Complementary GaAs SIS FET inverter using selective crystal regrowth technique by MBE
A first complementary GaAs semiconductor-insulator-semiconductor (SIS) FET inverter has been fabricated by constructing n-channel and p-channel GaAs SIS FET's on a single LEC GaAs substrate using MBE selective crystal regrowth technique. The fabricated inverter shows an inverter operation as a really low-power complementary inverter.
The potential of complementary heterostructure FET IC's
The performance capability of AlGaAs/GaAs complementary heterostructure FET (C-HFET) integrated circuits has been evaluated in computer simulations. The study is focused on C-HFET designs in which static currents and gate-leakage currents are sufficiently low to take full advantage of the speed, power dissipation, and logic function capabilities of CMOS-like circuitry. ASTAP computer simulations for loaded NAND and NOR circuits are examined over a wide supply-voltage range at both 300 and 77 K in order to determine the potential of various MODFET, MISFET, and SISFET approaches as well as the prospects of future designs. While performance is limited by FET threshold and gate leakage in present C-HFET approaches, the speed of properly designed 0.7-µm C-HFETs at 300 K is projected to be 3 × faster than comparable 300 K Si-CMOS circuits. C-HFET circuits at 77 K are projected to be more than 4 × faster than 77 K Si-CMOS circuits. It is also found that properly designed C-HFET's could operate at speeds close to those of DCFL n-channel HFET circuits while dissipating only 1/10 of the power.
Keeping Farmers on the Land: Adding Value in Agriculture in the Veneto Region of Italy
Italy's relatively small area, high population density, and high land and labor costs have created the challenges of ensuring profitably for agricultural producers, slowing urban encroachment onto arable land, and keeping farm families on land that has been handed down within the families for generations. As part of the solution to these issues, the European Union is enacting policies to reduce producer dependence on direct subsidies while increasing the competitiveness of agricultural products and returns to producers, reinvigorating rural communities, and encouraging environmentally sound production methods. These regulations provide incentives for producers to add value to their products by obtaining legal recognition of typical products, participating in agritourism, and helping to promote traditional products for regional food systems. This paper examines how E.U. and national policies are encouraging farmers in the Veneto region of Italy to adopt an agricultural production model that encourages limited production of high-quality, high-value products and more diversified land use.