H. Wulff Universität Greifswald, Institut für Cheie und Biocheie Röntgenographische Charakterisierung von plasagestützt abgeschiedenen ITO-Schichten Mühlleithen, 8.-. März 3
Gliederung. Einführung. Angewandte Methoden Röntgendiffraktoerie i streifenden Einfall (GIXRD) Röntgenreflektoetrie (GIXR) 3. Ergebnisse - Einfluß von Sauerstoff und Bias-Spannungen während der Schichtabscheidung - Teperatur- und zeitaufgelöste Untersuchung von ITO-Schichten (Diffusion, Kristallwachstu) 4. Zusaenfassung
Fil property X-ray ethod Alternatives phase coposition GIXRD:Bragg angle, TEM intensity cheical coposition GIXRD: Bragg angle EDX, XPS, RBS (ixed crystals) acrostress GIXRD: Bragg angle substrate curvature, laser optics grain size GIXRD: line profile, TEM, SEM line width icrostrain GIXRD: line profile preferred orientation crystal structure thickness density surface roughness interface roughness diffusion behavior crystallization rate GIXRD: intensity, polfigure GIXRD:Rietveld analysis, structure refineent GIXRD: intensity GIXR: Kiessig fringes GIXR: critical angle of total reflection GIXR: aplitude of Kiessig fringes in situ GIXRD, theral and tie resolved: intensity in situ GIXRD, theral and tie resolved: intensity interferoetry, ellipsoetry, TEM ellipsoetry SEM, ellipsoetry, AFM SIMS, AES, cobined with sputtering
onochroator detector x-ray source divergence slit SOLLER slit Har Wulff, Universität Greifswald, 3.. detector window incidence angle ω diffraction angle Θ layer substrate Scheatic diagra of grazing incidence X-ray diffractoetry (GIXRD), θ Bragg angle, ω angle of incidence
.3.5 µ.5 inforation depth T (µ)..5..5. µ.5 µ. 3 4 5 incidence angle ω (degrees) Inforation depth of Cu Kα radiation depending on incidence angles, calculated for.5,. and.5µ thick In fils
, x-ray source divergence slit detector incident x-ray reflected incidence angle Θ substrate reflection angle Θ layer Scheatic diagra of grazing incidence X-ray reflectoetry (GIXR)
Bias-Versorgung Substrat Target Gasversorgung DC-Magnetron Sputtering Syste
8 Intensity (cps) 7 6 5 scc O scc O scc O Har Wulff, Universität Greifswald, 3.. 4 3.5..5..5 3. Θ (degrees) GIXR easureents of fils deposited at different oxygen flows, U sub = V: scc O, thickness 5. n, roughness.5 n; scc O, thickness.5 n, roughness.98 n; scc O, thickness 7. n, roughness.75 n
8.7 7.6 density (g c -3 ) 6 5 V -5 V - V.5.4 dep. rate (n s - ).3 4...5..5. oxygen flow (scc) Density () and deposition rate ( ) of saples deposited at V, -5V and V substrate voltage vs. oxygen flow
n n n n n n n n n n n a) b) n AFM icrographs, saples deposited (a) without O and (b) at.5 scc O ; U sub = V, deposition tie 3 s
5 In() 4 U Sub = V In() Har Wulff, Universität Greifswald, 3.. In() 3 intensity (a.u.) scc O.5 scc O. scc O.5 scc O 6 8 3 3 34 36 38 4 Θ (degrees). scc O Diffraction patterns of ITO-fils deposited at different oxygen flows, U sub = V
U Sub = -5 V In() 5 In() 5 5 intensity (a.u.) scc O.5 scc O. scc O.5 scc O. scc O 6 8 3 3 34 36 38 4 Θ (degrees) Diffraction patterns of fils deposited at different oxygen flows, U sub = -5 V
Röntgenprofilanalyse h ( x) = f ( y) g( x y) dy F ( L) = H ( L) G( L) STOKES Methode F(L), H(L) G(L) sind die Fouriertransforierten von f(x), h(x) und g(x) Noriert auf F( ) = H () = G() = A( L) = a ( L) a ( L) a ( L) p s d A( L) = exp( L / T ) exp( K < ε > L ) exp( B ln( L / L) L ) und ln A( L) = L / T +K < ε > + B ln( L / L) L L = n d(hkl) T = T (hkl) B = B(hkl) L < ε >=< ε ( hkl) > Meßlänge in Richtung des Beugungsvektors effektive Teilchengröße ittlere Versetzungsdichte Abschneideradius (Spannungsfeld einer Versetzung) ittlere quadratische Spannungen infolge von Defekten. Art
, F(L),8,6 Fourier coefficients of the physical line profile V -5 V - V,4,, 5 5 5 3 35 4 45 5 55 6 L [n] Fourier coefficients of the Indiu() reflection for fils deposited at different substrate voltages without oxygen flow
WARREN-AVERBACH-plot γ ( L ) = ln A( L) / L = / T + K < ε ( L) > L KRIVOGLAZ-WILKENS-plot ψ(lnl) = lna( l)/ L = / TL+ ( K < ε > + BlnL ) BlnL
WARREN-AVERBACH-plot für In()-Reflex,8,7-5V - ln [F(L)]/nL,6,5,4 -V V,3, L = 3.7n 3 4 5 nl / n
Physical paraeters of In/Sn fils deposited at various substrate voltages U sub V -5 V - V T / n 74 43 7 <ε > /,87-3,4-3,98-3 ρ V / c -,56 -, -,64 - d / Å,783,74,7697 V / V Referenz -,455 -,49
scc O U Sub = V In O 3 () x In () x In O 3 (4) 3 In () In () 3 8 6 4 intensity (a.u.) 6 8 3 3 34 36 38 4 Θ (degrees) as-deposited after h at C after 4h at C after 7h at C after h at C Phase transforation of etallic In/Sn into crystalline ITO at C
d x dx dv=adx Substrat ω Θ I di dx C C A A I K B t di ) ( =..5. dx d x C/C x = d dx A t x C A I K B t I C ), ( ) ( ( ) ( ) = = e cos 4, n d Dt n n d x d n n C t x C π π π..5. x d A x z x t x A ), e µ ( = ( ) ( ) ( ) ( )( ). n x n n n x n x dx C C x f f dx C C f f x dx x µ µ µ µ µ µ µ µ µ µ µ + + = + + = = Diffusion odel () () (3) (4)
.. easureent siulation noralized intensity.9.8.7.6.5.4 scc O, U sub =V annealing at C D=8-6 c s -.3. 3 4 5 tie (s) The easured noralized X-ray integral intensities ( ) of ITO () reflection and the calculated intensity values (dashed line) versus tie of a fil deposited at scc O and V bias voltage
O -flow / scc bias / V D / -6 c s - f (aorphous ITO) 6.5 5.5.5. 6.75.5 -. - -5 3.5 7. 4.3.5 5.5. 6.7-9.4.5 9.. 9.6.5.5 9.6.65. 9.6.8
θ ( C) 35 3 5 5-34. -34.5-35. ln D -35.5-36. θ > 5 C E A =.3 kj/ol (V) E A = 3.4 kj/ol (-5V) E A =.8 kj/ol (-V) E A = 7.7 kj/ol E A = 6.7 kj/ol -36.5 E A = 7.8 kj/ol.6.8...4.6.8 /T ( 3 K - ) ARRHENIUS plot for the diffusion process: two different activation energies were found for T < 5 C and T > 5 C
Highly idealized polycrystalline fil -Modell D eff δ = D L D D vol + KG + ασ D vers
JOHNSON-MEHL-AVRAMI-plot für die Kristallisation aorphen ITO ś,, y = - exp(-(t/t ) n ),9 y (transforation stage),8,7,6,5,4,3, ln[ln(/(-y))],,5,,5, -,5 -, -,5 C 3 C 4 C, 7, 7, 7,4 7,6 7,8 8, 8, ln t,,5,,5,,5 3, 3,5 t/t
Target - In/Sn V Plasa Ar +, Ar *, In +, In *, Sn +, Sn * e - -5 V - V In/Sn kristallin In/Sn kristallin + Defekte In/Sn kristallin + weniger Defekte
Target - In/In O 3 V Plasa Ar +, Ar *, In +, In *, In x O y, O + O -, O *, e -,??? -5 V - V ITO aorph In/Sn kristallin + Defekte ITO aorph In/Sn ITO aorph