Techniques for measuring the thickness of a film formed on a substrate

DETAILED DESCRIPTION These and other objects are accomplished by the various aspects of the present invention, wherein, briefly and generally, the thickness of a film is determined by measuring the emissivity of the film and its supporting substrate, preferably by a non-contact optical technique having a very high resolution.
Advantage is taken of emissivity changes that occur as a function of the film's thickness.
This is believed to occur because the emissivity being measured is a combination of different emissivities of the film and its underlying substrate, the contribution of the film emissivity to this composite measurement thus being dependent upon its thickness.
The preferred optical technique is especially adapted for use with films having a thickness from a few Angstroms to a few thousand Angstroms.
According to a specific aspect of the present invention, the thickness measurement is performed in situ as the film is being formed so that its resulting thickness, rate of formation and similar parameters can be controlled in an efficient manner.
The process of forming the film can be automatically controlled as a result of the continuous emissivity measurements.
This is of particular advantage in integrated circuit processing techniques for monitoring and controlling the deposition or growth of dielectrics, the deposition of metals and metal compounds, and the formation of other material layers.
Additional objects, advantages and features of the present invention will become apparent from the following description of its preferred embodiments, which description should be taken in conjunction with the accompanying drawings.