Silicon wafer requirements for ULSI device processing

With the increasing integration density towards the sub-half micron devices, the design rules reduce up to 0.12 mum and below. Therefore the requirements for the base materials of the integrated circuits such as the silicon wafers are constantly rinsing. Along with the reduction of the structure size, a change in the wafer diameter is also occurring and some semiconductors companies are getting ready to move from 200 mm. wafer to 300 mm wafers technology to enhance the batch size of chips per wafer. On average every three years a new generation of memories devices has been introduced, the number of transistors per integrated circuit increases four times every three years, which is also known in literature as Moore's law, published in 1965. Therefore semiconductor devices present stringent requests for more pure silicon.