Effect of nitrogen incorporation on the electronic structure and thermal stability of HfO2 gate dielectric

Abstract

Effects of fluorine incorporation and forming gas annealing on high-k gated germanium metal-oxidesemiconductor with Ge O 2 surface passivation Appl. Phys. Lett. 93, 073504 (2008); 10.1063/1.2966367Electronic structure and thermal stability of nitrided Hf silicate films using a direct N plasma

Analysis of x‐ray irradiation effect in high‐k gate dielectrics by time‐dependent photoemission spectroscopy using synchrotron radiation

“…The valence band maxima for HfO 2 , HfSiO, and HfSiON are composed of the O 2p states and the N 2p states, respectively. [17] Since the N 2p states lie above the O 2p states, the E v for HfSiON is smaller than those for HfO 2 and HfSiO by more than 1 eV. The E v for HfSiO is slightly reduced by adding SiO 2 into HfO 2 .…”

“…The conduction band minima for HfO 2 -based dielectrics are mainly composed of the Hf 5d states. [17] Though the addition of SiO 2 into HfO 2 changes second-nearest neighbours of Hf atoms from Hf to Si, the Hf 5d energy level is not significantly changed. The x-ray irradiation effect directly affects the determination of band offsets by PES spectra.…”

On the phase formation of sputtered hafnium oxide and oxynitride films

“…6͑b͒ lies well below the to N-N ͑which would correspond to N 2 formation͒ or N-O ͑which would correspond to the formation of NO or NO 2 ͒ bonds 49,14,56,57 and can, therefore, be attributed to Hf-N bonds. 14,56,57 Thus, N atoms in the hafnium oxynitride crystal occupy O sublattice sites, 14,56,57 which is the configuration described in our DFT calculations ͑see Sec. III͒.…”

“…Therefore, HfO 2 films with the cubic and/or the tetragonal crystal structure are widely used as high-k dielectric layers in field effect transistors. 5 In film form, HfO 2 can be deposited by a variety of techniques, including atomic layer deposition, 6 electron beam evaporation, 7 radio frequency, [8][9][10][11][12] direct current, [13][14][15] pulsed 16 and high pressure 17 magnetron sputtering, molecular beam epitaxy, 18 and pulse laser deposition. 2,3 With all these techniques, growth at room temperature commonly results in the formation of the m-HfO 2 phase 10,12,16,17,19,20 or amorphous films.…”

<I>In-Situ</I> Transmission Electron Microscopy Investigation of the Interfacial Reaction between Er and SiO<SUB>2</SUB> Films

“…Among them, Hf-based dielectrics have attracted much attention for their promising electrical and chemical properties, such as reasonably high dielectric constants, relatively large band gaps, and a thermal stability in contact with Si. [5][6][7] However, substantially large threshold voltage (V th ) shifts and unacceptably high interface trap densities (D it ) serve as a major barrier to the applications of Hf-based dielectrics to deep submicron complementary metal-oxide-semiconductor (CMOS) technology. 8,9) Recently, Choi et al investigated the electrical and structural properties of high-k Er-silicate films formed by the interfacial reaction between Er and SiO 2 films, and showed that the increase of the rapid thermal annealing (RTA) temperature results in a reduction of the interface trap density, and an increase of the relative dielectric constant of the Er-silicate film, which is compatible with the standard CMOS flow.…”