Quality Test of L1 sensors

• HPK 10 sensors– Tested all, 6 sent to Fermilab– Test structures, HPK 133 L00 CDF

• ELMA 9 sensors– Tested 6 of 9

HPK

• V depletion ~120V consistent

• I leakage at V depletion ~ 50nA (except 07)

• Breakdown: seen once s/n20 at 750V

• Strip leakage ~ 0.04nA

• Poly resistor value ??

• Capacitance 70pF

• I dielectric: LCR noise

Bad Channels

Bad Channels– HPK01 none– HPK03 bad strip 42; – HPK04 bad strip 346; – HPK06 PH 13, 47, 267; – HPK07 bad strips 27, 320;– HPK09 none– HPK11 leaky 169;– HPK12 none– HPK13 none; Rpoly strange shape– HPK20 none; HPK claims two low Cac

Fermilab

Polysilicon Resistor

• Using 237 bias/no bias

R poly

0

500

1000

1500

2000

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3000

3500

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

Bias 0V

Bias 130V

Interstrip Resistor

• Using 237 Bias/NO Bias

Interstrip Resistance

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500

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3500

-1.0 -0.5 0.0 0.5 1.0

Bias 0V

Bias 130V

Polysilicon Resistor

• Using 487 Bias/NO Bias

R poly

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3500

-1.0 -0.5 0.0 0.5 1.0

no bias 487

ELMA

• V depletion ~ 26V

• I leakage at V depletion ~ 50nA

• Breakdown ALL at 250-350V

• Strip leakage ~ 0.15nA

• Poly resistor value: vary, better than HPK

• Capacitance ~ 80pF

• I dielectric

Bad Strips

• L1-001 1, 43, 140, 256, 276

• L1-002 95-109, 362, 383

• L1-003 275,384; Rpoly ~ 4MOhm

• L1-004 32, 168, 263, 356, 373

• L1-005 180, 368

• L1-006 107, Rpoly ~ 1.3 Mohm

Conclusion

• HPK – Polysilicon resistors are out of specs

• ELMA– Low breakdown voltage