Any motherboard with an Intel southbridge that supports RAID has "R" as a designator; i.e.; ICH8R (RAID support) as opposed to ICH8 (no RAID support), ICH9R as opposed to ICH9, and ICH10R as opposed to ICH10.
Is that the only way? Or there are other ways as well?
Yes, all enthusiast level (server mobos are different) Intel southbridge chipsets since the ICH7 series has the "R" designator for RAID support.
What about AMD motherboards?
As far as I can remember, all AMD chipset since the 700 series support RAID on the southbridge chipset.
The best way to tell is by reading the mobo specs and the make a list of motherboards that have the features you are looking for; like onboard RAID support. All mobo makers websites list the specs and most online retailers will also spell out if there is onboard RAID support.