III-V MOSFETs for Ultimate CMOS

During Collaborative Research between Freescale Semiconductors and Glasgow University, III-V MOSFET devices were made and characterised.

THE CLIENT: Freescale Semiconductors

THE BACKGROUND: The continued decrease in the size of silicon MOSFETs is slowing down and there is doubt whether they can continue below the 20nm technology node using the planar technology currently employed. Thus the use of higher mobility materials is being investigated, in particular III-V materials for n-type and Ge for p-type devices.

THE SOLUTION: Freescale had developed a method for un-pinning the Fermi level on GaAs and growing an oxide layer with sufficiently low leakage current to allow enhancement MOSFET devices to be made. Freescale undertook a collaboration with Glasgow University to take this forward because Glasgow has expertise in III-V material growth, nanoscale device processing, device modelling and physical and electrical characterisation.

THE KEY CLIENT BENEFITS: Freescale can explore a much wider parameter space and bring additional expertise to bear on their research into III-V MOSFETs

SUPA EXPERTISE: A key area of expertise is electron and ion beam techniques for characterizing materials. Transmission electron microscopy provides information on structure, chemistry and composition down to near-atomic resolution with true atomic resolution being available at SuperSTEM. These techniques gave key information on the oxides and their interfaces, the device structures, the process modules and the ohmic contacts. The focused ion beam system gives the three dimensional structure of the devices with a resolution of a few nanometers. A second area of expertise covers I-V-B-T and C-V-ω measurements to identify the nature of the conduction mechanisms and the nature of the carrier traps in the system.

THE COLLABORATION MECHANISM: Collaborative research. The project was EPSRC funded and Freescale contributed expertise, materials, access to equipment, staff time and funding for a research student.