Patent DE-102007015351-A1 (DE)
Title: Procedure and device for accurate positioning of ion beam during simultaneous determination of its abrasion profile, comprise an arrangement of optically transparent carrier material, which is covered with optically opaque thin layer
Inventor: HAENSEL THOMAS
IPC: H01L21/68
Filed: 2007-03-30
Abstract: The procedure and device for accurate positioning of an ion beam (3) during simultaneous determination of its abrasion profile, comprise an arrangement of an optically transparent carrier material (1), which is covered with an optically opaque thin layer (2) and illuminates by a light source (4) and which is seized with an electronic camera opposite to the light source. The optically opaque layer, which presents itself on the optically transparent carrier material, is set out to the ion beam for a given time. An argon ion beam is used with argon-ions energy of typically 1 keV. The procedure and device for accurate positioning of an ion beam (3) during simultaneous determination of its abrasion profile, comprise an arrangement of an optically transparent carrier material (1), which is covered with an optically opaque thin layer (2) and illuminates by a light source (4) and which is seized with an electronic camera opposite to the light source. The optically opaque layer, which presents itself on the optically transparent carrier material, is set out to the ion beam for a given time. An argon ion beam is used with argon-ions energy of typically 1 keV. The abrasion of the opaque layer produced by the effect of the ion beam locally effects a change of transparency. The produced transparency profile is electronically affiliated and evaluated with the help of an optical camera. The position and the abrasion profile of the ion beam are determined from the measured and digitalized transparency profile. The optically measured abrasion profile is correlated to the abrasion profile measured on to the material to be processed and correlated to a radiation profile electrically measured by Faraday probe. An etching rate, a half width and/or a geometrical focal point are computed from the optically measured and digitalized abrasion profile. A fit function consisting of several parameterized Gaussian functions is numerically adapted at the measured abrasion profile. The position, the half width and/or the depth of the abrasion profile are determined from the parameters of the adapted Gaussian functions. A charge-coupled device camera (5) is used for the optical evaluation of the abrasion profile. The transparent material is implemented in the form of a rotatable disk, which is rotated around a suspension point, so that several positions are on the disk. The several positions are set out to the ion beam for the optical determination of its abrasion profile. The transparent material is a flexible plastic film, which is moved over a system from rollers, so that several positions are on the film. The several positions are set out to the ion beam for the optical determination of its abrasion profile. The layer is an opaque coating with a thickness of 100 Nm. The transparent material is implemented in the form of squares or rectangles or circular areas, which are positioned with a motion system having two or more degrees of freedom.