Ge island formation on stripe-patterned Si(001) substrates

Self-assembled Ge islands were grown by solid-source molecular-beam epitaxy on the submicron stripe-patterned Si(001) substrates at 650 °C. Atomic-force microscopy shows that the Ge islands grow preferentially at the sidewall of the Si stripes, oriented along the [−110] direction. The migration of the Ge adatoms from the top terrace down to the sidewall accounts for the island formation at the sidewall of the stripes. However, most of the Ge islands are formed on the top terraces when the patterned stripes are covered by a strained GeSi multilayer buffer prior to Ge island growth. Apparently, the strained buffer layer acts as a stressor and contributes to the preferential growth of islands on the top terrace.Self-assembled Ge islands were grown by solid-source molecular-beam epitaxy on the submicron stripe-patterned Si(001) substrates at 650 °C. Atomic-force microscopy shows that the Ge islands grow preferentially at the sidewall of the Si stripes, oriented along the [−110] direction. The migration of the Ge adatoms from the top terrace down to the sidewall accounts for the island formation at the sidewall of the stripes. However, most of the Ge islands are formed on the top terraces when the patterned stripes are covered by a strained GeSi multilayer buffer prior to Ge island growth. Apparently, the strained buffer layer acts as a stressor and contributes to the preferential growth of islands on the top terrace.

[1]  C. Lent,et al.  Realization of a Functional Cell for Quantum-Dot Cellular Automata , 1997 .

[2]  T. Senden,et al.  Nucleation Transitions for InGaAs Islands on Vicinal (100) GaAs , 1997 .

[3]  Oliver G. Schmidt,et al.  Long-range ordered lines of self-assembled Ge islands on a flat Si (001) surface , 2000 .

[4]  R. Koch,et al.  Minute SiGe quantum dots on Si(001) by a kinetic 3D island mode. , 2001, Physical Review Letters.

[5]  R. Stanley Williams,et al.  Lithographic positioning of self-assembled Ge islands on Si(001) , 1997 .

[6]  H. Lüth,et al.  Growth of SiGe quantum wires and dots on patterned Si substrates , 1995 .

[7]  Stephen R. Leone,et al.  Two-dimensional periodic alignment of self-assembled Ge islands on patterned Si(001) surfaces , 2002 .

[8]  M. Lagally,et al.  Self-organization in growth of quantum dot superlattices. , 1996, Physical review letters.

[9]  James S. Speck,et al.  Controlled ordering and positioning of InAs self-assembled quantum dots , 2000 .

[10]  Kang L. Wang,et al.  Interfacet mass transport and facet evolution in selective epitaxial growth of Si by gas source molecular beam epitaxy , 1996 .

[11]  A. Larsen,et al.  Nanoscale Structuring by Misfit Dislocations in Si 1 − x Ge x / S i Epitaxial Systems , 1997 .

[12]  L. Coldren,et al.  Surface migration induced self‐aligned InAs islands grown by molecular beam epitaxy , 1995 .

[13]  K. Asakawa,et al.  Site control of InAs quantum dots on GaAs surfaces patterned by in situ electron-beam lithography , 2000 .

[14]  F. Schäffler,et al.  Molecular beam epitaxial growth and photoluminescence investigation of Si1−yCy layers , 1998 .

[15]  Kang L. Wang,et al.  Regimented placement of self-assembled Ge dots on selectively grown Si mesas , 2000 .

[16]  Gerhard Abstreiter,et al.  Two-dimensional ordering of self-assembled Ge islands on vicinal Si(001) surfaces with regular ripples , 1998 .

[17]  Zhang,et al.  Ab initio studies of the diffusion barriers at single-height Si(100) steps. , 1995, Physical review letters.

[18]  Bich-Yen Nguyen,et al.  Controlled arrangement of self-organized Ge islands on patterned Si (001) substrates , 1999 .