N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Characterization of n-on-p...

N. Zorzi Trento, Feb 28 – Mar 1, 2005Workshop on p-type detectors

Characterization of n-on-p devices Characterization of n-on-p devices fabricated at ITC-irstfabricated at ITC-irst

Nicola Zorzi

ITC-irst - Trento (Italy)


HistoryHistory

SMART collaboration

End 2003 finalized the layout

May 2004 first batch of p-on-n devices on different substrates (FZ, MCz, Cz, EPI) Various samples sent for irradiation.

August 2004 first batch of n-on-p devices with same layout Some samples sent for irradiation.

January 2005 irradiated samples available for test


LayoutLayout

14 + 9 + 6 Test pads including diode, MOS, gated diodes, resistor, etc.

27 MG diodes

5 (pitch 50m) + 5 (pitch 100m)Microstrip detectors AC coupled, poly-resistor biased

10 Small MG Diodes

Area 13.6 mm2

die 6x6mm2

Area 2.3 mm2

die 4x4mm2

die 6x47mm2


n-on-p batchn-on-p batch

# sub-type comments

3 FZ 525 p-spray 3E12




6 MCz no OG; p-spray 3E12

5 MCz no OG; p-spray 5E12

FZ <100> p-type >5000cm 200m

MCz <100> p-type >1.8kcm 300m

FZ <100> p-type >5000cm 525m


n-on-p – IV on MG diodes (1)n-on-p – IV on MG diodes (1)

High dose p-spray

1.00E-12

1.00E-11

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

0 100 200 300 400 500 600 700 800 900

1.00E-11

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

0 100 200 300 400 500 600 700 800 900

Diode current (A) vs Voltage (V) GR current (A) vs Voltage (V)

Leakage current ~ 10nA/cm2

Measurements on 3 diodes per 8 wafers

Breakdown voltage ~200-300V

blue=FZ, red=MCz blue=FZ, red=MCz


1.00E-12

1.00E-11

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

0 200 400 600 800 1000 12001.00E-11

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

0 200 400 600 800 1000 1200

n-on-p – IV on MG diodes (2)n-on-p – IV on MG diodes (2)

Diode current (A) vs Voltage (V) GR current (A) vs Voltage (V)

Leakage current ~ 10nA/cm2 Breakdown voltage >1000V

Low dose p-sprayMeasurements on 3 diodes per 9 wafers

blue=FZ, red=MCz blue=FZ, red=MCz


n-on-p – CV on diodes (1)n-on-p – CV on diodes (1)

FZ 200

64

66

68

70

72

74

76

78

80

82

T3 T5 T7 T8 T9 T10 T11 T12 T14

Wafer site

Vfd

[V]

008 014 024 037064 068 084

FZ 200

2.1E+12

2.2E+12

2.3E+12

2.4E+12

2.5E+12

2.6E+12

2.7E+12

T3 T5 T6 T7 T8 T9 T10 T11 T12 T14

Wafer siteN

a [c

m-3

]008 014 024 037064 068 084

Measurements on FZ wafers

Depletion voltage very uniform at the wafer level.



Measurements on MCz wafers

1.0E+12

1.5E+12

2.0E+12

2.5E+12

3.0E+12

3.5E+12

4.0E+12

0 50 100 150 200 250 300Depletion width [ m]

Nd [

cm-3

]

SMART1 - W091Doping concentration lower than n-type MCz (~2e12 against 7e12) but fluctuations of the same order

Example of Doping profile from CV measurement



Probably due to fluctuations of the oxygen concentration.

Quite high doping variations!!


Microstrip minisensors

3 51 2 4 8 106 7 9

det# pitchp+ implant

widthpolysilicon

width metal width[um] [um] [um] [um]

1 50 15 10 232 50 20 15 283 50 25 20 334 50 15 10 195 50 15 10 276 100 15 10 237 100 25 20 338 100 35 30 439 100 25 20 37

10 100 25 20 41

• AC coupled •poly resistor biased

die ~6x47mm2


Microstrip minisensors measurements

• BL&GR reverse IV (I_tot, Vrev 0÷200 V)

• Strip current scan (I_strip @ 100V Vrev)

•Bias resistors scan (R_bias @ 100V Vrev)

• Capacitors scan (I_AC @ 20V Vcap)

pitch 50 µm64 strips

pitch 100 µm32 strips

probe-card + automatic prober


1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

0 50 100 150 200

Vrev [V]

Ire

v [A

]

I_BL [A]I_GR [A]

SMART2_W108 S1

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

0 50 100 150 200

Vrev [V]

Ire

v [A

]

I_BL [A]I_GR [A]

SMART2_W108 S6

BL & GR I-V reverse currents (1)

FZ wafers

SMART2 - FZ - Bias Line current @ 100V

1E+1

1E+2

1E+3

1E+4

1E+5

S1 S2 S3 S4 S5 S6 S7 S8 S9 S10Sensor #

I_B

L [n

A/c

m2]

SMART2- MCz - Bias Line current @ 100V

1E+1

1E+2

1E+3

1E+4

1E+5


I_B

L [n

A/c

m2]

Low dose p-spray

high dose p-spray

MCz wafers

high dose p-spray

Low dose p-spray

Bias-line currents@ 100 V


SMART2 - FZ - Bias Line current @ 200V

1E+1

1E+2

1E+3

1E+4

1E+5


I_B

L [n

A/c

m2]

SMART2 - MCz - Bias Line current @ 200V

1E+1

1E+2

1E+3

1E+4

1E+5


I_B

L [n

A/c

m2]

FZ wafers MCz wafersBias-line currents @ 200 V

BL & GR I-V reverse currents (2)

Low dose p-spray

high dose p-spray

• design dependence of voltage handling capability (pitch and …);• low “break” voltage for high-dose p-spray;• substrate dependence?


1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

0 10 20 30

Strip #

Ilea

k [A

]

strip BL

SMART2_W108 S6

Strip current scan (100V)

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

0 20 40 60 80 100

Vrev [V]

Istr

ip [A

]

1-6

7

89-10

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

0 20 40 60 80 100

Vrev [V]

Vst

rip [A

]

1-6

7

8

9-10

Low current values on border strips

Single strip I-V

Floating strip potential

• high- and low-dose p-spray• 50µm and 100µm pitch• p and n substrates


SMART2 - Bias resistance mean values

300

400

500

600

700

800

900


Rb

ias

[k

]

500505510515520525530535540545550

0 10 20 30

Strip #

R [K

]

R_tot R_bias

SMART2_W108 S6

Bias resistor scan (100V)

-2.0E-7

-1.5E-7

-1.0E-7

-5.0E-8

0.0E+0

5.0E-8

1.0E-7

1.5E-7

2.0E-7

2.5E-7

-0.10 -0.05 0.00 0.05 0.10

Vstrip [V]

Istr

ip [A

]

1

10

Vback=100V 37 squareswidth=6 µm

Single strip I-V

Single strip scan

high dose p-spray

Low dose p-spray

Single scan uniformity: 0.2% ÷ 2%

No results available for sensors with low breakdown values


1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

0 10 20 30 40 50 60

Strip #

Ilea

k [A

]

strip BL

SMART2_W44 S5

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

0 10 20 30 40 50 60

Strip #

Ilea

k [A

]AC

SMART2_W44 S5

AC-scan:~23% sensors have broken capacitors(mainly 50µm pitch devices)

Defects

current-scan:only few sensors

Subtype Split S1 S2 S3 S4 S5 S6 S7 S8 S9 S10

FZ 525 low p-spray

FZ 525 low p-spray

FZ 525 low p-spray

FZ 525 high p-spray

FZ 525 high p-spray

FZ 525 high p-spray

FZ 200 low p-spray

FZ 200 high p-spray

FZ 200 high p-spray

MCz low p-spray

MCz low p-spray

MCz low p-spray

MCz low p-spray

MCz low p-spray

MCz high p-spray

MCz high p-spray

MCz high p-spray

MCz high p-spray

batch or sub problem?No AC-defects are present for p-on-n devices


ConclusionConclusion

Problems on n-on-p production:• non-uniformity of the depletion voltage (MCz subs)• design/p-spray-dose interaction (p-stop…?)

To be verified:• effectiveness of actual p-spray

Samples available for the collaboration.


n-on-p batch: samplesn-on-p batch: samples

# sub-type comments

3 FZ 200 p-spray 3E12 3 cut wafers

3 FZ 200 p-spray 5E12 2 cut wafers

6 MCz no OG; p-spray 3E12 3 cut wafers

5 MCz no OG; p-spray 5E12 3 cut wafers

FZ <100> p-type >5000cm 200m

MCz <100> p-type >1.8kcm 300m



More measurements on MCz wafers

Quite high doping variations!!

Map of the depletion voltageson three wafers.

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Characterization of n-on-p...

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