Researchers are trying to develop alternative materials such as gallium arsenide, graphene, and carbon nanotubes. Silicon will probably be the main material for quite a while but there will be more mixing of materials onto a mostly silicon chip and there will specialized chips with other materials.
One challenge is to make these materials work with the infrastructure built for silicon, which represents billions of dollars in investment for chip makers.
Previously reported here was the fundamental breakthrough to enable previously incompatible semiconductors and nanomaterials to be created. This will enable much wider usage of non-cilicon materials.
Gallium arsenide operates at higher speeds and lower voltages than silicon. But gallium arsenide is brittle, so devices made from it are difficult to manufacture in volume. Intel is trying to get around the problem by growing thin layers of this material on top of silicon wafers, hoping to improve silicon chips by adding a few high-performance gallium arsenide elements.
IBM made transistors from graphene (Feb 2010), a one-atom-thick mesh of carbon; they are much faster than silicon transistors, switching at the rate of 100 gigahertz. Crucially, the IBM researchers built the transistor arrays on wafers, using a manufacturing-friendly process. These graphene transistors are still much bigger than their silicon counterparts, however, and an integrated circuit hasn’t been made from them yet.
Stanford University scientists are developing techniques for fabricating three-dimensional integrated circuits based on carbon nanotubes.
IEEE Spectrum looked at the materials that could be used after silicon in 2008. Gallium arsenide then was 2 percent of the semiconductor market then and looked at the high-electron-mobility transistor. The raw materials of gallium arsenide are ten times more expensive as silicon.
The Journal Science looked at what lies beyond silicon in March of 2010 They looked at nitride semiconductors and redesigning the transistor and what is needed for onchip optical communication. Nitrides are used in LEDs, lasers, projectors, sensors and novel solar cells
The World Market for Silicon Carbide & Gallium Nitride Power Semiconductors
* The SiC & GaN power semiconductor market is not anticipated to make a substantial impact onto the power semiconductor industry until 2013, projected to be worth over $150 million.
* The market for SiC & GaN power devices is forecast to reach $2.8 billion by 2019.
* Hybrid and electric vehicles hold the greatest revenue opportunity for SiC power devices