Patent ID: 6073464
Filing Date: 2000-06-13
Classification: B24B,H01L

Abstract:
A method of laser surface treatment, wherein there is a series of at least a first zone and a second zone, substantially similar from a physico-chemical point of view and each comprising a layer of silicon, of given depth, and on each of which there is to be applied, on one or more occasions, a laser beam with an energy chosen for recrystallizing the layer of silicon in each of the first and second zones, the method comprising:a) effecting, before at least one of the applications of the laser beam to the first zone, at least one ellipsometry measurement on the first zone, in order to obtain a multiplet of physico-chemical characteristics of the first zone;b) determining the energy of the laser beam necessary for the recrystallization of the layer of silicon in the first zone, as a function at least of the multiplet of characteristics obtained at step a and a look-up table;c) effecting, on the first zone, at least one laser firing with an energy determined at step b;d) positioning the second zone opposite the laser beam; ande) effecting, on the second zone, at least one laser firing with an energy determined at step b, which makes it possible to optimize the process of recrystallization of the layer of silicon by the laser treatment on the first and second zones and controlling the application of the laser energy as a function of the ellipsometry measurement.