US 5,013,683 A · Method for growing tilted superlattices

Abstract

A method for growing a superlattice structure on a substrate. First, a periodic array of monoatomic surface steps are created on the surface of the substrate at an area to have the superlattice structure grown thereon. There is apparatus for creating a beam of a material being input thereto and for selectively including or not including respective ones of a plurality of materials within the beam. The beam is directed at the steps of the substrate. Finally, logic causes control apparatus to include and not include respective ones of the materials within the beam in a pre-established pattern of time periods which will cause the materials to be deposited on the steps in a series of stacked monolayers. Tilted Superlattices (TSLs) and Coherent Tilted Superlattices (CTSLs) are created. The method can create pseudo ternary semiconductor alloys as part of a CTSL by employing at least two binary compound semiconductor alloys in the deposition process. It can also create a quantum wire superlattice by sandwiching a thin CTSL layer between two wider band gap layers. Additionally, it can create a tilted superlattice with zero misfit strain by using three binary compounds to produce a pseudo-ternary compound in a direction parallel to the substrate normal while the tilted superlattice structure provides a desired band gap in a direction parallel to the substrate surface. One may form the CTSL as part of a field effect transistor (FET) wherein the CTSL is part of the FET gate or form the CTSL as the cladding layers of a quantum wire laser having a GaAs active layer.

Claims33

Dependent claims

The method for growing a superlattice structure on a substrate comprising the steps of:

(a) creating a periodic array of monoatomic surface steps on the substrate comprised of a plurality of equal and adjacent monoatomically thick steps on the surface of the substrate at an area to have the superlattice structure grown thereon wherein each step contains a plurality of atomic bonding sites on the surface thereof;
(b) providing means for creating a beam of a material being input thereto and control means operably connected for selectively including or not including respective ones of a plurality of materials within the beam;
(c) directing the beam at the steps of the substrate;
(d) establishing time periods for deposition of the materials for each of the monolayers such that the total number of atoms of the materials deposited will be equal in number to the number of the atomic bonding sites;
and
(e) causing the control means to include and not include respective ones of the materials within the beam in a pre-established pattern of the time periods from step (d) which will cause the materials to be deposited on the steps in a series of stacked monolayers.

3 more elements

The method for growing a superlattice structure on a substrate by depositing elements thereon in a stacked series of monolayers comprising the steps of:

(a) creating a periodic array of monoatomic surface steps on the substrate comprised of a plurality of equal and adjacent monoatomically thick steps on the surface of the substrate at an area to have the superlattice structure grown thereon wherein each step contains a plurality of atomic bonding sites on the surface thereof;
(b) providing means for creating a beam containing the elements to be deposited and control means operably connected for selectively including or not including respective ones of the elements within the beam;
(c) establishing time periods for deposition of the elements for each of the monolayers such that the total number of atoms of the elements deposited will be equal in number to the number of the atomic bonding sites;
(d) directing the beam at the steps of the substrate;
and,
(e) causing the control means to include and not include respective ones of the elements within the beam in a pre-established pattern of the time periods from step (c) which will cause the elements to be deposited on the steps in a series of stacked monolayers whereby a Coherent Superlattice (CSL) is formed.

3 more elements

Dependencies are inferred from the claim text.

Method for growing tilted superlattices

Life of this patent

Method for growing tilted superlattices

Life of this patent

Abstract

Claims33