Thermal Shrinkage Behavior of CH3O-Multielement-Molecular-Ion-Implantation-Induced Dislocation Loops Studied by Real-Time Transmission Electron Microscopy Observation

Abstract

We investigated the thermal behavior of dislocation loops formed in a CH3O-multielement-molecular-ion-implanted epitaxial silicon (Si) wafer by real-time cross-sectional TEM observation with in situ heating. We found that the CH3O-ion-implantation-induced faulted Frank dislocation loops (FDLs) shrink at a low rate at the beginning of heat treatment (1st stage), and then the shrinkage rate rapidly increased (2nd stage), resulting in the dissolution of the defects. The activation energies for the shrinkage of FDLs in the 1st and 2nd stages (E D-1 and E D-2) were found to be 2.94 ± 0.31 and 4.95 ± 0.25 eV, respectively. The shrinkage behavior in the 1st stage is the desorption of C and O atoms that segregated along the edge of an FDL because of the interaction between the CH3O-ion-implantation-induced FDL and the segregated impurities. On the other hand, the 2nd stage corresponds to the desorption of Si atoms from FDLs and its migration. Compared to our previous study on the shrinkage behavior of CH4N-ion-implantation-induced FDLs (J. Electrochem. Soc. 169, 047521 (2022)), E D-2 of the CH3O-ion-implantation-induced FDLs is almost the same as that of the CH4N-ion-implantation-induced FDLs, while the values of E D-1 are quite different. The difference between the E D-1 values of CH3O- and CH4N-ion-implantation-induced FDLs is suggested to be the difference of the kind of segregated impurities. Our experimental results suggest that thermal stability of the dislocation loop is determined by the kind of segregated impurities around the dislocation loop.