Disclosed is a semiconductor device including a bottom electrode, a dielectric layer, and a top electrode that are sequentially disposed on a substrate. The dielectric layer includes a hafnium oxide layer including hafnium oxide having a tetragonal crystal structure, and an oxidation seed layer including an oxidation seed material. The oxidation seed material has a lattice constant having a lattice mismatch of 6% or less with one of a horizontal lattice constant and a vertical lattice constant of the hafnium oxide having the tetragonal crystal structure.

A method for making a semiconductor device may include forming an isolation region adjacent an active region in a semiconductor substrate, and selectively etching the active region so that an upper surface of the active region is below an adjacent surface of the isolation region and defining a stepped edge therewith. The method may further include forming a superlattice overlying the active region. The superlattice may include stacked groups of layers, with each group of layers comprising 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 method for making a semiconductor device may include forming spaced apart first and second doped regions in a substrate. The first doped region may be larger than the second doped region to define an asymmetric channel therebetween. The method may further include forming 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. The method may also include forming a gate overlying the asymmetric channel.

A semiconductor device may include a semiconductor substrate, and a superlattice on the semiconductor substrate and including a plurality of stacked groups of layers. Each group of layers of the superlattice may include 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 first at least one non-semiconductor monolayer may be constrained within the crystal lattice of a first pair of adjacent base semiconductor portions and comprise a first non-semiconductor material, and a second at least one non-semiconductor monolayer may be constrained within the crystal lattice of a second pair of adjacent base semiconductor portions and comprise a second non-semiconductor material different than the first non-semiconductor material.

Superlattices and methods of making them are disclosed herein. The superlattices are prepared by irradiating a sample to prepare an alternating superlattice of layers of a first material and a second material, wherein the ratio of the first deposition rate to the second deposition rate is between 1.0:2.0 and 2.0:1.0. The superlattice comprises a multiplicity of alternating layers, wherein the multiplicity of layers of the first material have a thickness between 0.1 nm and 50.0 nm or the multiplicity of layers of the second material have a thickness between 0.1 nm and 50.0.

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 layer according to one embodiment of the present invention may exhibit a first number of electron states in a low-level electron energy range in a conduction band, and exhibit a second number of electron states in a high-level electron energy range higher than the low-level electron energy level in the conduction band, wherein localized states may exist between the low-level electron energy range and the high-level electron energy level.

A layer according to one embodiment of the present invention may exhibit a first number of electron states in a low-level electron energy range in a conduction band, and exhibit a second number of electron states in a high-level electron energy range higher than the low-level electron energy level in the conduction band, wherein localized states may exist between the low-level electron energy range and the high-level electron energy level.

A thin film transistor according to the inventive concept includes: a substrate; an insulating layer provided on the substrate; a superlattice channel layer provided on the insulating layer; and a source electrode and a drain electrode configured to cover a pair of opposite lateral surfaces of the superlattice channel layer, wherein the superlattice channel layer includes alternately stacked semiconductor layers and organic layers. A thickness of each semiconductor layer may be greater than about 3 nm to less than about 5 nm, and a thickness of each organic layer may be about 1 Å to about 1 nm.

A layer according to one embodiment of the present invention may exhibit a first number of electron states in a low-level electron energy range in a conduction band, and exhibit a second number of electron states in a high-level electron energy range higher than the low-level electron energy level in the conduction band, wherein localized states may exist between the low-level electron energy range and the high-level electron energy level.