Semiconductor device and process for producing the same
First Claim
Patent Images
1. A process for producing a semiconductor device, which comprises the following steps:
- a step of forming a first oxide film on a circuit forming side of a semiconductor substrate by a first oxidizing process of the semiconductor substrate, a step of forming an anti-oxidation film on the first oxide film, a step of forming a photoresist film on the anti-oxidation film, a step of removing a portion of the photoresist film, a step of removing portions of the anti-oxidation film and the first oxide film, a step of trenching a groove on the semiconductor substrate in a portion of the semiconductor substrate from which the first oxide film is removed, a step of removing another portion of the photoresist film on the antioxidation film, a step of forming a space by recessing the first oxide film to an extent of 5 nm to 40 nm from an element isolation region, a step of forming a second silicon oxide film in the space and on an inside wall of the groove by a second oxidizing process of the semiconductor substrate, wherein the radius of curvature of the semiconductor substrate around an upper edge of the groove is 3 nm or more, a step of embedding an element isolation film on the second oxide film in the groove, a step of removing the anti-oxidation film and the first oxide film on the semiconductor substrate, and a step of forming a gate dielectric film and a gate electrode on a portion of the semiconductor substrate from which the first oxide film is removed.
6 Assignments
0 Petitions
Accused Products
Abstract
A process of producing a semiconductor device having a highly reliable groove isolation structure with a desired radius of curvature formed at the groove upper edge and without formation of any step. The device is produced by reducing the stress generation around the groove upper edge of an element isolation groove on a semiconductor substrate, thereby optimizing the shape of an element isolation groove and making the device finer and improving the device electric characteristics.
-
Citations
21 Claims
-
1. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a first oxide film on a circuit forming side of a semiconductor substrate by a first oxidizing process of the semiconductor substrate, a step of forming an anti-oxidation film on the first oxide film, a step of forming a photoresist film on the anti-oxidation film, a step of removing a portion of the photoresist film, a step of removing portions of the anti-oxidation film and the first oxide film, a step of trenching a groove on the semiconductor substrate in a portion of the semiconductor substrate from which the first oxide film is removed, a step of removing another portion of the photoresist film on the antioxidation film, a step of forming a space by recessing the first oxide film to an extent of 5 nm to 40 nm from an element isolation region, a step of forming a second silicon oxide film in the space and on an inside wall of the groove by a second oxidizing process of the semiconductor substrate, wherein the radius of curvature of the semiconductor substrate around an upper edge of the groove is 3 nm or more, a step of embedding an element isolation film on the second oxide film in the groove, a step of removing the anti-oxidation film and the first oxide film on the semiconductor substrate, and a step of forming a gate dielectric film and a gate electrode on a portion of the semiconductor substrate from which the first oxide film is removed. - View Dependent Claims (2)
-
-
3. A process for producing a semiconductor device, which comprises the following steps:
-
(a) a step of thermally oxidizing a semiconductor substrate, thereby forming a first silicon oxide film as a pad oxide film on a surface of the semiconductor substrate, (b) a step of depositing a silicon nitride film as an anti-oxidation film on the first silicon oxide film, (c) a step of etching the silicon nitride film at a desired portion, (d) a step of etching the first silicon oxide film at the etched portion of the silicon nitride film, (e) a step of forming a groove having a space which is formed by recessing the first silicon oxide film to an extent of 5 nm to 40 nm on the surface of the semiconductor substrate at and around the portion in which the first silicon oxide film is etched, (f) a step of thermally oxidizing the semiconductor substrate, thereby forming a second silicon oxide film in the space and on the inside wall of the groove, (g) a step of depositing a third silicon oxide film on the surface of the semiconductor substrate, thereby embedding the third silicon oxide film in the groove, wherein the radius of curvature of the semiconductor substrate around an upper edge of the groove is 3 nm or more, (h) a step of removing the third silicon oxide film on the silicon nitride film, while leaving the third silicon oxide film in the groove, thereby forming an element isolation groove embedded on the third silicon oxide film, (i) a step of removing the silicon nitride film and said first silicon oxide film, and (j) a step of forming a semiconductor element in an active region at the semiconductor substrate.
-
-
4. A process for producing a semiconductor device, which comprises the following steps:
-
(a) a step of forming a first oxide film on a circuit forming side of a semiconductor substrate by a first oxidizing process of the semiconductor substrate, (b) a step of forming an anti-oxidation film on the first oxide film, (c) a step of removing the anti-oxidation film at a desired portion, (d) a step of removing the first oxide film at the portion of the anti-oxidation film removed, (e) a step of forming a groove having a space formed by recessing the first oxide film to an extent of 5 nm to 40 nm in and around a portion of the semiconductor substrate in which the first oxide film is etched, (f) a step of forming a second oxide film in the space and on an inside wall of the groove by a second oxidizing process of the semiconductor substrate, wherein the radius of curvature of the semiconductor substrate around an upper edge of the groove is 3 nm or more, (g) a step of embedding an isolation film on the second oxide film in the groove, (h) a step of removing the anti-oxidation film and said first oxide film, and (i) a step of forming a gate dielectric film and a gate electrode in an active region of the semiconductor substrate.
-
-
5. A process for producing a semiconductor device, which comprises the following steps:
-
(a) a step of forming a first oxide film on a circuit forming side of a semiconductor substrate by a first oxidizing process of the semiconductor substrate, (b) a step of forming an anti-oxidation film on the first oxide film, (c) a step of removing portions of the anti-oxidation film and the first oxide film at desired portions, (d) a step of forming a groove having a space by recessing the first oxide film to an extent of 5 nm to 40 nm in and around a portion of the semiconductor substrate where the first oxide film is removed, (e) a step of forming a second oxide film in the space and on an inside wall of the groove by a second oxidizing process of the semiconductor substrate, wherein the radius of curvature of the semiconductor substrate around an upper edge of the groove is 3 nm or more, (f) a step of embedding an isolation film on the second oxide film in the groove, (g) a step of removing the anti-oxidation film and said first oxide film on the semiconductor substrate, and (h) a step of forming a gate dielectric film and a gate electrode on the portion of the semiconductor substrate from which the first oxide film is removed.
-
-
6. A process for producing a semiconductor device, which comprises the following steps:
-
(a) a step of forming a pad oxide film on a circuit forming side of a semiconductor substrate, followed by formation of an anti-oxidation film on the pad oxide film, (b) a step of removing the anti-oxidation film and the pad oxide film from predetermined portions, and forming a groove having a predetermined depth and a space which is formed by recessing the pad oxide film to an extent of 5 mm to 40 nm, (c) a step of oxidizing a surface of the groove, said groove having a radius of curvature of the semiconductor substrate around an upper edge of the groove of 3 nm or more and being formed on the semiconductor substrate having the recessed pad oxide film, so as to form an oxide film which is embedded in the inside of the oxidized groove as an embedded insulating film, (d) a step of removing the embedded insulating film on the anti-oxidation film, followed by removing the anti-oxidation film on the circuit forming side of the semiconductor substrate, (e) a step of removing the pad oxide film formed on the circuit forming side of the semiconductor substrate, and (f) a step of forming a gate insulating film and a gate electrode on the circuit forming side of the semiconductor substrate from which the pad oxide film is removed. - View Dependent Claims (7, 8, 9)
-
-
10. A process for producing a semiconductor device, which comprises the following steps;
-
(a) a step of forming a pad oxide film on a circuit forming side of a semiconductor substrate, followed by formation of an anti-oxidation film on the pad oxide film, (b) a step of removing the anti-oxidation film and the pad oxide film from desired portions, forming a groove having a predetermined depth and a space which is formed by recessing the pad oxide film to an extent of 5 nm to 40 nm, (c) a step of oxidizing the groove having the recessed pad oxide film on the semiconductor substrate in an oxidation atmosphere with a gas ratio of H2/O2 of 0.5 or less to form an embedded insulating film in the inside of the oxidized groove, (d) a step of removing the embedded insulating film formed on the anti-oxidation film, followed by removal of the anti-oxidation film formed on the circuit forming side of the semiconductor substrate, (e) a step of removing the pad oxide film formed on the circuit forming side of the semiconductor substrate, and (f) a step of forming a gate insulating film and a gate electrode on the circuit forming side of the semiconductor substrate from which the pad oxide film is removed.
-
-
11. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a first oxide film on a semiconductor substrate, a step of forming a silicon nitride film on the first oxide film, a step of selectively removing the silicon nitride film using a photoresist having a desired pattern, a step of selectively removing the first oxide film using the photoresist having a desired pattern to expose the surface of the semiconductor substrate selectively, a step of forming a groove in accordance with the predetermined pattern of the photoresist by selectively removing the exposed semiconductor substrate surface, a step of oxidizing selectively an inside surface of the groove and the semiconductor substrate surface using the silicon nitride film as a mask in a state wherein the first oxide film at a periphery of the groove is recessed by 5 to 40 rim from an edge of the groove to form the groove having a radius of curvature of the semiconductor substrate at an upper edge portion of 3 nm or more, a step of depositing an insulating film on the Inside of the groove formed by the oxidation, a step of removing the silicon nitride film formed outside of the groove on the semiconductor substrate, a step of removing the first oxide film formed outside of the groove on the semiconductor substrate, and a step of forming a gate insulating film and a gate electrode on the semiconductor substrate from which the first oxide film is removed. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a plurality of first regions comprising a laminate of a first oxide film and an anti-oxidation film on a semiconductor substrate via a second region wherein the semiconductor substrate is exposed, a step of forming a concave region by removing the semiconductor substrate surface in the second region so as to make it lower than the substrate surface and equipped with a region wherein the first oxide film in the first region is narrowed by 5 nm to 40 nm from the boundary of the second region at an upper portion periphery, a step of conducting selective thermal oxidation of the concave region surface of the second region and the narrowed portion of the semiconductor substrate surface while retaining the anti-oxidation film to form the concave region having a semiconductor substrate concave region end with a radius of curvature of 3 nm or more, a step of burying a space on the second oxide film formed by the thermal oxidation of the concave region with an insulating film, a step of removing the anti-oxidation film and the first oxide film formed on the semiconductor substrate outside of the groove, and a step of forming a gate insulating film and a gate electrode on the semiconductor substrate from which the first oxide film is removed. - View Dependent Claims (18)
-
-
17. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a first oxide film on a main surface of a semiconductor substrate, a step of forming an anti-oxidation film on the first oxide film, a step of removing the anti-oxidation film and the first oxide film from desired portions wherein an element isolation region is to be formed, a step of forming a groove having an upper edge surrounding a space obtained by removing the first oxide film by etching and recessing 5 nm to 40 nm from an end of the anti-oxidation film on the semiconductor substrate exposed surface obtained by removing the first oxide film and the anti-oxidation film, a step of forming the groove having a space containing a second oxide film and a radius of curvature of 3 nm or more at an upper edge portion of the semiconductor substrate, a step of burying the groove by depositing a third oxide film on the second oxide film, a step of removing the anti-oxidation film and the first oxide film on the semiconductor substrate, and a step of forming a gate insulating film and a gate electrode on the semiconductor substrate, from which the first oxide film is removed.
-
-
19. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a pad oxide film on a circuit forming side of a semiconductor substrate by a first thermal oxidation, a step of forming an anti-oxidation film on the pad oxide film, a step of removing partially the anti-oxidation film and the pad oxide film from a region wherein an element isolation region is to be formed, a step of forming a groove in a region on the semiconductor substrate surface from which the anti-oxidation film and the pad oxide film are removed, a step of forming a space at an area outside of the groove by recessing the pad oxide film by 5 nm to 40 nm, a step of forming the space having a thermal oxide film by second thermal oxidation of the semiconductor substrate, the said groove having a radius of curvature of 3 nm or more at an upper edge portion of the semiconductor substrate, a step of burying an embedded insulating film on the thermal oxide film in the groove, a step of removing the anti-oxidation film and the pad oxide film formed on the circuit forming side of the semiconductor substrate, and a step of forming a gate insulating film and a gate electrode on the circuit forming side of the semiconductor substrate from which the pad oxide film is removed.
-
-
20. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a pad oxide film by a first thermal oxidation of a surface of a silicon substrate, a step of forming a silicon nitride film thicker than the pad oxide film on the pad oxide film, a step of forming a photoresist on the silicon nitride film, a step of removing the photoresist in a desired position by exposure to light, a step of removing the silicon nitride film from said desired position, a step of removing the pad oxide film from said desired position, a step of removing the exposed silicon substrate surface on said desired position to form a groove, a step of removing the photoresist positioned on the silicon nitride film, a step of recessing at a distance of 5 nm to 40 nm from the boundary of the pad oxide film formed by the removal of the pad oxide film, a step of conducting a second thermal oxidation of the recessed region and the formed groove to form the recessed region having a thermal oxide film, said groove having a radius of curvature of 3 nm or more at an upper edge portion of the semiconductor substrate, a step of depositing an embedded insulating film on the thermal oxide film and the silicon nitride film, a step of heat-treating the silicon substrate on which the embedded insulating film is formed, a step of removing the embedded insulating film formed on the silicon nitride film and a part of the silicon nitride film, a step of removing a remaining portion of the silicon nitride film formed on the pad oxide film, a step of removing the pad oxide film positioned in a region from which the silicon nitride film is removed, and a step of forming a gate insulating film and a gate electrode on the silicon substrate from which the pad oxide film is removed.
-
-
21. A process for producing a semiconductor device, which comprises the following steps:
-
a step of forming a pad oxide film on a circuit forming side of a semiconductor substrate by a first thermal oxidation, a step of forming an anti-oxidation film on the pad oxide film, a step of partially removing the anti-oxidation film and the pad oxide film in a region wherein an element isolation is to be formed, a step of forming a groove in the region from which the anti-oxidation film and the pad oxide film are removed, a step of forming a space outside of the groove by recessing the pad oxide film by 5 to 40 nm by etching, a step of forming a thermal oxide film in the space and the groove by a second thermal oxidation of the semiconductor substrate and forming the groove covered with the thermal oxide film to have a radius of curvature of 3 nm or more at an upper edge portion of the semiconductor substrate, a step of depositing an embedded insulating film on the thermal oxide film of the groove and the anti-oxidation film, a step of removing the embedded insulating film formed on the anti-oxidation film and a part of the anti-oxidation film by chemical mechanical polishing, a step of removing the anti-oxidation film on the pad oxide film which is retained without removing, a step of removing the pad oxide film in a region from which the anti-oxidation film is removed, and a step of forming a gate insulating film and a gate electrode on the circuit forming side of the semiconductor substrate in the region from which the pad oxide film is removed.
-
Specification