| Popis: |
Interferences injected to an RF circuit may strongly deteriorate the electrical performance. Parasitic coupling via substrate is one of the dominant interference transmission mechanisms in highly integrated systems. The effect of substrate coupling becomes more critical at higher circuit frequencies. This poses a particular challenge for highly integrated millimeter-wave systems, since isolation techniques become less efficient with an increasing operating frequency. This paper presents an experimental study on coupling via bulk silicon and RF-SOI substrates. We investigate in measurement up to 110 GHz efficiency of several isolation techniques, such as triple-well, p+ and n+ guard-rings and use of undoped highly resistive region. Additionally, RF-SOI substrates are known to be beneficial for higher crosstalk isolation. However, also this isolation degrades at higher frequencies. Hence, we investigate in measurement up to 110 GHz the isolation via low-resistivity and high-resistivity trap-rich SOI substrate variants. Test structures were realized in 40 nm bulk CMOS and 45 nm RF-SOI technology nodes. |
