Yes. Typically most PCB designs go down to 1 mil traces and spacing - which is the limit of most PCB Fabricators. However as design requirements keep getting smaller, you can set FAB 3000 to handle Micro dimension capabilities (50 nm trace/space).
Note: You will need to exit and restart FAB 3000 for the changes to adjust.
Note: If you're working with a very large design (over 1 meter), than you can set FAB 3000 database extents to "Large".