wafers to be received at the centers of said slots,
• placement means for translating said rotated support member so as to place said wafers in said slots in said holding boat,
• sensing means for sensing the locations of said slots relative to the edges of said wafers to be received therein, and
• processing means for determining said rotation angle from said locations,
• whereby said wafers are placed in said slots without their edges scraping the walls of the slots.

Apparatus for placing a first flat element in a precise receptacle location on a second element, there being at said precise receptacle location some known variation in the shape of said second element, said apparatus comprising

• a support member for supporting said first element while said member is translated toward said second element along a placement direction,
• first transport means for moving said support member or said second element along a direction transverse to said placement direction, and
• sensing means located on said support member for sensing the relative alignment along said transverse direction of said support member and said variation in shape,
• said sensing means comprising
• an energy-beam source adapted and positioned to direct an energy beam along a path that interacts with said variation in shape at said receptacle location at least when said support member and receptacle location are aligned so that more of said beam is transmitted along said path when said member and receptacle location are aligned than when said member and receptacle are not aligned and
• an energy beam sensor adapted and positioned to detect the difference in the amount of said beam transmitted along said path.