Line sensor for fast, time-resolved spectroscopy measurements

In this work a novel CMOS line sensor based on the lateral drift-field photodetector (LDPD) [1] pixel approach is presented. The proposed pixel structure features the photoactive area of 200 µm ×10 µm fulfilling the application requirements [2]. A specially designed n-well within the LDPD provides the fast and efficient transfer of the generated carries from the photoactive area into each of the sense or drain nodes. The grounded p+ layer localized on the surface of the LDPD n-well reduces the dark current generated by Schockley-Read-Hall recombination/generation centers located on the silicon surface. The UV-enhanced silicon-nitride based passivation layer guarantees the photodiode (PD) sensitivity down to 220 nm wavelength range. The presented line sensor LDPD pixel is to be employed in optical emission spectroscopy applications.