Piezoresistive effects of p-type polycrystalline silicon underline that longitudinal and transversal piezoresistive properties in monocrystalline silicon do not have the same physical origin, which is not accounted for in current models. This difference is highlighted by the study of the mechanical stress effect on the valence band, which shows that piezoresistive properties of p-type monocrystalline silicon can be explained in terms of both hole transfer between heavy-and light-hole valence bands and stress-dependent hole effective masses. The quantification of these phenomena points out that longitudinal piezoresistive properties are mainly due to the hole transfer, whereas transversal ones are mainly attributed to the effective mass change effects. This enables one to model p-type polycrystalline silicon piezoresistivity, in particular the sign change of the transversal gauge factor at high doping level. ͓S0163-1829͑98͒01615-4͔
Copper trace analysis using Transient Ion Drift (TID) combined with a Rapid Thermal Annealing (RTA) process is investigated. A double pulse method is implemented to allow unambiguous identification of the copper-induced capacitance signal. Use of a mercury probe as sensing Schottky barrier enhances the flexibility of the method and allows mapping of the contaminant. The method is evaluated on quantitatively contaminated silicon wafers and compared to Total X-ray fluorescence (TXRF).It is shown that in Czochralski grown material, the RTA is sufficient to dissolve most copper atoms into interstitial sites independently of their initial configuration. As a result, both, the surface and bulk contamination can be monitored by RTA/TID with a bulk detection limit close to 1011cm-3.In Float Zone material mapping of the quenched interstitial copper revealed the existence of defect reactions involving presumably vacancy clusters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.