Interfacial and Electrical Characterization of HfO2 Gate Dielectric Film with a Blocking Layer of Al2O3

✍ Scribed by Xinhong Cheng; Dawei He; Zhaorui Song; Yuehui Yu; Dashen Shen

• Publisher: Elsevier
• Year: 2009
• Weight: 336 KB
• Volume: 38
• Category: Article
• ISSN: 1875-5372
• DOI: 10.1016/s1875-5372(10)60016-1

✦ Synopsis

HfO 2 gate dielectric films with a blocking layer of Al 2 O 3 inserted between HfO 2 layer and Si layer (HfO 2 /Si) were treated with rapid thermal annealing process at 700 . The interfacial structure and electrical properties were reported. The results of X-ray photoelectron spectroscopy showed that the interfacial layer of SiO x transformed into SiO 2 after the annealing treatment, and Hf-silicates and Hf-silicides were not detected. The results of high-resolution transmission electron microscopy indicated that the interfacial layer was composed of SiO 2 for the annealed film with blocking layer. The results of the electrical measurements indicated that the equivalent oxide thickness decreased to 2.5 nm and the fixed charge density decreased to -4.5×10 11 /cm 2 in comparison with the same thickness of HfO 2 films without the blocking layer. Al 2 O 3 layer could effectively prevent the diffusion of Si into HfO 2 film and improve the interfacial and electrical performance of HfO 2 film.