Electrical properties of cw laser-annealed ion-implanted polycrystalline silicon

Abstract

Resistivity and Hall measurements were performed on O.3‐μm‐thick polycrystalline‐silicon film after implantation with 10¹²–5×10¹⁴ boron or phosphorus ions/cm² and annealing with a cw Kr‐ion laser (green lines). The laser‐induced increase of grain size drastically alters the resistivity and Hall mobility. The largest effect occurs for average doping levels between 4×10¹⁶ and 10¹⁸ cm⁻³, where resistivity decreases by up to four and mobility increases by up to two orders of magnitude, compared with unirradiated parts of the same wafers. Values approaching those of single crystals are obtained. The results are interpreted in terms of a published grain‐boundary trapping model.