Non-contact method and apparatus for measurement of sheet resistance and leakage current of p-n junctions
US7019513B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Jan 19, 2005 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Jan 19, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/304
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.