PAD-SCAN

The PAD-Scan offers a new quality for highly sensitive VPD analysis of silicon wafers. Its fully automated operation eliminates all particle contamination caused by human operators and decreases blank values substantially resulting in superior detection limits.

With its precisely controlled scanning procedure the PAD-Scan converts VPD into a reliable preparation method with good repeatability, ideally suited for quality control of wafer surfaces in front end processing.
Thanks to sophisticated partial scanning modes any area of the wafer can be selected for collecting the VPD residue. Robotic wafer handling capability is available for all wafer diameters up to 300 mm.

full wafer scan

selected area scan

inner- outer scan

edge scan

A calibrated droplet (50 - 350 µl) of a chemical solution or DI water is pipette onto a wafer and guide ba y high purity tube over the wafer surface following a programmable pattern. After completion of the scan the tube is detached from the droplet with a short nitrogen pulse.
The droplet can be allowed to dry at a predefined position on the scanned wafer or on a reference wafer for TXRF or SIMS analysis or it can be transferred to a programmable microvial carousel by the pipette for ICP-MS or AAS analysis. Both, scan and pipette tube, can be chemically cleaned and rinsed before and after each scan.