Radiation image sensor with SOI technology

Outline

I.! Introduction II.! SOI Pixel Process III.!SOIPIX Detectors IV.! Advanced R&D V.! Summary

I. Introduction

KEK Tokai J-PARC (30 GeV Proton) KEK Tsukuba

Super KEKB (4 GeV e+ - 7 GeV e-) Photon Factory (2.5 & 6.5 Gev Sync. Rad.)

High Energy Accelerator Research Organization (KEK)

International Linear Collider Project

30 km Long

By Colliding Accelerated Beams,Many Secondary Particles are Generated

We must measure their position and timing in µm and ns precision.

ATLAS Detector@CERN

Silicon Vertex Detector

~3µm

Visible Light(~2 eV)

Si + - + -

~300µm

X-ray(<20keV)

Si +

- + -

Visible Light ~ 1 e-h / 1 photon High Energy Particle ~ 80 e-h / µm X-ray ~ 3000 e-h @10 keV

~50µm

Charged Particle ( > MeV)

Si + - + +

- - - +

Sensing Part

>300µm

X-ray(>20keV), !-ray

Si +

- + -

e-

Present Advanced Pixel Radiation Sensor (Sensor and LSI Hybrid with large number of bump bondings)

!!Large number of metal bump bondings. !!Performances are limited by the bump size. !!Large unwanted materials which bend particle track.

(from Medipix picture)

Silicon-On-Insulator Pixel Detector (SOIPIX)

Bulk Device

Gate Gate Oxide

Si

SOI Device

Gate

Si

SOI has higher soft error immunity due to its ultra thin body Silicon.

Buried Oxide

Depletion Layer

Charged Particle

Charged Particle

•!No mechanical bonding. Fabricated with semiconductor process only, so high reliability, low cost are expected.

•!Fully depleted thick sensing region with Low sense node capacitance.

•!On Pixel processing with CMOS transistors.

•!Can be operated in wide temperature (and has low single event cross section.

•!Based on Industry Standard Technology.

Tohoku U.

Kyoto U.Tsukuba U.

JAXA/ISAS

AIST

We operate Multi-Project Wafer (MPW) run. (~twice/year)

Kanazawa I.T.

Only one SOI radiation pixel process in the world!

RIKEN

Lawrence Berkeley Nat'l Lab. Fermi Nat'l Accl. Lab.

U. Heidelberg

Louvain Univ.

IHEP/IMECAS/SARI China

AGH & IFJ, Krakow

KEK

Shizuoka U.

Hokkaido U.Osaka U.

II. SOI Pixel Process

MPW Run Mask 24.6 x 30.8 mm

Lapis Semi.(*) 0.2 µm FD-SOI Pixel Process

µ

" µ#

## #

(*) Former OKI Semiconductor Co. Ltd.

Main Issue in the SOIPIX: Back-Gate Effect

Detector Voltage act as a Back Gate of the Transistors, and open back channel.

•!•!•!•!

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%&'(%)!*+),-(&.)-,(/!&01

•!•!

•!•!

").,2 ",+)34,+52

Ids-Vgs and BPW

•!•!

Produce 26.7 mm x 64 mm Sensing Area (3 Stitching).

SOPHIAS by RIKEN

III. SOIPIX Detectors

An example of SOIPIX: Integration Type Pixel (INTPIX)

18.4 mm

12.2 mm

µ

INTPIX5

X-ray Image of a small dried sardine taken by a INTPIX4 sensor (3 images are combined).

INTPIX4 Pixel Size : 17 um x 17 um No. of Pixel : 512 x 832 (= 425,984) Chip Size : 10.3 mm x 15.5 mm Vsensor=200V, 250us Int. x 500 X-ray Tube : Mo, 20kV, 5mA

14.144mm

8.70

4mm

PF-AR NE7A 33.3keV Acrylic resin 40mm 200us x 250 frames

Needle

Acrylic Resin

Stent Wire

CA

RA

-46000

8700

Arb. unit

(INTPIX4)

Examples of X-ray Image with the SOIPIX

Examples of SOIPIX Imaging

noise 18e- rms

IV. Advanced R&D

Double SOI waferSensor and Electronics are located very near. This cause ..

Then we newly introduced additional conductive layer under the transistors to reduce all effects (" Double SOI).

BPW

At first, we successfully introduced BPW layer to remove the back gate effect.

Transistor

Sensor Contact

Middle Si Contact

Metal 5

Middle Si

Metal 1

New Sensor Structures

20µm

1µm

•! Deplete from Back Side •! Very Low Input Capacitance •! Lower Leakage current •! Better charge collection

Shizuoka Univ.

STJ (Superconducting Tunnel Junction) on SOI

SOI transistors work at temperature below 1K.

By building STJ sensors on SOI, multiple channel readout becomes possible!

Signal from Nb/Al STJ on SOI

NMOS at 960mK

PMOS at 750mK

Tsukuba Univ. : Detection of Far Infra Red Photon

V. Summary

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