As device scaling is an ever present concern in semiconductor manufacturing, the need for thin, conformal films with which to fabricate these devices is paramount. One technology that appears prominently placed to fill this need is Atomic Layer Deposition. This work presents a study on atomic layer deposited alumina (Al2O3), hafnia (HfO2), and silicon dioxide (SiO2) as dielectric materials characterized using capacitance-voltage (CV) analysis. MOS capacitors were fabricated utilizing various combinations of alumina or hafnia and silicon dioxide as an interfacial layer. Each dielectric film was characterized optically to determine the thickness, and then CV analysis was performed on each device. The results showed that the dielectric and interface quality of Al2O3 on bare silicon was superior to HfO2 on bare silicon. However the performance of Al2O3 devices dropped with the addition of interfacial SiO2, while the performance of the HfO2 devices was greatly enhanced. The treatment that had HfO2 with a monolayer of interfacial SiO2 on silicon produced the best results.
"Optimization of ALD High-K Dielectrics via C-V Analysis,"
Journal of the Microelectronic Engineering Conference: Vol. 20
, Article 1.
Available at: http://scholarworks.rit.edu/ritamec/vol20/iss1/1