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 Selected Consulting and Training Services

Materials and Devices Engineering and Characterization^ª            

Materials design, device design and modelling of semiconductor and superconductor devices:

Materials, including: Semiconductor wafers – III/V compounds GaAs, InP, Si. MBE- and MOVPE-grown III/V binary, ternary, quaternary alloy layers and heterostructures. Ion-implanted GaAs, Si. Quantum well structures – lattice-matched, strained. Laser mirror passivation, coatings. Conventional superconductors – Sn, Nb, Pb-alloys.

Devices, including: Quantum well laser diodes 670 – 1300nm. Non-absorbing mirrors. Light-emitting diodes. Electro-absorption modulators. Mode expanders. Resonant tunnelling diodes. MESFETs and MOSFETS. Superconducting tunnel junctions and circuits.

Use of software packages such as, ASTAP, BeamPROP, PICS3D, LASTIP, Matlab to model electrical, optical, thermal device characteristics.

Optimization of product functionality by using information from custom-designed speciality experiments.

Measurements include parameters such as: Semiconductor wafer quality uniformity. Laser mirror temperatures. Temperatures along laser cavity. Temperature-monitored laser degradation. Mechanical stress. Stress-induced defects. Deep traps / impurity identification, concentration and location. Contaminant mapping. Chemical and elemental analysis. Impurity trapping in quantum well lasers. Interface quality. Lattice disorder in laser facets. Laser mirror coating material instability. Silicon recrystallization effects. Magnetic penetration depths in thin superconducting films. Spatial uniformity of superconducting tunnel junction barrier.

Correlations between material properties and relevant device parameters to enhance device quality.

Examples include: Triple correlation between structural / compositional disorder in laser mirrors, laser mirror temperatures and catastrophic optical mirror damage level. Correlations between local stress, defect concentration, electron-beam-induced-current signal and strength of susceptibility to local laser degradation. Correlations between tunnel barrier uniformity and optimum performance of Josephson tunnel junctions used in superconducting driver and memory circuits.

Device engineering through optimized product and process design including wafer growth and manufacturing.

Reliability qualifications including setting up test programs and failure analysis strategies as required.

Programs comprise step stress tests, accelerated life tests (current, optical power, temperature, humidity), burn-in, environmental stress tests, temperature cycling, high temperature storage life, moisture sensitivity assessment level, electrostatic discharge and latch-up tests.

Failure analyses include techniques and tools such as optical microscopy, electron microscopies (SEM, TEM), scanning acoustic microscopy, light emission microscopy, liquid crystal thermography, photoluminescence spectroscopy and scanning, electroluminescence, Raman spectroscopy, optical absorption spectroscopy, thermoreflectance, deep-level transient spectroscopy, x-ray energy dispersive spectroscopy, electron-beam induced current.

Recommendation of experimental approaches to differentiate bad devices with inherent low reliability from good devices with high reliability without performing any life tests.

See also: “Acting in advisory / training capacities” at end of relevant sector in Page “Expertises Detailed”

^ª For more details, see Page “Originalities” about “Issue Resolution through Innovative Experiments on Materials and Devices”.

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