WP15.5 - Si for large fluence irradiation monitoring Variations of - PowerPoint PPT Presentation

WP15.5 - Si for large fluence irradiation monitoring Variations of carrier recombination and trapping parameters in Si irradiated with various particles J.Vaitkus, E.Gaubas, T. Č eponis, A.Mekys, D.Meskauskaite,V.Rumbauskas, V.Vertelis Vilnius University, Institute of Applied Research, Vilnius, Lithuania M.Moll, C.Gallrapp, F.Ravotti CERN Our purpose in AIDA-2020 is to find a most convenient Si for the irradiation fluence monitoring and imaging: to find a cost effective solution, therefore we analyze, the high resistivity , electronic grade , solar energy grade , multicrystalline samples , and we still wait a special “cheap Si” wafers of Si from Lancaster U, and in general we concentrate on details of different Si differently irradiated . The series of samples are ready for calibration at CERN).

The device for integrated fluence monitoring • The device for the contactless fluence monitoring delivered to CERN, the instruction book given, the seminar for the staff members organized, Vilnius team member is ready to come if necessary. • The calibration procedure has started, and to proton and neutron irradiation the irradiation by pions was added.

Fluence imaging ( our proposal for LHC(b) - our vision ): 1. Two Si wafer pieces (Fig.) put around the proton beam. 2. Irradiate. 3. Remove. 4. Scan the lifetime distribution across both pieces. 5. Transform the lifetime map to the integrated fluence image. The fluence range 1e12- more that 1e16 hadrons/cm2. (If the irradiation will be more than 3e16 cm-2, then this area will be necessary to scan by other method, purely optical)

This device for 2D integrated fluence imaging up to 3“. Cross-sectional scans within wafer depth It can scan sample in different regimes: transmission, reflectance and probe Laisvakrūvės Laisvakrūvės zondavimo būdai zondavimo būdai  = arctg  eff  = arctg  eff  = arctg  eff I pr (t) f I pr (t) f I pr (t) f U (t) f U (t) f U (t) f probe probe probe MW MW MW sample sample sample sample sample sample sample sample sample IR IR IR I(t) I(t) I(t) MW, IR MW, IR MW, IR L,  L,  L,  I(t) I(t) I(t) excite excite excite pulsed laser beam pulsed laser beam pulsed laser beam probe/ excite probe/ excite probe/ excite excite / probe excite / probe excite / probe cw MW or IR cw laser beam cw MW or IR cw laser beam cw MW or IR cw laser beam Single mode Needle-tip coaxial MW antenna fiber Si d~300  m

Comparison of characteristics of the pion, neutron and proton as irradiated and isothermally ( T an =80 C) annealed Si FZ n-Si (native oxide) 300 MeV pions 2 as -irradiated 10 80 C annealed 510 min. 26 GeV protons (non-corr.  s ) 1 10 as -irradiated 80 C annealed 70 min. 0 reactor neutrons MCz n-Si 10  R (  s) surfaces passivated with therm.SiO as -irradiated -1 10 80 C annealed 1440 min. -2 10 -3 10 -4 10 11 12 13 14 15 16 10 10 10 10 10 10 -2 )  1 MeV n eqv. (cm

Deep level spectroscopy 1E-7 Fisherbrand 260868-1-41 1E16 m7 1E-9 U = -50V T=30 K 1E-8 1E-9 MCZ Si microstrip (43  m) 1e17 cm-2 neutrons 1E-10 1E-10 10 V, 21 K I, A 1E-11 I, if h  increases I, A decrease I-I 0 1E-12 increase I-I 0 decrease decrease h  1E-13 1E-11 I-I 0 increase 1E-14 1E-15 0,6 0,8 1,0 1,2 1,4 1E-12 E, eV 0,4 0,6 0,8 1,0 1,2 1,4 h  , eV • The high neutron fluence introduce deep donors that increased the dark conductivity • The main deep centers are at ~0,5 and ~0,8 eV (optical activation energy)

Recombination and trapping MW-PC signal (arb. units.) 16 e/cm 2 , T an =280 o C n-Cz,  =4 ´ 10 1 T=110 K 0 (a) 10 2 130 K 3 250 K 4 290 K -1 10 1 2 3 -2 10 4 -3 10 0 50 100 150 t (  s)

. Trapping and recombination lifetime variations dependent on trap concentration, level activation energy and excitation density T N      tr C , V , e , h , Ttr K ; K 1 inst , tr R tr tr   2 ( N n ) C , V , e , h , Ttr 0 0 10 10 1 - E tr = 0.2 eV 1 - E tr = 0.2 eV E tr = 0.3 eV E tr = 0.3 eV 2 - 0.3 2 - 0.3 3 3 6 6 10 10 3 - 0.35 3 - 0.35 4 - 0.4 4 - 0.4 5 - 0.5 5 - 0.5 -1 -1 10 10 5 5 2 2 10 10 2 2  I (a.u.)  I (a.u.) 5 5  I (a.u.)  I (a.u.) 4 4 3 3 3 3 1 1 1 1 10 10 14 cm 14 cm -3 -1 -3 -1 4 4 M tr = 1*10 M tr = 1*10 -2 -2 10 10 14 -2 14 -2 5*10 5*10 2 2 15 -3 15 -3 1*10 1*10 0 0 15 -4 15 -4 10 10 5*10 5*10 16 -5 16 -5 1 1 1*10 1*10 16 -6 16 -6 E r = 0.43 eV, E tr = 0 E r = 0.43 eV, E tr = 0 5*10 5*10 be prilipimo -7 be prilipimo -7 7 7 -3 -3 -1 -1 10 10 10 10 20 20 30 30 40 40 50 50 60 60 20 20 30 30 40 40 50 50 60 60 -1 ) -1 ) -1 ) -1 ) 1/kT (eV 1/kT (eV 1/kT (eV 1/kT (eV a- Simulated trapping coefficient dependence on temperature for trapping level with activation energy of 0.23 eV in Si. b- Variations of recombination and instantaneous trapping lifetimes as a function of reciprocal thermal energy varying activation energy and concentration of trapping centres.

DLTS spectra in electron irradiated Si samples after isochronal (24 h) anneals C-DLTS signal (arb. units.) n-Cz 16 e/cm 2  =10 = V 5 as irradiated 2 Annealed VO - 4 o C V 60 (b) V 2 O T an = 80 2 V 3 O ln(  em ´ v th ´ N C ) o C 180 58 = 3 V o C 2 280 VO 56 - V 2 3 54 V 3 O V 2 O VP - 1 V 52 3 50 0 50 100 150 200 250 300 50 100 150 200 250 -1 ) 1/kT (eV T (K) DLTS spectra dependent on annealing temperature recorded on Schottky diodes irradiated with fluence of Φ =10 16 e/cm 2 . b- The Arrhenius plots obtained for different spectral peaks obtained in diodes annealed at 280 ° C.

MW-PC characteristics in electron irradiated Si samples after isochronal (24 h) anneal at T an =280 C varying scan temperature T for transients MW-PC signal (arb. units.) T (K) 16 e/cm 2 , T an =280 o C n-Cz,  =4 ´ 10 280240 200 160 120 1 T=110 K 2 0 10 (a) 10 2 130 K (b) 3 250 K 4 290 K  R ,  tr (  s) -1 10 16 cm -2  =4 ´ 10 1 1 10 o C T an =280 2  R  tr 3 -2 10 4 0 10 40 60 80 100 -3 -1 ) 10 1/kT (eV 0 50 100 150 t (  s) a- The MW-PC transients recorded on the diode sample irradiated with fluence 4 × 10 16 e/cm 2 the carrier recombination ( τ R ) and using different scan temperatures T . b-Variations of trapping ( τ tr ) lifetimes as a function of the reciprocal thermal energy ( kT ) for sample irradiated with fluence 4 × 10 16 e/cm 2 after heat treatment at T a = 280 ° C.

Trapping spectra measured by MW-PC in 6.6 MeV electron irradiated Si samples after isochronal (24 h) anneal at T an =280 C varying scan temperature T of transients Comparison of the simulated (curves) and experimental (symbols) variations of the carrier trapping lifetimes τ tr as a function of reciprocal thermal energy for samples irradiated with fluence 4 ´ 10 16 e/cm 2 and annealed for 24 h at temperatures T an =180 0 C (a) and T an =280 0 C (b). Here, the bold curve represents a sum of emission flows from different trapping levels those form the single thermal emission peaks, shown by thin solid curves. Simulations of the resultant τ tr ( T ) spectrum were performed including temperature dependent changes of the recombination lifetime τ R (T).

Trapping spectra measured by MW-PC in proton irradiated n-Fz and p-Cz Si samples after isochronal (24 h) anneal at T an =250 C varying scan temperature T of transients  =1 ´ 10 2 , T an = 250  C 24h 14 p/cm n-Fz,  =5 ´ 10 2 , T an = 250  C 24h 15 p/cm p-Cz n-Fz 0.05 E xperiment Simulations  R  R  R  tr,i single trap (a) (b)  tr  tr (  traps )  tr  tr 0.04 VO = 10 V 2  R ,  tr (  s)  R ,  tr (  s) 0.03 - V 2 1 0.02 0.01 0.1 0.00 40 50 60 70 80 90 40 50 60 70 80 -1 ) -1 ) 1/kT (eV 1/kT (eV a-Variations of the carrier recombination ( τ R ) and trapping ( τ tr ) lifetimes as a function of the reciprocal thermal energy ( kT ) for p-Cz and n-Fz samples irradiated with fluence 1 × 10 14 e/cm 2 after heat treatment at T an = 250 ° C. b- Comparison of the simulated (curves) and experimental (symbols) variations of the carrier trapping lifetimes τ tr as a function of reciprocal thermal energy for n-Fz Si sample irradiated with fluence 5 ´ 10 15 e/cm 2 and annealed for 24 h at temperatures T an =250 0 C

Trapping spectra measured by MW-PC in pion irradiated Si samples after isochronal (24 h) anneal at T an =150 C varying scan temperature T of transients n-Fz,  =1×10 14  /cm 2 , T an =150 o C n-Cz,  =1 ´ 10 14  /cm 2 , T an =150 o C E xperiment 1.5 Simulations 200 Experiment Simulations  R  tr,i single trap VO (a)  R  tr,i single trap  tr  tr (  traps )  tr  tr (  traps )  R ,  tr (  s) =  R ,  tr (  s) V 2 1.0 (b) C i O i 100 0.5 VO = V 2 C i O i 0.0 0 40 50 60 70 80 90 50 60 70 80 90 -1 ) 1/kT (eV -1 ) 1/kT (eV Comparison of the simulated (curves) and experimental (symbols) variations of the carrier trapping lifetimes τ tr as a function of reciprocal thermal energy for n-Fz Si (a) and n-Cz Si (b) samples irradiated with fluence 1 ´ 10 14 e/cm 2 and annealed for 24 h at temperatures T an =150 0 C