a.a. grillo scipp-ucsc atlas 3-may-2007 1 evaluation of sige technology – status report us-atlas...

3-May-2007 1

Evaluation of SiGe Technology – Status ReportUS-ATLAS Upgrade Meeting

A.A. GrilloSCIPP-UCSC

ATLASATLAS

Evaluation of SiGe TechnologyEvaluation of SiGe Technology- Status Report -- Status Report -

US-ATLAS Upgrade Meeting

3-May-2007

Alex Grillo

SCIPP - UCSC

3-May-2007 2



ATLASATLAS

Along with the 130 nm CMOS technology, IBM offers two silicon-germanium (SiGe) bipolar options (CMOS8HP and CMOS8WL) to allow full biCMOS ICs.

If these technologies are sufficiently radiation hard, a SiGe bipolar front-end may significantly reduce the power dissipation of the readout IC.

The 8WL is a less expensive option and may provide sufficient performance.

There is interest for both the upgrade Inner Tracker and the LAr Calorimeter.

The SiGe Bipolar OptionThe SiGe Bipolar Option

3-May-2007 3



ATLASATLAS

Participating Institutions (US)Participating Institutions (US)• UCSC

– Project coordination and general data management– Neutron and Proton irradiation studies– Inner Tracker front-end IC design

• Georgia Tech– Expert in SiGe technologies, source of test structures

• BNL– Gamma irradiation studies– IC design for LAr

• Penn– Will test gamma irradiated parts including annealing studies– IC design for LAr

• Columbia– Not yet started, interested in doing proton studies– IC design for LAr

• LBNL– New addition – helping to analyze data and device performance

3-May-2007 4



ATLASATLAS

Participating Institutions (non-US)Participating Institutions (non-US)

Spain:• CNM Barcelona

– So far irradiation studies on German IHP technologies– Will do neutron irradiations of IBM 8WL and

low dose rate effect (LDRE) studies

France:• IN2P3

– Working on AMS 0.35 m technology for LAr and ILC applications

3-May-2007 5



ATLASATLAS

Radiation TestingRadiation Testing

Arrays of transistors have been obtained for three generations of IBM SiGe technologies (from Georgia Tech), the 5HP/AM, 7HP and 8HP, and for two SiGe technologies from the company IHP.

For IBM technologies, irradiations have been done with:• Gammas up to 100 Mrad

– Some parts died due to ESD and broken bonds– More parts being irradiated to 100 Mrad– 1 Mrad, 10 Mrad and 50 Mrad not yet analyzed

• Neutrons up to 6x1015 n/cm2– Initial post-rad testing showed some odd results – contamination found

on some irradiation PCBs– Retesting and analysis in progress

• Protons up to 3x1015 p/cm2– Not all requested fluences reached due to CERN PS problems last year– Still trying to understand some data, especially bias vs. non-bias results

3-May-2007 6



ATLASATLAS

Focus on Two IBM TechnologiesFocus on Two IBM TechnologiesWhen this program started, it was not clear which technologies might be readily available for the Upgrade. Therefore, attempts were made to test several, possibly to learn the differences in rad-hardness. Now with the frame contract between IBM and CERN, the two IBM technologies available through that contract are the most interesting.

• It was a fortunate coincidence that our collaborator from Georgia Tech (J. Cressler) had been working closely with IBM, which meant we had already started to evaluate one of these two (the 8HP).

• We only learned of the 8WL later and so it was not included in the original test sample.

The 8WL is less expensive with lower electrical performance. • The specifications for 8WL indicate that its electrical performance is

probably quite adequate for our needs. • However, Cressler has not worked with the 8WL and we have no knowledge

of its radiation hardness compared to the 8HP.

We just received a few 8WL parts from Georgia Tech. More are promised from IBM through CERN.

3-May-2007 7



ATLASATLAS

Gamma Irradiation Neutron Irradiation

These results look quite promising given the Inner Tracker radiation specification of:

Short Strips: 1x1015 nEq/cm2 displacement and 24 Mrad ionizationLong Strips: 5x1014 nEq/cm2 displacement and 5 Mrad ionization

Arrows show typical bias

for large front

transistor

Preliminary Results for the IBM 8HPPreliminary Results for the IBM 8HP

Proton Irradiation

3-May-2007 8



ATLASATLAS

To gain some experience designing with SiGe technology, UCSC designed a small test IC (the HRFE) using the IHP SG25H1 SiGe BiCMOS process through Europractice. This was an inexpensive test vehicle and roughly equivalent to IBM’s first generation SiGe technology married to 0.25 m CMOS.

Design of Front-End SiGe Test ChipDesign of Front-End SiGe Test Chip

3-May-2007 9



ATLASATLAS

PCNI6534Spartan3

BoardPlug-inBoard

SiGeChip

Board

8-bit command

16-bit data(16th bit = valid data)

8 LVDSchannels

PulserTrigger

Cal.strobe

Amplitude

Power, VthresVoltages

On a command from the PC, the Spartan-3 (Xylinx) chip sends multiple triggers to the Pulser and collects the number of hits recorded by the chip under test in a given time interval. The PC monitors the Spartan-3 output data bus, and reads out the number. This procedure is repeated for a set of Amplitudes and Voltages.

Test Setup

With no “back-end” on the test chip a special test setup was needed.

3-May-2007 10



ATLASATLAS

Measured vs. Simulation Results

Noise vs. Front-end Load was simulated and measured using two different bias settings for the front transistor as might be used for short and long strips of the upgraded silicon tracker.

The measured noise agrees well with the simulations showing that acceptable noise can be achieved at these very low power levels.

Measured analogue current is 32.8 A plus the front-end transistor bias, i.e. 186 W and 346 W for the short and long strips.

Measured shaping time is 17ns – 19ns

3-May-2007 11



ATLASATLAS

In late 2006 Cressler’s group at Georgia Tech made a fabrication submission to IBM on the 8HP process. There was a small open space available so they invited us to include a pre-amp design.

With only 1mm2 available, the design could only include the pre-amp and shaper for 8 channels.

• The design is basically the same as the previous IHP submission except that the comparator is removed and a voltage adjustment for the shaping time is added.

We are expecting to have some parts back later this month.

Test Chip on IBM 8HPTest Chip on IBM 8HP

3-May-2007 12



ATLASATLAS

Complete initial gamma total does irradiations of 8HP, 7HP and 5AM.• BNL & Penn

Finish analysis of initial neutron & proton irradiations of 8HP, 7HP & 5AM.• UCSC & LBNL

Complete initial total dose/fluence tests of 8WL with gammas & neutrons.• Irradiations at BNL (with Penn) & Ljubljana (by Barcelona)

Test 8HP test chip when it arrives.• UCSC

If initial 8WL radiation data looks good, choose it for first prototype IC. Design and submit for fabrication full front-end (Pre-amp through

comparator) IC for 64 or 128 channels.• UCSC

Initiate Low Dose Rate Effect (LDRE) study of 8WL and 8HP.• Barcelona & UCSC

Initiate final radiation study to qualify either 8WL or 8HP for the Upgrade.• Perhaps all

PlansPlans

3-May-2007 13



ATLASATLAS

• IC Fab $85k– Assumes 8WL;

8HP will cost considerably more

• Georgia Tech 30k

• Travel 4k

• Misc. M&S 5k

• Labor 94k– Includes: 17% FTE EE

25% FTE Tech Physicist 108% FTE ETech 25% FTE Undergrad Student

• Indirects 49k

• Total $267k

UCSC Budget for FY08UCSC Budget for FY08

a.a. grillo scipp-ucsc atlas 3-may-2007 1 evaluation of sige technology – status report us-atlas...

Documents