Wafer bonding and hydrogen implantation exfoliation techniques have been used to fabricate a thin InP template layer on GaAs with intermediate silicon nitride bonding layers. This template layer was used to directly compare subsequent metal organic vapor phase epitaxial growth of InGaAs∕InAlAs quantum-well structures on these wafer-bonded templates to growth on a standard InP substrate. Chemical mechanical polishing of the bonded structure and companion InP substrates was assessed. No effects from the coefficient of thermal mismatch are detected up to the growth temperature, and compositionally equivalent structures are grown on the wafer-bonded InP template and the bare InP substrate. However, after growth dislocation, loops can be identified in the InP template layer due to the ion implantation step. These defects incur a slight mosaic tilt but do not yield any crystalline defects in the epitaxial structure. Low-temperature photoluminescence measurements of the InGaAs grown on the template structure and the InP substrate exhibit near-band-edge luminescence on the same order; this indicates that ion implantation and exfoliation is a viable technique for the integration of III-V materials.

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Articles you may be interested inImpact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon AIP Advances 5, 057149 (2015); 10.1063/1.4921757 Structural, morphological, and defect properties of metamorphic In0.7Ga0.3As/GaAs0.35Sb0.65 p-type tunnel field effect transistor structure grown by molecular beam epitaxy J. Vac. Sci. Technol. B 31, 041203 (2013); 10.1116/1.4812793 μm emission from type-I quantum wells grown on InAsxP1−x/InP metamorphic graded buffersStrain relaxation properties of InAs y P 1 − y metamorphic materials grown on InP substrates Impact of arsenic species ( As 2 ∕ As 4 ) on the relaxation and morphology of step-graded In As x P 1 − x on InP substrates J.In this study, metamorphic compositionally graded In x Al 1−x As layers grown on InP by molecular beam epitaxy with a final indium mole fraction of x = 1.0 ͑6.05 Å͒ are investigated. To examine the effects of relative growth temperature on strain relaxation and surface morphology at different stages of the buffer layer growth, a series of samples was produced with the indium mole fraction graded from x = 0.52 to x = 0.64, 0.79, and 1.0 with a constant grading rate. The high misfit dislocation velocity in this system allows the grading to be accomplished with a thin layer ͑ϳ1 m͒, complete strain relaxation and low threading dislocation densities. The evolution of the strain relaxation, threading dislocation density, and surface morphology were evaluated by triple axis x-ray diffraction, transmission electron microscopy (TEM), etch pit density (EPD), and atomic force microscopy. Higher growth temperature led to threading densities as low as 10 6 cm −2 , as measured by plan-view TEM and EPD. The final surface roughness was controlled by the growth temperature of a constant composition cap layer.

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In As ∕ Al Sb high-electron-mobility transistor technology has transitioned from research to development stages in recent years. Development efforts at Northrop Grumman Space Technology, in collaboration with the Naval Research Laboratory and the University of California, Los Angeles, have focused on X-band and W-band low-noise amplifier monolithic millimeter-wave integrated circuits fabricated for applications requiring ultralow-power dissipation. The materials for the circuits discussed in this article were grown at Northrop Grumman Space Technology on 3-in.-diameter semi-insulating GaAs substrates by molecular-beam epitaxy. Atomic-force microscopy of the as-grown surface on each wafer showed that the rms roughness for all of the wafers ranged between 0.5 and 3.5nm, and this range of roughness was fully compatible with the fabrication process. The high electron mobility that InAs can provide was achieved reproducibly in these materials. It was maintained almost always above 25000cm2V−1s−1, and in several cases even exceeded 30000cm2V−1s−1. The associated electron sheet concentration ranged between 1.2×1012 and 1.8×1012cm−2. These combined mobilities and sheet concentrations gave corresponding sheet resistances in the range of 170±40Ω∕sq, with nonuniformity below 6% over these 3-in.-diameter wafers. These materials characteristics enabled successful fabrication of several recently published X-band and W-band low-noise amplifier circuits, and figures of merit for the circuits that were made specifically from these materials are referenced in this article.

Structural and morphological properties of GaN buffer layers grown by ammonia molecular beam epitaxy on SiC substrates for AlGaN/GaN high electron mobility transistorsComparison of As-and P-based metamorphic buffers for high performance InP heterojunction bipolar transistor and high electron mobility transistor applications In x Al 1−x As/ In x Ga 1−x As heterojunction bipolar transistors ͑HBTs͒ with lattice parameters ranging from 6.00 to 6.058 Å employing the use of narrow band gap In x Ga 1−x As base epitaxial layers toward InAs ͑0.86Ͻ X ln Ͻ 1͒ allows for the development of high speed digital and mixed signal circuits to perform at half the power required for conventional group III-V-based HBT device technologies. However, one of the key challenges inhibiting the development of low power narrow band gap HBT device circuits is the absence of semi-insulating ͑SI͒ substrates with lattice parameters towards 6.058 Å. Therefore, a metamorphic In x Al 1−x As ͑0.52Ͻ X ln Ͻ 0.86͒ graded buffer layer ͑GBL͒ grown on InP by molecular beam epitaxy was investigated as a means to enable a SI template with a lattice parameter of 6.00 Å. The metamorphic In x Al 1−x As GBL thickness is desired to be less than a micron in order for this approach to be compatible with the aggressive design rules of high-density transistor circuits. In this study, In 0.86 Al 0.14 As/ In 0.86 Ga 0.14 As double heterojunction bipolar transistor devices were grown on 0.90, 0.45, and 0.23 m thick In x Al 1−x As GBLs to assess the role of buffer layer thickness on both defect formation and device performance. The material characterization results for the 0.90 and 0.45 m thick buffer layers exhibited a crosshatch pattern with a surface rms roughness of 4 nm and threading dislocation densities of ϳ10 6 cm −2 . Excellent dc and rf characteristics from metamorphic HBT devices with submicron emitter widths were observed with low turn-on voltage of 0.45 V, high current gain, low reverse junction leakage ͑Ͻ1 A͒, and rf peak performance in the vicinity of 150 GHz. Finally, preliminary circuits ͑dividers and delay chains͒ have been designed, fabricated, and demonstrated with the 6.00 Å HBT technology.

We report an advanced InP/InGaAs double heterojunction bipolar transistor technology using aggressive scaling in device layout and epitaxial stack. The device employs a 220Å highly doped base and a 1200Å collector designed to support current densities in excess of 12 mA/Pm 2 . Transistors with emitter width of 0.25-Pm have exhibited simultaneous measured f T and f max frequencies in the 500 GHz range. Frequency divide-bytwo digital circuits designed and fabricated with this InP bipolar technology have demonstrated maximum clock frequency of 172 GHz. Manufacturing capabilities for mixed-signal circuits of increased complexity are also reported with improvements in resolution and bandwidth.