Self-organised Growth of Silicon Structures on Silicon during Oxide Desorption

The creation of structures on silicon surfaces with dimensions below current production limits (ca. 150 nm) is one of the most important objectives for future development in the microelectronics industry. Although features with dimensions down to atomic levels can be produced by field diffusion using the tip of a scanning tunnelling microscope (STM), an enormous amount of time would be required for building useful production devices. We have investigated the use of the self-organisation of surface atoms on Si[100] during UHV thermal treatment for the production of silicon island structures of dimensions in the 10-500 nm range. STM images show that the dimensions of these structures depend upon the quantity of oxide present on the surface before beginning the thermal treatment. By 'freezing' the thermal desorption of the surface oxide it is possible to obtain a surface with silicon islands at the centre of naked silicon 'voids'. Further treatment allows the formation of a series of smaller islands around the original central one. The key element in such a methodology is the rapid self-construction of small silicon structures over large areas of a silicon surface. Verification of the possibility of nucleating a regular array of primary structures is proposed.