Minority carrier Lifetime maps on 450 mm wafers

 

 

Since several years there is the plan to enlarge the wafer size from 300 mm (12 inch) to 450 mm (18 inch) diameter, in order to gain more yield. Of course these wafers also need to be checked for extrinsic and intrinsic impurities and hence highly spatially resolved lifetime measurements are needed.

With the MDPmap and MDPingot it is possible to map even 450 mm wafers. Figure 1 shows one of the first measured lifetime maps of a 450 mm wafer.

Fig. 1: minority carrier lifetime map of a 450 mm wafer