Reduced microwave attenuation in coplanar waveguides using deep level impurity compensated Czochralski-silicon substrates

We show that deep level doping of Czochralski-grown silicon wafers is capable of providing high resistivity handle wafers suitable for radio frequency integrated circuits. Starting from n-type Czochralski silicon wafers having a nominal resistivity of 50 Ω cm, we use ion implantation and subsequent annealing to increase the resistivity of the wafers to over 10 kΩ cm at room temperature. Coplanar waveguides fabricated on implanted wafers show strongly reduced attenuation down to 0.3 dB mm-1 from 0.8 dB mm -1 for un-implanted wafers in the 1-40 GHz range, providing clear evidence that the technique is effective in improving performance of passive devices at GHz range frequencies. © 2011 IOP Publishing Ltd