Thermal Conductivity of Silicon-28 and Separation Technology for Its Production

摘要

1. Introduction: With microprocessors now consuming hundreds of watts, chip manufacturers have to find a path to control the tremendous heat generated by faster computer chips. The estimations show that the total power dissipation of a 3.4GHz processor, for example, may be reduced to 50 Watts, but it could be as high as 100W/cm2 in certain areas (so called "hot spots") [1]. Probably silicon-on-insulator (SOI) wafer technology using highly enriched silicon-28 could break the heat barrier to the semiconductor manufacturers [2]. The possibility to use highly enriched silicon-28 in SOI wafers is under discussion since the mid of 90s. It grounds on the US patent [3] covering semiconductor devices using isotopically engineered materials. By using an isotopically pure silicon-28 layer, the crystal structure is more perfect, and less scattering of the electrons take place, generating less heat and electromagnetic noise. The average temperature of the chip will probably not be affected. However, the very localized temperatures, say, at the p/n junction of a transistor can be generally affected. The higher conductivity of silicon-28 layer spreads the heat from the hot spots better than natural silicon, thus reducing the maximum temperatures [4].