SIMS depth profiling of ultrashallow P, Ge and As implants in Si using MCs ₂ ⁺ ions

Abstract

Abstract Quantitative determination of dose and junction depth in the source/drain region of future CMOS devices (typically 50 nm for the contact and 25 nm for the extension) requires SIMS instruments capable of measuring dopant profiles with high depth resolution and low detection limits. In this work we investigate the analytical usefulness of monitoring MCs 2 + ions for semiconductor profiling of n‐type dopants such as P, Ge or As with a primary (Cs + beam) impact energy of 1 keV on a SIMS Cameca IMS‐5f instrument. The results obtained on ultrashallow implants in Si and SiO 2 indicate an improvement in the characterization by using the MCs 2 + technique; this technique has the advantage over the MCs + technique of providing higher useful yields for electronegative elements by up to 10 2 and can therefore be applied to perform more precise junction measurements in terms of concentration, dose, decay length and detection limit. Copyright © 2002 John Wiley & Sons, Ltd.