Wafer Analyzer

The PW2830 XRF wafer analyzer from Philips Analytical determines layer composition, layer thickness, contamination, dopant levels, and surface uniformity on semiconductor wafer sizes up to 300 mm. The new metrology tool features 4 kW X-ray power for faster measurement, especially of critical light elements such as boron and nitrogen, which dictate overall counting times. Monitoring of boron and phosphorous in BPSG planarization is accomplished within three minutes. Further time saving options include facilities for automated batch loading from cassettes or FOUP pods.

Systems are custom configured with up to 20 fixed measuring channels. Equipping the wafer analyzer with one or two scanning channels gives additional flexibility for non-routine testing, contaminant identification and trouble shooting. A small footprint and narrow faceprint, plus the possibility of through-wall installation, minimizes the impact on valuable clean-room space. In accordance with normal fab procedures, wafers are measures in surface up orientation. Automatic alignment on a unique x-y sample stage minimizes results calculation errors due to unwanted background from the silicon substrate. Once aligned, the orientation remains constant for spot measurements at all point on the surface. Standard stages accept 150, 200, and 300 mm wafers. Special fittings are also available for manual insertion of small wafers and fragments.

A built-in control PC with touch-screen program selection makes routine operation extremely easy. User assigned function keys or large on-screen speed button permit rapid initiation of measurement for single wafers or complete batches. Philips SuperQ software, running under Windows 95 or NT, includes simple procedures for the setup of standard measurement recipes or individually customized programs. Uniformity patterns are easy to define with a software-switchable choice of spot-sizes. Results are presented in tabular or graphic form, and may be flagged to provide immediate GO/NO-GO indications. The PW2830 also integrates readily into plant-wide process control and quality assurance networks, using SECSII/GEM/HSMS protocols to communicate with the host computer.

Philips Analytical. Lelyweg 1, 7602 EA, Almelo, The Netherlands. Tel: 31 546 534430