Epitaxial growth of large-area p+n diodes at 400 ºC by Aluminum-Induced Crystallization

Aluminum-Induced Crystallization is applied on crystalline Si substrates. By this method a physical-vapor-deposited amorphous Si layer is successfully transformed into a monocrystalline solid-phase epitaxy (SPE) p-doped layer at an anneal temperature of 400°C. The as-grown epitaxial layer takes on the orientation and the lattice constant of the substrate. It is shown that a complete coverage over large areas is possible if the c-Si interface is free of nucleation centers. This can be achieved by the proper oxide-patterning and/or chemical treatments of the substrate surface before deposition of the Al mediator layer. High-quality p⁺n diodes have been fabricated with areas up to 1×1 cm², having ideality factors down to 1.02 and low leakage currents in the 2-3 nA/cm² range. The full coverage by p⁺ SPE-Si is confirmed by material analysis.