Patent Number: 052182096
Section: claims

1. An ion implanter for implanting ions into a batch of semiconductor wafers, comprising: a centrifugal type wafer holding disk having a conically curved peripheral portion;  a plurality of wafer rests aligned along the peripheral portion of said wafer holding disk, wherein the bottom holding surfaces of said wafer rests are curved nearly in the shape of said conically curved peripheral portion of said wafer holding disk.  a plurality of wafer rests aligned around the periphery of the semiconductor wafer holding disk, each wafer rest having a bottom holding surface which is conically curved.  a centrifugal type wafer holding disk having a conically curved peripheral portion;  a plurality of wafer rests aligned around said peripheral portion of said wafer holding disk, said wafer rests having a bottom holding surface which is a fragment of a conical surface having the same axis and slope as said conically curved peripheral portion of said wafer holding disk. 2. The ion implanter of claim 1, wherein said plurality of wafer rests each have a diameter of at least 150 mm. 3. A semiconductor wafer holding disk for an ion implanter, comprising: 4. An ion implanter for implanting ions into a batch of semiconductor wafers, comprising: