Method of making low resistance polysilicon gate transistors and low resistance interconnections therefor via gas deposited in-situ doped amorphous layer and heat-treatment

A method of fabricating a plurality of transistors across essentially the entire surface of a crystalline wafer;

• said transistors being of the type that have source and drain regions in said wafer with low resistance gates and low resistance interconnections lying thereabove;
• said method including the steps of:
• forming an insulating layer across the surface of said wafer with a thickness that is suitable for separating said transistor gates from said wafer;
• exposing said insulating layer to a gas mixture of silicon and dopant atoms to deposit thereon an unpatterned layer of in-situ doped silicon, with said silicon layer being deposited in an amorphous state to improve the layer's uniformity in thickness and smoothness across the entire surface;
• patterning said silicon layer to the shape of said transistor gates and said interconnections therefor while said silicon is in said amorphous state to improve the accuracy with which the gates and interconnections are defined by removing selected portions thereof;
• implanting said source and drain regions of said wafer with dopant atoms;
• and
• heating said implanted source and drain regions to repair any crystal damage caused by said implant while simultaneously heating said patterned amorphous layer of silicon to change it to a patterned polycrystalline layer and thereby decrease the electrical resistivity of said gates and interconnections to about 10.sup.-3 .OMEGA.-cm.