Silicon Photonics / Photovoltaics
Wafer Bonding: Light Emitters
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The luminescence properties of dislocations in silicon were studied for more than 20 years. Measurements on plastically deformed silicon revealed the existence of 4 main lines which are labelled D1 – D4 successively. The nature of the lines is hitherto not completely understood. The lines appear between 0.8 eV and about 1.0 eV corresponding to wavelengths ranging from 1.5 µm to 1.3 µm. This wavelength region is important for on chip optical interconnects in future electronic devices.
Plastic deformation, however, cannot be used to form reproducible regular arrangements of dislocations. Alternatively, regular dislocation networks can be generated in a reproducible manner by hydrophobic wafer bonding. Analysis showed that the luminescence depends on the dislocation network making it possible to create monochromatic light emitters in silicon.
Fig. 1: TEM cross-sectional image of a dislocation network formed in the interface of hydrophobically bonded silicon wafers (a). Photoluminescence measurements show the existence of the D1 line at 1.5 µm (b). Measurement at 80 K. | Semiconductor Wafer BondingDislocations in SiDislocation-induced light emitters |
