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Estados de transición entre pirámides y cúpulas durante el crecimiento de la isla Ge/Si
1IBM T. J. Watson Research Center, Post Office Box 218, Yorktown Heights, NY 10598, USA.
Science (New York, N.Y.)
|December 3, 1999
Resumen
La transición de las islas germanio-silicio de las pirámides a las cúpulas durante el crecimiento en silicio. Este cambio de forma, influenciado por la temperatura, se produce a través de estados intermedios y es reversible al enfriarse, apoyando un modelo de grueso anómalo.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Ciencias de la superficie Ciencias de la superficie.
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- Las islas de germanio-silicio (GeSi) cultivadas en superficies de silicio (001) exhiben una evolución de formas complejas.
- La comprensión de la morfología de la isla es crucial para la fabricación de dispositivos de semiconductores y la gestión de la deformación.
Objetivo del estudio:
- Para investigar la transformación en tiempo real de la forma de las islas GeSi de estructuras piramidales a estructuras de cúpula durante el crecimiento.
- Para dilucidar las formas intermedias y el papel de la temperatura en esta transición.
Principales métodos:
- Observación in situ en tiempo real del crecimiento de las islas de GeSi en Si(001).
- Análisis de la morfología de la isla, incluida la evolución de las facetas, durante el crecimiento y el recocido posterior al crecimiento.
- Estudios dependientes de la temperatura de las transiciones de forma y la reversibilidad.
Principales resultados:
- Las pequeñas islas GeSi son piramidales, mientras que las más grandes adoptan formas de cúpula.
- La transición implica formas intermedias asimétricas con un número creciente de facetas altamente inclinadas.
- El recocido posterior al crecimiento de las pirámides induce un cambio de forma similar, que es dependiente de la temperatura y reversible al enfriarse.
Conclusiones:
- La transición de forma de pirámide a cúpula observada en las islas GeSi está mediada por distintos estados intermedios.
- La naturaleza reversible y dependiente de la temperatura de la transición apoya un modelo anómalo de endurecimiento para el crecimiento de las islas.
- Estos hallazgos proporcionan información sobre los mecanismos fundamentales que rigen la formación de nanoestructuras en las superficies.
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