Fabrication of SiGe-on-insulator substrates by a condensation technique: an experimental and modelling study

Today, to our knowledge, only two techniques are used to perform GeOI substrates: the Smart-CutTM technique and the Ge condensation technique. The latter is very sensitive to the initial parameters but is the only one which allows Si and Ge-on-insulator co-integration. Predictions of experimental results are then necessary to associate the best processes with the defined starting structures. This paper presents for the first time studies on Ge condensation technique simulations. Enrichment kinetics occurring in the classical one-dimensional condensation process have been simulated by the TCAD Silvaco Athena tool and analytical calculations. The good correlation with experimental data permits us to confirm the process dependence to the initial parameters. The influence of the process-induced non-homogeneities for the prestructure fabrication is also highlighted by the simulation results. The analytical model is efficient to predict a lot of experimental data with short calculation times. For more complex processes involving a two- or three-dimensional oxidation, enrichment prediction accuracy obtained by the analytic model is limited. Mechanism predictions under these experimental conditions are necessary to be studied by TCAD simulations.