Ivestigatio of carrier lifetime temerature variatios i the roto irradiated silico by MWA trasiets E.Gaubas, J.Vaitkus Istitute of Material Sciece ad Alied Research, Vilius Uiversity, Lithuaia i collaboratio with J. Härköe, E.Tuovie, P. Luukka, E. Tuomie Helsiki Istitute of Physics, Helsiki Uiversity, Filad ad Hamburg grou
Problem Role of oxygeatio i modificatio of the recombiatio characteristics i roto irradiated silico Outlie roto irradiated samles fabricated i Helsiki RT characteristics: lateral, itesity, irradiatio fluece, iitial//irradiated lifetime temerature variatios,-comariso of Helsiki&Hamburg samles ossible recombiatio flow redistributio rocesses ad simulated characteristics
Iitial material ad roto irradiated Si samles Helsiki Si ieces. There is a icture of irradiatio arragemet. Two ieces (e.g. samles #5 ad #6) were irradiated at the same time. I the icture, it is marked with red aroximately the roto beam sot, whe oe side of the samle is more irradiated with give dose. The beam sot has a radius of about 2,5cm. The o-irradiated ieces are assivated with thermally grow SiO 2 (at C), so the surface recombiatio velocity should be lower i the latter samles. ID # 1 2 3 4 5 6 7 8 9 11 12 Fluece 0 0 0 0 5e12 5e12 5e12 5e12 1e13 1e13 1e13 1e13 Tye of Si TD treatmet Proto eergy ID # 13 14 15 16 17 18 19 20 Fluece 9e12 9e12 9e12 9e12 2e13 2e13 2e13 2e13 Tye of Si TD treatmet Proto eergy
Lateral lifetime variatio due to irradiatio geometry with roto beam sot of 25 mm cw BI hoto detector fiber MWdetector to osc.+pc A YAG: Nd 3+ ulsed laser samle MWwaveguide cold/hot figer A slit-shae MWatea Gu oscillator GHz samle slidig short MWwaveguide otical waveguide cold/hot chuck 2 1 0-1 25 mm 0-20 mm 20 mm 20 mm -Si (H07) TD MeV 5* 12 cm -2 0 5 15 20 x (mm) Short mooexoetial decay i the irradiated area Two-comoetial decay with traig effect i the oirradiated area Strog icrease of lifetime at boudary of irradiated ad oirradiated areas U MWA, (a.u) 2 -Si o TD (HB 14), 64 m, irradiated regio τ eff i/asymt = 112s/301s U MWA 2 -Si o TD (HB 14), 64 m, o-irradiated regio τ eff i/asymt = 62µs/130µs 1 C-Beam ceter B-Beam boudary C B 1 0 200 300 400 0 t (s) 0 0 200 400 600 800 00 t (µs)
Recombiatio-traig i the iitial material TD treated o TD treatmet -Si U MWA/64 m 0 HB1, 64m MWA as-fabricated -Si TD treated τ 1 = 238 µs, τ 2 = 1670 µs BI o τ 1 = 5 µs, τ 2 = 514 µs -1 U MWA 2 as-fabricated -Si/ o TD treatmet HB02 64m MWA τ 1 = 274 µs τ 2 = 2670 µs BI o τ = 290 µs 1-2 0 0 00 000 t (µs) 0 0 0 00 000 t (µs) 2 HB03, 64m MWA as-fabricated -Si TD treated τ 1 = 13 µs τ 2 = 2920 µs BI o τ 1 = 1253 µs τ 2 = 2090 µs 2 HB04, MWA 64m, as-fabricated -Si o TD treatmet BI o τ 1 = 196 µs τ 2 = 230 µs τ 1 = 218 µs τ 2 = 273 µs -Si U MWA/64 m U MWA/64 m 1 1 0 00 2000 3000 4000 00 t (µs) 0 0 200 400 600 800 00 t (µs)
Decay variatio with excitatio itesity i the iitial ad irradiated samles at RT U MWA H01 o-irradiated -Si TD 4 BI o BI o 3 BI o BI o 2 BI o 1 3 H01 -Si TD τ i τ as BI o 0 00 2000 3000 4000 t(µs) 2 0 0 1 200 2 I ex 4 H11 -Si TD MeV 13 cm -2 3 Traig is iheret for iitial material ad decreases with excitatio U MWA 2 1 I ex =190 BI o I ex =190 I ex =1 BI o I ex =1 I ex =55 BI o I ex =55 I ex =40 I ex =6 BI o I ex =6 sigificat traig at RT i the irradiated samles 0 0 0 200 300 400 0 600 700 t(s)
Recirocal lifetime vs. rotos irradiatio fluece at RT 3 -Si TD treated BI o τ 1 /o-irradiated irradiated -Si o TD tr 2 irradiated -Si TD treated irradiated -Si o TD tr irradiated 1 0-1 0 12 13 Fluece (cm -2 ) τ eff -1 (µs -1 ) 2 I//Hm H -Si H -Si TD 1 0 τ -1 (s -1 ) -1-2 MWA decay lifetime i irradiated Si τ ex =30 s HMB// s HLS, λ ex =64 m o O diff HMB O diff 24 h HMB o TD -Si HLS TD -Si HLS TD o O treatmets -1-2 8 9 11 12 13 14 15 16 Irradiatio fluece (cm -2 ) -3 13 14 15 Fluece (cm -2 )
Effective lifetime deedece o temerature i the iitial material ad i the irradiated samles 4 Iitial material 3 2 -Si H15 -Si TD MeV H + 9* 12 H16 -Si o-td MeV H + 9* 12 H08 -Si o-td MeV H + 5* 12 H19 -Si TD MeV H + 2* 13 H03 -Si TD o-irradiated 1 0 3 2 80 120 160 200 240 280 320 T (K) H03 -Si TD τ 1 τ 2 BI o τ 1 τ 2-1 2 1 80 120 160 200 240 280 320 T (K) 3 -Si -Si o TD MeV 2* 13 cm -2 (H18) TD MeV 2* 13 cm -2 (H17) TD MeV 9* 12 cm -2 (H13) TD MeV 5* 12 cm -2 (H05) 0-1 80 120 160 200 240 280 320 T (K)
Variatio of the artial decay amlitudes 1 as / i, τ as (µs) 0 as / i H16, o TD; 9x 12 cm -2 as / i H15, TD; 9x 12 cm -2 τ (T) H15-1 80 120 160 200 240 280 320 T (K)
Correlatio betwee lifetime vs. kt lots i the roto irradiated samles fabricated i Hamburg ad Helsiki Hamburg Helsiki 0 CW22A3 3.3* 14 /cm 2, O i diff 24 h τ a CW24A3 9.9* 14 /cm 2, O i diff 24 h τ a 4 3 2 H15 -Si TD MeV H + 9* 12 H16 -Si o-td MeV H + 9* 12 H08 -Si o-td MeV H + 5* 12 H19 -Si TD MeV H + 2* 13 H03 -Si TD o-irradiated -1 1 0-1 40 60 70 80 90 0 1/kT (ev -1 ) 40 60 70 80 90 0 1/kT (ev -1 )
Possible traig rocesses ad characteristics R Tra fillig effects T τ I 0-1 -2 1 - E tr = 0.2 ev 2-0.3 3-0.35 4-0.4 5-0.5 5-3 20 30 40 60 4 E r = 0.43 ev, E tr = 0 3 2 kt -1 (ev -1 ) 1 τ I 3 E tr = 0.3 ev 2 1 0-1 M tr = 1* 14 cm -3-1 5* 14-2 1* 15-3 5* 15-4 1* 16-5 5* 16-6 without traig -7 20 30 40 60 1/kT (ev -1 ) 4 2 1 7 6 5 3
Possible traig rocesses ad characteristics Metastable cetres TD,V-O, etc. A S R Tra fillig effects MS B EB CC Ec Ev T TD1++e Ev τ I 0.15 ev 0.07 ev 0-1 -2 1 - E tr = 0.2 ev 2-0.3 3-0.35 4-0.4 5-0.5 5-3 20 30 40 60 TD Si TD12++2e TD1o A 4 E r = 0.43 ev, E tr = 0 0.47 ev 0.48 ev B 3 2 kt -1 (ev -1 ) TD1*+e+h TD1* 1 τ I 3 E tr = 0.3 ev 2 1 0-1 M tr = 1* 14 cm -3-1 5* 14-2 1* 15-3 5* 15-4 1* 16-5 5* 16-6 without traig -7 20 30 40 60 1/kT (ev -1 ) TD O i +V Si O Si +V Si O + Si V- Si O + Si V- Si O2+ Si V- Si + e- O 2+ Si A- Si + e- A - Si :irrv Si ; Cu Si ; Al Si O 2+ Si A 1 - Si A 2 - Si 4 2 1 7 6 5 3
Methodological summary The decay of hotocoductivity excited by short light ulse eables oe to distiguish the slow traig ad recombiatio rocesses. The determied lifetime values i roto irradiated Cz Si for flueces i the rage of 5x 12-2x 13 cm -2 fits ito the earlier revealed lifetime fluece deedecy, but a existece of the domiat defect tye chage still requires further, the more detail examiatio of this lifetime vs. fluece characteristic. The traig effect is observable i the temerature rage of 240-120 K for these roto irradiated samles, but alicatio of the simle recombiatio-traig model is comlicated due to the quite abrut lifetime chages i its temerature deedecy.
Techological otetial The temerature deedet traig effect is iheret for all the irradiated samles, irresective of TD treatmet is domiat the iteractio betwee oxyge ad the radiatio defects i TD trasformatios? The ost-irradiatio history of lifetime variatios would eable to reveal these TD trasformatios. The MWA hoto-resose decay cotroller, the τmeter, allows a o-ivasive moitorig of the traig -recombiatio rocesses. Thak you for your attetio