Power performance of 65 nm CMOS integrated LDMOS transistors at WLAN and X-band frequencies
C. Pralla, K. Haberlandb, C. Kasparib, F. Brunnerc, M. Weyersc, D. Ruetera
Published in:
Proc. SPIE 9768, Photonics West, San Francisco, USA, Feb. 13-18, 97681A (2016).
Abstract:
Development and manufacturing of LED structures is still driven by production cost reduction and performance improvements. Therefore, in-situ monitoring during the epitaxial process plays a key role in view of further yield improvement and process optimization. With the continuing trend towards larger wafers, stronger bow and increased aspherical curvature are additional challenges the growers have to face, leading to non-uniform LED-emission. Compared to traditional in-situ metrology like curvature measurement and near UV pyrometry, in-situ photoluminescence measurements can provide a more direct access to the quantum well emission already during growth. In this paper we show how in-situ photoluminescence measurements can be used in a production type multi-wafer MOCVD system to characterize the quantum well emission already during growth. We also demonstrate how deviations from the desired wavelength can be detected and corrected in the same growth run. Since the method is providing spatially resolved linescans across the wafer, also the uniformity of the emission wavelength can be characterized already during growth. Comparison of in-situ and ex-situ photoluminescence data show excellent agreement with respect to wavelength uniformity on 4 inch wafers.
a Institute of Measurement Engineering and Sensor Technology, University of Applied Sciences Ruhr West, PO Box 10 07 55, 45407 Muelheim a.d. Ruhr, Germany
b LayTec AG, Seesener Str. 10-13, 10709 Berlin, Germany
c Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
Keywords:
characterization, metal organic chemical vapor deposition, light-emitting diodes, photoluminescence.
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