POLARIZED STRESS IMAGINGwww.semilab.com

PSIPolarized Stress Imager tool uses polarized IR light in transmission mode for the inspection and visualization of crystal defect related mechanical stress fields in the Si wafers.For production and R&D applications

Facts• Non-contact, non-destructive full wafer

depolarization imaging in transmission mode.• 1-36 megapixel images depending on wafer

size and platform with pixel scale of 50 μm.• High resolution image allows finding of

localized defects such as dislocations or extended stress fields such as slip lines.

• Automatic defect finding.

Benefits

• SAM2™ (Semilab Automation Manager2) user interface compliant to SEMI® standard (E95-0200)

• Open frame XY scanning stage• Automated platforms: High precision robot

with edge-grip or backside contact end effector

• Option for all platforms: dual side particle detection measurement in the same time and with the same resolution for the sake of distinguishing the surface particles from real localized mechanical stress fields.

Applications

1. Epi process monitoring

Localized defects

Dislocations running through the ingot. On wafer level identified localized (point-like) defects.

* possibility of measuring smaller, rectangular or irregular shaped samples (may need specially shaped adapter)** for one selected sample size*** for one or two additional diameters

Slip lines

Problem

Hidden areas on the edge and mechanical stress induced by fixed holders

PSI-2100 PSI-3000

Wafer size [mm] 50-315* 150 / 200 / 300

Loading Manual Automatic** / Manual***

Solution

Released edge during scanningNo edge exclusion, zero induced stress

Epi defects

2. Czochralski crystal testing

Twin lines