Method of and apparatus for forming a metal interconnection in the contact hole of a semiconductor device

• US 6,139,700 A
• Filed: 09/30/1998
• Issued: 10/31/2000
• Est. Priority Date: 10/01/1997
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Sang-In, Kang, Sang-Bom
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US09/163,479
• Time in Patent Office: 762 Days
• Field of Search: 204/192.15, 204/192.17, 204/192.22, 204/298.12, 204/298.13, 204/298.25, 204/298.28, 204/298.27, 118/728, 118/729, 118/730, 118/723 MP, 118/723 E, 438/602, 438/618, 438/622, 438/624, 438/637, 438/648, 438/656, 438/643, 438/653, 438/685, 427/585, 427/523
• US Class Current: 204/192.17
• CPC Class Codes: C23C 16/14 Deposition of only one other metal element
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53257 the principal metal being a refractory metal
• 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

A method and an apparatus of fabricating a metal interconnection in a contact hole of a semiconductor device reduces contact resistance and improves step coverage. A contact hole is opened in an interlayer insulating film formed on a semiconductor substrate. A conductive layer used as an ohmic contact layer is formed on the interlayer insulating film including the contact hole. An upper surface of the conductive layer is nitrided to form a protective layer. An ALD (atomic layer deposition)-metal barrier layer is formed on the protective layer. The resulting metal barrier layer has good step coverage and no impurities, and the protective layer prevents defects in the conductive layer caused by precursor impurities used during the formation of the metal barrier layer.

Claims

1. A method of fabricating a metal interconnection in a semiconductor device comprising:

etching a contact hole in an insulating film layer formed on a semiconductor substrate, the contact hole exposing a surface region of the semiconductor substrate;

forming a conductive layer on the insulating film layer and the contact hole such that the conductive layer is in ohmic contact with the semiconductor substrate;

forming a protective layer on the conductive layer by nitriding an upper surface of the conductive layer; and

forming a metal barrier layer, by atomic layer deposition (ALD), on the protective layer.

2. The method according to claim 1, wherein the conductive layer comprises a titanium (Ti) layer.

3. The method according to claim 1, wherein the conductive layer is formed by one selected from the group consisting of a sputtering method and a plasma enhanced chemical vapor deposition (PE-CVD) method.

4. The method according to claim 1, wherein the protective layer comprises a metal nitride layer.

5. The method according to claim 1, wherein the protective layer is formed by a rapid thermal nitridation (RTN) method in an atmosphere selected from the group consisting of nitrogen (N₂) and ammonia (NH₃).

6. The method according to claim 1, wherein the protective layer is formed by a plasma method in an atmosphere selected from the group consisting of nitrogen (N₂) and ammonia (NH₃).

7. The method according to claim 1, wherein said forming the metal barrier layer comprises:

(a) chemisorbing a first precursor on the protective layer;

(b) purging any non-chemisorbed first precursor using a purge gas;

(c) chemisorbing a second precursor on the protective layer;

(d) purging any non-chemisorbed second precursor using the purge gas;

(e) reacting the chemisorbed first precursor and second precursors to induce a ligand exchange among the first and second precursors;

(f) purging byproduct resulting from said reacting using the purge gas; and

(g) repeating steps (a) to (f) to increase the thickness of a metal barrier layer.

8. The method according to claim 7, wherein the first precursor is one selected from the group consisting of a Ti-precursor and a W-precursor.

9. The method according to claim 8, wherein the Ti-precursor is one selected from the group consisting of a halide material and a metal-organic material.

10. The method according to claim 8, wherein the W-precursor comprises WF₆.

11. The method according to claim 7, wherein the second precursor comprises an N-precursor.

12. The method according to claim 11, wherein the N-precursor is one selected from the group consisting of NH₃ and N₂ H₄.

13. The method according to claim 7, wherein the purge gas is one selected from a group consisting of argon (Ar) and nitrogen (N₂).

14. The method according to claim 7, wherein during said forming the metal barrier layer, the protective layer is operative to prevent defects in the conductive layer caused by a ligand exchange among the first and second precursors used for forming the metal barrier layer.

15. The method according to claim 14, wherein the protective layer comprises a titanium nitride (TiN) layer.

16. An apparatus used in fabricating a metal interconnection in a semiconductor device, the semiconductor device having an ohmic contact layer and a metal barrier layer sequentially formed within a contact hole etched in an insulating layer formed on a semiconductor substrate, the apparatus comprising:

a transfer chamber;

a load lock chamber for loading and unloading a wafer into the transfer chamber;

a first process chamber, for forming the ohmic contact layer on the wafer, connected to the transfer chamber;

a second process chamber, for forming a protective layer on the ohmic contact layer, connected to the transfer chamber; and

a third process chamber, for forming the metal barrier layer on the protective layer, connected to the transfer chamber;

wherein the third process chamber is one selected from the group consisting of an atomic layer deposition (ALD)-titanium nitride (TiN) chamber and an atomic layer deposition (ALD)-tungsten nitride (WN) chamber.