Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Nanoscale Science and Engineering


Nanoscale Sciences

Content Description

1 online resource (xxi, 245 pages) : PDF file, illustrations (some color)

Dissertation/Thesis Chair

Alain C Diebold

Committee Members

Fatemeh Shahedipour-Sandvik, Gert Leusink, Kathleen Dunn, Robert Geer


capacitance-voltage, high-k, lanthanum oxide, spectroscopic ellipsometry, VT shift, X-ray photoelectron spectroscopy, Metal oxide semiconductor field-effect transistors, Lanthanum compounds, Metal oxide semiconductors, Complementary, Gate array circuits

Subject Categories

Materials Science and Engineering | Nanoscience and Nanotechnology | Physics


The semiconductor industry continues to scale (shrink) transistor dimensions to both increase the number of transistors per integrated circuit and their speed. One important aspect of scaling is the need to decrease the equivalent oxide thickness of the transistor gate dielectric while minimizing leakage current. Traditional thin layer SiO2 or SiOxNy films have been replaced by higher dielectric constant film stacks Here we study one example, the HfO2/La2O3/SiO2 stack. This dissertation describes an investigation of the use of La2O3 to reduce the threshold voltage of TiN/HfO2/SiO2/Si stacks (high-k/metal gate stacks). A significant aspect of this study is the determination of band alignment for a series of high-k/metal gate stacks that explore the effect of placement and thickness of the Lanthanum oxide layer. In order to achieve this goal, a number of film stack properties were determined including film thicknesses, band gap of the high-k oxides, the flat band voltages, Si band bending, and the valence band and conduction band offsets.