26-01-2010, 10:36 AM
abstract:
a crystalline diamond film that could produce more resilient semiconductor chips than those made from silicon,commonly synthetic diamonds have proved a poor semiconducting material. Their microscopic crystals are a disorderly hodgepodge, and their edges are not evenly aligned, impeding the flow of current. Now but by growing the diamond film on a surface of iridium, instead of on silicon, they can keep its grain boundaries aligned. Adding atoms of boron or nitrogen enables the diamond film to conduct electricity. Manufacturers plan to build a diamond chip that can withstand temperatures of 500 C, compared to only about 150 C for silicon chips. The chips would be most useful in devices located near hot-burning engines, such as those used in automobiles or airplanes.
Diamond has an extremely high thermal conductivity, can withstand high electric fields, and can be made into a semiconductor -- ideal for power devices
A diamond semiconductor that operates on the 81 GHz frequency, which is more than twice the speed of earlier devices, has been developed by the Nippon Telegraph and Telephone Corp. (NTT).According to NTT, this latest development will allow amplification in the millimeter-wave band from 30 to 300 GHz possible for the first time.
diamond chips can work at a much higher frequency or faster speed and be placed in a high-temperature environment, such as a vehicle's engine.Diamond can also resist voltages up to around 200 volts, compared to around 20 volts for a silicon chip. This means power electronics, such as an inverter, can become much smaller in size. At present, a large number of silicon chips are used together to handle high voltages which makes devices large
However, diamond chips are not expected to completely replace silicon chips for another 20 years because of two major bottlenecks, . artificial diamond for chips is still much more expensive than silicon. A four-millimeter-square diamond substrate costs several tens of thousands of yen compared to virtually nothing for silicon, Another problem is that electricity cannot travel smoothly through diamond. Thus, researches are seeking impurities that can be added to aid electricity flow.