To maintain the growth and profitability of the semi-conductor industry new materials and techniques are to be found out. To increase the capabilities of the current silicon technologies for replacing current semiconductors, semiconducting carbon nanotubes doped like silicon are one of the best candidate materials. It has been demonstrated that nanotube has excellent electrical properties. University of Maryland physicists have found that semiconducting carbon nanotubes have the highest mobility of any known material at room temperature having a mobility almost 25 percent higher than any known semiconducting material and more than 70 times higher than the mobility of the silicon used in today's computer chips. Purification ofgenerally refers to the separation of nanotubes from other entities such as carbon nanoparticles, amorphous carbon, residual catalyst, and other unwanted species. But, current production methods create a mixture of nanotubes with both semiconducting and metallic properties that makes them expensive and difficult to use. Different methods have been developed for producing clean, well-dispersed, high purity semiconducting carbon nanotubes. The Oxford Invention has developed a patented technique for purifying samples of carbon nanotubes both single-walled nanotubes and multi-walled nanotubes to remove both general metallic and graphitic contamination and to produce pure nanotube having more than 90% semiconducting nanotubes. Other methods include a microwave-assisted purification technique developed for multiwalled carbon nanotubes (MWNTs) in a closed vessel at 180 °C for 30 min in the presence of 20% hydrogen peroxide and a magnetophoretic continuous purification method which is reported to gives a purity of about 99 % ,