Contactless Evaluation Using a Laser/Microwave Method for the Silicon-on-Insulator Made by Wafer Bonding

Akira USAMI  Takahisa NAKAI  Hideki FUJIWARA  Shun-ichiro ISHIGAMI  Takao WADA  

IEICE TRANSACTIONS on Electronics   Vol.E75-C   No.9   pp.1043-1048
Publication Date: 1992/09/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Silicon Devices and Materials)
SOI,  wafer bonding,  void,  laser/microwave method,  lifetime,  

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In this study, we evaluate the electrical characteristics of the SOI layer made by the wafer bonding method using a laser/microwave method. We use a He-Ne laser pulse for the photoconductivity modulation method and a semiconductor laser diode for the photoconductivity decay method as the carrier injection light source. The detected signal intensity at the void area decreases as compared with that at the center area of the SOI layer where there are no voids. The positions of the voids revealed by the proposed method are in good agreement with those by X-ray topography. We also measure the lifetime by the photoconductivity decay method using a laser diode. The lifetime at the void area is much shorter than that at the center area. It is considered that the decrease in the detected signal intensity at the void area is due to reduction in the minority carrier lifetime.