Abstract: A transistor structure is provided. This structure has a source electrode and a drain electrode. A doped cap layer of GaxIn1-xAs is disposed below the source electrode and the drain electrode and provides a cap layer opening. An undoped resistive layer of GaxIn1-xAs is disposed below the cap layer and defines a resistive layer opening in registration with the cap layer opening and having a first width. A Schottky layer of AlyIn1-yAs is disposed below the resistive layer. An undoped channel layer is disposed below the Schottky layer. A semi-insulating substrate is disposed below the channel layer. A top surface of the Schottky layer beneath the resistive layer opening provides a recess having a second width smaller than the first width. A gate electrode is in contact with a bottom surface of the recess provided by the Schottky layer.

Abstract: A transistor structure is provided. This structure has a source electrode and a drain electrode. A doped cap layer of GaxIn1−xAs is disposed below the source electrode and the drain electrode and provides a cap layer opening. An undoped resistive layer of GaxIn1−xAs is disposed below the cap layer and defines a resistive layer opening in registration with the cap layer opening and having a first width. A Schottky layer of AlyIn1−yAs is disposed below the resistive layer. An undoped channel layer is disposed below the Schottky layer. A semi-insulating substrate is disposed below the channel layer. A top surface of the Schottky layer beneath the resistive layer opening provides a recess having a second width smaller than the first width. A gate electrode is in contact with a bottom surface of the recess provided by the Schottky layer.

Abstract: A field effect transistor including a substrate comprised of a material having a spinel crystal structure and a buffer layer lattice matched to the crystal structure of the substrate comprising gallium aluminum indium arsenide is described. Several types of field effect transistors are possible with the described substrate arrangement, including metal semiconductor field effect transistors, insulating gate field effect transistors, pseudomorphically strained and pseudomorphically strain compensated metal semiconductor field effect transistors, as well as, high electron mobility transistor structures.

Abstract: A metalorganic chemical vapor deposition (MOCVD) reactor vessel is provided for the growth of Group II-VI, Group III-V, or Group IV layers particularly for use in thin heterostructure devices. The reactor vessel includes a chamber having a top surface substantially parallel to a semiconductor substrate disposed within the chamber and an inlet through which a vapor stream is directed. The chamber further includes a plate having a plurality of apertures disposed therethrough and a block disposed adjacent to the plate, to increase the uniformity and decrease the turbulence of the vapor stream.

Abstract: A pseudomorphic high electron mobility transistor includes a substrate for supporting a semiconductor active region. The semiconductor active region includes a channel layer comprised of InGaAs, which when disposed over said substrate develops an intrinsic lattice tensile strain and charge donor layer comprised of a wide bandgap Group III-V material, said layer being arranged to donate charge to said channel layer. The HEMT further includes a strain compensating layer having an intrinsic lattice compressive strain which is disposed between said channel layer and said substrate. The strain compensating layer has a strain characteristic which compensates for the tensile strain in the channel layer permitting said channel layer to be grow thicker or with high In concentration prior to reaching its so-called critical thickness.

Abstract: A photo-enhanced pyrolytic technique for growing Group II-VI materials is described. Reactant vapors preferably low stability reactant vapors which form Group II-VI materials at relatively low temperatures are introduced into a reactor vessel. Disposed in the reactor vessel is a substrate which is heated to a growth temperature of generally less than about 400.degree. C. The surface of the substrate is illuminated by ultraviolet radiation and during pyrolytic decomposition of the vapors introduced to the growth vessel, the surface kinetic energy of migrating species on the surface of the substrate is increased by the radiation resulting in a reduction in defect levels in the material grown over the substrate.

Abstract: A method for growing a Group II-VI epitaxial layer on a substrate is described. The method includes the steps of directing a plurality of vapor flows toward the substrate including a Group II metalorganic vapor, a Group VI organic vapor, with said Group VI organic having an organic group bonded to the Group VI element selected from the group consisting of a secondary alkyl, a tertiary alkyl, an allyl, a cycloallyl, and a benzyl, and a Group II elemental metal vapor. The directed flows of Group II metalorganic vapor, Group VI organic vapor and Group II metal vapor are chemically reacted to provide the epitaxial layer.

Abstract: A method for growing a Group II-IV epitaxial layer over a substrate is described. The method includes the steps of directing a plurality of vapor flows towards the substrate, including a Group II organic vapor, a Group VI organic vapor, and a Group II elemental mercury vapor. At least one of the Group II organic vapor and Group VI organic vapor has organic groups which sterically repulse the second one of the Group II and Group VI organic vapors or which provide electron transfer to the Group II atom or electron withdrawal from the Group VI atom. With the particular arrangements described, it is believed that substantially independent pyrolsis of the Group II organic vapor is provided over the growth region of the substrate, and accordingly, Group II depletions such as cadmium depletion in the epitaxial films provided over the substrate is substantially reduced.

Abstract: A method for growing a Group II-VI epitaxial layer on a substrate, said epitaxial layer having an electron mobility greater than 1.5.times.10.sup.5 cm.sup.2 /V-sec at 77.degree. K. and a carrier concentration less than 4.times.10.sup.15 (cm.sup.-3) is described. The method includes the steps of directing a plurality of vapor flows towards the substrate including a Group II metalorganic vapor having a mole fraction in the range of 3.0.times.10.sup.-4 to 4.5.times.10.sup.-4, a Group VI metalorganic vapor having a mole fraction in the range of 2.9.times.10.sup.-3 to 3.5.times.10.sup.-3 and a Group II elemental metal vapor having a mole fraction in the range of 2.6.times.10.sup.-2 to 3.2.times.10.sup.-2. The source of Group II metal is heated to at least 240.degree. C. while radiant energy is directed toward the reactor vessel to warm the zone of the reactor vessel between the Group II metal source and the substrate to at least 240.degree. C.