Fixed-angle, energy-dispersive x-ray reflectivity measurement of thin tantalum film thickness

In this work, we employed a fixed-angle, energy-dispersive x-ray reflectivity technique to obtain the thickness of thin tantalum films (examples <9 nm) within seconds using a conventional, low-energy x-ray copper or chromium source (20 kV/20 mA/400 W). We compared this fixed-angle, energy-dispersive result with more conventional fixed-energy (monochromatic source), angular-dispersive x-ray reflectivity to establish the validity of the energy-dispersive method. This x-ray technique may be particularly useful for the metrology of growing thin-barrier layers, atomic-layer passivation, and seed-layer measurements in future microelectronics applications. Currently, thickness precision is limited by modeling assumptions and the energy discrimination available from x-ray detectors.     

Parallel-optical interconnects >100 gb/s

A parallel-optical interconnect with 12 channels operating at 8.5 Gb/s giving an aggregate data rate of 102 Gb/s is demonstrated, to the authors' knowledge, for the first time. The paper describes and demonstrates 13 /spl times/ 16-mm cross-section 12-channel parallel-optic transmitter and receiver modules with each channel operating at a data rate of 8.5-10 Gb/s. This was achieved using bottom-emitting 990-nm vertical-cavity surface-emitting lasers and bottom-illuminated InGaAs-InP photodetectors flip-chip bonded directly to 12-channel transmitter and receiver integrated circuits, respectively. In addition, 102-Gb/s link results are demonstrated over 100 m of 50-/spl mu/m-core standard multimode ribbon fiber. A bit-error ratio of <10/sup -13/ was measured on a single channel after transmission through 100 m of multimode fiber at a data rate of 8.5 Gb/s with all 12 channels operating simultaneously.