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.