BJT Technology Specification

Dear all,

A number of papers with BiCMOS circuitry would use emitter length as the primary specification, like in one paper it says "0.180um*5um" with a specific npn hbt...what i conclude from this specification is that this hbt (high freq bjt) shall be built with 180nm technology with an emitter length of 5um, is this conclusion right?

On other places the specification is written as follows: e.g 9*0.17um^2 this is an area...is this emitter area???

The technology file i have from a certain company does not allow me to change these parameters but i change the collector current.....i know changing above parameters mean changing the collector(or emitter) current but is there any way to relate the changing emitter length with the changing emitter current???

Current scales (first order) with area. But you may be allowed only one
degree of freedom (L or W), or none (unit emitter, times N) for the
geometry.

Usually you want L (in the direction of base current flow) to be minimum
and W the variable, for least emitter debiasing and base pinched
resistance.

HBT, h usually means hetero-something. Such as SiGe base region being
a heterojunction.