Is Hawking radiation "smaller" than a Planck length..?.. If so what does that imply..If not what role does anti-matter play in this..?

No Hawking radiation is the (invevitable) process by which the quantum foam generate particles with energy more than one plank length above the event horizon - the particle escapes and the matching negative energy erodes the Black Hole by cancelling mass above the event horizon..

The particle escaping is real and more than a Plank length long.

It is anti-matter in a sense as the "in" particle is anti matter in association with negative energy. Initially the anti matter and negative energy annihilate the mass above the event horizon. Once that has gone then it starts cancelling the mass/energy within the event horizon - the theory is a little vague about process as the anti matter with negative energy cannot move within the event horizon due to time dilation. Bit of a paradox there - the anti matter with negative energy shouldn't be time dilated.