J. Vaitkus, E.Gaubas, K.Jarasiunas, A.Kadys LIFETIME IN HIGHLY IRRADIATED SILICON J. Vaitkus, E.Gaubas, K.Jarasiunas, A.Kadys Institute of Materials Science and Applied Research, Vilnius University, Vilnius, Lithuania, E.Fretwurst Institute of Experimental Physics, Hamburg University, Hamburg, Germany OUTLINE Motivation Free carrier lifetime (trapping time) and diffusitivity measurement by transient grating method Deep centers existence in highly irradiated samples demonstration Lifetime measurement by microwave absorption progress Excess carrier decay temperature variations Comparison with DLTS data in e-irradiated diodes Summary
Free carrier lifetime (trapping time) measurement by transient grating method Il sample I-1 I L I+1 I0
I0 = 0.2 mJ/cm2, grating period 60 m (decay time ~ recombination (trapping) time)
Grating period 5 m (diffusion influence). naudotas gautasis matavimuose su 60 mikronų gardele.
Excitation. Si (CE2419). Si (CE2459). Si (CH2259) (mJ/cm2). 1 Excitation Si (CE2419) Si (CE2459) Si (CH2259) (mJ/cm2) 1.06 1014cm-2 6.36 1014cm-2 9.80 1014cm-2 0.7 D (cm2/s) 16 ( 0.1) 15.7 ( 0.1) 17.2 ( 0.1) R (ns) > 30 >30 20 ( 2) 5.0 D (cm2/s) 13.6 ( 0.1) 13.1 ( 0.1) 12.5 ( 0.3) R (ns) > 30 > 30 5.7 ( 0.3)
Generation of carriers via deep centers Macfarlane, G. G., T. P. McLean, J. E. Quarrington, and V. Roberts, J.Phys.Chem.Solids 8,(1959) 388-392.
Generation of carriers via deep centers Il sample I-1 I L I+1 I0
27 micron grating
Integrated MWR module Back side Face side Sample holder MW bridge Sliding short Holder of neutral intensity filters Fiber or laser mount Gunn oscillator module Integrated MWR module Face side MW bridge Slit antenna or MW cable mount Sliding short Sample holder
Integrated MWR module Gunn oscillator module detector chamber Gunn oscillator chamber MW ventil with load MW circulator detector chamber
Thermo-couple Fiber excitation Laser Cryo-chamber MW cable
Excess carrier decay transients in proton irradiated diodes. Material: Wacker FZ Si, <100>, 6k cm. Diodes processed: CIS CE O-diff no CIS CH O-diff 75hN2 1150C
Decay lifetime dependence on irradiation fluence
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