Properties of BaTiO₃Films Sputter Deposited on PET for Pulse Power Capacitors

Supplementary document for Hybrid Electro-Optic Modulator Combining Silicon Photonic Slot Waveguides with High-k Radio-Frequency Slotlines - 5053736.pdf

“…We attribute these differences to small deviations between the simulated and the fabricated cross section of the CPW, which become more relevant at low frequencies where RF currents flow in the entire cross section of the metal traces. Note also that our finding of a frequency-independent relative permittivity of r,BTO 18 ε = is in good agreement with literature [3,5,28,29], where permittivities r,BTO ε between 14 and 20 were found in the frequency range between 1 kHz and 40 GHz. Regarding future CC-SOH devices, the modulation efficiency can be greatly improved by using polycrystalline BTO films, for which with relative permittivities in excess of 100 [5,28] have been measured over a few GHz [30].…”

“…We hence consider this loss tangent a conservative estimate for the dielectric losses of the amorphous BTO films used in the current devices. The extracted material loss parameter agreement with previously published values of similar amorphous BTO films[3].…”

“…A rather low RF power of 30 W is applied to the target to keep the temperature of SOI substrates below the glass transition temperature of the PMMA mask to enable a proper lift-off. Due to the low process temperature, the BTO thin film is known to be amorphous [3,4], which may be overcome by subsequent annealing [5]. The width of the BTO film is chosen to be 1 µm for good trade-off between the optical losses due to the gold transmission line and the capacitance of the BTO film, see Section 5 for details.…”

Hybrid electro-optic modulator combining silicon photonic slot waveguides with high-k radio-frequency slotlines

“…and a loss tangent BTO tan 0.05   at 60 GHz, which is in good agreement with measurements of amorphous BTO films [38][39][40][41]. Details of the RF characterization of BTO thin films can be found in Supplementary Information 1, Section 1B.…”

Capacitively Coupled Silicon-Organic Hybrid Modulator for 200 Gbit/s PAM-4 Signaling

“…1(a). Amorphous BTO slabs (red) having a height of 150 nm, a width of 1 µm, and a high electric permittivity 7 of r > 50 are deposited between the optical slot waveguide and the transmission line to enhance capacitive coupling of the RF signal to the slot. The finite difference time domain (FDTD) simulations in Fig.…”