Planar Pixel Sensor Production at CiS Planar Pixel Sensor Production at CiS Anna Macchiolo - MPP Munich 009 g, 5 th June 20 � Project aimed to explore the possible range of application in fluence (hence detector radii) for planar pixels sensors at SLHC detector radii) for planar pixels sensors at SLHC. hop, Freiburg � Wafer layouts for the n-in-n and n-in-p batches have been submitted to CiS RD50 Worksh � R&D areas to be covered by this project: � Comparison of performances between n- and p-bulk pixels: yeald, p p p p y , cchiolo, 14 th R reliability, radiation hardness � Slim edges, increase of the fraction of active area � Cost reduction � Cost reduction A. Mac � Vertical integration 1
R&D for Planar Pixel Sensors for SLHC � Common RD50 production with the contribution of: ATLAS groups participating in the Planar Pixel Sensor Project (coordinator C. � 009 Goessling TU Dortmund) established in view of the Insertable B-Layer upgrade Goessling, TU Dortmund), established in view of the Insertable B-Layer upgrade g, 5 th June 20 and SLHC � CMS pixel group at PSI hop, Freiburg � Parallel productions of n-on-p pixel sensors on 6” wafers within the ATLAS Planar Pixel Sensor Project : HPK HPK, organized by the KEK group organized by the KEK group � � RD50 Worksh MICRON, organized by the Liverpool group � � Planar technology is a natural baseline for pixel upgrades: cchiolo, 14 th R proven and reliable � recent data from the RD50 Collaboration indicate sufficient radiation hardness � even at b-layer fluences � thanks to using industrial standard processes, cost effective production of large A. Mac pixel sensor areas is achievable 2
Foreseen production parameters � Production with CiS (Erfurt, Germany) on 4” wafers � Parallel production of n-in-p and n-in-n wafers with several common test devices to achieve a full comparison between the two technologies 009 g, 5 th June 20 n-in-n batch ~10 Fz wafers ~ 10 MCz wafers Double sided process n-in-p batch p ~ 34 Fz wafers ~ 6 MCz wafers Single sided process g p hop, Freiburg Resistivity [K Ω .cm] Thickness RD50 Worksh FZ n-type 3.5-5.7 285 MCZ n-type 0.85-1 300 cchiolo, 14 th R FZ p-type > 10 285 MCZ p-type > 2 300 A. Mac � Inter-pixel isolation methods: homogenous p-spray and moderated p- spray for both batches 3
Wafer layout of the n-in-p batch � FE-I3 (present ATLAS ASIC) Single Chip Modules (SCM) with variations of the GR structure and isolation schemes 009 g, 5 th June 20 � FE-I4: new ATLAS pixel ASIC (for IBL and SLHC outer layers): pitch 50x250 μ m 2 , 22,6 x 19,2 mm². , , hop, Freiburg � CMS Module (16 chips) + 5 SCM � same geometry as in the present CMS n-in-n th t CMS i RD50 Worksh sensors (design by T. Rohe). � 80 μ m pitch strips: 4 cchiolo, 14 th R sensors with the RD50 standard design (large inactive edge for cutting trials) and 2 with a MPP-HLL design (AC coupled). A. Mac 4
Wafer layout of the n-in-n batch n-in-n design realized by the Dortmund group (T. Wittig) � 20 different SCM FE-I3 versions (see slides about slim edges). 009 Included the design of n in p SCM with Included the design of n-in-p SCM with g, 5 th June 20 GR on the front side � comparison to real p-bulk after type conversion � FE I4 � FE-I4 4-chips Module: 4 hi M d l hop, Freiburg � Current ATLAS pixel guard ring design � Proposed sensor for the Insertable b-Layer (IBL): I t bl b L (IBL) RD50 Worksh because of the length of the sensor it is possible to reach an inactive fraction of ~1.5% (without shingling) using the ( ith t hi li ) i th cchiolo, 14 th R current guard ring design. � 2 samples of FE-I4 SCM A. Mac � RD50 design strip detectors adapted to n-in-n technology. 5
ATLAS pixels: Isolation schemes (I) � Standard SCM dimensions , 1100 μ m from cutting edge to guard rings � Moderated p-spray: standard Moderated p-spray 009 isolation scheme between pixels isolation scheme between pixels 545 545 g, 5 th June 20 adopted by the present n-in-n ATLAS 16 rings and CMS sensors. hop, Freiburg � An opening in the nitride layer determines an increase of the boron implanted dose in the central region implanted dose in the central region RD50 Worksh between the strips. Moderated p-spray cchiolo, 14 th R n + n + nitride opening p spray p-spray A. Mac 6
ATLAS pixels: Isolation schemes (II) Homogenous p-spray Homogenous p-spray Moderated p-spray Moderated p-spray 009 545 545 g, 5 th June 20 16 rings635 19 rings hop, Freiburg RD50 Worksh � Implementation in the pixel design of the isolation scheme with homogenous p-spray : good performances observed in the pre-irradiation characterization of the MPP-HLL thin pixel production where this isolation method was th MPP HLL thi i l d ti h thi i l ti th d cchiolo, 14 th R implemented (see M. Beimforde’s talk, this workshop). � Effects of different p-spray implantation parameters simulated and tested with CiS p-type micro-strip detectors irradiated with X-rays: isolation holds ith CiS p t pe micro strip detectors irradiated ith X ra s isolation holds A. Mac after irradiation also for very low p-spray doses (~ 0.7x10 12 cm -2 ) (M.Beimforde, 13 th RD50 Workshop). 7
ATLAS p-type pixels: Guard Ring Design (I) • The guard-ring design used in the p-type CiS pixel submission is based on the Th d i d i d i th t CiS i l b i i i b d th one implemented in the MPI-HLL thin pixel production. Performances of these sensors in terms of V break are extremely good. Still some possible improvements suggested by the pre-irradiation characterization of these devices. gg y p 009 g, 5 th June 20 • Investigation of the breakdown location with PHEMOS : probe-station equipped with a CCD camera to detect hot spots in the sensor. • Structures with homogenous p-spray: breakdown in the GRs @ 425 V hop, Freiburg RD50 Worksh cchiolo, 14 th R A. Mac 8
ATLAS p-type pixels: Guard Ring Design (I) • The guard-ring design used in the p-type CiS pixel submission is based on the Th d i d i d i th t CiS i l b i i i b d th one implemented in the MPI-HLL thin pixel production. Performances of these sensors in terms of V break are extremely good. Still some possible improvements suggested by the pre-irradiation characterization of these devices. gg y p 009 g, 5 th June 20 • Investigation of the breakdown location with PHEMOS : probe-station equipped with a CCD camera to detect hot spots in the sensor. • Structures with moderated p-spray: breakdown in the GRs @ 585 V � redesign Structures with moderated p spray: breakdown in the GRs @ 585 V � redesign hop, Freiburg of the 4th and 5th rings for the CiS production RD50 Worksh • The location of the hot spot in the bottom left corner is probably linked cchiolo, 14 th R with the direction of the small misalignments among the different layers A. Mac 9
ATLAS p-type pixels: Guard Ring Design (II) CiS d CiS design: Increase of the metal overhang on the inner i I f th t l h th i Thanks to Rainer side of the 4 th and 5 th rings both for the moderated and Richter for discussions homogenous p-spray versions and suggestions 009 1 1 Rings #1 and #2 in the CiS Rings #1 and #2 in the CiS g, 5 th June 20 SOI hom. p-spray design are wider but with the 1 same inter-distances and 2 overhang structure as in the 2 SOI ones hop, Freiburg 3 3 3 3 4 4 5 CIS hom. p-spray CIS hom. p spray 5 RD50 Worksh SOI mod. p-spray CIS mod. p-spray 1 1 cchiolo, 14 th R 2 2 3 3 4 4 5 5 A. Mac 6 5 10
Area of R&D: Slim Edges for ATLAS SLHC Pixel Detector � Outer staves in the SLHC ATLAS pixel detector will probably be double- sided. In the inner layers of the pixel system (single-sided) it is strongly Moderated p-spray Moderated p-spray 009 desired to avoid shingling: desired to avoid shingling: 545 545 g, 5 th June 20 - deteriorates thermal performances 16 rings - complicates stave design and add cost � slim edges needed at least on hop, Freiburg two sides! � Different methods explored to achieve a larger fraction of active area: p g RD50 Worksh - fewer guard rings (both n- and p-type) - instrument with pixels the area corresponding to the guard ring on the back- side (n in n only) side (n-in-n only) cchiolo, 14 th R - alternative dicing method with respect to sawing (laser and DRIE) A. Mac 11
Slim Edges: reduced guard ring structures n-in-p � Design of slimmed guard-rings structures aided by simulation activities Moderated p-spray Moderated p-spray carried out by the ATLAS LAL-LAPNHE y 009 545 545 g, 5 th June 20 groups. 16 rings � Both in the n-in-n and n-in-p designs 515 μ m the slimmed edge versions have been g hop, Freiburg implemented mostly in the FE-I3 sensors 16 rings � more variations are possible due to the reduced size with respect to the FE-I4 sensors sensors RD50 Worksh � Encouraging results from the MPP-HLL 240 μ m thin pixel production : p-type diodes with a reduced set of guard rings (10 guard reduced set of guard rings (10 guard 8 rings 8 i cchiolo, 14 th R rings, homogenous p-spray) yield the same Vbreak (~ 400-500 V depending on p-spray dose) as those with the standard guard-ring structure. A. Mac 12
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