  We demonstrate 3D microwave projection sideband cooling of trapped, neutral
atoms. The technique employs state-dependent potentials that enable microwave
photons to drive vibration-number reducing transitions. The particular cooling
sequence we employ uses minimal spontaneous emission, and works even for
relatively weakly bound atoms. We cool 76% of atoms to their 3D vibrational
ground states in a site-resolvable 3D optical lattice.
