Semiconductor device and making thereof

• US 20050062130A1
• Filed: 09/23/2003
• Published: 03/24/2005
• Est. Priority Date: 09/23/2003
• Status: Active Grant

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Ciancio, Anthony, Morrison, Jennifer H., Griswold, Mark D., Irudayam, Amudha R.
• Granted Patent: US 7,078,785 B2
• Time in Patent Office: Days
• US Class Current: 257/532
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 28/65 comprising a noble metal or a noble metal oxide, e.g. platinum (Pt), ruthenium (Ru), ruthenium dioxide (RuO2), iridium (Ir), iridium dioxide (IrO2)
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

By forming a conductive smoothing layer over the bottom electrode and/or a capacitor dielectric, a MIM capacitor with improved reliability due to reduction of geometrically enhanced electric fields and electrode smoothing is formed. In one embodiment, layer including a refractory metal or a refractory metal-rich nitride, is formed over a first capping layer formed of a refractory nitride. In addition, a second refractory metal or a refractory metal-rich nitride layer may be formed on the capacitor dielectric. The smoothing layer could also be used in other semiconductor devices, such as transistors between a gate electrode and a gate dielectric.

Claims

1. A semiconductor device comprising;

a semiconductor substrate;

a first electrode formed over the semiconductor substrate;

a first conductive smoothing layer formed over the first electrode, wherein the first conductive smoothing layer has a surface roughness less than that of the first electrode;

a dielectric layer formed on the first conductive smoothing layer; and

a second electrode formed over the dielectric layer;

2. The semiconductor device of claim 1, further comprising:

a second conductive smoothing layer formed between the dielectric layer and the second electrode, wherein the second conductive smoothing layer has a roughness less than that of the second electrode.

3. The semiconductor device of claim 2, wherein the second conductive smoothing layer comprises a refractory metal.

4. The semiconductor device of claim 1, wherein the first electrode comprises a first layer comprising a metal and a second layer comprising a refractory nitride and the second electrode comprises a metal.

5. The semiconductor device of claim 1, wherein the first electrode and the second electrode comprise a refractory nitride.

6. The semiconductor device of claim 5, wherein the refractory nitride comprises a material selected from the group consisting of titanium nitride and tantalum nitride.

7. The semiconductor device of claim 5, wherein the first conductive smoothing layer comprises titanium rich nitride.

8. The semiconductor device of claim 1, wherein the dielectric layer comprises a high dielectric constant material.

9. The he semiconductor device of claim 1, wherein the first electrode, the first conductive smoothing layer, the dielectric layer and the second electrode are part of a metal-insulator-metal (MIM) capacitor.

10. The he semiconductor device of claim 9, further comprising:

a capping layer over the first electrode, wherein the capping layer comprises a refractory nitride and the first electrode comprises a metal.

11. A semiconductor device comprising:

a conductive layer,

a smoothing layer formed in contact with the conductive layer, wherein the smoothing layer has a surface roughness less than that of the conductive layer; and

a dielectric layer formed in contact with the smoothing layer.

12. The semiconductor device of claim 11, wherein the smoothing layer comprises titanium rich nitride.

13. The semiconductor device of claim 11, wherein the conductive layer comprises titanium nitride and the smoothing layer comprises titanium.

14. The semiconductor device of claim 11, wherein the conductive layer, the smoothing layer and the dielectric layer are part of a device selected from the group consisting of a transistor and a capacitor.

15. The semiconductor device of claim 11, wherein the conductive layer comprises a first layer comprising a metal and a second layer comprising a refractory nitride.

16. The semiconductor device of claim 11, wherein the dielectric layer is a high dielectric constant material.

17. A semiconductor device comprising:

a semiconductor substrate;

a first electrode formed over the semiconductor substrate, wherein the first electrode comprises a first layer comprising metal and a second layer over the first layer, wherein the second layer comprises a refractory nitride;

a first smoothing layer formed over the first electrode, wherein the first smoothing layer comprises titanium rich nitride;

a dielectric layer formed on the first smoothing layer; and

a second electrode formed over the dielectric layer, wherein the second electrode comprises a third layer comprising a refractory nitride and a fourth layer over the third layer, wherein the fourth layer comprises a metal.

18. The semiconductor device of claim 17, wherein the refractory nitride comprises a material selected from the group consisting of titanium nitride and tantalum nitride.

19. The semiconductor device of claim 18, wherein the refractory metal comprises titanium.

20. A method for forming semiconductor device comprising:

providing a semiconductor substrate;

forming a first electrode formed over the semiconductor substrate;

forming a first conductive smoothing layer formed over the first electrode, wherein the first smoothing layer has a surface roughness less than that of the first electrode;

forming a dielectric layer formed on the first smoothing layer; and

forming a second electrode formed over the dielectric layer.