Method of fabricating capacitor having hafnium oxide

• US 6,583,021 B2
• Filed: 05/09/2002
• Issued: 06/24/2003
• Est. Priority Date: 06/30/2001
• Status: Expired due to Fees

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: Song, Chang-Rock
• Primary Examiner(s): Fourson, George
• Assistant Examiner(s): GARCIA, JOANNIE A
• Application Number:
  US10/141,713
• Publication Number:
  US 20030003648A1
• Time in Patent Office: 411 Days
• Field of Search: 438/244, 438/239, 438/386, 438/396, 438/660, 438/768, 438/FOR.212, 438/FOR.220, 148/DIG.14
• US Class Current: 438/396
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31683 of metallic layers, e.g. Al deposited on the body, e.g. formation of multi-layer insulating structures
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: Y10S 148/014 Capacitor

Abstract

Disclosed herein is a method of fabricating a capacitor. The method includes the steps of: forming a Ti_1−xHf_xN layer on a substrate, wherein x is in a range from 0 to 0.5; forming an electrode layer on the Ti_1−xHf_xN layer; and forming a HfO₂ layer on an interface between the electrode layer and the Ti_1−xHf_xN layer by performing a thermal treatment in an oxygen gas-containing atmosphere.

Claims

1. A method of fabricating a capacitor, the method comprising the steps of:

(a) forming a Ti<sub>1−

x</sub>Hf_xN layer on a substrate, wherein x is in a range from 0 to about 0.5;

(b) forming an electrode layer on the Ti<sub>1−

x</sub>Hf_xN layer; and

(c) forming a HfO₂ layer on an interface between the electrode layer and the Ti<sub>1−

x</sub>Hf_xN layer by performing a thermal treatment in an oxygen gas-containing atmosphere,

said capacitor comprising a bottom electrode formed from the Ti<sub>1−

x</sub>Hf_xN layer, a dielectric layer is formed with the HfO₂ layer, and a top electrode formed from the electrode layer.

2. The method of claim 1, wherein the HfO₂ layer is formed to a thickness of about 50 Å

to about 300 Å

.

3. The method of claim 1, wherein the thermal treatment is performed in an atmosphere comprising a gas mixture of oxygen and nitrogen, or oxygen and argon.

4. The method of claim 1, wherein the thermal treatment is performed at a temperature of about 400°

C. to about 800°

C. for about 10 seconds to 10 minutes.

5. The method of claim 1, wherein the Ti₁₋

xHf_xN layer is formed by sputtering, chemical vapor deposition (CVD), or atomic layer deposition (ALD).

6. The method of claim 1, wherein the Ti₁₋

xHf_xN layer is formed to a thickness of about 100 Å

to about 300 Å

.

7. The method of claim 1, wherein the Ti₁₋

xHf_xN layer is formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD) said method further comprising the step of gradually increasing a molar fraction of Hf relative to TiN to Ti_0.5Hf_0.5N.

8. A method of fabricating a capacitor, the method comprising the steps of:

(a) forming an inter-layer dielectric layer on a silicon semiconductor substrate;

(b) forming a contact hole by selectively etching the inter-layer dielectric layer to expose the surface of the semiconductor substrate;

(c) forming a Ti<sub>1−

x</sub>Hf_xN layer in the contact hole, wherein x is in a range from 0 to about 0.5;

(d) forming an electrode layer on the Ti₁₋

Hf_xN layer; and

(e) forming a HfO₂ layer on an interface between the electrode layer and the Ti<sub>1−

x</sub>Hf_xN layer by performing a thermal treatment in an oxygen gas-containing atmosphere,

said capacitor comprising a bottom electrode formed from the Ti<sub>1−

x</sub>Hf_xN layer, a dielectric layer formed from the HfO₂ layer, and a top electrode formed from the electrode layer.

9. The method of claim 8, further comprising the step of forming an ohmic contact layer between the semiconductor layer and the Ti₁₋

xHf_xN layer.

10. The method of claim 8, wherein the HfO₂ layer is formed to a thickness of about 50 Å

to about 300 Å

.

11. The method of claim 8, wherein the thermal treatment is performed in an atmosphere comprising a gas mixture of oxygen and nitrogen, or oxygen and argon.

12. The method of claim 8, wherein the thermal treatment is performed at a temperature of about 400°

C. to about 800°

C. for about 10 seconds to about 10 minutes.

13. The method of claim 8, wherein the Ti₁₋

xHf_xN layer is formed by sputtering, chemical vapor deposition (CVD), or atomic layer deposition (ALD).

14. The method of claim 13, wherein the Ti₁₋

xHf_xN layer is formed to a thickness of about 100 Å

to about 300 Å

.

15. The method of claim 8, wherein Ti₁₋

xHf_xN layer is formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD), said method further comprising the step of gradually increasing a molar fraction of Hf relative to TiN to Ti_0.5Hf_0.5N.

16. The method of claim 8, wherein step (c) comprises the steps of:

(i) forming an anti-polish layer or an etch mask on the Ti<sub>1−

x</sub>Hf_xN layer in the contact hole; and

(ii) applying a chemical mechanical polish or an etch-back process to the Ti<sub>1−

x</sub>Hf_xN layer until the surface of the inter-layer dielectric layer is exposed.

17. The method of claim 16, wherein the anti-polish layer or the etch mask is formed of photoresist or spin-on-glass.