Laser cleaning of silicon wafers : prospects and problems

Abstract

The removal of particle contamination from surfaces is one of the crucial prerequisites for a further increase in the integration density of ICs and for the progress in nanotechnology. At all stages of the production of ICs, e.g., from the bare Si wager to the patterned chip, particles even smaller than 100 nm in size can cause a damage to the produced structure and hence be responsible for the failure of the final device. In the late 1980s, the experts in the field of cleaning technology predicted that traditional cleaning methods such as ultrasonics and wet techniques would reach their limit of capability (1,2). In addition these traditional techniques were and still are harmful to the environment as they consume large quantities of aggressive chemicals and water. Although the traditional methods have been continuously improved (3), still particle contamination causes considerable production losses (4), and with further shrinking of line widths (5) there is a definite need to replace traditional methods by new cleaning technologies.