IBM just let us know about the development of an alternate type of transistor that it says could lead to major performance, function, and power consumption improvements in semiconductors within several years. Called a "double-gate" transistor, the device can carry twice the electrical current, operate at up to twice the speed and be smaller than today's transistors. IBM says the breakthrough was made possible by a series developments in new device designs and materials such as SOI, but still lets them be built on conventional manufacturing lines. IBM's work on the double-gate transistor and its latest SOI developments will be presented at the International Electronic Device Manufactures (IEDM ) conference in Washington, D.C., as will AMD's new CMOS development, discussed in another story today. Big Blue says that improved transistors like the double-gate are expected to be needed in five-to-ten years, when transistors shrink so small that it becomes difficult to shut them off. IBM will also be showing off other goodies at the conference, including a 2 terahertz (2 THz) SOI-based transistor, an SRAM cell that measures 1.8 square microns, an SOI-based photodetector for optical communications, a paper on carbon nanotube transistors (which it says may perform better than silicon transistors), and an analysis showing that the ultimate speed of transistors could reach 30 TeraHertz, about 15 times faster than today's transistors.