Spectral Responsivity Characteristics Of Front-Side Illumination Ingaas Photofets On Si

InGaAs photo field-effect transistor (photoFET) on Si is the most promising candidate for a high responsivity shortwave infrared (SWIR) photodetector toward monolithic integration with Si-LSI. To evaluate spectral responsivity characteristics of front-side illumination (FSI) InGaAs photoFETs integrated on Si wafer, the photocurrent measurement system with a wide area SWIR illumination is developed. This allows us to extract more accurate incident power density illuminating on the whole sensing area. From the incident power dependence of the responsivity, the spectral responsivity characteristics at a constant incident power are derived. It is found that the spectral responsivity characteristics of InGaAs photoFETs on Si present higher and broader responsivity than that of InGaAs photodiode.