Estimation of detrimental impact of new metal candidates in advanced microelectronics

摘要

Thanks to simple physical short loops, physical and chemical measurements (silicon lifetime, oxide thickness and roughness, oxide integrity, contamination analysis) this paper identifies and explains the behavior, on the Si and SiO_2 properties, of a large number of metal candidates in advanced microelectronics. These results are valid for the conditions of the wafer's treatment, i.e. 950℃/30 minutes oxidation followed by a H_2 annealing (425℃/30 minutes). Possible volatility of some elements has not been considered in this work. It presents for the first time the impact of Dy, Er, Ga, Ge, Gd, K, La, Li, Mg, Nb, Pr, Sc, Sb, Sn, Sr, V, Yb metal elements. The choice of grouping the metal contaminant elements on a physical-chemistry level (i.e. their diffusion coefficients and chemical behaviors toward silicon and silicon dioxide) is quite relevant regarding their impact on the silicon carrier lifetime and the oxide integrity. However in each of the three categories, exceptions occur and some may show large variations of their impact compared to the other metal elements of the group. Nevertheless we consider that this classification is preferable to a classification by impact which would lead to as many classifications as type of impacts.