Edward E. Jones

Properties of Diboron Tetrafluoride (B2F4), a New Gas for Boron Ion Implantation

Currently, boron trifluoride, BF3, is the primary feed gas for boron implantation in manufacturing of semiconductor devices. However, BF3 molecule is difficult to ionize and fragment, and therefore only a small fraction is is converted into B+ ions that can be used for ion implantation. This results in low B+ beam currents even at relatively high extraction currents, which can limit process throughput and system performance. The problem is particularly severe at low energies. ATMI has demonstrated that use of diboron tetrafluoride, B2F4, as a feed gas for boron implantation may offer advantages over BF3. It has been shown that B2F4 is capable of generating higher B+ and BF2+ beam currents at lower ion source power settings, and that the molecule can be used on the existing installed base of implanters without any major equipment modifications.