Method of manufacturing a semiconductor device
First Claim
Patent Images
1. A method of manufacturing a semiconductor device comprising the steps of:
- forming a trench in a semiconductor substrate;
forming an insulating film on an inner wall and a bottom surface of said trench;
filling said trench with a first semiconductor layer containing an impurity;
removing a portion of said insulating film from an upper portion of said inner wall of said trench;
using selective epitaxial growth for growing a second semiconductor layer on said semiconductor substrate, including said upper portion of said inner wall of said trench, and said first semiconductor layer;
diffusing the impurity in said first semiconductor layer to form a diffusion layer in said second semiconductor layer; and
forming a MOSFET having source and drain regions on said second semiconductor layer, one of said source and drain regions overlapping with said diffusion layer.
0 Assignments
0 Petitions
Accused Products
Abstract
In formation of a DRAM, a silicon nitride film is used as a mask to simultaneously expose a semiconductor substrate serving as an active region where an MOSFET is formed and a portion of the periphery of a trench. Therefore, even if the alignment offset of a resist pattern occurs, an interval between adjacent memory cells does not change. The interval between the adjacent memory cells is constantly the same as that when no alignment offset of the resist patter occurs. That is, only an n-type diffusion layer of the memory cell formed at a position adjacent to the trench comes close to source and drain regions of the adjacent memory cell.
-
Citations
9 Claims
-
1. A method of manufacturing a semiconductor device comprising the steps of:
-
forming a trench in a semiconductor substrate; forming an insulating film on an inner wall and a bottom surface of said trench; filling said trench with a first semiconductor layer containing an impurity; removing a portion of said insulating film from an upper portion of said inner wall of said trench; using selective epitaxial growth for growing a second semiconductor layer on said semiconductor substrate, including said upper portion of said inner wall of said trench, and said first semiconductor layer; diffusing the impurity in said first semiconductor layer to form a diffusion layer in said second semiconductor layer; and forming a MOSFET having source and drain regions on said second semiconductor layer, one of said source and drain regions overlapping with said diffusion layer. - View Dependent Claims (2, 3)
-
-
4. A method of making a semiconductor memory device comprising the steps of:
-
forming a first insulating film over a semiconductor substrate; forming a trench in said semiconductor substrate through said first insulating film; forming a second insulating film over an inner wall and a bottom surface of said trench; filling said trench with a first semiconductor layer doped with an impurity; forming a third insulating film on said first semiconductor layer; depositing a fourth insulating film over said first insulating film and said third insulating film; using said fourth insulating film as a mask, removing a portion of said first insulating film and said third insulating film so as to expose a portion of said semiconductor substrate and said first semiconductor layer; forming a second semiconductor layer on said exposed portion of said semiconductor substrate and said exposed portion of said first semiconductor layer; diffusing the impurity from said first semiconductor layer into said second semiconductor layer to form a diffusion layer; and forming a transistor having source and drain regions on said second semiconductor layer, one of said source and drain regions of said transistor overlapping with said diffusion layer. - View Dependent Claims (5, 6, 7, 8, 9)
-
Specification