Buried seed one-shot interlevel crystallization

A method is provided for crystallizing a semiconductor film using a buried seed one-shot interlevel crystallization process. The method forms a first semiconductor film having a crystallographic structure, overlying a transparent substrate. An insulator layer is formed overlying the first semiconductor film, and an opening is formed in the insulator layer, which exposes a portion of a first semiconductor film top surface. Then, a second semiconductor film with an amorphous structure is formed overlying the insulator layer. Typically, the first and second semiconductor films are Si, and the insulator is often an oxide or nitride. The second semiconductor film is laser annealed. In one aspect, the annealing is accomplished with a single laser shot. In response to the laser annealing, the second semiconductor film is completely melted and the first semiconductor film is partially melted. Using unmelted first semiconductor film as a seed, the second semiconductor film is crystallized.