300mm wafer scanner gives double throughput

Sonoscan Inc. has released its automated 300mm bonded wafer inspection system that simultaneously scans two wafers and gives user double throughput of other systems. The system inspects wafer pairs intended for SOI, MEMS and other applications for 300mm and 200mm wafers bonded by virtually any method. It images disbonds, delaminations, voids and particles at the bond interface, and cracks at any depth.

Based on Sonoscan's C-SAM acoustic microscope systems, the AW300 also automates the entire inspection system from carrier attachment and wafer selection through aligning and acoustic imaging to drying and sorting.

A robotic arm feeds wafers from tow load ports that accept either FOUP or FSOB carriers. Wafers are fed into either of two scanners. To ensure maximum throughput, wafers are sequenced in a staging area where wafers are processed and temporarily stored.

The AW300 uses Sonoscan-made transducers (lenses) ranging from 100–400MHz. The UHF transducers are designed, manufactured and matched in-house to ensure optimum performance.

Sonoscan's AW300 is capable of imaging inter-wafer voids as small as 5?m wide, and delaminations as thin as 100?. Scanning employs Sonoscan's non-immersion Waterfall transducers and vacuum-assisted stages. Analysis software automatically measures the percentage of bonded and unbonded interface between the two wafers, and the sizes and number of voids. Accept/reject decisions are made automatically according to the user's specific criteria.