HOLDER FOR GROUP DIFFUSION TREATMENT OF SILICON WAFERS Russian patent published in 2009 - IPC H01L21/22 

FIELD: electrical engineering.

SUBSTANCE: present invention relates to devices for holding silicon wafers during diffusion treatment when making semiconductor devices. The holder for group diffusion treatment of silicon wafers is made from three polysilicon rods. Two lateral rods are put on each side of the silicon wafers being treated in the holder and one bottom rod, which is the bottom of the holder, is put below the silicon wafers being treated in the holder. The lateral rods are placed such that, their longitudinal axes and the centre of wafers being treated in the holder lie in the same plane. Slots where each treated wafer is fit into are brought together such that, they are in one vertical plane and are made for placing treated wafers in this plane, perpendicular the longitudinal axis of the rods. Slots on both lateral rods have a flat-topped shape. The width of the slot is (30-80) % greater than the thickness of the treated wafer. Slots in the bottom rod have an inverted trapezium shape such that, the upper (bigger) base of the trapezium is (100-200) % bigger than the thickness of the treated wafer. The lower (smaller) base of the trapezium is also larger than the thickness of the treated wafer so that, when the treated wafers are put into the holder they are not wedged, reaching the bottom of the slot in the bottom rod.

EFFECT: invention prevents loss of wafers due to prevention of wafers getting stuck inside the slots.