Apparatus and method for investigating semiconductors wafer
AssigneeMetryx Limited
InventorRobert John Wilby
Life of this patent
Estimating the term…
Abstract
In order to determine the dielectric constant of a layer deposited on a semiconducotr wafer (2), the density of the layer is obtained. To obtain that density, the wafer (2) without the layer is weighed in a weighing chamber (4) in which a weighing pan (7) supports the wafer on a weighing balance. The weight of the wafer is determined taking into account the buoyancy exerted by the air on the wafer (2). Then the layer is deposited on the wafer (2) and the weighing operation repeated. Alternatively a reference wafer may be used. If the material of the layer is known, the weight of the layer can be used to derive its density using a thickness measurement. Alternatively, if the density is known, the thickness can be obtained.
Claims6
A method of Statistical Process Control for monitoring the statistical variation in properties of layers deposited on a semiconductor wafer according to a plurality of manufacturing processes, and for providing a statistical analysis of the accuracy of the processes being carried out, wherein measurement of the mass of said deposited layers is used to provide said statistical analysis.
Dependencies are inferred from the claim text.