Improving the RF performance of 0.18 mu m CMOS with deep n-well implantation

The radio-frequency (RF) figures of merit of 0.18 mum complementary metal-o xide-semiconductor (CMOS) technology are investigated by evaluating the uni ty-current-gain cutoff frequency (F-t) and maximum oscillation frequency (F -max). The device fabricated with an added deep n-well structure is shown t o greatly enhance both the cutoff frequency and the maximum oscillation fre quency, with negligible dc disturbance. Specifically, 18% increase in F-t a nd 25% increase in F-max are achieved. Since the deep n-well implant can be easily adopted in a standard CMOS process, the approach appears to be very promising for future CMOS RF applications.