Oxygen recoil implant from SiO2 layers into single-crystalline silicon

Abstract

It is important to understand the distribution of recoil-implanted atoms and the impact on device performance when ion implantation is performed at a high dose through surface materials into single crystalline silicon. For example, in ultralarge scale integration impurity ions are often implanted through a thin layer of screen oxide and some of the oxygen atoms are inevitably recoil implanted into single-crystalline silicon. Theoretical and experimental studies have been performed to investigate this phenomenon. We have modified the Monte Carlo ion implant simulator, UT-Marlowe (B. Obradovic, G. Wang, Y. Chen, D. Li, C. Snell, and A. F. Tasch, UT-MARLOWE Manual, 1999), which is based on the binary collision approximation, to follow the full cascade and to dynamically modify the stoichiometry of the Si layer as oxygen atoms are knocked into it. CPU reduction techniques are used to relieve the demand on computational power when such a full cascade simulation is involved. Secondary ion mass spectrometry (SIMS) profiles of oxygen have been carefully obtained for high dose As and BF2 implants at different energies through oxide layers of various thicknesses, and the simulated oxygen profiles are found to agree very well with the SIMS data.

Atomic Spectrometry Update. Atomic mass spectrometry

“…A modified UT-Marlowe Monte Carlo code was used by Wang et al 211 to model oxygen recoil during ion implantation in thin silicon dioxide layers on crystalline (instead of amorphous) silicon. The stoichiometry of the silicon layer was dynamically changed as oxygen atoms were knocked out of the layers.…”