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Proceedings Paper

Degradation zones of semiconductor target (Si) formed as a result of nanosecond UV laser material processing
Author(s): Andrew R. Novoselov; Anatoly G. Klimenko
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Paper Abstract

The results of laser-semiconductor material interaction are presented. The laser source for these experiments was an UV laser at 0.34 mkm wavelength with 7 ns pulses at 100 Hz repetition rate focused at the spot of 3 mkm diameter, laser fluence was more than 1.1 J/sq cm corresponding to the minimum energy density required to forming kerf. Material of target was p-Si with thermal oxide silicon. We have investigated changes of electrophysical (dynamic and static) performance of diagnostic structures vs. distance between the edge of laser kerf and the edge of diagnostic structures for definition of characteristic zones around the spot of laser - material interaction. The diagnostic structures included p-n junction or source of MOSFET. From the measurement made, back current for p-n junction and transfer characteristic for MOSFET and time carrier storage in source capacity of MOSFET were studied. We have determined the 3 zones around the spot of laser material processing: Zone 1. The electrophysical (dynamic and static) performance of diagnostic structures heavily changed at a distance as small as 4 - 5 mkm. It is bigger than length of region recrystallized material extracted from laser kerf (about 2 mkm). The leakage current increased. The length of zone depends from supply voltage to the diagnostic structures. For example, the length of zone 1 for supply voltage 8 V was 4 - 5 mkm and for supply voltage 20 V - 30 mkm. Zone 2. For distance between the edge of laser kerf and boundary of diagnostic structures larger than 5 mkm, the electrophysical (dynamic and static) performance of diagnostic structures changed, but restored in time. Time of 50 percent restore of electrophysical performance of diagnostic structure was about 408 min. Zone 3. For distance between the edge of laser kerf and boundary of diagnostic structures large than 70 mkm, the free electrons generated by laser irradiation, filled charge traps which began to release after laser material processing. Time of discharge traps was about 408 min. In our experiments we have realized a distance of 5 mkm form the laser kerf to the diagnostic structures and 28 mkm to the working multiplexer circuit.

Paper Details

Date Published: 27 August 1999
PDF: 8 pages
Proc. SPIE 3884, In-Line Methods and Monitors for Process and Yield Improvement, (27 August 1999); doi: 10.1117/12.361359
Show Author Affiliations
Andrew R. Novoselov, Institute of Semiconductor Physics (Russia)
Anatoly G. Klimenko, Institute of Semiconductor Physics (Russia)


Published in SPIE Proceedings Vol. 3884:
In-Line Methods and Monitors for Process and Yield Improvement
Sergio A. Ajuria; Jerome F. Jakubczak, Editor(s)

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