Small-Area Inductor for Silicon CMOS Chips

This study proposes a small-area inductor on a Si CMOS chip. The inductor is evaluated using simulated and measured results. From the viewpoint of device area, a solenoid-type inductor is known to be superior to the other conventional on-chip inductors. The area of a proposed snake-type inductor is smaller than that of a solenoid-type inductor. Two types of snake inductor have been fabricated. Thier measured inductances are 1.46 nH at 10 GHz and 2.09 nH at 5.25 GHz. The maximum values of the quality factors are 1.76 at 10 GHz and 1.13 at 5.25 GHz.