In this work we present a detailed study of PIN photodetectors manufactured in generic InP process on two substrate types, N+ and semi-insulating. We designed and manufactured several photodetector designs optimized for high responsivity (DC photodetectors) or RF performance (RF photodetectors). Measurement results of the key performance parameters, namely dark current, responsivity and RF bandwidth, are presented. For the DC photodetector design a responsivity of 0.92 A/W at 1550nm was achieved with a dark current of 0.67?A at -5V reverse bias. The typical RF bandwidth of RF detectors is >8 GHz.