France Telecom/cnet

France Telecom

French State, Minister of Post, Telecommunications and Space

Annie Tissier

Jean Galvier

Philippe Gayet

Alain Prola

Jean-Francois Teissier

Blandine Minghetti

Eric Schwartz

A process and device for adjusting a photolithographic exposure machine, which is used for manufacturing integrated circuits. A guide wafer being furnished with identical test patterns, these test patterns are successively illuminated with white light beam and the coefficient of reflectivity of each test pattern is thus measured. For each location of the corresponding pattern, the law of correspondence of the coefficient of reflectivity as a function of the defocusing parameter for the illuminating beam is thus established. The optimum sharp focus value is determined by criterion of threshold of the value of the coefficient of reflectivity.

Process for adjusting a photolithographic exposure machine and

A method for determining the complete elimination of a thin layer (3) deposited on a substrate (1) includes the steps of providing on an area of the substrate (1) an optical diffraction grating (2, 2'), the thin layer deposited on the substrate also covering this diffraction grating, and the etching of the thin layer being also carried out in the area of the diffraction grating; illuminating the grating (2, 2') with a monochromatic light beam; and observing the evolution of the diffracted light during the etching of the thin layer, in order to determine the moment when the material of the thin layer is entirely removed.

Method for determining the complete elimination of a thin layer on a non

A method for measuring the viscosity of a material consists in forming an array of parallel strips of material for constituting a diffraction grating; illuminating the array with a monochromatic light beam which produces a diffraction grating comprised of a main light spot (5) and of a plurality of adjacent diffraction spots, the envelope of which exhibits a major lobe (LO) including the main spot (5) and minor lobes (L1, L2); subjecting the array to a thermal process consisting in rapidly heating it at a predetermined temperature (T) and maintaining it at such temperature; selecting the brightest spot (6) among those of the first lobe (L1) and measuring the evolution of its light intensity (HL1) during the thermal process; determining the time interval elapsing until the first passage by a minimum intensity value (HL1b) of the spot (6); and deducting therefrom the value (.nu.) of the viscosity of the material constituting the array by the formula 1/.nu.=.alpha.d.

Method for measuring the viscosity of a material

A process for measuring the dimensions of a spacer consisting in forming in a substrate (1) an array of parallel stripes (2), having a rectangular cross section; forming spacers (7) on the lateral edges (6) of the parallel stripes (2); lighting the array through a monochromatic light beam to supply a diffraction pattern, the envelope of which exhibits a major lobe and secondary lobes; measuring the sum of light intensities of a predetermined number of spots pertaining to the first secondary lobe; and deducting therefrom the width l and angle .theta. of the spacer (7) according to the following formulas:

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Saint Ismier, France

Annie Tissier