Fully integrated blue/UV SOI CMOS photosensor for biomedical and environmental applications

Abstract

In this paper, we present a microsystem for measuring optical power in blue/UV wavelengths (from k = 200 nm to k = 450 nm) which includes a photodiode and the analog processing circuit of the photodiode signal, fully integrated in 2 lm SOI CMOS technology. The photodiode has a maximum responsivity for k = 400 nm. Th photosensor functions as a current to frequency converter. Measurements of the microsystem illuminated by blue and UV LEDs demonstrate the good linear behavior, sensitivity and efficiency of the system.

Complete microsystem using SOI photodiode for DNA concentration measurement

“…Measurements and simulations (according to a Matlab implementation of the model as described in [6]) prove its UV favorable behavior for target measurements in figure 2.…”

“…The photoreceiver in SOI technology was fully described in [6] where the dimensions and doping levels of the structure can be found. It consists in a lateral PIN diode (whose total area is 1mm 2 ) that can achieve high efficiency in the UV range thanks to the small thickness (i.e.…”

“…For future experiments, a complete system-on-a-chip has been designed in [6]. The circuit includes a SOI PIN photodiode and processes the photocurrent into a digital output easily treatable by a digital system interface.…”

Temperature, Silicon Thickness and Intrinsic Length Influence on the Operation of Lateral SOI PIN Photodiodes

“…The absorption of light varies with the penetration depth into the material [4]. Lateral PIN SOI photodiodes implemented in thin silicon films, are efficient alternatives for the absorption of short wavelengths [4]. For example, UV and blue light penetration depths in silicon are around 100 nm and 500 nm, respectively [1].…”

“…These characteristics contribute to optical power measurements through the detection of short wavelengths (λ) in the range of blue and UV, in the spectral range below 400 nm. They are widely used in various applications such as in the environment [3], measurements of UV and ozone rates, measurement of DNA concentration, detection of bacteria [4], and on high-density DVDs that operate with a wavelength of 405 nm [5].…”