That doesn't make any sense. What wud u gain by doing this? Let me tell you why. Even if this is possible with a s/w Raid controller, it server no practical purpose.
Raid 0 - improves performance by allowing multiple HDDs to participate in the IO process. When one is working away to find info, the other one can get new requests, etc.
If you have both "hard drives" in one physical hard drive, Raid 0 is pointless as there is only "one" HDD and the improvement of multiple HDDs participating in IO is not present.
Raid 1-whatever - this is used for redundancy. If one disk fails, you can recover data. If you have your "raid HDDs" in one physical drive, where is the redundancy? If the drive fails, the data is lost!!