Self-organization of step bunching instability on vicinal substrate

2006 ◽  
Vol 89 (10) ◽  
pp. 104108 ◽  
Author(s):  
A. Pascale ◽  
I. Berbezier ◽  
A. Ronda ◽  
A. Videcoq ◽  
A. Pimpinelli
2001 ◽  
Vol 707 ◽  
Author(s):  
N. Motta ◽  
A. Sgarlata ◽  
A. Balzarotti ◽  
F. Rosei

ABSTRACTWe have studied by Scanning Tunneling Microscopy (STM) the effect of step bunching on Ge/Si(111) epitaxy. We have verified that self-organization of Ge islands is greatly influenced by “step bunching” which arises from the flash-annealing procedure used to reconstruct the Si surface. Two different growth regimes arise: initially islands nucleate and evolve only at steps, up to complete ripening; subsequently the same evolution is observed on flat areas of the sample. The average distance between islands and steps is nearly constant, originating a single row of equally spaced islands, followed by other rows of islands in between. The exploitation of this phenomenon, which is governed by the surface diffusion length of Ge on Si (estimated from our data) and by the terrace width, constitutes one possible path to achieve self-organization of quantum dots.


2001 ◽  
Vol 43 (2-4) ◽  
pp. 45-126 ◽  
Author(s):  
Katsumichi Yagi ◽  
Hiroki Minoda ◽  
Masashi Degawa

2001 ◽  
Vol 696 ◽  
Author(s):  
N. Motta ◽  
A. Sgarlata ◽  
A. Balzarotti ◽  
F. Rosei

AbstractWe have studied by Scanning Tunneling Microscopy (STM) the effect of step bunching on Ge/Si(111) epitaxy. We have verified that self-organization of Ge islands is greatly influenced by “step bunching” which arises from the flash-annealing procedure used to reconstruct the Si surface. Two different growth regimes arise: initially islands nucleate and evolve only at steps, up to complete ripening; subsequently the same evolution is observed on flat areas of the sample. The average distance between islands and steps is nearly constant, originating a single row of equally spaced islands, followed by other rows of islands in between. The exploitation of this phenomenon, which is governed by the surface diffusion length of Ge on Si (estimated from our data) and by the terrace width, constitutes one possible path to achieve self-organization of quantum dots.


Author(s):  
A. Yamanaka ◽  
H. Ohse ◽  
K. Yagi

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].


1994 ◽  
Vol 39 (9) ◽  
pp. 916-916
Author(s):  
Terri Gullickson

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