| abstract |
An inductor is integrated in VLSI and ULSI technology products for very high frequency applications. The inductor is in a microstrip transmission line configuration which can be designed in a form of straight line, spiral line or Meander line. The inductor is formed by shorting the microstrip center conductor to the lower level ground plane at one end of the transmission line. This results in an inductance which, for a given design of transmission line, and in a specified frequency range, is independent of frequency, within the operating design range. The microstrip transmission line provides an inductance which could be used on any type of substrate, with either low or high resistivity. The microstrip transmission line could utilize two or all of the metal wiring levels of the technology, allowing a wide range of inductance and quality factor design tradeoffs. An important feature in this trade-off is the ability to utilize lower (below the inductor) metal wiring levels, as well as lower silicon and polysilicon areas for other than inductor design purposes, without affecting the operation of the inductor. This is because of the isolation properties of this inductor system. By utilizing isolation layers with low relative dielectric constant, Further enhancements of the system are achieved. The inductance of this system is constant within 10% over a frequency range extending from about 8 GHz to about 35 GHz This inductor system allows the design to be optimized, through several parameters, to achieve the desired performance. |