A LINEAR-ARRAY POSITION-SENSITIVE DETECTOR BASED ON AMORPHOUS-SILICON

A linear array thin film position sensitive detector (LTFPSD) based on hydrogenated amorphous silicon (a-Si:H) is proposed for the first tim e. Taking advantage of the optical properties presented by a-Si:H devi ces, we have developed a LTFPSD with 128 integrated elements able to b e used in 3D inspections/measurements. Each element consists of a one- dimensional LTFPSD, based on a p-i-n diode produced in a conventional PECVD system, where the doped layers are coated with thin resistive la yers to establish the required device equipotentials. By proper incorp oration of the LTFPSD into an optical inspection camera it will be pos sible to acquire information about an object/surface, through the opti cal cross-section method. The main advantages of this system, when com pared with the conventional CCDs, are the low complexity of hardware a nd software used and that the information can be continuously processe d (analog detection). (C) 1995 American Institute of Physics.