The ability to reduce device features to increasingly smaller dimensions offers the potential for remarkable circuit performance and low power consumption. CMOS (Complementary Metal-Oxide-Semiconductor) devices with 100 nm channel lengths offer a 2X performance gain over 0.25 μm technology at a reduced power supply as well as the potential for a 20X reduction in active power at comparable performance levels. Continued scaling of devices beyond 100 nm dimensions faces various fundamental limitations. Overcoming these limitations will require technological innovation in both device design and fabrication.

We present a high-power tunable laser based on a DFB array, designed for use in coherent optical systems. The linewidth is below 500 kHz for 30 mW fiber-coupled power across the C-band.

A novel DFB laser array is demonstrated for application to the 10 Gbit Ethernet LX4 scheme. The array delivers multiple mW output power and high-speed operation (3.125 Gb/s) at 85/spl deg/C.

We describe a 12-element distributed feedback laser array, with 10-μm pitch, covering a 36-nm tuning range, and having an integrated heater on each element. The novel heater design heats just the active laser yet requires only one additional contact for the entire array. Each individual laser element can be temperature tuned more than 3.2 nm in under 100 μs using its heater.

We present high-yield efficient distributed-feedback lasers with excellent wavelength control. An array of 12 lasers with highly reflecting/antireflecting facets is fabricated on a single chip with precisely controlled variations in the grating period or phase relative to the facets. The stripe that best meets requirements is selected for bonding. From 200 unscreened chips, 93% contained lasers that achieved the specified power of 25 mW at 175 mA, 55/spl deg/C, and 41% achieved a /spl plusmn/0.1-nm wavelength tolerance at 25 mW, 55/spl deg/C. This low-cost high-precision device requires little thermal tuning for wavelength-division-multiplexed applications and reduces the power consumption of the transmitter.

A wide-range tunable laser component has been developed, based on a closely spaced array of 12 distributed feedback (DFB) grating lasers, 3 nm apart in wavelength, fabricated by electron-beam lithography. Coarse wavelength selection is achieved by selecting the appropriate laser stripe with a microelectromechanical system tilt mirror. We describe the application of direct-wire e-beam lithography to array DFB grating manufacture, with accurate multiple wavelengths and phase shifts required to optimize the spectral characteristics of the laser. The grating pitch is approximately 0.24 mum, but must be controlled to better than 0.01 nm. We have used an averaging technique with relatively coarse address unit and pixel size to fabricate multiple-pitch gratings without rescaling. This allows the use of a conventional thermal-field-emission Gaussian-beam system, at high throughput appropriate for manufacturing. (C) 2002 American Vacuum Society.

The high spatial resolution of the atomic force microscope (AFM) has motivated recent efforts to apply the technique to high-density data storage. However, little attention has been given to satisfying the other necessary attributes required of any new data storage technology. Using a system based on reading topographic data features on a rotating disk with a high-frequency piezoresistive cantilever, we address several of these issues. A timing-based control method for data tracking is demonstrated and shown to maintain the radial tip position to within a standard deviation of 31 nm. While maintaining the tip position under both load and tracking control with a disk velocity of 3 cm/s, 200 nm diameter marks are read continuously for over 145 h without any significant change in signal amplitude. This represents a tip travel distance of 16 km, and each bit was read over 500 000 times.

We report the emission properties of concentric-circle-grating, surface-emitting (CCGSE), distributed-feedback semiconductor lasers oscillating in single high-order azimuthal spatial modes. The evolution of the spatial profile of the beam emitted by such lasers with increasing excitation depends upon the spatial gain distribution and the depth of the circular waveguide grating. The polarization of the high-order spatial modes is predominantly radial.

We have used a simple self-aligned process to fabricate magnetic tunnel junctions down to submicron sizes. Optical and electron-beam lithographies were used to cover a range of areas spanning five orders of magnitude. The bottom magnetic electrodes ~Co or permalloy! in our junctions were exchange biased by an antiferromagnetic layer ~MnFe!. The top electrodes were made of soft magnetic materials ~Co or permalloy!. We have consistently obtained large magnetoresistance ratios ~15%–22%! at room temperature and in fields of a few tens of Oe. The shape of the field response of the magnetoresistance was varied from smooth to highly hysteretic by adjusting the shape anisotropy of one junction electrode. © 1997 American Institute of Physics. @S0021-8979 ~97!56608-4#

We describe the operating characteristics of optically pumped concentric-circle-grating surface-emitting semiconductor lasers. The circular grating defines the laser resonant cavity and provides for a symmetric surface-emitted beam. We present detailed experimental studies of the influence of epitaxial semiconductor material and grating design on lasing characteristics. We emphasize the effect of grating parameters on the lasing and damage thresholds and on the shape, polarization, diffraction, and spectral purity of emitted radiation. (C) 1997 Optical Society of America.

We have used a simple self-aligned process to fabricate magnetic tunnel junctions down to submicron sizes. Optical and electron-beam lithographies were used to cover a range of areas spanning five orders of magnitude. The bottom magnetic electrodes (Co or permalloy) in our junctions were exchange biased by an antiferromagnetic layer (MnFe). The top electrodes were made of soft magnetic materials (Co or permalloy). We have consistently obtained large magnetoresistance ratios (15%–22%) at room temperature and in fields of a few tens of Oe. The shape of the field response of the magnetoresistance was varied from smooth to highly hysteretic by adjusting the shape anisotropy of one junction electrode.

This paper presents the characteristics of a silicon IC process compatible, nonvolatile memory. The basic storage element is a thin-film stripe that consists of a pair of 9-nm ferromagnetic (NiFe) layers spaced with 2.2-2.5 nm of non-magnetic Cu film. The magnetization, M, of one of the layers is pinned along the longitudinal direction of the stripe with an antiferromagnetic material (FeMn), while the M of the other layer is free to rotate. This structure is known as a spin valve. When the Ms of the pair are in the same (parallel) direction, the resistance is lower than when they are in the opposite (anti-parallel) direction by 5-8%. This property is well known as the giant magneto-resistive effect. The memory cell is made up of a storage resistor stripe and the x/y select wires, typically 100 nm thick. The current pulses in the select wires generate a vector sum of magnetic field that switches the cell state. The switching field in the longitudinal direction is lowered when a transverse field is applied. The memory cells were fabricated on thermal oxide on silicon wafers. The sputter deposition and etch process of the spin valve does not affect the leakage nor does it alter the Vt of FETs, and thus may be integrated into the metallization steps of the silicon wafer processing

Very high performance sub-0.1 /spl mu/m channel nMOSFET's are fabricated with 35 /spl Aring/ gate oxide and shallow source-drain extensions. An 8.8-ps/stage delay at V/sub dd/=1.5 V is recorded from a 0.08 /spl mu/m channel nMOS ring oscillator at 85 K. The room temperature delay is 11.3 ps/stage. These are the fastest switching speeds reported to date for any silicon devices at these temperatures. Cutoff frequencies (f/sub T/) of a 0.08 /spl mu/m channel device are 93 GHz at 300 K, and 119 GHz at 85 K, respectively. Record saturation transconductances, 740 mS/mm at 300 K and 1040 mS/mm at 85 K, are obtained from a 0.05 /spl mu/m channel device. Good subthreshold characteristics are achieved for 0.09 /spl mu/m channel devices with a source-drain halo process. >