JVX7300F-C

Full wafer maps at high throughput give information on the quantity of the contaminants and their location on the wafer surface. This information is critical for troubleshooting trace metal excursions and monitoring of trace metal levels at every process step in the fab.

The JVX7300F-C offers mapping capability with zero mm edge exclusion. Wafer edge TXRF measurements give engineers valuable information on trace metal levels in a critical area of the wafer, which is prone to cross contamination through FOUPS and edge grippers. As chip processing edge exclusions decrease, detecting contamination at the wafer edge is critical.

The Challenge

Trace metal contamination is a continually growing concern for semiconductor device fabrication. Contamination is especially critical for advanced technology nodes. Trace metals at the surface affect semiconductor device performance and product yields in multiple ways. During high temperature processing steps, metals at the surface can diffuse into silicon substrates, act as recombination centers, and degrade minority carrier lifetimes. Metals at the surface can also adversely affect silicon oxidation rates and become incorporated in gate oxides and degrade oxide integrity. Surface measurement of trace metal contamination is thus a crucial step in device manufacturing.

The Solution

Total Reflection X-ray Fluorescence (TXRF) is standard monitoring metrology for in-line semiconductor surface trace metal analysis. The JVX7300F-C TXRF makes quick, non-destructive, in-line, and completely automated measurements. The tool allows fab technicians to collect critical contamination measurement data required for quality control with customizable recipes. Furthermore, the software allows for reanalysis of already acquired data.

How TXRF Works

In TXRF a beam of X-rays is directed at a glancing angle incident on the wafer surface. The glancing angle is chosen to allow total internal reflection of the incident X-ray to improve excitation from material only at the wafer surface. The incident X-ray beam energy is chosen to excite certain elements X-ray emissions from the surface contamination. The X-rays emitted from contamination species have characteristic energies that are element specific. This allows for quantification of the metal contamination. The X-ray fluorescence process is non-destructive to the wafer. The measured spot size is defined by the silicon drift detector size.