  Future tracking systems in High Energy Physics experiments will require large
instrumented areas with low radiation length. Crystalline silicon sensors have
been used in tracking systems for decades, but are difficult to manufacture and
costly to produce for large areas. We are exploring alternative sensor
materials that are amenable to fast fabrication techniques used for thin film
devices. Indium Phosphide pad sensors were fabricated at Argonne National Lab
using commercially available InP:Fe 2-inch mono-crystal substrates.
Current-voltage and capacitance-voltage characterizations were performed to
study the basic operating characteristics of a group of sensors. Micro-focused
X-ray beams at Canadian Light Source and Diamond Light Source were used to
study the response to ionizing radiation, and characterize the uniformity of
the response for several devices. The results show a high degree of performance
uniformity in our evaluations, both within a device and between the 48 tested
devices. This motivates further studies into thin film devices for future
tracking detectors.
