New Technique Infuses' Wafer Surface

摘要

A new surface processing technique that has applications in areas as diverse as ultrashallow junction (USJ) doping, epitaxial strained silicon and low-k pore sealing is now commercially available from a company called Epion (Billerica, Mass.). Based on gas cluster ion beam (GCIB) processing, the technique works in a way similar to ion implantation in that a charged mass is accelerated through a beam line and directed at the wafer surface; the wafer is moved beneath the beam. In the Epion approach, however, only a very small charge is added to the cluster (one ion per several thousand atoms). This allows for high total energy interactions (>30 keV) but very low energies per atom (<10 eV), so that penetration into the substrate is minimal. The composition of the cluster can be modified depending on the application to etch, deposit, dope, ash, seal, etc. (Fig. 1). As in an ion im-planter, dosimetry is performed by measuring the ion beam with a Faraday cup.