Phosphorous Contamination from Ultrapure Water in Wet Cleaning of Silicon Wafers

By Drew Sinha et al.

Boron Phosphorus Resistivity Particles Monitoring

Download Full Article


Phosphorous is one of the most commonly used N-type dopant for the manufacturing of semiconductor devices. A silicon wafer is normally doped with phosphorous during crystal growth, diffusion, ion implantation, or during the epitaxial deposition process. Phosphorous addition, other than the intentional doping of silicon wafers, is considered to be phosphorous contamination. Depending on the type and level of the doped silicon, the phosphorous contamination can alter the resistivity and hence affect the breakdown voltage and depletion width of p-n junction of devices. The contamination can also cause a shift in threshold voltage for PMOS devices. This is particularly critical for lightly doped (high resistivity) P-types, where it can cause counter-doping during the subsequent annealing/oxidation process. Furthermore, excessive phosphorous contamination of a silicon surface is known to increase oxide growth rate (1).

Log in or Subscribe to Access the Full Article

To read or download full-length articles you need a subscription to Ultrapure. Please log in or subscribe below.