The Structure of Plasma-Deposited and Annealed Pseudo-Binary ZrO₂-SiO₂ Alloys

Abstract

The internal structures of various (ZrO2)x(SiO2)1-x alloys (x ≤ 0.5) were investigated. A remote plasma enhanced-metal organic chemical vapor deposition (RPEMOCVD) process was used to deposit films with varying alloy composition on Si(100) substrates. This study indicates that for the glassy silicate phase, g-ZrSiO4, a glass transition temperature, Tg, exists between 800°C and 900°C at which phase separation into the end-member components, SiO2 and ZrO2, occurs.

High-temperature phase stability of hafnium aluminate films for alternative gate dielectrics

“…High-k metal oxides that are potentially stable in contact with Si include HfO 2 and ZrO 2 , and their alloys with SiO 2 (silicates) and Al 2 O 3 (aluminates), respectively [1][2][3][4]. Device processing requires temperatures around 1000 °C, and it is now well established that amorphous Hf-or Zrsilicate films phase separate at high temperatures into a silica-rich and a transition metal (Hf or Zr)-oxide-rich phase [5][6][7][8][9]. Phase separation produces local variations in the dielectric properties of the films that may be detrimental for devices, for example by causing electric field variations in the underlying Si channel [7].…”

Four-Wave-Mixing in Zirconia-Yttria-Aluminum Erbium Codoped Silica Fiber

“…In bulk zirconia-silicate glass, phase-separation has been observed at temperatures below the onset of crystallizationwhich also results in structural inhomogeneity [31,32]. Phase separation, or immiscibility, is a phenomenon that is known to exist in amorphous binary systems [33]; however in some ZrO 2 -SiO 2 systems immiscibility exists even in the stable liquid phase above the melting point.…”

Local Bonding, Phase Stability and Interface Properties of Replacement Gate Dielectrics, Including Silicon Oxynitride Alloys and Nitrides, and Film ‘Amphoteric’ Elemental Oxides and Silicates

“…Far-IR spectra extending to 50 cm -1 show no additional discrete features. Broader spectral features of an as-deposited x ~0.5 film have been attributed to a random close packing of Zr 4+ and SiO4 4-ions [8,23]. The 800 to 1200 cm -1 band includes internal SiO 4 4-vibrations, and the ~450 cm -1 band is assigned to Zr-O vibrations.…”

“…The 800 to 1200 cm -1 band includes internal SiO 4 4-vibrations, and the ~450 cm -1 band is assigned to Zr-O vibrations. After a 900°C anneal, changes in these spectra indicate a chemical phase separation into i) a noncrystalline low Zr-content silicate alloy with ~1-2 atomic % Zr, or SiO 2 , and ii) noncrystalline (x~0.1 and ~0.23) or crystalline ZrO 2 (x~0.5) [23]. As in bulk silicate glasses, introduction of oxides of electropositive Zr(Hf)-atoms into the SiO 2 network results in a break-up or modification of that network [7,8].…”

“…Homogeniety in bulk silicate glasses quenched from high temperatures is limited by chemical phase separation, and in many instances homogeneous glasses are obtained only at relatively low metal oxide compositions, <5-10 mol percent. This is not a limitation in thin film silicates deposited at temperatures <500°C [22,23,[27][28][29][30], The analysis presented below applies to these films, as well as films prepared at low temperatures, and subsequently processed at temperatures <800°C. The capacitors with Zr(Hf) silicate dielectrics in Refs.…”