Abstract: A method for polishing peripheral chamfers of a semiconductor wafer comprising steps of: (a) turning a cylindrical cup-like rotatory buff having an internal polish groove formed in the inner wall surface thereof, the groove having a profile complementary to the profile of the chamfered wafer edge to be polished; (b) disposing the wafer inside the turning buff; (c) turning the wafer at a relatively low rate; and (d) pressing the wafer edge into the running internal polish groove with an appropriate pressure; furthermore there is proposed an apparatus for this novel method including the cylindrical cup-like rotatory buff as described above.

Abstract: A disposable pipette comprises a tube having first and second ends, a porous barrier plug mounted in the tube at the second end, and a sealing device mounted in the tube between the second end and the barrier plug. The sealing device has a closed position and an open position into which it must be forced. The pipette further comprises a closure mounted in the tube between the second end and the sealing device, wherein the first end is immersed in a fluid, when the sealing device is forced to the open position and when the second end is connected to a suction, fluid is suctioned into the pipette. A safety pipette adaptor comprises an annular sleeve for mounting on the suction end of a pipette. A rod is provided in the sleeve in the direction of an axis for insertion into a pipette or pipette insert and is capable of displacing a sealing device in a pipette or pipette insert into an open position.