Dielectric-filled-groove isolation structures for semiconductor devices

Claim 1

A method of producing a semiconductor device having a dielectric-filled-groove isolation structure, in which method an isolation groove is formed in a silicon substrate, silicon oxide is formed inside the groove, the groove is filled with dielectric material and the filling of the groove levelled with the surface of the substrate in which the groove is formed; the method comprising the steps of:- (a) forming a first silicon oxide layer on the substrate and a first silicon nitride layer on the first silicon oxide layer; (b) selectively removing both the first silicon oxide layer and the first silicon nitride layer from above a region of the substrate in which an isolation groove is to be formed, and from above a specified region surrounding that groove formation region, said specified region having an extent sufficient for preventing a spread of silicon oxidation in subsequent processes; (c) forming a second silicon nitride layer on the substrate; (d) anisotropically etching the second silicon nitride layer, whereby the substrate surface corresponding to the groove formation region is exposed with the second silicon nitride layer remaining on the specified region; (e) etching the exposed substrate to form the isolation groove, using the second silicon nitride layer as a mask; (f) forming a further silicon oxide layer, inside the isolation groove; (g) filling the groove with dielectric material; and (h) removing excess dielectric material for levelling the substrate surface, and forming another silicon oxide layer on the dielectric material.

Claim 2

A method of producing a semiconductor device having a dielectric-filled-groove isolation structure, in which method an isolation groove is formed in a silicon substrate, silicon oxide is formed inside the groove, the groove is filled with dielectric material and the filling of the groove levelled with the surface of the substrate in which the groove is formed; the method comprising the steps of:- (a) forming a first silicon oxide layer on the substrate and a first silicon nitride layer on the first silicon oxide layer; (b) selectively removing both the first silicon oxide layer and the first silicon nitride layer from above a region of the substrate in which an isolation groove is to be formed, and from above a specified region surrounding that groove formation region, said specified region having an extent sufficient for preventing a spread of silicon oxidation in subsequent processes; (c) forming a second silicon nitride layer on the substrate; (d) anisotropically etching the second silicon nitride layer, whereby the substrate surface corresponding to the groove formation region is exposed with the second silicon nitride layer remaining on the specified region; (e) etching the exposed substrate to form the isolation groove, using the second silicon nitride layer as a mask; (f) forming a further silicon oxide layer, inside the isolation groove; (g) filling the groove with dielectric material; and (h) removing excess dielectric material for levelling the substrate surface, and forming another silicon oxide layer on the dielectric material.

Claim 3

A method of producing a semiconductor device having a dielectric-filled-groove isolation structure, in which method an isolation groove is formed in a silicon substrate, silicon oxide is formed inside the groove, the groove is filled with dielectric material and the filling of the groove is levelled with the surface of the substrate in which the groove is formed, the method comprising the steps of:- (a) forming a first silicon oxide layer on the substrate; (b) selectively removing the first silicon oxide layer from above a specified region of the substrate, the specified region surrounding a region of the substrate in which an isolation groove is to be formed and the specified region having an extent sufficient for preventing a spread of silicon oxidation in subsequent processes; (c) forming a silicon nitride layer on the first silicon layer and the substrate where exposed in step (b); (d) etching selectively both the silicon nitride layer and the first silicon oxide layer, so that the substrate surface corresponding to the region in which the isolation groove is to be formed is exposed, leaving the silicon nitride layer over the specified region, with overhanging eaves over the specified region, and above an active region of the substrate; (e) etching the exposed substrate to form the isolation groove, using the silicon nitride layer as a mask; (f) forming a further silicon oxide layer, inside the groove; (g) filling the groove with dielectric material; and (h) removing excess dielectric material for levelling the substrate surface, and forming another silicon oxide layer on the dielectric material.

Claim 4

A method of producing a semiconductor device having a dielectric-filled-groove isolation structure, in which method an isolation groove is formed in a silicon substrate, silicon oxide is formed inside the groove, the groove is filled with dielectric material and the filling of the groove is levelled with the surface of the substrate in which the groove is formed, the method comprising the steps of:- (a) forming a first silicon oxide layer on the substrate; (b) selectively removing the first silicon oxide layer from above a specified region of the substrate, the specified region surrounding a region of the substrate in which an isolation groove is to be formed and the specified region having an extent sufficient for preventing a spread of silicon oxidation in subsequent processes; (c) forming a silicon nitride layer on the first silicon layer and the substrate where exposed in step (b); (d) etching selectively both the silicon nitride layer and the first silicon oxide layer, so that the substrate surface corresponding to the region in which the isolation groove is to be formed is exposed, leaving the silicon nitride layer over the specified region, with overhanging eaves over the specified region, and above an active region of the substrate; (e) etching the exposed substrate to form the isolation groove, using the silicon nitride layer as a mask; (f) forming a further silicon oxide layer, inside the groove; (g) filling the groove with dielectric material; and (h) removing excess dielectric material for levelling the substrate surface, and forming another silicon oxide layer on the dielectric material.

Claim 9

A method as claimed in any preceding claim, wherein the specified region has a width of at least substantially 3,000 Angstrom.