Abstract: Thickness measurement apparatus for measuring layer thicknesses on patterned areas of a semiconductor wafer, comprises: a spectrum analyzer for obtaining reflection data taken from a patterned area and obtaining therefrom a frequency spectrum, a peak detector for searching the spectrum to find peak frequencies within said spectrum, the search being restricted to regions corresponding to peak frequencies found in an earlier learning stage, a frequency filter, associated with the peak detector, for filtering the spectrum about said peak frequencies, and a maximum likelihood fitter for using parameters obtained in the learning stage to carry out maximum likelihood fitting of said filtered spectrum to obtain the desired layer thicknesses. By carrying out maximum likelihood fitting using parameters obtained beforehand in a high resolution non-real time learning stage, it is possible to provide high resolution results in real time.

Abstract: A method or apparatus for measuring lateral variations of a property such as thickness or refractive index of a transparent film on a semiconductor, in a region of repeated patterning comprises: illuminating over the patterned area with a beam of light of multiple wavelengths, the beam having dimensions to include repeated patterning; detecting the intensity of light reflected over the patterned area for each wavelength; producing a signal defining the variation of the intensity of the detected light as a function of the wavelength of the detected light; decomposing the signal into principal frequencies thereof, determining from the principal frequencies, values of the thickness etc. of the transparent film; and applying the values to repetitions within the repeated patterning.

Abstract: The use of an intensity spectrum as a fingerprint to determine the layer structure of a semiconductor wafer product or partial product, thereby to determine the routing history of the product through a production line and prevent routing errors. Also, a production line having a plurality of successive stages for construction of a product such as a semiconductor wafer, and routers for transferring partly constructed product between the stages such that each stage receives a respective predefined partly constructed product as its input.

Abstract: Thickness measurement apparatus for measuring layer thicknesses on patterned areas of a semiconductor wafer, comprises: a spectrum analyzer for obtaining reflection data taken from a patterned area and obtaining therefrom a frequency spectrum, a peak detector for searching the spectrum to find peak frequencies within said spectrum, the search being restricted to regions corresponding to peak frequencies found in an earlier learning stage, a frequency filter, associated with the peak detector, for filtering the spectrum about said peak frequencies, and a maximum likelihood fitter for using parameters obtained in the learning stage to carry out maximum likelihood fitting of said filtered spectrum to obtain the desired layer thicknesses. By carrying out maximum likelihood fitting using parameters obtained beforehand in a high resolution non-real time learning stage, it is possible to provide high resolution results in real time.

Abstract: Integrated measurement apparatus and method for measuring layer thickness and bow in a wafer. The apparatus comprises: a monochromatic light source, a white light source, a first switch for switching between the white light source and the monochromatic light source, a plurality of optical heads for directing light from the switched light source onto different locations on a semiconductor wafer surface, a first optical processor for spectral processing of reflected light from the wafer, a second optical processor for processing of reflected light to determine an extent of bow in the wafer, and a second optical switch to switch reflected light from the wafer between the first optical processor and the second optical processor so that the white light is spectrally processed to determine layer thicknesses and the monochromatic light is processed for bowing.

Abstract: Integrated measurement apparatus and method for measuring layer thickness and bow in a wafer. The apparatus comprises: a monochromatic light source, a white light source, a first switch for switching between the white light source and the monochromatic light source, a plurality of optical heads for directing light from the switched light source onto different locations on a semiconductor wafer surface, a first optical processor for spectral processing of reflected light from the wafer, a second optical processor for processing of reflected light to determine an extent of bow in the wafer, and a second optical switch to switch reflected light from the wafer between the first optical processor and the second optical processor so that the white light is spectrally processed to determine layer thicknesses and the monochromatic light is processed for bowing.

Abstract: The use of an intensity spectrum as a fingerprint to determine the layer structure of a semiconductor wafer product or partial product, thereby to determine the routing history of the product through a production line and prevent routing errors. Also, a production line having a plurality of successive stages for construction of a product such as a semiconductor wafer, and routers for transferring partly constructed product between the stages such that each stage receives a respective predefined partly constructed product as its input.