Pushing Heterjunction Bipolar Performance
SI Diamond Technology subsidiary Applied Nanotech has produced new carbon nanotube composites for electron field emission applications. The proprietary composite consists of carbon nanotubes (CNT) combined with other conductive and non-conductive nanoparticles.
The combination is designed to significantly lower the voltage necessary for optimal electron emission. Generally, the electric field threshold necessary for field emission applications varies in the range 2.5-4.5V/micron, depending on the carbon nanotube quality. In the new composites the threshold voltages range between 1.5-3.0V/micron under the same conditions.
The mixture also contains fewer carbon nanotubes - the highest cost component in the composite. It is hoped these advantages will accelerate the use of carbon nanotube field emission technology for home television applications.
Intel has a new ultra low voltage processor for fanless, small form-factor embedded computing board applications. The Ultra Low Voltage Intel Celeron processor at 400MHz is designed for applications that include storage devices, such as entry-level network attached storage, and industrial computing, such as ruggedised computer systems used in manufacturing environments.
The processor has a typical power dissipation of 3.4W and a maximum power dissipation of 4.2W. The lower wattage decreases the overall thermal dissipation of the system so that it can operate under restricted heat and space constraints. The processor is produced on Intel's 0.13micron process and comes in a microFCBGA package.
Boards featuring the processor are currently under development from Aaeon, Advantech, Kontron, MicroIndustries, Portwell and other major OEMs.
The x86 processors produced by Intel (such as the Celeron and Pentium) are not commonly used in the embedded market because of cost restrictions. Motorola, for example, has a range of low-cost processors and extensive customer support aimed at this market.
Schottky barrier semiconductor developer Spinnaker Semiconductor has made an R&D agreement with MIT's Lincoln Laboratory. Spinnaker Semiconductor is developing a Schottky barrier source and drain silicon CMOS technology (SB-CMOS) for use in ultra-high performance ICs. The approach will create transistors with channel lengths less than 50nm. Implementation will be in a standard silicon process. The agreed development will use the Spinnaker Semiconductor SB-CMOS approach with Lincoln Laboratory's process capabilities to demonstrate a commercially viable SB-CMOS process, sufficient for transfer to existing semiconductor manufacturers.
US company Cymbet has produced a thin-film rechargeable battery, trademarked as "application specific solid energy technology" (ASSET). These batteries can be customised in physical size and energy capacity to fit on or within IC packages with little or no impact on profiles.
The battery can be a stand-alone power source on a flexible or rigid substrate, or fabricated on the circuit or device that it is intended to power, such as on the lid of an IC package or on the surface of a printed circuit board. Applications include non-volatile SRAMs, real-time clocks, supply supervisors, active RFID tags and microsystem devices.
The nominal cell voltage is 3.8V, with capacities ranging from several microA-hours to several mA-hours, depending on the desired footprint and discharge current requirements. Cells can be as thin as 25microns. The cells are capable of greater than 10,000 deep charge and discharge cycles and operate at temperatures from
-40°C to +120°C.
Air Products and Pennsylvania State University are to continue cooperative research efforts to understand the effects of gas source purity on Group III-nitride (AlGaInN)-based thin films and device structures. The programme has been underway since the beginning of 2002.
Work has been carried out to evaluate typical residual and other metallic impurity levels in layers grown by MOVPE (metalorganic vapour phase epitaxy) using high purity ammonia sources and to assess the impact of these impurities on the structural, electrical and optical properties of the compound semiconductor materials.
The objective of the programme is to conclusively identify and reduce sources of oxygen and other impurities within the MOVPE environment, including the development of new high-purity ammonia sources.
The programme with Penn State is an outgrowth of relationships built by Solkatronic Chemicals - now a business unit of Air Products' Electronics division.