METHOD FOR FORMING POLYSILICON

摘要

A method for forming polysilicon on a semiconductor substrate that include providing amorphous silicon on a semiconductor substrate, exposing at least an area of the amorphous silicon to a first laser beam and a second laser beam, characterized in that during exposing the area to the second laser beam no displacement of the laser beam relative to the area occurs. In addition, the use of such method for producing large grain polysilicon. In particular, the use of such method for producing vertical grain polysilicon. Further, the use of such method for producing sensors, MEMS, NEMS, Non Volatile Memory, Volatile memory, NAND Flash, DRAM, Poly Si contacts and interconnects.

主权项

1. A method for forming polysilicon on an insulator or semiconductor substrate comprising:
providing an amorphous silicon layer on said insulator or semiconductor substrate, defining an interface between said amorphous silicon layer and said insulator or semiconductor substrate; a first step of exposing at least an area of the amorphous silicon layer to a first laser beam and a second step of exposing said area to a second laser beam, characterized in that during exposing the area to the second laser beam no displacement of the laser beam relative to the area occurs, and in that: during the first step, the energy density and/or pulse duration generated by the first laser beam is selected to fully melt the amorphous silicon layer up to said interface, and so as to form by recrystallization a polysilicon layer with relatively small polysilicon grains, and during the second step, the energy density and/or pulse duration generated by the second laser beam is lower than the energy density and/or, respectively, pulse duration generated by the first laser beam, the energy density and/or pulse duration generated by the second laser beam being selected to partially melt the polysilicon grains formed by the first laser beam, and so as to enhance growth and solidification of relatively larger grain polysilicon with grain sizes of more than 1 micrometer in a direction perpendicular to the substrate surface area.