Search

Abstract: Roughness development is one of the most often addressed issues in the secondary ion mass spectrometry (SIMS) ultra-shallow depth profiling. The effect of oxygen flooding pressure on the roughness development has been investigated under the bombardment of 500eV O2 + beam with simultaneous sample rotation. Oxygen flooding had two competing effects on the surface roughening, i.e., enhancement of initiating roughening and suppression of roughening development, which were suggested to be described by the onset depth z on and transient width w tr of surface roughening. Both z on and w tr decreased as oxygen flooding pressure increased. As the result, surface roughening was most pronounced at the intermediate pressure from 4.4E−5Pa to 5.8E−5Pa. The surface roughening is negligible while without flooding or with flooding at the saturated pressure. No flooding is preferable for depth profiling ultra-shallow B implantation because of the better B profile shape and short analysis time. [Copyright &y& Elsevier]

Abstract: Ultra-thin silicon oxynitride (SiO x N y ) is the leading candidate to replace pure silicon oxide (SiO2) before high k dielectrics come into place because oxynitrides demonstrate several properties superior to those of the conventional gate oxides. The performance of the transistor was reported to depend on the N dose and its distribution in the gate oxide. Therefore, accurate characterization of SiO x N y is prerequisite to control the quality of the ultra-thin nitrided gate oxide. However, secondary ion mass spectrometry (SIMS) faces big challenges in analyzing ultra-thin gate oxide because of surface effect and matrix effect. In this work, MCs2 + (M stands for matrix element) was detected to reduce the matrix effect in depth profiling the ultra-thin oxynitride. However, N profile was very close to the top surface if the oxynitirde was fabricated by decoupled plasma nitridation (DPN). With the conventional approach, the N dose was overestimated and the N profile was distorted near the top surface. To obtain a reliable N profile, the oxynitride was capped with a thin layer of oxide. The N profile of interest was hence in the region of sputtering equilibrium, i.e. the surface effect was minimized. As the results, reliable N dose and profile have been obtained. [Copyright &y& Elsevier]