Thermal stability of lanthanum scandate dielectrics on Si(100)

The authors have examined the thermal stability of amorphous, molecular beam deposited lanthanum scandate dielectric thin films on top of Si (100) after a $1000°C$⁠, $10s$ rapid thermal anneal. After the anneal, crystallization of $LaScO3$ is observed. Excellent suppression of lanthanum and scandium diffusion into the substrate silicon is indicated by the back-side secondary ion mass spectrometry (SIMS) analyses. In contrast, front-side SIMS and high-resolution electron energy loss analyses of the amorphous $Si∕LaScO3∕Si$ (100) stack indicated the outdiffusion of lanthanum and scandium into the silicon capping layer during the anneal.