In Situ Transmission Electron Microscopy Study of Shrinkage Kinetics of CH₄N-Molecular-Ion-Implantation-Induced Extended Defects

Abstract

The thermal stability of end-of-range (EOR) defects formed in a CH4N-molecular-ion-implanted epitaxial silicon (Si) wafer was studied by transmission electron microscopy (TEM). We found that the density and size of the CH4N-ion-implantation-induced EOR defects negligibly changed upon heat treatment at temperatures below 1000ºC, whereas the EOR defect density was drastically reduced by heating at 1100ºC. Additionally, in situ cross-sectional TEM observation during heat treatment showed that the EOR defects gradually shrank at the beginning of heat treatment (1st stage), and then the shrinkage rate rapidly increased (2nd stage), finally resulting in the dissolution of the defects. The activation energies for the shrinkage of EOR defects in the 1st and 2nd stages were found to be 7.55±1.03 and 4.57±0.32 eV, respectively. The shrinkage behavior in the 1st stage might be attributed to the desorption of C and N species that segregated along the edge of an EOR defect. On the other hand, the shrinkage behavior in the 2nd stage might be due to the desorption of interstitial Si atoms. These findings suggest that the interaction between the EOR defect and the impurities segregated at the edge of the defect affects the thermal robustness of the CH4N-ion-implantation-induced EOR defects.

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

“…Previously, we have clarified the thermal stability and shrinkage behavior of FDLs formed in CH 4 N-multielement-molecular-ion-implanted epitaxial Si wafer. 35 We found that the faulted Frank dislocation loops (FDLs) formed in a CH 4 N-ion-implanted epitaxial Si wafer are thermally stable up to 1000 °C, and at temperatures above 1100 °C, most of them lose stability and finally dissolve. In addition, we also found that the FDLs formed in the CH 4 N-ion-implanted Si wafer shrink with two different shrinkage rates during heat treatment.…”