| Zugriffsnummer | 14687 |
| Dokumenttyp | Konferenzartikel in Zeitschrift |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | NDE of semiconductor samples and photovoltaic devices with high spatial resolution utilizing SQUID photoscanning [invited paper] |
| Autor(in); Institution |
Schurig, Thomas; 7.13, Kryosensorik, PTB-Berlin
Beyer, Jörn; 7.13, Kryosensorik, PTB-Berlin
Drung, Dietmar; 7.13, Kryosensorik, PTB-Berlin
Ludwig, Frank; 7.13, Kryosensorik, PTB-Berlin
Lüdge, Anke; Institut für Kristallzüchtung Berlin, GERMANY
Riemann, Helge; Institut für Kristallzüchtung Berlin, GERMANY
|
| Quelle/Jahr | International Superconductive Electronics Conference 2001. IEICE Transactions on Electronics: E85-C (2002), 665 - 669 |
| ISSN | 0916-8524 |
| Verlag | Tokyo: IEICE |
| Konferenzangaben | International Superconductive Electronics Conference 2001, Osaka, 19-22, June, 2001, Japan |
| Freie Schlagworte | SQUID ; NDE ; semiconductor analysis |
| Zusammenfassung | The aim of this talk is to give a description of a SQUID based analytical tool intended for the evaluation of semiconductor wafers and photovoltaic devices and to discuss its potential for practical implementation. Recently, we have demonstrated on silicon wafers that SQUID magnetometers are capable of detecting the magnetic field of photo-generated currents locally excited in areas exhibiting doping inhomogeneities by illuminating the sample with a focused laser beam. This effect enables the nondestructive investigation of such lateral doping fluctuations in semiconductor wafers by scanning the sample under investigation with a laser and synchronously detecting the magnetic signal obtained by the SQUID sensor placed at a certain position near the excitation spot on the sample surface. Besides the investigation of doping fluctuations this technique can be utilized for detecting electrically active defects, such as grain boundaries in multicrystalline silicon or artifacts in photovoltaic devices. The SQUID sensors used for this technique are conventional low-Tc and high-Tc magnetometers of 3.6 mm x 3.6 mm and 9 mm x 9 mm size, respectively. The spatial resolution achieved by this method is of the order of a few 10 micrometers determined by the diameter of the laser spot and the excitation volume surrounding it. Typical signal amplitudes obtained from the samples cover a range of about 100 fT for slight doping inhomogeneities in high purity silicon wafers up to several nT for photocurrent distributions in solar cells. |
