Hi,
If you are designing electronics devices using different CMOS technologies inside some components, it does not matter terribly much. The um -figures you mention refer to the internal feature sizes ("line widths") of the circuits. Of course, those dimensions have consequences to the performance and other properties of the cmos-based component. The dimensions tell more about the process technology used than properties of the part.
However, look rather closely at the data sheets and application notes from suppliers. The most relevant things for electronics circuitry and device design are usually expressed on data sheets, and measured often in units closer to electronics world, such as Volts, Ohms, Decibels, milliAmps and nanoseconds. And very seldom in um, ml or mg. Application notes give ideas for the circuitry around the chips, and can give sometimes pretty smart cookbook-solutions.
br ted