IR permittivities for silicides and doped silicon

Abstract

The complex permittivity for Pt, Pd, Ni, and Ti-silicide films as well as heavily doped p-and n-type silicon were determined by ellipsometry over the energy range 0.031 eV to 4.0 eV. Fits to the Drude model gave bulk plasma and relaxation frequencies. Rutherford backscattering spectroscopy, X-ray diffraction, scanning electron microscopy, secondary ion mass spectrometry, and four-point probe measurements complemented the optical characterization. Calculations from measured permittivities of waveguide loss and mode confinement suggest that the considered materials are better suited for long-wavelength surface-plasmon-polariton waveguide applications than metal films.

Review of mid-infrared plasmonic materials

“…Examples of intermetallics are the silicides and germanides, [19][20][21] often formed by sequentially deposited semiconductors (silicon or germanium, respectively) and metals (Cu, Co, Pd, Pt, Ni, Ti, for example) followed by a high temperature anneal to form a conducting material. While the majority of silicide and germanide research has focused on integration into CMOS fabrication technology, such materials are also of particular interest for longer-wavelength plasmonic applications, 22 due to their CMOS compatibility, and plasmonic behavior at frequencies below the band-edge of Si or Ge (and thus spectrally separated from interband absorption losses). Figure 3 shows the experimental and Drude model permittivity for representative silicide materials (NiSi and TiSi), from Ref.…”

“…Figure 3 shows the experimental and Drude model permittivity for representative silicide materials (NiSi and TiSi), from Ref. 22. As can be seen from the data in Fig.…”

Palladium Germanides for Mid- and Long-Wave Infrared Plasmonics

“…However, these materials are not useful in the infrared spectrum as their plasma frequency is typically in the UV or visible range [3,4]. For mid-wave infrared (MWIR, 3-5μm) and longwave infrared (LWIR, 8-12μm) applications, materials such as doped silicon and germanium [5,6], transparent conducting oxides [7], metal silicides [5,8] and metal germanides [9] have been investigated. A comprehensive review of these materials can be found in [2].…”

Investigation of plasmon resonance tunneling through subwavelength hole arrays in highly doped conductive ZnO films

“…The investigation of alternative plasmonic materials has recently been accelerated 7,[14][15][16][17][18][19][20][21][22][23][24][25][26] due to the push to the infrared where noble metals are not as useful due to weak mode confinement and lack of CMOS compatibility. Two promising candidates, aluminum and gallium doped ZnO, have been proposed as possible plasmonic materials in the near- 17,19 and mid-IR 26 as these materials typically demonstrate plasma wavelengths $1 lm.…”