Effect of temperature on advanced Si-based substrates performance for RF passive integration

• PSi and TR HR-Si substrates provide HR properties (>3 kΩ-cm) for RF applications.
• The resistivity of trap-rich HR-Si and PSi decrease with temperature increase.
• Permittivity of PSi is almost 4 times lower than TR HR-Si.
• The non-linear properties of PSi and TR HR-Si increase with temperature.
• At high temperature (175 °C) PSi behaves better than TR HR-Si.

This paper analyses RF substrate losses and non-linearity on Si-based substrates. Through measurements it is shown that trap-rich high resistivity silicon and porous silicon substrates are virtually lossless up to 120 °C. Although, RF losses and CPW attenuation increases with temperature on both Si-based solutions, they remain acceptable for high temperature RF applications. Porous locally grown silicon shows better linearity than a comparable trap-rich high-resistivity (HR) Si substrate up to 175 °C. Both Si-based solutions are considered as promising substrates for RF integration and system-on-chip applications.

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