Germanium Nanosheets and Methods of Forming the Same

A method of forming a semiconductor device, the method comprising:

• forming a stack of layers over a substrate, the stack of layers comprising a first material layer over the substrate, a first semiconductor layer over the first material layer, a second material layer over the first semiconductor layer, and a second semiconductor layer over the second material layer;
• patterning the substrate and the stack of layers to form a fin having a stack of nanowires over the fin, the stack of nanowires comprising a first material nanowire on the substrate, a first semiconductor nanowire on the first material nanowire, a second material nanowire on the first semiconductor nanowire, and a second semiconductor nanowire on the second material nanowire, each nanowire of the stack of nanowires comprising a first section, a second section, and a channel region interposed between the first section and the second section;
• removing the first material layer and the second material layer in the channel region;
• and
• forming a dielectric layer around the first semiconductor nanowire and the second semiconductor nanowire in the channel region.

A method of forming a semiconductor device, the method comprising:

• forming a stack of nanosheets over a fin, the stack of nanosheets comprising alternating layers of germanium and a first material, wherein the first material comprises silicon germanium tin or silicon tin, each nanosheet of the stack of nanosheets having a first end portion, a second end portion, and a channel region interposed between the first end portion and the second end portion;
• thinning the stack of nanosheets in the channel region;
• removing the layers of the first material in the channel region, wherein the layers of germanium remaining in the channel region;
• and
• forming a gate dielectric on the layers of germanium.