Silicon -Calorimeters at SaclayMain Architecture:• All-Si STANDARD Technologies including collective approach for large

(1024 pixels) buttable X-rays arrays. (Based on Herschel Development at LETI/LIR)

• “MESA process” for Thermometer realization. High temperature diffusion after implantation reliable homogeneous thermometer (as NTD Ge). Known and reliable Technologies. Extrapolation from High impedance

• (cf. IR exp.) to low impedance sensors.• High Impedance Readout Circuitry (MUX based on Herschel Development)

cryogenic followers, pixel read-out on trigger.R&D now :• Tantalum Absorber : Metallurgy and modeling.• Absorber on the thermometers matrices.

– Gluing of the absorber membrane on a silicon holder and micromachining– Hybridization through Indium Versus Gluing

• Proximity Electronics : Cryogenic Followers (HEMT or MOSFET)

Oxide simox

Removed CdTe substrate

HgTe

sensor plate

Etching of SOI dioxide back and front side

Removed Silicon substrate

High Z superconductor

glue

Silicon -Calorimeters at Saclay

Figure 2 : under-bump metallurgy

Photoresist

Figure 3 : Photolithography defining Indium volume

Figure 4 : Indium deposition Figure 5: Photoresist lift-off Figure 6 : Indium reflow

Mesa Thermometer

Figure 1 : Reception of the absorber

Passivation

Indium Bump Hybridisation

Silicon -Calorimeters at Saclay

The indium bump process allows for a self alignment (through the full array) between the absorbers and the sensors which contrasts with a classical gluing process.

Figure 9 : self alignment

x

Figure 8 : placing and heating

Figure 7 : alignment

Silicon -Calorimeters at Saclay

Silicon -Calorimeters at Saclay

• General Layout on double-SOI substrate.

• X-ray Array and Followers Array on the same wafer at 2 different Temperatures.

-calorimeters around 100 mK and Followers around 2K.

Thermal insulation via superconducting leads, etching of the substrate and IR insulation.

• Buttable on 2 sides allowing to fill any FOV.

Silicon -Calorimeters at Saclay

• LETI/LIR (Grenoble) develops the Si Technologies. (P. Agnese)

• Prototypes tested at CEA-Saclay/Dapnia/Sap in coll. with Dapnia/SEDI (X.F. Navick)

2 test cryostats available (dilution, down to 10 mK)

• HEMT developed in coll with LPN/CNRS. (Young-Jin)

Common development with EDELWEISS

• Absorber developed in collaboration with CSNSM/CNRS (L. Dumoulin)

Thermal treatment, coating and measurement of thermal characteristics at CSNSM

• Thermal Modellization of Absorber and Links by Palermo (G. Vaiana).

• General Architecture and MUX at Sap (C. Cara).

• First Fundings from CEA/Sap and CNES

Main Characteristics & Conclusions:• Full Energy Coverage (up to 30 keV)• Spectral Resolution (~ 5-10 eV @ 6.5 keV)• Quasi-Classical MUX• Low Count rate (up to 10 Hz)• Large covering of FOV• Good (Excellent) filling Factor

Silicon -Calorimeters at Saclay