A Broad Photon Energy Range Multi-Strip Imaging Array Based upon Single Crystal Diamond Schottky Photodiode

A multi-strip detector made of synthetic single crystal diamond (SCD), based on a p-type/intrinsic diamond/Schottky metal transverse configuration and operating at zero bias voltage, was developed for imaging from extreme UV (EUV) to soft X-rays. The photodetector was patterned with 32 strips made of boron-doped diamond directly deposited, by means of the CVD technique and the standard lithographic technique, on top of the HPHT diamond growth substrate. The width of each strip and the gap between two adjacent strips were 100 μm and 20 μm, respectively. The strips were embedded in intrinsic SCD of an active area of 3.2 × 2.5 mm², also deposited using the CVD technique in a separate growing machine. In the present structure, the prototype photodetector is suitable for 1D imaging. However, all the dimensions above can be varied depending on the applications. The use of p-type diamond strips represents an attempt to mitigate the photoelectron emission from metal contacts, a non-negligible problem under EUV irradiation. The detector was tested with UV radiation and soft X-rays. To test the photodetector as an imaging device, a headboard (XDAS-DH) and a signal processing board (XDAS-SP) were used as front-end electronics. A standard XDAS software was used to acquire the experimental data. The results of the tests and the detector’s construction process are presented and discussed in the paper.