Semiconductor device and manufacturing method thereof
View Patent ↗A ferroelectric capacitor including a bottom electrode ( 15 ), a ferroelectric film ( 16 ) and a top electrode ( 17 ) is covered with an interlayer insulating film ( 18 ). One end of the bottom electrode ( 15 ) is formed like comb teeth. To match with the remaining portion of that end, a plurality of contact holes ( 21 ) are formed in the interlayer insulating film ( 18 ). In other words, gaps (notches) are formed in the bottom electrode ( 15 ) between lower ends of at least two of the contact holes ( 21 ). And a wiring ( 25 ) connected to the bottom electrode ( 15 ) through the contact holes ( 21 ) is formed on the interlayer insulating film ( 18 ).
1. A semiconductor device, comprising:
a ferroelectric capacitor including a bottom electrode, a ferroelectric film and a top electrode;
an interlayer insulating film formed on said ferroelectric capacitor, in said interlayer insulating film a plurality of contact holes being formed to said bottom electrode; and
a wiring formed on said interlayer insulating film and connected to said bottom electrode through said contact holes,
wherein a first notch is formed in said bottom electrode between lower ends of at least two of the contact holes,
a second notch is formed in said bottom electrode between lower ends of at least two of said contact holes,
said contact holes are arranged in an array pattern, and
said first notch and said second notch are formed in a stripe pattern.
2. The semiconductor device according to claim 1 , wherein a gap is formed in said wiring between upper ends of at least two of said contact holes.
3. The semiconductor device according to claim 2 , wherein a relative area of portions outside said contact holes is 1.3 or less in a case where an area inside said contact holes is 1 in a region where said wiring overlaps said bottom electrode in a plan view.
4. The semiconductor device according to claim 1 , wherein a relative area of portions outside said contact holes is 1.9 or less in a case where an area inside said contact holes is 1 in a region where said wiring overlaps said bottom electrode in a plan view.
5. The semiconductor device according to claim 1 , further comprising
a barrier metal film formed between said bottom electrode and said wiring,
wherein said barrier metal film comprises:
a first TiN film in direct contact with said bottom electrode;
a Ti film formed on said first TiN film; and
a second TiN film formed on said Ti film.
6. The semiconductor device according to claim 1 , further comprising
a barrier metal film formed between said bottom electrode and said wiring,
wherein said barrier metal film comprises:
a first TiN film in direct contact with said bottom electrode; and
an iridium oxide film formed on said first TiN film.
7. The semiconductor device according to claim 6 ,wherein said barrier metal film further comprises a second TiN film formed on said iridium oxide film.
8. The semiconductor device according to claim 1 , further comprising
a barrier metal film formed between said bottom electrode and said wiring,
wherein said barrier metal film comprises:
a first TiN film in direct contact with said bottom electrode;
a first Ti film formed on said first TiN film;
an iridium oxide film formed on said first Ti film;
a second Ti film formed on said iridium oxide film; and
a second TiN film formed on said second Ti film.
9. The semiconductor device according to claim 1 ,
wherein said wiring includes an Ir film or a Pt film.
10. The semiconductor device according to claim 9 , further comprising a TiN film formed on said wiring.
11. A semiconductor device, comprising:
a ferroelectric capacitor including a bottom eletrode, a ferroelectric film and a top electrode;
an interlayer insulating film formed on said ferroelectric capacitor, in said interlayer insulating film a plurality of contact holes being formed to said bottom electrode; and
a wiring formed on said interlayer insulating film and connected to said bottom electrode through said contact holes,
wherein a first notch is formed in said wiring between upper ends of at least two of said contact holes,
a second notch is formed in said wiring between upper end of at least two said contact holes,
said contact holes are arranged in an array pattern, and
said first notch and said second notch are formed in a stripe pattern.
12. The semiconductor device according to claim 11 , wherein a relative area of portions outside said contact holes is 1.8 or less in a case where an area inside said contact holes is 1 in a region where said wiring overlaps said bottom electrode in a plan view.
13. The semiconductor device according to claim 11 , further comprising a barrier metal film formed between said bottom electrode and said wiring,
wherein said barrier metal film comprises:
a first TiN film in direct contact with said bottom electrode;
a Ti film formed on said first TiN film; and
a second TiN film formed on said Ti film.
14. The semiconductor device according to claim 11 , further comprising a barrier metal film formed between said bottom electrode and said wiring,
wherein said barrier metal film comprises:
a first TiN film in direct contact with said bottom electrode; and
an iridium oxide film formed on said first TiN film.
15. The semiconductor device according to claim 14 , wherein said barrier metal film further comprises a second TiN film formed on said iridium oxide film.
16. The semiconductor device according to claim 11 , further comprising a barrier metal film formed between said bottom electrode and said wiring,
wherein said barrier metal film comprises:
a first TiN film in direct contact with said bottom electrode;
a first Ti film formed on said first TiN film;
an iridium oxide film formed on said first Ti film;
a second Ti film formed on said iridium oxide film; and
a second TiN film formed on said second Ti film.
17. The semiconductor device according to claim 11 , wherein said wiring includes an Ir film or a Pt film.
18. The semiconductor device according to claim 17 , further comprising a TiN film formed on said wiring.
19. A manufacturing method of a semiconductor device, comprising the steps of:
forming a ferroelectric capacitor including a bottom electrode, a ferroelectric film and a top electrode;
forming an interlayer insulating film on the ferroelectric capacitor, in the interlayer insulating film a plurality of contact holes being formed to the bottom electrode; and
forming a wiring connected to the bottom electrode through the contact holes on the interlayer insulating film,
wherein, on forming the bottom electrode, a first notch is formed in the bottom electrode between lower ends of at least two of the contact holes,
a second notch is formed in said bottom electrode between lower ends of at least two of said contact holes,
said contact holes are arranged in an array pattern, and
said first notch and said second notch are formed in a stripe pattern.
20. The manufacturing method of a semiconductor device according to claim 19 , wherein, on forming the wiring, a gap is formed in the wiring between the upper ends of at least two of the contact holes.
21. The manufacturing method of a semiconductor device according to claim 19 , further comprising the step of, between said step of forming the interlayer insulating film and said step of forming the wiring,
forming a barrier metal film on a bottom and a side of the contact holes,
wherein said step of forming the barrier metal film comprises the steps of:
forming a first TiN film in direct contact with the bottom electrode;
forming a Ti film on the first TiN film; and
forming a second TiN film on the Ti film.
22. The manufacturing method of a semiconductor device according to claim 21 , wherein said step of forming the first TiN film is performed under two kinds of conditions of:
a first condition; and
a second condition for having the film formed on the sides of the contact holes more easily than the first condition.
23. The manufacturing method of a semiconductor device according to claim 22 , wherein said step of forming the barrier metal film further comprises the step of forming a second TiN film on the iridium oxide film.
24. The manufacturing method of a semiconductor device according to claim 19 , further comprising the step of, between said step of forming the interlayer insulating film and said step of forming the wiring,
forming a barrier metal film on a bottom and a side of the contact holes,
wherein said step of forming the barrier metal film comprises the steps of:
forming a first TiN film in direct contact with the bottom electrode; and
forming an iridium oxide film on the first TiN film.
25. The manufacturing method of a semiconductor device according to claim 19 , further comprising the step of, between said step of forming the interlayer insulating film and said step of forming the wiring,
forming a barrier metal film on a bottom and a side of the contact holes,
wherein said step of forming the barrier metal film comprises the steps of:
forming a first TiN film in direct contact with the bottom electrode;
forming a first Ti film on the first TiN film;
forming an iridium oxide film on the first Ti film;
forming a second Ti film on the iridium oxide film; and
forming a second TiN film on the second Ti film.
26. The manufacturing method of a semiconductor device according to claim 25 , wherein said step of forming the first TiN film is performed under two kinds of conditions of:
a first condition; and
a second condition for having the film formed on the sides of the contact holes more easily than the first condition.
27. The manufacturing method of a semiconductor device according to claim 25 , further comprising the step of annealing between said step of forming the barrier metal film and said step of forming the wiring.
28. The manufacturing method of a semiconductor device according to claim 19 , wherein said step of forming the wiring comprises the step of forming an Ir film or a Pt film.
29. The manufacturing method of a semiconductor device according to claim 28 , wherein said step of forming the wiring further comprises the steps of:
patterning the Ir film or the Pt film by dry etching at 300° C or higher.
30. The manufacturing method of a semiconductor device according to claim 29 , wherein, on the dry etching, a gas including a halogen gas of Cl 2 or HBr and O 2 as an etching gas is used with a rate of the halogen gas in the etching gas at 0.4 or less.
31. The manufacturing method of a semiconductor device according to claim 28 , wherein said step of forming the wiring further comprises the steps of:
forming a TiN film on the Ir film or the Pt film;
patterning the TiN film with using a resist mask so as to form a hard mask;
eliminating the resist mask; and
patterning the material film with using the hard mask.
32. A manufacturing method of a semiconductor device, comprising the steps of:
forming a ferroelectric capacitor including a bottom electrode, a ferroelectric film and a top electrode;
forming an interlayer insulating film on the ferroelectric capacitor, in the interlayer insulating film a plurality of contact holes being formed to the bottom electrode; and
forming a wiring connected to the bottom electrode through the contact holes on the interlayer insulating film,
wherein, on forming the wiring, a first notch is formed in the wiring between upper ends of at least two of the contact holes,
a second notch is formed in said wiring between upper ends of at least two of said contact holes,
said contact holes are arranged in an array pattern, and
said first notch and said second notch are formed in a stripe pattern.
33. The manufacturing method of a semiconductor device according to claim 32 , further comprising the step of, between said step of forming the interlayer insulating film and said step of forming the wiring, forming a barrier metal film on a bottom and a side of the contact holes,
wherein said step of forming the barrier metal film comprises the steps of:
forming a first TiN film in direct contact with the bottom electrode;
forming a Ti film on the first TiN film; and
forming a second TiN film on the Ti film.
34. The manufacturing method of a semiconductor device according to claim 33 , wherein said step of forming the first TiN film is performed under two kinds of conditions of:
a first condition; and
a second condition for having the film formed on the sides of the contact holes more easily than the first condition.
35. The manufacturing method of a semiconductor device according to claim 34 , wherein said step of forming the barrier metal film further comprises the step of forming a second TiN film on the iridium oxide film.
36. The manufacturing method of a semiconductor device according to claim 32 , further comprising the step of, between said step of forming the interlayer insulating film and said step of forming the wiring, forming a barrier metal film on a bottom and a side of the contact holes,
wherein said step of forming the barrier metal film comprises the steps of:
forming a first TiN film in direct contact with the bottom electrode; and
forming an iridium oxide film on the first TIN film.
37. The manufacturing method of a semiconductor device according to claim 32 , further comprising the step of, between said step of forming the interlayer insulating film and said step of forming the wiring, forming a barrier metal film on a bottom and a side of the contact holes,
wherein said step of forming the barrier metal film comprises the steps of:
forming a first TiN film in direct contact with the bottom electrode;
forming a first Ti film on the first TiN film;
forming an iridium oxide film on the first Ti film;
forming a second Ti film on the iridium oxide film; and
forming a second TiN film on the second Ti film.
38. The manufacturing method of a semiconductor device according to claim 37 , wherein said step of forming the first TiN film is performed under two kinds of conditions of:
a first condition; and
a second condition for having the film formed on the sides of the contact holes more easily than the first condition.
39. The manufacturing method of a semiconductor device according to claim 37 , further comprising the step of annealing between said step of forming the barrier metal film and said step of forming the wiring.
40. The manufacturing method of a semiconductor device according to claim 32 , wherein said step of forming the wiring comprises the step of forming an Ir film or a Pt film.
41. The manufacturing method of a semiconductor device according to claim 40 , wherein said step of forming the wiring further comprises the step of patterning the Ir film or the Pt film by dry etching at 300° C. or higher.
42. The manufacturing method of a semiconductor device according to claim 41 , wherein, on the dry etching, a gas including a halogen gas of Cl 2 or HBr and O 2 as an etching gas is used with a rate of the halogen gas in the etching gas at 0.4 or less.
43. The manufacturing method of a semiconductor device according to claim 40 , wherein said step of forming the wiring further comprises the steps of:
forming a TiN film on the Ir film or the Pt film;
patterning the TiN film with using a resist mask so as to form a hard mask;
eliminating the resist mask; and
patterning the material film with using the hard mask.