estradasphere
Member level 4
Hi,
I use BSIM3v3.3 MOS transistor models for RFIC design. BSIM 3v3.3 does not include a substrate network but just a drain-bulk capacitance which may be insufficient at high frequencies. I decided to use a grounded substrate contact surrounding the transistors
to reduce the substrate resistance. The distance between the transistor and the contact is about 0.2 um. This is the smallest distance which doesn't cause a DRC error.
Does someone have experience with the substrate effect, let's say up to 20 GHz? How critical would be the effect of the substrate resistance on the output matching characteristics of an amplifier, even if a bulk contact surround the transistor is used?
Thanks.
I use BSIM3v3.3 MOS transistor models for RFIC design. BSIM 3v3.3 does not include a substrate network but just a drain-bulk capacitance which may be insufficient at high frequencies. I decided to use a grounded substrate contact surrounding the transistors
to reduce the substrate resistance. The distance between the transistor and the contact is about 0.2 um. This is the smallest distance which doesn't cause a DRC error.
Does someone have experience with the substrate effect, let's say up to 20 GHz? How critical would be the effect of the substrate resistance on the output matching characteristics of an amplifier, even if a bulk contact surround the transistor is used?
Thanks.