ABSTRACT
The next generation, state-of-the-art, Si-based, microelectronic devices (critical feature dimensions approaching 0.18 nm) will utilize sub-keV dopant implants and gate dielectrics <4 nm thick [1], Characterization of these critical processes and materials will push the limits of existing materials analysis techniques, especially those with depth-resolved analysis capabilities. Secondary ion mass spectrometry (SIMS) has proven itself to be an indispensable analytical tool in the semiconductor industry by providing high depth resolution profiling capabilities. In recent years, however, characterization of ultra-shallow dopant implants and ultra-thin dielectric films has exposed fundamental weaknesses in conventional SIMS protocols. The presence of several SIMS artifacts, some well-known and some new, have conspired to make ultra-high depth resolution profiling problematic. These artifacts include (but are not limited to): sputter rate variations [2], surface transient effects [3], and ion beam-induced sample roughening [4]. Most of these artifacts have been identified while profiling shallow B implants but can also be encountered in other samples.
