Abstract: A method of forming a trench isolation (e.g., an STI) for an integrated circuit includes forming a pad oxide layer and then a nitride layer over a semiconductor substrate, performing a trench etch through the structure to form a trench, depositing a trench oxide layer over the structure to form a filled trench, depositing a sacrificial planarizing layer, which is etch-selective to the trench oxide layer, over the deposited oxide, performing a planarizing etch process that removes the sacrificial planarizing layer and decreases surface variations in an upper surface of the trench oxide layer, performing an oxide etch process that is selective to the trench oxide layer to remove remaining portions of the trench oxide layer outside the filled trench, and removing the remaining nitride layer such that the remaining oxide-filled trench defines a trench isolation structure that projects above an exposed upper surface of the semiconductor substrate.

Abstract: A method of forming a trench isolation (e.g., an STI) for an integrated circuit includes forming a pad oxide layer and then a nitride layer over a semiconductor substrate, performing a trench etch through the structure to form a trench, depositing a trench oxide layer over the structure to form a filled trench, depositing a sacrificial planarizing layer, which is etch-selective to the trench oxide layer, over the deposited oxide, performing a planarizing etch process that removes the sacrificial planarizing layer and decreases surface variations in an upper surface of the trench oxide layer, performing an oxide etch process that is selective to the trench oxide layer to remove remaining portions of the trench oxide layer outside the filled trench, and removing the remaining nitride layer such that the remaining oxide-filled trench defines a trench isolation structure that projects above an exposed upper surface of the semiconductor substrate.

Abstract: A layer of partially planarized organosilicate (DUO) is spin-coated onto a layer of high density plasma (HDP) oxide on a silicon wafer after the shallow trench isolation (STI) is filled with the HDP oxide. Then the DUO layer is etched using a specialized process specifically tuned to etch the DUO and high density plasma (HDP) oxide at a certain selectivity. The higher areas of the wafer topography (active Si areas) have thinner DUO and as the etch process proceeds it starts to etch through the HDP oxide in these areas (active Si areas). The etch process is stopped after a certain depth is reached and before touching down on the silicon nitride oxidation layer. The DUO is removed and a standard chemical-mechanical polish (CMP) is performed on the silicon wafer. After the CMP step the silicon nitride is removed, exposing the silicon substrate between the field oxides.

Abstract: A method of forming a trench isolation (e.g., an STI) for an integrated circuit includes forming a pad oxide layer and then a nitride layer over a semiconductor substrate, performing a trench etch through the structure to form a trench, depositing a trench oxide layer over the structure to form a filled trench, depositing a sacrificial planarizing layer, which is etch-selective to the trench oxide layer, over the deposited oxide, performing a planarizing etch process that removes the sacrificial planarizing layer and decreases surface variations in an upper surface of the trench oxide layer, performing an oxide etch process that is selective to the trench oxide layer to remove remaining portions of the trench oxide layer outside the filled trench, and removing the remaining nitride layer such that the remaining oxide-filled trench defines a trench isolation structure that projects above an exposed upper surface of the semiconductor substrate.

Abstract: A layer of partially planarized organosilicate (DUO) is spin-coated onto a layer of high density plasma (HDP) oxide on a silicon wafer after the shallow trench isolation (STI) is filled with the HDP oxide. Then the DUO layer is etched using a specialized process specifically tuned to etch the DUO and high density plasma (HDP) oxide at a certain selectivity. The higher areas of the wafer topography (active Si areas) have thinner DUO and as the etch process proceeds it starts to etch through the HDP oxide in these areas (active Si areas). The etch process is stopped after a certain depth is reached and before touching down on the silicon nitride oxidation layer. The DUO is removed and a standard chemical-mechanical polish (CMP) is performed on the silicon wafer. After the CMP step the silicon nitride is removed, exposing the silicon substrate between the field oxides.