Isolation method to replace STI for deep sub-micron VLSI process including epitaxial silicon

摘要

In accordance with the objectives of the invention a new method is provided for the definition and delineation of active regions in the surface of a semiconductor substrate. A layer of pad oxide is grown on the surface of the substrate, the layer of pad oxide is patterned and etched whereby the pad oxide remains in place over areas where the isolation regions are to be created. The underlying silicon substrate is in this manner exposed; the regions of the silicon substrate that are exposed are the regions of the substrate where active devices are to be created. The exposed surface of the substrate is cleaned; the openings in the layer of pad oxide are selectively filled with a deposition of epitaxial silicon. The created structure is heat treated to improve the interface between the patterned and etched layer of pad oxide and the deposited epitaxial silicon. The created pattern of pad oxide can now be used as regions of field isolation over the surface of the substrate.