Semiconductor device
View Patent ↗In a semiconductor device including a capacitor which has an upper electrode, a polycrystalline silicon layer on the upper electrode, and a metallic member on the polycrystalline silicon layer, the polycrystalline silicon layer includes germanium so that an upper portion of the polycrystalline silicon layer is lower than a lower portion thereof in a concentration of germanium.
1. A semiconductor device comprising:
a lower electrode formed over a semiconductor substrate;
a dielectric film formed on the lower electrode;
an upper electrode formed on the dielectric film;
a polycrystalline silicon layer formed on the upper electrode; and
a metallic member contacted with an upper surface of the polycrystalline silicon layer;
wherein a concentration of germanium in an upper portion of the polycrystalline silicon layer is lower than that in a lower portion of the polycrystalline silicon layer.
2. The semiconductor device as claimed in claim 1 , wherein the lower electrode has a cylindrical shape.
3. The semiconductor device as claimed in claim 2 , wherein the polycrystalline silicon layer is filled within a concave portion of the upper electrode which is located within a concave portion of the lower electrode.
4. The semiconductor device as claimed in claim 1 , wherein the polycrystalline silicon layer has a thickness which is 20 nm or more.
5. The semiconductor device as claimed in claim 1 , wherein the polycrystalline silicon layer includes boron.
6. The semiconductor device as claimed in claim 1 , wherein the upper electrode includes a metallic film.
7. The semiconductor device as claimed in claim 1 , wherein the metallic member is a metallic contact plug which is located over the lower electrode.
8. The semiconductor device as claimed in claim 1 , wherein the dielectric film includes a metal oxide film.
9. The semiconductor device as claimed in claim 8 , wherein the metal oxide film includes at least one oxide film selected from a group consisting of a titanium oxide film, a zirconium oxide film, a hafnium oxide film, and an aluminum oxide film.
10. The semiconductor device as claimed in claim 1 , wherein the metallic member includes tungsten.
11. The semiconductor device as claimed in claim 2 ,
wherein a width of a plane cross section of an upper end portion of the lower electrode is larger than a width of a plane cross section of a bottom end portion thereof.
12. The semiconductor device as claimed in claim 2 , wherein a width of a plane cross section of the lower electrode simply increased from a bottom end portion of the lower electrode towards a top end portion of the lower electrode.
13. The semiconductor device as claimed in claim 12 , wherein the metallic member is a metallic contact plug which is located over the lower electrode.
14. A semiconductor device comprising:
a cylindrical lower electrode formed over a semiconductor substrate;
a dielectric film formed on the cylindrical lower electrode;
an upper electrode formed on the dielectric electrode;
a polycrystalline silicon layer which is laminated on the upper electrode; and
a metallic contact plug which is located over the cylindrical lower electrode and which electrically connects the upper electrode to a metal wiring layer,
wherein a concentration of germanium in an upper portion of the polycrystalline silicon layer is lower than that in a lower portion of the polycrystalline silicon layer.
15. The semiconductor device as claimed in claim 14 , wherein the upper electrode includes a metal film.
16. The semiconductor device as claimed in claim 14 , wherein the dielectric film includes a metal oxide film.
17. The semiconductor device as claimed in claim 16 , wherein the metal oxide film includes at least one oxide film selected from a group consisting of a titanium oxide film, a zirconium oxide film, a hafnium oxide film, and an aluminum oxide film.
18. The semiconductor device as claimed in claim 14 , wherein the metallic contact plug includes tungsten.
19. The semiconductor device as claimed in claim 14 ,
wherein a width of a plane cross section of an upper end portion of the lower electrode is larger than a width of a plane cross section of a bottom end portion thereof.
20. The semiconductor device as claimed in claim 14 , wherein a width of a plane cross section of the lower electrode simply increased from a bottom end portion of the lower electrode towards a top end portion of the lower electrode.