Idealized Growth Modes in Homoepitaxy

Idealized Growth Modes in Homoepitaxy
step-flow
layer-by-layer
mound formation
self-affine
Fig. 6.20

Growth Go on Pt(111) - Overview
e
200 K 300 K 400 K 500 K 600 K
0.17 ML
1560 Å
5.0 ML
Fig. 6.21

Absence of self-affine growth of Pt on Pt(111)
5MLof Pt on Pt(111) deposited at 50 K (no diffusion possible).
Image size 35 nm x 35 nm.
Fig. 6.22

Diffusion of Ir adatoms on Ir(111); imaging with field ion microscopy
S.C. Wang, G. Ehrlich, Phys. Rev. Lett. 62 (1989) 2297
Fig. 6.23

Diffusion of Ir adatoms on Ir(111)
S.C. Wang, G. Ehrlich, Phys. Rev. Lett. 62 (1989) 2297
Fig. 6.24

Interaction Between Nucleation and Growth
F
n 2
*
F
*
Fig. 6.25

(a)
(b)
150 K 165 K
Pt Islands on Pt(111)
(c)
(d)
180 K 195 K
(e)
210 K 225 K
(f)
(g)
(h)
245 K 265 K
[112]
Fig. 6.26

Island Density as a Function of θ and T for Pt Islands on Pt(111)
island density as a function of coverate at 180 K
island density at coverage 0.1Ml
linear regression to STM data:
E a = 0.26 eV
M. Bott et al. PRL 76 (1996) 1304
Fig. 6.27

Step Edge - or Ehrlich-Schwoebel Barrier
E ΔE S
Fig.6.28
E
ΔE

The Zeno Model
1D MC simulation
T. Michely, J. Krug, Islands, Mound and Atoms, Springer 2004
Fig. 6.29

Nucleation on Top Terrace and Mound Profile for Finite Barriers
shape analysis:
ν '
τ
Δt
p =
nuc
τ
Δt
3 5
ν'
= 3.1 α 3 F L
5
ΔE = 0.18 eV ( ν = 7 x 10 s )
' 11 -1
S 0
60
30
Poisson
profile
0
30 60
-30
-60
(h - h)
0
-30
-1,0 -0,5 0,0 0,5 1,0
Radius r Fig. 6.30

Reading Atomistic Parameters from the Morphology
Fig. 6.31

Zeno-Effect
Fig. 6.32

Examples
10 ML
25 ML
300 K
420 K, CO
3000 Å 3200 Å
300 ML
440 K
≈ 19 ML
pentacene on
amorphous
substrate
3500 Å 40000 Å
Fig. 6.33

Fig. 6.34