Semiconductor processing methods of forming field oxidation regions on a semiconductor substrate

A semiconductor processing method of forming a pair of adjacent field oxide regions on a semiconductor substrate, the method comprising the following steps:

• providing a sacrificial pad oxide layer over a semiconductor substrate;
• providing a layer of Ge.sub.x Si.sub.y over the pad oxide layer, where x is greater than 0.2, y is from 0 to 0.8, and x+y=1.0;
• providing a patterned nitride oxidation masking layer over the Ge.sub.x Si.sub.y layer to define at least one pair of adjacent nitride masking blocks overlying desired active area regions of the substrate;
• etching exposed portions of the Ge.sub.x Si.sub.y layer inwardly to and through the pad oxide layer and thereby outwardly exposing the substrate and defining exposed sidewall edges of the Ge.sub.x Si.sub.y layer;
• after exposing the substrate and the sidewall edges of the Ge.sub.x Si.sub.y layer, etching laterally into the Ge.sub.x Si.sub.y layer to laterally recess the Ge.sub.x Si.sub.y layer relative the masking nitride layer and the pad oxide layer;
• providing an oxidation restriction layer over the respective Ge.sub.x Si.sub.y sidewalls, the oxidation restriction layer restricting rate of oxidation of the Ge.sub.x Si.sub.y layer from what would otherwise occur if the oxidation restriction layer were not present;
• oxidizing portions of the substrate unmasked by the masking layer to form at least one pair of adjacent SiO.sub.2 field oxide regions on the substrate;
• stripping the patterned masking layer from the substrate;
• after stripping the masking layer, stripping the Ge.sub.x Si.sub.y layer or any oxidation product therefrom from the substrate selectively relative to SiO.sub.2 ;
• and
• after stripping the Ge.sub.x Si.sub.y layer or any oxidation product therefrom, stripping the pad oxide and any other oxide from the substrate between the pair of adjacent field oxide regions to outwardly expose substrate active area between the pair of field oxide regions.

A semiconductor processing method of forming a pair of adjacent field oxide regions on a semiconductor substrate, the method comprising the following steps:

• providing a sacrificial pad oxide layer over a semiconductor substrate;
• providing a secondary buffering layer over the pad oxide layer;
• providing a patterned nitride oxidation masking layer over the secondary buffering layer to define at least one pair of adjacent nitride masking blocks overlying desired active area regions of the substrate;
• etching exposed portions of the secondary buffering layer inwardly to and through the pad oxide layer and thereby outwardly exposing the substrate and defining exposed sidewall edges of the secondary buffering layer;
• after exposing the substrate and the sidewall edges of the secondary buffering layer, etching laterally into the secondary buffering layer to laterally recess the secondary buffering layer relative the masking nitride layer and the pad oxide layer;
• providing an oxidation restriction layer over the respective secondary buffering layer sidewalls, the oxidation restriction layer restricting rate of oxidation of the secondary buffering layer from what would otherwise occur if the oxidation restriction layer were not present;
• oxidizing portions of the substrate unmasked by the masking layer to form at least one pair of adjacent SiO.sub.2 field oxide regions on the substrate;
• stripping the patterned masking layer from the substrate;
• after stripping the masking layer, stripping the secondary buffering layer or any oxidation product therefrom from the substrate selectively relative to SiO.sub.2 ;
• and
• after stripping the secondary buffering layer or any oxidation product therefrom, stripping the pad oxide and any other oxide from the substrate between the pair of adjacent field oxide regions to outwardly expose substrate active area between the pair of field oxide regions.

A semiconductor processing method of forming a pair of adjacent field oxide regions on a semiconductor substrate comprising the following steps:

• providing a pair of etched Ge layers over a substrate, individual Ge layers being provided between the substrate and respective adjacent nitride masking blocks overlying desired active area regions of the substrate, individual Ge layers having exposed sidewalls;
• providing oxidation rate restricting layers over the Ge sidewalls;
• oxidizing portions of the substrate unmasked by the nitride masking blocks to form at least one pair of adjacent SiO.sub.2 field oxide regions on the substrate;
• and
• stripping the nitride masking blocks and the Ge layers or any oxidation product therefrom from the substrate between the pair of adjacent field oxide regions to outwardly expose substrate active area between the pair of field oxide regions.

A semiconductor processing method of forming field oxide regions on a semiconductor substrate comprising the following steps:

• forming a pair of etched Ge layers over a substrate, individual Ge layers being formed between the substrate and respective adjacent nitride masking blocks overlying desired active area regions of the substrate, individual Ge layers having exposed sidewalls;
• forming oxidation rate restricting layers over the Ge sidewalls;
• oxidizing portions of the substrate unmasked by the nitride masking blocks to form at least one pair of adjacent SiO.sub.2 field oxide regions on the substrate;
• and
• stripping the nitride masking blocks and the Ge layers or any oxidation product therefrom from the substrate between the pair of adjacent field oxide regions to outwardly expose substrate active area between the pair of field oxide regions.

A semiconductor processing method of forming a pair of adjacent field oxide regions on a semiconductor substrate, the method comprising the following steps:

• providing a sacrificial pad oxide layer over a semiconductor substrate;
• providing a layer comprising Ge over the pad oxide layer;
• providing a patterned nitride oxidation masking layer over the Ge layer to define at least one pair of adjacent nitride masking blocks overlying desired active area regions of the substrate;
• etching exposed portions of the Ge layer inwardly to and through the pad oxide layer and thereby outwardly exposing the substrate and defining exposed sidewall edges of the Ge layer;
• after exposing the substrate and the sidewall edges of the Ge layer, etching laterally into the Ge layer to laterally recess the Ge layer relative the masking nitride layer and the pad oxide layer;
• providing an oxidation restriction layer over the respective Ge sidewalls, the oxidation restriction layer restricting rate of oxidation of the Ge layer from what would otherwise occur if the oxidation restriction layer were not present;
• oxidizing portions of the substrate unmasked by the masking layer to form at least one pair of adjacent SiO.sub.2 field oxide regions on the substrate;
• stripping the patterned masking layer from the substrate;
• after stripping the masking layer, stripping the Ge layer or any oxidation product therefrom from the substrate selectively relative to SiO.sub.2 ;
• and
• after stripping the Ge layer or any oxidation product therefrom, stripping the pad oxide and any other oxide from the substrate between the pair of adjacent field oxide regions to outwardly expose substrate active area between the pair of field oxide regions.