A method for making a semiconductor device may include forming a superlattice adjacent a semiconductor layer. The superlattice may include a plurality of stacked groups of layers, with each group of layers including 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. The at least one non-semiconductor monolayer in a first group of layers of the superlattice may comprise oxygen and be devoid of carbon, and the at least one non-semiconductor monolayer in a second group of layers of the superlattice may comprise carbon.

A semiconductor device may include a semiconductor substrate and a memory device on the semiconductor substrate including a metal induced crystallization (MIC) channel adjacent the semiconductor substrate, and a gate associated with the MIC channel. The semiconductor device may further include a superlattice gettering layer between the substrate and the MIC channel. The superlattice gettering layer may include a plurality of stacked groups of layers, with 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. The superlattice gettering layer may further include gettered metal particles from the MIC channel.

A method for making a semiconductor device may include forming a superlattice gettering layer on a substrate. The superlattice may include a plurality of stacked groups of layers, with 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. The method may also include forming a memory device above the superlattice gettering layer including a metal induced crystallization (MIC) channel adjacent the semiconductor substrate, and a gate associated with the MIC channel. The superlattice gettering layer may further include gettered metal particles from the MIC channel.

A semiconductor device may include a substrate and spaced apart first and second doped regions in the substrate. The first doped region may be larger than the second doped region to define an asymmetric channel therebetween. The semiconductor device may further include a superlattice extending between the first and second doped regions to constrain dopant therein. The superlattice may include a plurality of stacked groups of layers, with 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. A gate may overly the asymmetric channel.

A semiconductor device may include a semiconductor layer, and a superlattice adjacent the semiconductor layer and including stacked groups of layers. Each group of layers may include stacked base semiconductor monolayers defining a base semiconductor portion, and at least one oxygen monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The at least one oxygen monolayer of a given group of layers may include an atomic percentage of .sup.18O greater than 10 percent.

A semiconductor device may include a substrate having a channel recess therein, a plurality of spaced apart shallow trench isolation (STI) regions in the substrate, and source and drain regions spaced apart in the substrate and between a pair of the STI regions. A superlattice channel may be in the channel recess of the substrate and extend between the source and drain regions, with the superlattice channel including a plurality of stacked group of layers, and each group of layers of the superlattice channel including 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. A replacement gate may be over the superlattice channel.

A method for making a semiconductor device may include forming a plurality of stacked groups of layers on a semiconductor substrate, with each group of layers including 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. The method may further include implanting a dopant in the semiconductor substrate beneath the plurality of stacked groups of layers in at least one localized region, and performing an anneal of the plurality of stacked groups of layers and semiconductor substrate and with the plurality of stacked groups of layers vertically and horizontally constraining the dopant in the at least one localized region.

A method for processing a semiconductor wafer in a single wafer processing chamber may include heating the single wafer processing chamber to a temperature in a range of 650-700 C., and forming at least one superlattice on the semiconductor wafer within the heated single wafer processing chamber by depositing silicon and oxygen to form a plurality of stacked groups of layers. Each group of layers may include 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. Depositing the oxygen may include depositing the oxygen using an N.sub.2O gas flow.

A semiconductor device may include a substrate having a channel recess therein, a plurality of spaced apart shallow trench isolation (STI) regions in the substrate, and source and drain regions spaced apart in the substrate and between a pair of the STI regions. A superlattice channel may be in the channel recess of the substrate and extend between the source and drain regions, with the superlattice channel including a plurality of stacked group of layers, and each group of layers of the superlattice channel including 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. A replacement gate may be over the superlattice channel.

A method for making a semiconductor device may include forming a plurality of stacked groups of layers on a semiconductor substrate, with each group of layers including 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. The method may further include implanting a dopant in the semiconductor substrate beneath the plurality of stacked groups of layers in at least one localized region, and performing an anneal of the plurality of stacked groups of layers and semiconductor substrate and with the plurality of stacked groups of layers vertically and horizontally constraining the dopant in the at least one localized region.