development of silicon microstrip sensors in 150 mm p-type wafers
DESCRIPTION
Development of Silicon Microstrip Sensors in 150 mm p-type Wafers. Y. Unno , S.Terada, Y.Ikegami, T. Kohriki, K.Hara, and the ATLAS R&D collaboration of " Development of non-inverting Silicon strip detectors for the ATLAS ID upgrade" K. Yamamura, S. Kamada (Hamamatsu Photonics). - PowerPoint PPT PresentationTRANSCRIPT
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Development of Silicon Microstrip Sensors in 150 mm p-type Wafers
Y. Unno, S.Terada, Y.Ikegami, T. Kohriki, K.Hara, and the ATLAS R&D collaboration of "Development of non-
inverting Silicon strip detectors for the ATLAS ID upgrade"
K. Yamamura, S. Kamada (Hamamatsu Photonics)
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Some History of Development
• 1995 p-type 4-inch (100 mm) wafer (p95)– FZ(111) (~6 kΩcm) wafers
• 2005 p-type 4-inch (100 mm) wafer (ATLAS05)– FZ(111) (~6k Ωcm)
– MCZ(100) (~900 Ωcm) wafers
• 2006 p-type 6-inch (150 mm) wafer (ATLAS06)– FZ-1(100)(~6.7k Ωcm), FZ-2(100)(~6.2k Ωcm)
– MCZ(100)(~2.3k Ωcm)
• 2007 p-type 6-inch (150 mm) wafer (ATLAS07)– FZ-1(100)(~6.7k Ωcm), FZ-2(100)(~6.2k Ωcm)
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
p95 p-type Sensors• A prototype n-in-p sensor was
fabricated in 1995– 6 cm x 3 cm x 300 um, 50 um
pitch, common p-stop • no DC-field plate over p-stop
– p-bulk, (111), ~6 kΩcm– Irradiated up to 1.1 x 1014 p/cm2
at 12 GeV PS at KEK– A report was made in NIM
A383(96)159– Re-measurements after 10yrs
(irrad. stored at 0 C)• I-V• C-V• CCE with laser
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
ATLAS05 p-type Sensors
• Investigation of isolation of n-strips– p-stop with/without p-spray
– With/without field-plate
– p-stop doping levels
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
ATLAS05 p-type Sensors• p-type wafers
– 4-inch wafer for cost reason
– MCZ: • ~900 Ωcm
• Orientation (100)
– FZ: • ~6k Ωcm
• Orientation (111)
• Sensors– Miniature: 1cm x 1cm
– Large: ((~1cm x ~6cm) x6 zones)
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
ATLAS06 p-type Sensors
• 6 inch (150 mm) wafer– FZ-1 (100), FZ-2 (100), MCZ
• Further R&D of isolation structures– No DC-field plate
– Width of (common) p-stop
– p-stop/p-spray doping variations
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
ATLAS06 p-type Sensors
• Many miniature (1cm x 1cm) sensors – One sensor per one "Zone"
• Large (3cm x 6 cm) sensors with 2 striplets– Variation of Polysilicon bias resistor connections
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
ATLAS07 p-type Sensors• 6-inch (150 mm) wafer• Maximum size sensor (~10 cm x ~10
cm) prototyping• R&D's
– Candidate isolation structures– "Punch-thru Protection" structures– Wide/Narrow metal effect– Wide/Narrow pitch effect
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
ATLAS07 p-type Sensors
• Full size (9.75 cm x 9.75 cm) prototype sensors– 4 segments: two "axial" and two "stereo" (inclined) strips
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Proton Irradiation at CYRIC
• Facility associated with Univ. Tohoku, Sendai, Japan
Beamline 32
Beamline 31-2
KEK70 MeV protons
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Proton irradiations at CYRIC• AVF Cyclotron at Tohoku University
– Beam energy: 70 MeV– Beam intensity: 10nA ~ 800nA– Beam spot size: ~5 mm FWHM
• ~4 min. for 1x1015 at 800 nA
• Irradiation history– Beamline 31-2
• 2005.10.17 - 1st and beamline study• ATLAS05 - up to 5x1015
– 2006.01.27 +2006.03.14 +2006.06.26 + 2006.10.16
• ATLAS06 - up to 2x1015
– 2007.05.18,
– Beamline 32– 2007.08.28
• ATLAS07 - up to 1x1015
– 2008.03.11
• Change of beamline– Machine time/user conflict in 31– Straight, simpler line in 32
Beamline 31-2
Beamline 32
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Laser for FDV and CCE• Full Depletion Voltages (FDV)
– C-V method– Laser method
• Charge Collection Efficiencies (CCE)– Laser method
Pulsed laser (1064nm) focused to 4um x 4um
Referencesensor
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Full Depletion Voltages
• Very different fluence development in 4 inch and 6 inch!!– All p-type– 4 inch FZ (111), though
• FZ and MCZ are similar in 6 inch!!– except below ~2x1014 , no advantage in MCZ
ATLAS05CCE
CCE
CV
CV
ATLAS06
CCE
FDV~500V!!at 1x1015
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
CCE
• Charge loss up to 1x1015 is small– 2x1015 appreciably less
• No obvious difference is FZ and MCZ
not fully depletedVB=1kV
ATLAS05ATLAS06
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Microdischarge• Onset voltage (VMD)
– >600 V in FZ– some trouble in MCZ– Zone5 exceptional
• After irradiation (>1x1014)– >1000 V!!– Even Zone5 and MCZ
ATLAS06
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
N-strip Isolations
• Showing Vbias voltages to achieve isolation– Isolation gets worse as fluence accumulates– Number of observations can be seen from the plots....
+ p-spray
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
TCAD Simulations
• N-P gap was too narrow
• Potential of 2nd p-stops makes effective p-stop width as wide up to 2nd p-stop
Y.Unno, 3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain, 14-16 April. 2008
Summary• n-in-p p-type microstrip sensors have been fabricated in p-FZ and p-
MCZ wafers, for several years by now
• Proton irradiations, 70 MeV, are being routinely carried out at CYRIC of Tohoku Univ.,
• Fluence development of full depletion voltage (FDV) of 4-inch (100 mm) and 6-inch (150 mm) is very different
• In 6-inch, FDV is ~500 V at 1x1015 neq/cm2
• CCE is near full up to 1x1015 neq/cm2
• Onset voltage of the microdischarge has been achieved to be >600 V in general
• Number of isolation structures are being investigated and we are narrowing the candidates
• A full size microstrip sensor has been prototyped and we have the first look in hand