Leica Microsystems Jena Gmbh

Vistec Semiconductor Systems Gmbh

Kuno Backhaus

Joachim Wienecke

Matthias Slodowski

Lambert Danner

Hakon Mikkelsen

Horst Engel

Detlef Wolter

Horst-Dieter Jaritz

The invention concerns an arrangement () for inspecting preferably unpatterned wafers, and comprises: a first optical inspection device () for examining reference wafers (R), which operates using image data processing methods and thereby recognizes defects on the reference wafers; a scattered-light measuring instrument () that is calibrated with the reference wafers (R) by defining at least one threshold value for the recognition of defects on wafers (W) to be inspected, and that comprises means () for recording the locations of threshold value exceedances for the wafers (W) to be inspected; and a second optical inspection device () for examination, only at those locations at which a threshold value exceedance is identified, of the wafers (W) to be inspected, which also comprises a classification device. The scattered-light measuring instrument () and the second optical inspection device () are arranged in one production line (P) as sequentially located stations. The first optical inspection device (), on the other hand, is arranged outside the production line (P). A corresponding method is also described.

Arrangement and method for inspecting unpatterned wafers

The invention refers to an optical measurement arrangement, in particular for layer thickness measurement and for ascertaining optical material properties such as refractive index, extinction factor, etc. of a specimen (P), having an illumination device ( ) for emitting a measurement light beam ( ), a beam splitter ( ) for dividing the measurement light beam ( ) into a specimen light beam ( ) and a reference light beam ( ), a measurement objective for directing the specimen light beam ( ) onto a measurement location (M) on the surface of the specimen (P) and for acquiring the light reflected from the measurement location (M), and an analysis device ( ) into which the reference light beam ( ) and the specimen light beam ( ) reflected from the specimen (P) are coupled in order to obtain information about the specimen (P), in particular about layer thicknesses present thereon. Light-guiding devices ( ) having a plurality of light-guiding fibers are provided for coupling the specimen light beam ( ) and the reference light beam ( ) into the analysis device ( ). The result is to create a compact optical measurement arrangement that can be flexibly set up and is insensitive to disturbance, which is suitable in particular for automatic monitoring of continuous production processes, in particular in semiconductor chip manufacture.

Optical measurement arrangement, in particular for layer thickness measurement

In a method for monitoring the measurement light emitted from an illumination apparatus for an optical measuring instrument, a continuous sensing of measurement light parameters is performed. The sensed measurement light parameters are compared to predefined setpoints. Any deviation from the predefined parameter ranges associated with the setpoints is signaled. This signal is used to initiate a lamp exchange on the illumination apparatus, which has multiple lamps that can be selectively switched on and off individually or in groups. Also described is a corresponding illumination apparatus that preferably performs a lamp exchange automatically. The result is to identify a point in time for a lamp change that is optimal with regard to measurement accuracy and the longest possible utilization of the lamps, so that a measurement light quality that remains consistent during continuous operation can reliably be maintained within predefined tolerance ranges.

Method and apparatus for monitoring the light emitted from an illumination apparatus for an optical measuring instrument

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Zoellnitz, Germany

Kuno Backhaus