CDF Run IIb silicon: the new innermost layer

The innermost layer (L00) of the Run Ila silicon detector of CDF was planned to be replaced for the high luminosity Tevatron upgrade of Run IIb. This new silicon layer (L0) is designed to be a radiation tolerant replacement for the otherwise very similar L00 from Run Ila. The data are read out via long, fine-pitch, low-mass cables allowing the hybrids with the chips to sit at higher z (∼ 70 cm), outside of the tracking volume. The design and first results from the prototyping phase are presented. Special focus is placed on the amount and the structure of induced noise as well as signal to noise values.