Silicon sensors status Vclav Vrba Institute of Physics
Silicon sensors status Václav Vrba Institute of Physics, AS CR, Prague IFR Praha 2004, 16 th April 2004 1 Václav Vrba, Institute of Physics, AS CR
Pad array design consideration Along with the diodes, the technique used for fabrication of bias resistors and coupling capacitors represents an important issue: a) polysilicon resistors – production of the tile needs about 7 -8 masks; can be the source of additional yield reduction. b) punch through resistors – production of the tile needs about 5 masks; easy to produce – needs to check whether required parameters can be achieved. c) ion implantation resistors – not considered here. IFR Praha 2004, 16 th April 2004 2 Václav Vrba, Institute of Physics, AS CR
Design consideration: Polysilicon resistors Bias lines Top view Bias resistor Coupling capacitor Direct contact on diode – e. g. for testing Vertical cross section IFR Praha 2004, 16 th April 2004 3 Václav Vrba, Institute of Physics, AS CR
Design consideration: Polysilicon resistors IFR Praha 2004, 16 th April 2004 4 Václav Vrba, Institute of Physics, AS CR
Design consideration: Punch through resistors Bias lines Top view Bias resistor Coupling capacitor Direct contact on diode – e. g. for testing Vertical cross section IFR Praha 2004, 16 th April 2004 5 Václav Vrba, Institute of Physics, AS CR
Design consideration: a partial summary a) polysilicon resistors: should not be a problem to have resistors 10 M ; capacitors 1 -10 n. F. b) punch through resistors: resistors to be tested; if acceptable then it is a simple solution; capacitors as a). Compatibility of process for variants a) and b) on one wafer? Option a) as a baseline for main sensor tile? IFR Praha 2004, 16 th April 2004 6 Václav Vrba, Institute of Physics, AS CR
Pre-prototyping IFR Praha 2004, 16 th April 2004 7 Václav Vrba, Institute of Physics, AS CR
Tests outlines A) Diode tests a) I-V curves: - Vbreak-down Vop - Ileak @ Vop < cca 30 n. A/cm 2 b) C-V curves: à determination of Vfull-depletion; Vop = Vfull-depletion + 50 V. c) Long term stability tests: - Ileak @ Vop. Tile should be rejected if: - Vbreak-down < Vop - Ileak > I crit (to be defined). IFR Praha 2004, 16 th April 2004 8 Václav Vrba, Institute of Physics, AS CR
Electric characterization IFR Praha 2004, 16 th April 2004 9 Václav Vrba, Institute of Physics, AS CR
Tests outlines B) Bias resistors a) shorts b) breaks c) outside specifications C) Capacitance couplings a) shorts b) breaks c) outside specifications IFR Praha 2004, 16 th April 2004 10 Václav Vrba, Institute of Physics, AS CR
Tests outlines Basic equipment: - micromanipulators with contact needles; - I-V: Keithley 487 A; - C-V: LCR meter HP IFR Praha 2004, 16 th April 2004 11 Václav Vrba, Institute of Physics, AS CR
Probestation IFR Praha 2004, 16 th April 2004 12 Václav Vrba, Institute of Physics, AS CR
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