Like so the option of "size not welcome"?
"The major characteristics of a CPU are: the clock frequency, performance, power consumption, norms of the lithographic process used in manufacture (for microprocessors)
and architecture." wiki
; micro, nano is the characteristics dimension of lithography.
I understand that you are interested in the mechanism used for processing, then the CPU is the transistor, the microprocessor is a transistor on the graphite substrate, nanoprocessor is graphene transistors, however, there is a limit of possibilities, for this I recommend to familiarize with the concept of Half Shrink
To increase computing power, you probably want to look towards quantum computing systems.