Semiconductor device and semiconductor product
View Patent ↗The embodiments discussed herein reduce, in a semiconductor device having a ferroelectric capacitor, the film thickness of an interlayer insulation film covering the ferroelectric capacitor without degrading yield, and reduce the invasion of water into the ferroelectric capacitor. A semiconductor device includes a first interlayer insulation film formed on a substrate, a ferroelectric capacitor formed on the first interlayer insulation film, a second interlayer insulation film formed on the first interlayer insulation film so as to cover the ferroelectric capacitor, and a hydrogen barrier film formed on the second interlayer insulation film, the ferroelectric capacitor is formed of a lower electrode, a ferroelectric film formed on the lower electrode, an upper electrode formed on the ferroelectric film in contact therewith, and a polish-resistant film formed on the upper electrode, wherein the second interlayer insulation film covers the polish-resistant film with a film thickness of 50-100 nm.
1. A semiconductor device, comprising:
a first interlayer insulation film formed over a substrate;
a ferroelectric capacitor formed over the first interlayer insulation film;
a second interlayer insulation film formed on the first interlayer insulation film so as to cover the ferroelectric capacitor,
wherein
the ferroelectric capacitor includes a lower electrode, a ferroelectric film formed on the lower electrode, an upper electrode formed on the ferroelectric film in contact therewith, and a polish-resistant film formed on the upper electrode,
a top surface of the second interlayer insulation film being coincident to a top surface of the polish-resistant film in the part covering the ferroelectric film, and
the top surface of the second interlayer insulation film causing dishing with a depth of 20% or more with regard to a film thickness of the second interlayer insulation film.
2. The semiconductor device of claim 1 , wherein the upper electrode is formed of a conductive oxide of Ir or Ru.
3. The semiconductor device as claimed in claim 2 , wherein the conductive oxide constituting the upper electrode is characterized by larger oxygen content at a side contacting the ferroelectric film and smaller oxygen content at a side contacting the polish-resistant film.
4. The semiconductor device as claimed in claim 1 , wherein the conductive oxide constituting the upper electrode is characterized by larger oxygen content at a side contacting the ferroelectric film and smaller oxygen content at a side contacting the polish-resistant film.
5. The semiconductor device as claimed in claim 1 , wherein the polish-resistant film is formed of any of Pt, Ir, Ti, TiN, W, Al or SrRuO 3 .
6. The semiconductor device as claimed in claim 1 , wherein the second interlayer insulation film is formed by a plasma CVD process that uses TEOS as a source material.
7. The semiconductor device as claimed in claim 1 , further comprising
a first hydrogen barrier film formed on the second interlayer insulation film.
8. The semiconductor device as claimed in claim 7 , further comprising a third interlayer insulation film formed on the first hydrogen barrier film.
9. A method for fabricating a semiconductor device, the method comprising:
forming a first interlayer insulation film over a substrate;
forming a ferroelectric capacitor including a lower electrode, a ferroelectric film formed on the lower electrode, an upper electrode formed on the ferroelectric film in contact therewith, and a polish-resistant film formed on the upper electrode,over the first interlayer insulation film;
forming a second interlayer insulation film formed over the first interlayer insulation film so as to cover the ferroelectric capacitor
polishing the second interlayer insulation film until the polish-resistant film is exposed so as to form a dishing at the top surface of the second interlayer insulation film with a depth of 20% or more of a film thickness of the second interlayer insulation film.
10. The method for fabricating a semiconductor device as claimed in claim 9 , wherein the polish-resistant film is formed of any of Pt, Ir, Ti, TiN, W, Al or SrRuO 3 .
11. The method for fabricating a semiconductor device as claimed in claim 9 , further comprising:
forming a hydrogen barrier film on the second interlayer insulating film.
12. The method for fabricating a semiconductor device as claimed in claim 9 , further comprising covering a sidewall surface and a top surface of the ferroelectric capacitor with another hydrogen barrier film.
13. The method for fabricating a semiconductor device as claimed in claim 7 , wherein the forming the second interlayer insulation film is conducted by a plasma CVD process that uses TEOS as a source material.
14. The method for fabricating a semiconductor device as claimed in claim 7 , wherein the polishing is conducted by CMP process.
15. The method for fabricating a semiconductor device as claimed in claim 11 , further comprising forming a third interlayer insulation film on said hydrogen barrier film.