Method for making semiconductor device with selective etching of superlattice to accumulate non-semiconductor atoms

A method for making a semiconductor device comprising:

• forming a superlattice above a semiconductor layer, the superlattice comprising a plurality of stacked groups of layers, each group of layers comprising a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions;
• selectively etching the superlattice to remove semiconductor atoms and cause non-semiconductor atoms to accumulate adjacent the semiconductor layer;
• removing the accumulated non-semiconductor atoms;
• epitaxially growing an active semiconductor device layer above the semiconductor layer after removing the accumulated non-semiconductor atoms;
• and
• forming at least one circuit in the epitaxially grown active semiconductor device layer.

A method for making a semiconductor device comprising:

• forming first and second superlattices above a semiconductor layer, the first and second superlattices each comprising a plurality of stacked groups of layers, each group of layers comprising a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions;
• selectively etching the second superlattice to remove semiconductor atoms and cause non-semiconductor atoms to accumulate adjacent the first superlattice;
• removing the accumulated non-semiconductor atoms;
• epitaxially growing an active semiconductor device layer above the first superlattice after removal of the accumulated non-semiconductor atoms;
• and
• forming at least one circuit in the epitaxially grown active semiconductor device layer by forming spaced apart source and drain regions in the active semiconductor device layer, and forming a gate defining a channel region between the spaced apart source and drain regions.

A method for making a semiconductor device comprising:

• forming a superlattice above a silicon layer, the superlattice comprising a plurality of stacked groups of layers, each group of layers comprising a plurality of stacked base silicon monolayers defining a base silicon portion, and at least one oxygen monolayer constrained within a crystal lattice of adjacent base silicon portions;
• selectively etching the superlattice to remove silicon atoms and cause oxygen atoms to accumulate adjacent the silicon layer;
• removing the accumulated oxygen atoms;
• epitaxially growing an active silicon device layer above the silicon layer after removal of the accumulated oxygen atoms;
• and
• forming at least one circuit in the epitaxially grown active silicon device layer.