Method of manufacturing semiconductor devices involving the detection of impurities
AssigneeAT&T Bell Laboratories
InventorsJohn M. Andrews, Jr., Nadia Lifshitz, Gerald Smolinsky
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Abstract
The TVS method is a voltammetric method for detecting mobile ionic impurities in the dielectric layer of a MOS capacitor structure. Disclosed here is a method of semiconductor device fabrication involving a modified TVS method in which the voltage is changed in discrete steps rather than varied continuously, and charge, rather than induced current, is measured. The modified TVS method can be faster than conventional TVS, and calibration is unnecessary.
Claims7
A method of semiconductor device fabrication including the step of detecting an impurity in a dielectric layer which is a part of the body such device, wherein the detecting step comprises:
- heating the body to an elevated temperature;
- applying a voltage across the dielectric layer;
- and varying the voltage between a maximum negative amplitude and a maximum positive amplitude;
- characterized in that
- the varying step comprises changing the voltage in discrete increments separated by time intervals, whereby a charge is induced by ionic impurity motion during each time interval;
- and
- the method further comprises the step of recording the induced charges.
Dependencies are inferred from the claim text.