Paper AS-TuP22
Electrical and Surface Studies of the High-k Gate Dielectrics Al₂O₃, HfO₂, and Al_xHf_yO_z on Silicon via Atomic Layer Deposition

Tuesday, November 1, 2011, 6:00 pm, Room East Exhibit Hall

As the demand for high speed electronics remains ever increasing, the dimensions of MOSFET technology are continuously scaled down to the smallest possible levels. Traditional gate dielectrics such as SiO₂ are unable to effectively stop electron tunneling from degrading device performance at thicknesses below 1-1.2 nm. We propose using high dielectric materials instead, which can effectively limit leakage current and have a band gap close to SiO₂. This study will focus on the dielectrics Al₂O₃, HfO₂, and Al_xHf_yO_z deposited using ALD. Several ratios of aluminum and hafnium in the Al_xHf_yO_z compound will be investigated to find a level that maximizes both electrical and physical properties of the film. The electrical properties of each dielectric will be characterized by XPS, AFM, spectroscopic ellipsometry, and by taking IV and CV measurements of fabricated transistors and capacitors. We will also investigate the effects of different annealing and deposition temperatures on the interface by TEM.