Laser removal of thin layers for surface cleaning

In micro- and nano- device fabrication technology, localized material removal is one of the basic operations for structure formation. Classical methods for structure formation on the surface of a silicon wafer are based mainly on chemical processing, starting with photo etching, chemical etching, and chemical-mechanical linearization. In order to propose new methods of higher quality from the point of view of both environment protection and processing quality, we have studied the possibility of thin films controlled removal under the action of laser radiation. We are presenting some qualitative results of laser induced surface removal of polymer thin films, of interest for microelectronic industry (e.g. photoresist), under the action of different laser sources. As laser sources we have used the most spread and commercially available laser systems with different wavelengths and pulse lengths in order to compare their action on the surfaces and to establish the characteristic parameters for removal of thin layers for surface cleaning.