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Details of Grant 

EPSRC Reference: GR/H67294/01
Principal Investigator: Wilkinson, Professor C
Other Investigators:
Doughty, Dr G Stanley, Professor C
Researcher Co-Investigators:
Project Partners:
Department: Electronics and Electrical Engineering
Organisation: University of Glasgow
Scheme: Standard Research (Pre-FEC)
Starts: 01 August 1992 Ends: 31 October 1994 Value (£): 339,629
EPSRC Research Topic Classifications:
Optoelect. Devices & Circuits
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:  
Summary on Grant Application Form
MBE growth of complex, multi-layer structures in (Al,Ga)As-GaAs and (In,Ga)As-GaAs, with wafer scale uniformity of composition and thickness, for 850 nm and 1047 nm devices respectively; design and fabrication of S-SEED arrays and diffractive optical devices; III-V process development as required by the SCIOS demonstrator objectives, including flip-chip bonding to silicon CMOS circuitry.Progress:Progress in the molecular beam epitaxy (MBE) of III-V semiconductors, device fabrication and diffractive optics undertaken in collaboration with our SCIOS partners has included;(1) CW operation of a GaAs bistable etalon has been successfully demonstrated for the first time.(2) A new, optically bistable device based on the negative resistance of a low-responsivity GaAs-AlAs multiple quantum well (MQW) modulator combined with an A1xGa1-XAs (x+2%) photodetector has been designed and demonstrated. Subsequently, large area devices and arrays with individual pixels ranging in size from +1()0 -m x 10() -m down to +10 -m x 10 -m, and with a mirror stack incorporated into the vertical structure to enable operation in reflection-mode have been fabricated.(3) An extensive study of In incorporation into In(Al,Ga)As by RHEED intensity oscillations has been completed, driven by the need for good control over the composition and thickness of complex strain-balanced MQW (In,Ga)As structures required for S-SEEDs at +1047 nm. (4) Significant developments in the dry etch processing of both (Al,Ga)As and (In,Ga)As have occurred, resulting in large contrasts in the etch-rates of GaAs and (Al,Ga)As under specific etch conditions and excellent etch anisotropy for both (Al,Ga)As and (In,Ga)As.Good control of etch depth has been realised with the incorporation of in situ optical monitoring. (5) Strain-balanced MQW (In,Ga)As structures have been grown by MBE with improved band-edge exciton characteristics and excellent uniformity across the 2 wafer (e.g. exciton peak variation of 0.2 nm at 1060 nm within an area 1 in diameter). Large area devices have been evaluated as R-SEEDs with on/off contrast ratios +1.9.(6) 4 x 4 flip-chip smart pixel array for an Exchange/Bypass Self Routing Node, 16 x 16 S-SEED arrays for flip-chip bonding to Si-CMOS SLM and a 96 x 48 S-SEED array for optical switching have been fabricated. Optical tests on individual elements in the 16 x 16 arrays show all but two to be functioning successfully.(7) Flip-chip bonding of an (In,Ga)As S-SEED array to silicon has been demonstrated, with the height of the solder bumps defined by controlled polyimide planarisation, metal evaporation and lift-off. (8) Detour grating devices with ().8 -m average pitch and a linewidth deliberately varied between 360-440 nm have been fabricated for the first time. These yield a modulated diffraction pattern with >80% diffraction efficiency. These gratings can be made by either lift-off or direct etching into quartz.
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Organisation Website: http://www.gla.ac.uk