Minnesota Mining and Manufacturing Company

3m Innovative Properties Company

Chorus, LLC

Hwa Cheng

Michael Albert Haase

James M DePuydt

Jun Qiu

Robert M Park

Scott W Priddy

Jun Oiu

James M Depuydt

A laser diode for emitting a coherent beam of light in the blue and/or green portions of the spectrum. The laser diode includes a plurality of layers of II-VI semiconductor forming a pn junction, including at least a first light-guiding layer. A short-period strained-layer superlattice (SPSLS) CdZnSe quantum well active layer is positioned within the pn junction. The layers of II-VI semiconductor are supported by a substrate. First and second electrodes on opposite sides of the layers of II-VI semiconductor couple electrical energy to the laser diode.

II-VI laser diodes with short-period strained-layer superlattice quantum

A unibody, monolithic, one-piece PBN plasma chamber for an MBE gas plasma source. The chamber has a cylindrical configuration with at least one effusion orifice and a gas inlet opening. The gas inlet opening is preferably communicatively connected to an elongated, tubular inlet member. The inlet member is preferably coupled to a liquid cooled gas source by an intermediary connection member which is preferably constructed of a refxactory metal. The chamber minimizes leakage and maximizes efficiency. A gas plasma source assembly and a method for making the chamber are also disclosed.

Unibody gas plasma source technology

An electromagnetic radiation transducer is provided having a p-type ZnSe layer and an n-type layer. The p-type ZnSe layer has a net donor to net acceptor ratio (N.sub.D /N.sub.A) of less than or equal to about 0.8. The net acceptor concentration is greater than about 5.times.10.sup.15 cm .sup.-3 and the resistivity is less than 15 .OMEGA.-cm. The p-type ZnSe layer is deposited by doping the ZnSe during fabrication with a neutral free-radical source.

Doping of IIB-VIA semiconductors during molecular beam epitaxy

A buried-ridge or buried-heterostructure II-VI laser diode. Polycrystalline II-VI semiconductor such as ZnS, ZnSSe, ZnSe or CdS deposited by vacuum evaporation buries the etched ridge.

Method of fabricating a buried-ridge II-VI laser diode

A II-VI compound semiconductor laser diode includes a plurality of layers of II-VI semiconductor forming a pn junction supported by a single crystal GaAs semiconductor substrate. The layers forming the pn junction include a first cladding layer of a first conductivity type, a second cladding layer of a second conductivity type, and at least a first guiding layer between the first and second cladding layers. A CdZnSe or other II-VI semiconductor quantum well active layer is positioned within the pn junction. Electrical energy is coupled to the laser diode by first and second electrodes.

Blue-green laser diode

Buried ridge II-VI laser diode

A II-VI laser diode including a substrate, a device layer of p-type II-VI semiconductor, an electrode and an ohmic contact layer between the electrode and device layer. The ohmic contact layer comprises a graded composition semiconductor compound including ZnTe. The relative amount of ZnTe in the semiconductor compound increases with increasing distance of the ohmic contact layer from the device layer. In a first embodiment the ohmic contact layer comprises a graded composition semiconductor alloy including the semiconductor compound of the device layer and ZnTe. The amount of ZnTe in the alloy increases with increasing distance of the ohmic contact layer from the device layer in the first embodiment. In a second embodiment the ohmic contact layer includes layers of ZnTe spaced between layers of the semiconductor compound of the device layer. The thickness of the layers of ZnTe increase, or the thickness of the layers of the semiconductor compound of the device layer decrease, with increasing distance of the ohmic contact layer from the device layer in the second embodiment.

Graded composition ohmic contact for P-type II-VI semiconductors

A method for using atomic layer epitaxy (ALE) and/or migration enhanced epitaxy (MEE) to grow high efficiency quantum wells in II-VI laser diodes. The substrate and previously grown layers of the laser diode are heated to a temperature less than or equal to about 200.degree. C. in an MBE chamber. Sources of Cd, Zn, and Se are injected alternately into the chamber to grow a short-period strained-layer superlattice (SPSLS) quantum well layer including overlaying monolayers of Cd, Zn and Se. The quantum well layer is described by the notation [(CdSe).sub.m (ZnSe).sub.n ].sub.p where m, n and p are integers.

Growth of II VI laser diodes with quantum wells by atomic layer epitaxy

A single quantum well II-VI laser diode without semiconductor cladding layers includes a pn junction formed by overlaying light-guiding layers of p-type and n-type ZnSe on an n-type GaAs substrate. A CdSe/ZnSe short-period strained-layer superlattice single quantum well active layer is positioned between the guiding layers. An Au electrode overlays the p-type guiding layer opposite the single quantum well active layer. The guiding layers have thicknesses which enable the substrate and Au electrode to confine the light beam generated by the device within the active layer and the guiding layers.

Single quantum well II-VI laser diode without cladding

A II-VI compound semiconductor laser diode includes a N-type GaAs substrate, a first cladding layer of N-type ZnSSe overlaying the substrate, a first guiding layer of N-type ZnSe semiconductor overlaying the first cladding layer. A quantum well layer of strained CdZnSe semiconductor overlaying the first guiding layer, a second guiding layer of p-type ZnSe semiconductor overlaying the quantum well layer, and a second cladding layer of p-type ZnSSe semiconductor overlaying the second guiding layer.

A ZnSe semiconductor device includes a ZnSe pn junction having p-type and n-type layers, and an ohmic contact to both layers. The ohmic contact to the p-type layer includes a p-type ZnSe crystalline semiconductor contact layer, and a conductive electrode layer characterized by a Fermi energy. The contact layer is doped with nitrogen shallow acceptors, characterized by a shallow acceptor energy, to a net acceptor concentration of at least 5.times.10.sup.17 cm.sup.-3. The contact layer also includes sufficient deep energy states between the shallow acceptor energy and the electrode layer Fermi energy to enable cascade tunneling by charge carriers.

Ohmic contact for p-type group II-IV compound semiconductors

A method and apparatus for enhanced doping of IIB-VIA semiconductors through the use of a free-radical source is described. The process involves the simultaneous production of beams of free-radicals together with group IIB molecules or atoms and group VIA molecules or atoms in a standard molecular beam epitaxy crystal growth system. These beams react on a substrate producing single crystal films of doped IIB-VIA semiconductors such as ZnSe:N, for example. The improved doping characteristics result from the high reactivity of radicals produced by the free-radical source with the surface of the growing crystal.

Doping of IIB-VIA semiconductors during molecular beam epitaxy using

A method for producing an ohmic contact to a p-type ZnSe semiconductor body in a molecular beam epitaxy chamber. Zinc, thermally cracked Se.sub.2 and nitrogen are injected into the chamber. A ZnSe contact layer is grown by heating the semiconductor body to a temperature less than 250.degree. C., but high enough to promote crystalline growth of the layer doped with nitrogen to a net acceptor concentration of at least 1.times.10.sup.18 cm.sup.-3.

Growing community of inventors

Woodbury, MN, United States of America

Hwa Cheng