Sandwich epi channel for device enhancement

摘要

The present disclosure relates to a method of forming a transistor device having a channel region comprising a sandwich film stack with a plurality of different layers that improve device performance, and an associated apparatus. In some embodiments, the method is performed by selectively etching a semiconductor substrate to form a recess along a top surface of the semiconductor substrate. A sandwich film stack having a plurality of nested layers is formed within the recess. At least two of the nested layers include different materials that improve different aspects of the performance of the transistor device. A gate structure is formed over the sandwich film stack. The gate structure controls the flow of charge carriers in a channel region having the sandwich film stack, which is laterally positioned between a source region and a drain region disposed within the semiconductor substrate.

主权项

1. A method of forming a transistor device, comprising:
selectively etching a semiconductor substrate to form a recess along a top surface of the semiconductor substrate; forming a sandwich film stack comprising a plurality of nested layers, wherein at least two of the plurality of nested layers comprise different materials configured to improve different aspects of performance of the transistor device, wherein the plurality of nested layers comprise:
a lower epitaxial layer formed onto the semiconductor substrate within the recess;a middle epitaxial layer of silicon carbide (SiC) formed onto a top surface and interior sidewalls of the lower epitaxial layer; andan upper epitaxial layer formed onto a top surface and interior sidewalls of the middle epitaxial layer; and forming a gate structure over the sandwich film stack, wherein the gate structure is configured to control a flow of charge carriers in a channel region comprising the sandwich film stack, which is laterally positioned between a source region and a drain region disposed within the semiconductor substrate.