Abstract:
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 DEG 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)m(ZnSe)n]p where m, n and p are integers.
Abstract:
A II-VI semiconductor device includes a stack of semiconductor layers (10). An ohmic contact (34) is provided that electrically couples to the stack. The ohmic contact has an oxidation rate when exposed to an oxidizing substance. A passivation capping layer (42) overlies the ohmic contact and has an oxidation rate that is less than the oxidation rate of the ohmic contact.
Abstract:
A semiconductor heterojunction, guided-wave, electroabsorption modulator (10). The device (10) includes a rib waveguide (12) fabricated on a substrate (14). The waveguide (12) includes a relatively thin and off-center undoped electroabsorbing layer (42) within a light-guiding region (16). Electrodes (26, 28) configured for interconnection to an external voltage source produce an electric field within the waveguide (12). Heavily doped field confining layers (38, 40) on opposite sides of the electroabsorbing layer (42) confine the electric field within the electroabsorbing layer to cause the electroabsorption of radiation in accordance with the Franz-Keldysh effect.
Abstract:
A II-VI compound semiconductor laser diode (10) is formed from overlaying layers of material including an n-type single crystal semiconductor substrate (12), adjacent n-type and p-type guiding lasers (14) and (16) of II-VI semiconductor forming a pn junction, a quantum well active layer (18) of II-VI semiconductor between the guiding layers (14) and (16), first electrode (32) opposite the substrate (12) from the n-type guiding layer (14), and a second electrode (30) opposite the p-type guiding layer (16) from the quantum well layer (18). Electrode layer (30) is characterized by a Fermi energy. A p-type ohmic contact layer (26) is doped, with shallow acceptors having a shallow acceptor energy, to a net acceptor concentration of at least 1 x 10 cm , and includes sufficient deep energy states between the shallow acceptor energy and the electrode layer Fermi energy to enable cascade tunneling by charge carriers.
Abstract translation:II-VI化合物半导体激光二极管(10)由包括n型单晶半导体衬底(12),相邻的n型和p型引导激光器(14)和II的(16)的材料的重叠层形成 形成pn结的-VI半导体,在引导层(14)和(16)之间的II-VI半导体的量子阱有源层(18),与衬底(12)相对的第n电极(32)与n型引导 层(14)和与量子阱层(18)相对的p型引导层(16)的第二电极(30)。 电极层(30)的特征在于费米能量。 掺杂p型欧姆接触层(26),具有浅受主能量的浅受主至至少1×10 17 cm -3的净受体浓度,并且包括足够的深能态 浅受主能量和电极层费米能量,以实现电荷载体的级联隧穿。
Abstract:
A II-VI compound semiconductor laser diode (10) includes a plurality of II-VI semiconductor layers forming a pn junction supported by a single crystal GaAs semiconductor substrate (12). The layers formed in the pn junction include a first cladding layer (20) of a first conductivity type, a second cladding layer (22) of a second conductivity type, and at least a first guiding layer (14) between the first and second cladding layers (20, 22). A quantum well active layer (18) is positioned within the pn junction. Electrical energy is coupled to the laser diode (10) by first and second electrodes (40, 41). Various layers (14, 16, 20, 22, 36, 38) in the laser diode are formed using Be.
Abstract:
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.
Abstract:
A II-VI semiconductor device is fabricated using a selective etchant in the form of aqueous solution of HX where X is Cl or Br. The II-VI semiconductor device is composed of a number of layers. Selective etching can be enabled by introducing Mg into one of the semiconductor layers. The resultant device may include a semiconductor layer containing Mg.
Abstract:
A method for repeatably fabricating GaAs/ZnSe and other III-V/II-VI semiconductor interfaces with relatively low stacking fault densities in II-VI semiconductor devices such as laser diodes. The method includes providing a molecular beam epitaxy (MBE) system (50, 150) including at least a group III element source (68, 170), a group II element source (72, 92'), a group V element source (70, 172) and a group VI element source (74, 98'). A semiconductor substrate (12) having a III-V semiconductor surface on which the interface is to be fabricated is positioned within the MBE system (50, 150). The substrate (12) is then heated to a temperature suitable for III-V semiconductor growth, and a crystalline III-V semiconductor buffer layer (14) grown on the III-V surface of the substrate. The temperature of the semiconductor substrate is then adjusted to a temperature suitable for II-VI semiconductor growth, and a crystalline II-VI semiconductor buffer layer (16) grown on the III-V buffer layer by alternating beam epitaxy. The group II and group VI sources are operated to expose the III-V buffer layer to a group II element flux before exposing the III-V buffer layer to a group VI element flux.
Abstract:
A II-VI laser diode including a substrate, a device layer of p-type II-VI semiconductor, and 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 increases, or the thickness of the layers of the semiconductor compound of the device layer decreases, with increasing distance of the ohmic contact layer from the device layer in the second embodiment.
Abstract:
A single quantum well II-VI laser diode without semiconductor cladding layers includes a pn junction formed by overlaying light-guiding layers (14, 16) 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 (12) is positioned between the guiding layers. An Au electrode (24) 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.