Fabrication of a photoconductive or a cathoconductive device using lateral solid overgrowth method

Abstract

A method for crystallizing an amorphous film formed on an underlying layer having an unfavorable crystalline growth morphology is disclosed. The method includes providing a favorable growth substrate and then forming a first unfavorable growth layer on a seeding surface of the favorable growth substrate. An aperture is etched in the first unfavorable growth layer so that the aperture extends through the first unfavorable growth layer down to the seeding surface thereby exposing a portion of the seeding surface. An amorphous media layer is then formed on the first unfavorable growth layer. The amorphous media layer fills the aperture and is in contact with the seeding surface of the favorable growth substrate. A crystallized media layer is formed by annealing the amorphous media layer so that nucleation of a crystalline phase of the amorphous media layer begins at the seeding surface and propagates throughout the entirety of the amorphous media layer so that the remainder of the amorphous media layer is crystallized to form the crystallized media layer. Consequently, the crystallized media layer has a useful morphology due to nucleation of crystallization on the favorable growth substrate while being formed on the first unfavorable growth layer which tends to induce an unfavorable crystalline growth morphology. The crystallized media layer can be used as a data storage medium in an ultra-high density data storage device.