Evaluation of the Use of p-n Structures as Photodetectors in Silicon Integrated Circuits

摘要

The light sensitivity of p-n junctions in silicon integrated circuits has been investigated and the spectral and temporal response of several structures in an integrated circuit measured. A model for the spectral response was developed based on models previously used to study solar cell response. This model takes into account the depth and the active area of the carrier collecting junction and demonstrates the shifting of the peak spectral response towards shorter wavelengths as junction depth and active area decreases. Measurements of the spectral response of junctions in an integrated circuit were compared with the predicted responses. An investigation into the temporal response of p-n photodiodes has shown that the response time of the diode is dependent on both the geometry of the junction and the wavelength of light generating the carriers. Response times for structures in the integrated circuit were measured using a He-Ne laser operating at 0.632 micron. Keywords include: Integrated optoelectronics; Integrated photodetectors; Optical interconnects; Optical testing; and Laser testing.