Diffusion and interface growth in hafnium oxide and silicate ultrathin films on Si(001)

Abstract

Medium energy ion scattering (MEIS) has been used in combination with 16 O and 18 O isotope tracing to determine elemental depth distributions and elucidate oxygen transport in 2-5 nm thick HfO 2 and HfSiO x films grown by atomic layer deposition on Si(001). Both the oxygen isotope exchange rate in the dielectric as well as the interfacial silicon oxide growth rates were examined as a function of time, temperature, film stoichiometry (HfO 2 , HfSiO x and HfSiO x N y ) and crystallinity. The amount of exchanged oxygen in the oxide was found to decrease with increasing SiO 2 content. When the SiO 2 to HfO 2 ratio reaches 1:1 in HfSiO x almost full suppression of oxygen exchange is observed. The activation barrier for the SiO 2 growth at the HfO 2 /Si and HfSiO x /Si interface was found to be much lower than that in the SiO 2 /Si and SiO x N y /Si cases, which is attributed to distinctly different oxygen incorporation mechanisms.Primary route for oxygen delivery to the interface responsible for the SiO 2 growth is via exchange, however direct oxidation by molecular oxygen cannot be discounted completely. In the presence of an interfacial nitride layer the 18 O-16 O exchange is replaced by the 18 O-N exchange, which slows diffusion and reduces the oxidation rate.2

Interfacial reaction induced strain relaxation in Hf-silicate film on strained Si0.7Ge0.3(001) as a function of annealing temperature

“…Following PDA at 900 8C, a thicker IL was observed at the HfSiO/SiGe interface as compared that observed in the case of HfO 2 /SiGe. This was a result of the catalytic effect of phase separation in the partiallycrystallized HfSiO film [14][15][16]. In other words, the thicker IL in HfSiO film after PDA at 900 8C resulted from a large amount of O 2 inter-diffusion along the diffusion path by grain boundaries of partially crystallized HfO 2 compared to fully crystallized HfO 2 film with lack of grain boundary.…”

New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector

“…• , the crystal direction [11][12][13][14][15][16][17][18][19][20][21][22][23], a direction with the same symmetry as the direction of the incoming beam, is seen as a dark spot. Two unwanted artifacts can also be seen.…”

“…Electronic mail: marga@kth.se. b) Present address: HORIBA Jobin Yvon SAS, [16][17][18] Rue du Canal, 91165 Longjumeau Cedex, France. it was shown that the ToF concept in combination with a twodimensional detector was a useful way for MEIS analyzes. 8 This ToF concept introduces an additional degree of freedom in the diagnostics, making three-dimensional (3D) MEIS possible.…”

“…[14][15][16][17] This paper reports on the new MEIS beam line at the Ångström laboratory, Uppsala University, Sweden. This MEIS system is based on a ToF concept for determining the kinetic energy distribution and a position sensitive detector for the angular distribution of the backscattered ions.…”

Growth and thermal oxidation of Ru and ZrO2 thin films as oxidation protective layers

“…Apart from the characterization of the grown layers, in some of these oxide studies, oxygen diffusion through the gate dielectric towards deeper layers has also been investigated. 91,96,98,99,100,102,103 In addition, the thermodynamic stability in contact with Si of most of the mentioned binary oxides, has been evaluated. 32 All presented oxide materials have been considered as a replacement of the typical SiO2 gate dielectric layer, which exhibits high gate leakage current at small thicknesses (<1 nm), required for the continuous downscaling of microelectronics.…”