Nanowire transistor structures with merged source/drain regions using auxiliary pillars

摘要

A nanowire transistor structure is fabricated by using auxiliary epitaxial nucleation source/drain fin structures. The fin structures include semiconductor layers integral with nanowires that extend between the fin structures. Gate structures are formed between the fin structures such that the nanowires extend through the gate conductors. Following spacer formation and nanowire chop, source/drain regions are grown epitaxially between the gate structures.

主权项

1. A method comprising:
obtaining a first structure including a base substrate, a plurality of gate structures on the base substrate, and a plurality of semiconductor fin structures on the base substrate, each of the gate structures including a gate conductor and a vertically stacked arrangement of nanowires extending through the gate conductor, each fin structure including a plurality of semiconductor layers and being positioned between a pair of the gate structures, the step of obtaining the first structure including:
obtaining a starting substrate including alternating layers of first and second semiconductor materials, the first and second semiconductor materials being selectively etchable with respect to each other;forming the semiconductor fin structures from the alternating layers of first and second semiconductor materials, the step of forming the semiconductor fin structures further including forming a plurality of parallel pads on the starting substrate and removing portions of the starting substrate between the pads;forming the vertically stacked arrangement of the nanowires from the layers of second semiconductor material by forming a plurality of fins from the layers of first and second semiconductor materials within the starting substrate, the fins intersecting the fin structures, and selectively etching the layers of first semiconductor material from the fins, andforming spacers on the fin structures and the gate structures, andchopping the nanowires outside the gate structures and fin structures, and epitaxially growing source/drain regions between the gate structures such that the source/drain regions contact the nanowires extending through the gate structures and one or more of the semiconductor layers of the fin structure.