Metallization technology for tenth-micron range integrated circuits

摘要

A critical step in the fabrication of integrated circuits is the deposition of metal layers which interconnect the various circuit elements that have been formed in earlier process steps. In particular, columns of copper several times higher than the characteristic dimension of the circuit elements was needed. Features with a diameter of a few tenths of a micron and a height of about one micron need to be filled at rates in the half to one micron per minute range. With the successful development of a copper deposition technology meeting these requirements, integrated circuits with simpler designs and higher performance could be economically manufactured. Several technologies for depositing copper were under development. No single approach had an optimum combination of performance (feature characteristics), cost (deposition rates), and manufacturability (integration with other processes and tool reliability). Chemical vapor deposition, plating, sputtering and ionized-physical vapor deposition (I-PVD) were all candidate technologies. Within this project, the focus was on I-PVD.