STMicroelectronics Industrial and Multisegment Sector RD Catania Pico

STMicroelectronics Industrial and Multisegment Sector R&D - Catania - Pico. SEC STMicroelectronics activities Overview D. Sanfilippo

Outline The Silicon Photo. Multiplier Technology overview Electro-optical characteristics STMicroelectronics activities overview 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 2

The Silicon Photo Multiplier (Si. PM) The Silicon Photo. Multiplier (Si. PM) is a multi-cell semiconductor photon sensor; each cell operates as an independent photon counter Cells are biased above the breakdown voltage and operate in Geiger mode; the discharge is quenched by a resistor connected to each diode The individual signal amplitude does not depend on the number of photons firing the cell: each element operates digitally as a binary device The Si. PM output signal amplitude is the sum of signals from all the fired cells: it works as an analog detector that can measure light intensity 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 3

Technological features Thin optical trench with metal filling Tunable Anti-reflection coating Dedicated gettering techniques Double layer passivation N on P technology Shallow junction In-situ doped poly-silicon cathode layer Integrated poly-silicon resistors ARC double layer P+ type Anode backside contact 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 4

Device layout Single pixel Monolithic Array 2 x 2 Single pixel 19 January 2012 Pixel 1 Pixel 2 Pixel 3 Pixel 4 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 5

SMD Optical Package Top view Bottom view Cross section 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 6

Si. PM electrical characteristics Typical Breakdown voltage: 28 V Operative over-voltage range (OV): 3 ÷ 6 V Gain: ~ 3*106 · @ 3 V OV Dark current: ~ 250 n. A/mm 2 @ 3 V OV High bias discharge Breakdown Bias range 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 7

Optical characterization Experimental Setup Pulse Amplitude Spectrum Oscilloscope acquisition 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 8

Activities overview STMicroelectronics core activity: Develop a dedicated photon sensor for the Project, in particular a Silicon Photo. Multiplier (Si. PM). Specific items: Design a new device with a dedicated layout Optimize the fabrication process Design and develop a functional package Perform the electrical characterization Perform the optical characterization 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 9

! u o Y nk a h T 19 January 2012 D. Sanfilippo - Silicon Photo. Multiplier - IMS R&D Catania 10