Simultaneous Oxide and Metal Removal from Silicon Surfaces

摘要

The microelectronics industry has long consideredthe removal of chemical oxide a part of a general process forcontamination control. Currently, oxide removal is accomplishedin a separate step from other cleaning steps, including metalremoval. This paper reports the first attempt to combine metalremoval with bulk oxide removal in a single cleaning step.Theprocess combines 2,2,6,6-tetramethy1-3, 5-heptanedione withanhydrous hydrogen fluoride in the vapor phase to remove bulkoxide and transition metals, including Fe, Cu, Zn, and Ni, fromintentionally contaminated surfaces. The maximum measuredoxide removal rate was about 45 ?/min for dry thermal silicondioxide. Surface metal concentrations were reduced by as muchas three orders of magnitude within the experimental conditions of this study.