Method of manufacturing a semiconductor device
View Patent ↗In a method of manufacturing a semiconductor device, a body region is formed in an epitaxial layer provided on a semiconductor substrate. A part of a semiconductor material forming the body region surface is removed to form a convex-type contact region protruding from the body region surface and to form a shallow trench surrounding the convex-type contact region. A deep trench region is formed so as to extend from the shallow trench surface to inside of the epitaxial layer. A gate insulating film is formed on an inner wall of the deep trench region which is filled with polycrystalline silicon that is held in contact with the gate insulating film. A source region and a body contact region are formed in the shallow trench and the convex-type contact region, respectively, and a silicide layer is formed to connect the source region and the body contact region to each other.
1. A method of manufacturing a semiconductor device, comprising:
forming, on a semiconductor substrate of a first conductivity type, a buried layer of a second conductivity type;
forming an epitaxial layer of the second conductivity type on the buried layer;
forming a body region of the first conductivity type at a certain depth from a surface of the epitaxial layer of the second conductivity type;
selectively lowering a surface of the body region to form a convex-type contact region which protrudes from the lowered surface of the body region and form a shallow trench around the convex-type contact region;
forming a deep trench region in the shallow trench so as to extend from a part of the lowered surface of the body region to inside of the epitaxial layer of the second conductivity type;
forming a gate insulating film on an inner wall of the deep trench region;
filling the deep trench region with polycrystalline silicon so that the polycrystalline silicon is held in contact with the gate insulating film;
forming a source region of the second conductivity type in the shallow trench in the surface of the body region;
forming a body contact region of the first conductivity type in the convex-type contact region on the surface of the body region; and
forming a silicide layer for connecting the source region and the body contact region to each other,
wherein the body contact region comprises an entire surface of the convex-type contact region, and the entire surface and a surface of the source region are covered with the silicide layer.
2. A method of manufacturing a semiconductor device according to claim 1 , wherein the shallow trench has a depth in a range of 200 nm to 600 nm.
3. A method of manufacturing a semiconductor device according to claim 1 , wherein the forming of the shallow trench comprises:
forming a LOCOS oxide film; and
removing a part of the LOCOS oxide film.
4. A method of manufacturing a semiconductor device according to claim 3 , wherein the LOCOS oxide film has a thickness in a range of 50 nm to 150 nm.
5. A method of manufacturing a semiconductor device according to claim 1 , wherein the convex-type contact region is made only from a silicon material.
6. A method of manufacturing a semiconductor device, comprising:
forming a buried layer of a second conductivity type on a semiconductor substrate of a first conductivity type;
forming an epitaxial layer of the second conductivity type on the buried layer;
forming a body region of the first conductivity type at a certain depth from a surface of the epitaxial layer;
removing part of a semiconductor material forming the surface of the body region so as to lower the surface of the body region and form a convex-type contact region protruding from the lowered surface of the body region and form a shallow trench around the convex-type contact region;
forming a deep trench region in the shallow trench so as to extend from a part of the lowered surface of the body region to inside of the epitaxial layer;
forming a gate insulating film on an inner wall of the deep trench region;
filling the deep trench region with polycrystalline silicon so that the polycrystalline silicon is held in contact with the gate insulating film;
forming a source region of the second conductivity type in the shallow trench;
forming a body contact region of the first conductivity type in the convex-type contact region; and
forming a silicide layer for connecting the source region and the body contact region to each other,
wherein the body contact region comprises an entire surface of the convex-type contact region, and the entire surface and a surface of the source region are covered with the silicide layer.
7. A method of manufacturing a semiconductor device according to claim 6 , wherein the shallow trench has a depth in a range of 200 nm to 600 nm.
8. A method of manufacturing a semiconductor device according to claim 6 , wherein the forming of the shallow trench comprises: forming a LOCOS oxide film; and removing a part of the LOCOS oxide film.
9. A method of manufacturing a semiconductor device according to claim 8 , wherein the LOCOS oxide film has a thickness in a range of 50 nm to 150 nm.
10. A method of manufacturing a semiconductor device according to claim 6 , wherein the convex-type contact region is made only from a silicon material.
11. A method of manufacturing a semiconductor device, comprising:
forming an epitaxial layer on a buried layer provided on a semiconductor substrate;
forming a body region in the epitaxial layer at a preselected depth from a surface of the epitaxial layer;
selectively lowering a surface of the body region to form a convex-type contact region protruding from the lowered surface of the body region and form a shallow trench around the convex-type contact region;
forming a deep trench region in the shallow trench so as to extend from a part of the lowered surface of the body region to inside of the epitaxial layer;
forming a gate insulating film on an inner wall of the deep trench region;
filling the deep trench region with polycrystalline silicon so that the polycrystalline silicon is held in contact with the gate insulating film;
forming a source region in the shallow trench;
forming a body contact region in the convex-type contact region; and
forming a silicide layer on the source region and the body contact region to connect the source region and the body contact region to one another.
12. A method of manufacturing a semiconductor device according to claim 11 , wherein the shallow trench has a depth in a range of 200 nm to 600 nm.
13. A method of manufacturing a semiconductor device according to claim 11 , wherein the forming of the shallow trench comprises: forming a LOCOS oxide film; and removing a part of the LOCOS oxide film.
14. A method of manufacturing a semiconductor device according to claim 13 , wherein the LOCOS oxide film has a thickness in a range of 50 nm to 150 nm.
15. A method of manufacturing a semiconductor device according to claim 11 , wherein the semiconductor substrate, the body region, and the body contact region have a first conductivity type; and wherein the buried layer, the epitaxial layer, and the source region have a second conductivity type different from the first conductivity type.
16. A method of manufacturing a semiconductor device according to claim 11 , wherein the body contact region comprises an entire surface of the convex-type contact region.
17. A method of manufacturing a semiconductor device according to claim 16 , wherein the silicide layer is formed so as to cover the entire surface of the convex-type contact region and a surface of the source region.