Spin-on-glass filled trench isolation method for semiconductor circuits

Claim 3

The method in claim 1, wherein step h) comprises the steps of: masking portions of said spin-on-glass layer over said trench regions with negative imaging to expose portions of said spin-on-glass layer covering active regions of the semiconductor circuit; removing said portions of said spin-on-glass layer covering said active regions; and stripping said silicon nitride layer.

Claim 4

The method of claim 1, wherein said substrate comprises monocrystalline silicon.

Claim 5

The method of claim 1, wherein the trench regions have a depth of up to approximately 0.5 micrometers.

Claim 6

The method of claim 1, wherein said step f) is carried out in an environment of about 10% oxygen by volume.

Claim 7

The method in claim 1, wherein step g) is carried out in an environment of steam.

Claim 8

The method in claim 1, further comprising the step of depositing, by a chemical vapor deposition process, a first oxide layer in said trench regions, before said step e).

Claim 9

The method in claim 7, further comprising the step of, depositing by a chemical vapor deposition process, a second oxide layer on said oxidized SOG layer, after said step h).

Claim 10

The method in claim 1, wherein the silicon oxide layer has a thickness of at least 100 angstroms.

Claim 11

The method of claim 1, wherein said trench regions have a width in the range of about 0.5 to 10 micrometers.

Claim 12

The method in claim 1, wherein in step g) said SOG layer is oxidized for about 15 minutes.

Claim 13

The method in claim 1, wherein said spin-on-glass layer includes a siloxane polymer.

Claim 14

The method in claim 1, wherein the spin-on-glass layer includes a silicate polymer.

Claim 15

A spin-on-glass-filled trench isolation method, the method comprising the steps of: a) forming a silicon oxide layer over the surface of a substrate; b) depositing a layer of silicon nitride overlying said silicon oxide layer; c) forming and patterning a photoresist layer over said silicon nitride layer; d) etching said silicon nitride layer and said silicon oxide layer to form openings exposing portions of said substrate; e) forming trench regions in said openings; f) removing said photoresist layer; g) filling said trench regions with spin-on-glass to form a spin-on-glass layer in said trenches and over said silicon nitride layer; h) heating said spin-on-glass layer at a temperature of about 1,000° C. in an environment of 10% oxygen by volume to form a cured and annealed spin-on-glass layer; i) heating said cured and annealed spin-on-glass layer at a temperature of about 900° C. in an environment of steam to form an oxidized spin-on-glass layer having an etch rate of less than about 350 Å/minute in a 10 parts by volume of water and 1 part by volume of hydrofluoric acid etchant at a temperature of about 25° C.; j) selectively forming and patterning a negative photoresist layer on said oxidized spin-on-glass layer over said trench regions; k) etching said oxidized spin-on-glass layer in regions other than said trench regions; l) removing said negative photoresist layer; and m) removing said silicon nitride layer.

Claim 16

A spin-on-glass-filled trench isolation method, the method comprising the steps of: a) forming a silicon oxide layer over the surface of a substrate; b) depositing a layer of silicon nitride overlying said silicon oxide layer; c) forming and patterning a photoresist layer over said silicon nitride layer; d) etching said silicon nitride layer and said silicon oxide layer to form openings exposing portions of said substrate; e) forming trench regions in said openings; f) removing said photoresist layer; g) filling said trench regions with spin-on-glass to form a spin-on-glass layer in said trenches and over said silicon nitride layer; h) heating said spin-on-glass layer at a temperature of about 1,000° C. in an environment of 10% oxygen by volume to form a cured and annealed spin-on-glass layer; i) heating said cured and annealed spin-on-glass layer at a temperature of about 900° C. in an environment of steam to form an oxidized spin-on-glass layer having an etch rate of less than about 350 Å/minute in a 10 parts by volume of water and 1 part by volume of hydrofluoric acid etchant at a temperature of about 25° C.; j) selectively forming and patterning a negative photoresist layer on said oxidized spin-on-glass layer over said trench regions; k) etching said oxidized spin-on-glass layer in regions other than said trench regions; l) removing said negative photoresist layer; and m) removing said silicon nitride layer.

Claim 17

The method of claim 14, wherein said substrate comprises monocrystalline silicon.

Claim 18

The method of claim 14, wherein the trench regions have a depth of up to approximately 0.5 micrometers.

Claim 19

The method of claim 14, wherein said step h) is carried out in an environment of about 10% oxygen by volume.

Claim 20

The method in claim 14, wherein step i) is carried out in an environment containing steam.

Claim 21

The method in claim 15, further comprising the step of, depositing by a chemical vapor deposition process, a second oxide layer on said oxidized spin-on-glass layer, after said step m).

Claim 22

The method in claim 14, wherein the silicon oxide layer has a thickness of at least 100 angstroms.

Claim 23

The method of claim 14, wherein said trench regions have a width in the range of about 0.5 to 10 micrometers.

Claim 24

The method in claim 14, wherein in step i) said spin-on-glass layer is oxidized for about 15 minutes.

Claim 25

The method in claim 14, wherein said spin-on-glass polymer is a siloxane polymer.

Claim 26

The method in claim 14, wherein said spin-on glass polymer is a silicate polymer.

Claim 27

The method of claim 1, wherein said oxidized SOG layer has an etch rate approximately the same as that of a thermally grown oxide on silicon.

Claim 28

The method of claim 14, wherein said oxidized spin-on-glass layer has an etch rate approximately the same as that of a thermally grown oxide on silicon.

Claim 29

A spin-on-glass-filled trench isolation method, the method comprising the steps of: a) forming a silicon oxide layer over the surface of a substrate; b) depositing a layer of silicon nitride overlying said silicon oxide layer; c) forming and patterning a photoresist layer over said silicon nitride layer; d) etching said silicon nitride layer and said silicon oxide layer to form openings exposing portions of said substrate; e) forming trench regions in said openings; f) removing said photoresist layer; g) depositing by a chemical vapor deposition process, a first oxide layer in said trench regions; h) filling said trench regions with spin-on-glass to form a spin-on-glass layer in said trenches and over said silicon nitride layer; i) heating said spin-on-glass layer at a temperature of about 1,000° C. in an environment of 10% oxygen by volume to form a cured and annealed spin-on-glass layer; j) heating said cured and annealed spin-on-glass layer at a temperature of about 900° C. in an environment of steam to form an oxidized spin-on-glass layer having an etch rate of less than about 350 Å/minute in a 10 parts by volume of water and 1 part by volume of hydrofluoric acid etchant at a temperature of about 25° C.; k) selectively forming and patterning a negative photoresist layer on said oxidized spin-on-glass layer over said trench regions; l) etching said oxidized spin-on-glass layer in regions other than said trench regions; m) removing said negative photoresist layer; and n) removing said silicon nitride layer.

Claim 30

A spin-on-glass-filled trench isolation method, the method comprising the steps of: a) forming a silicon oxide layer over the surface of a substrate; b) depositing a layer of silicon nitride overlying said silicon oxide layer; c) forming and patterning a photoresist layer over said silicon nitride layer; d) etching said silicon nitride layer and said silicon oxide layer to form openings exposing portions of said substrate; e) forming trench regions in said openings; f) removing said photoresist layer; g) depositing by a chemical vapor deposition process, a first oxide layer in said trench regions; h) filling said trench regions with spin-on-glass to form a spin-on-glass layer in said trenches and over said silicon nitride layer; i) heating said spin-on-glass layer at a temperature of about 1,000° C. in an environment of 10% oxygen by volume to form a cured and annealed spin-on-glass layer; j) heating said cured and annealed spin-on-glass layer at a temperature of about 900° C. in an environment of steam to form an oxidized spin-on-glass layer having an etch rate of less than about 350 Å/minute in a 10 parts by volume of water and 1 part by volume of hydrofluoric acid etchant at a temperature of about 25° C.; k) selectively forming and patterning a negative photoresist layer on said oxidized spin-on-glass layer over said trench regions; l) etching said oxidized spin-on-glass layer in regions other than said trench regions; m) removing said negative photoresist layer; and n) removing said silicon nitride layer.