STMicroelectronicsIndustrial and Multisegment Sector R&D - Catania

- PicoSEC -STMicroelectronics activities

Overview

D. Sanfilippo

19 January 2012

Outline

The Silicon PhotoMultiplierTechnology overviewElectro-optical characteristicsSTMicroelectronics activities overview

2D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

The Silicon Photo Multiplier (SiPM)

The Silicon PhotoMultiplier (SiPM) is a multi-cell semiconductor photon sensor; each cell operates as an independent photon counterCells are biased above the breakdown voltage and operate in Geiger mode; the discharge is quenched by a resistor connected to each diodeThe individual signal amplitude does not depend on the number of photons firing the cell: each element operates digitally as a binary deviceThe SiPM output signal amplitude is the sum of signals from all the fired cells: it works as an analog detector that can measure light intensity

+Vbias

OUT

one cell

SPAD Rquenching

Rout

n cells

K

nK

1 photon

n photons

K

nK

1 photon

n photons

K

nK

1 photon

n photons

3D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

Technological features

N on P technologyShallow junctionIn-situ doped poly-silicon cathode layerIntegrated poly-silicon resistors

4

Anode backside contact

P+ type

ARC double layer

Thin optical trench with metal fillingTunable Anti-reflection coatingDedicated gettering techniquesDouble layer passivation

D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

Device layout

Single pixel

5

Pixel 1 Pixel 2

Pixel 3 Pixel 4

Single pixel

Monolithic Array 2x2

D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

SMD Optical Package

6

Bottom viewTop view

Cross section

D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

SiPM electrical characteristics

Bias range

High bias discharge

Breakdown

7

Typical Breakdown voltage: 28 VOperative over-voltage range (OV): 3 ÷ 6 VGain: ~ 3*106 · @ 3 V OVDark current: ~ 250 nA/mm2 @ 3 V OV

D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

Optical characterization

8

Laser HeadLaser Driver

Computer

Power Supply

Optical Fiber

Oscilloscope

Dark Box

SiPM

Experimental Setup

Pulse Amplitude Spectrum

Oscilloscope acquisition

0 0.01 0.02 0.03 0.04 0.05 0.060

5

10

15

20

25

Pulse Amplitude (V)C

ount

s

D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

9

STMicroelectronics core activity:

Develop a dedicated photon sensor for the Project,in particular a Silicon PhotoMultiplier (SiPM).

Specific items:Design a new device with a dedicated layoutOptimize the fabrication processDesign and develop a functional packagePerform the electrical characterizationPerform the optical characterization

Activities overview

D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania

19 January 2012

Thank You!

10D. Sanfilippo -

Silicon PhotoMultiplier - IMS R&D

Catania