Other

Ahbee 1, L.p.

Timothy Wong

Michael I Current

Vladimir Faifer

Phuc Van

A non-contact apparatus and method for measuring of the leakage current and capacitance of p-n junctions in test structures within scribe lanes of IC product wafers is disclosed. The apparatus comprises of a light source optically coupled with a fiber to a transparent electrode at the end of the fiber, which is brought close to the p-n junction under test. The ac signal generated from the test p-n junction is captured by this transparent and conducting coating electrode. The leakage current of a test p-n junction is determined using the frequency dependence of junction photo-voltage signal and reference signals from a p-n junction with low leakage current and known capacitance.

Non-contact method and apparatus for measurement of leakage current of p-n junctions in IC product wafers

A non-contact apparatus and method for measuring of the leakage current and capacitance of p-n junctions in test structures within scribe lanes of IC product wafers is disclosed. The apparatus has a light source optically coupled with a fiber to a transparent electrode at the end of the fiber, which is brought close to the p-n junction under test. The ac signal generated from the test p-n junction is captured by this transparent and conducting coating electrode. The leakage current of a test p-n junction is determined using the frequency dependence of junction photo-voltage signal and reference signals from a p-n junction with low leakage current and known capacitance.

A contactless sheet resistance measurement apparatus and method for measuring the sheet resistance of a surface p-n junction and its leakage current is disclosed. The apparatus comprises an alternating light source optically coupled with a transparent and conducting electrode brought close to the junction, a second electrode placed outside of the illumination area, and a third grounded electrode surrounding the first and second electrodes. For measurements of junction capacitance, a calibration wafer with known sheet resistance is used to provide reference photovoltage signals. Using the measurement of the junction photovoltage (JPV) signals from the illuminated area and outside this area for calibration and test wafers at different light modulation frequencies, p-n junction sheet resistance and conductance (leakage current density) are determined.

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San Jose, CA, United States of America

Timothy Wong