Method of forming a surface coating layer within an opening within a body by atomic layer deposition

• US 6,716,693 B1
• Filed: 03/27/2003
• Issued: 04/06/2004
• Est. Priority Date: 03/27/2003
• Status: Expired due to Term

• Current Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Original Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Inventors: Chu, Sanford, Chan, Lap, Ng, Chit Hwei, Pradeep, Yelehanka Ramachandramurthy, Zheng, Jia Zhen
• Primary Examiner(s): NGUYEN, THANH T
• Application Number:
  US10/400,511
• Time in Patent Office: 376 Days
• Field of Search: 438/238, 438/381, 438/618-645, 438/667-681, 438/687
• US Class Current: 438/238
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 41/042 by thin film techniques
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 23/522 including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 27/08 including only semiconductor components of a single kind
• CPC Class Codes: H01L 28/10 Inductors
• 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

An improved new process for fabricating multilevel interconnected vertical channels and horizontal channels or tunnels. The method has broad applications in semiconductors, for copper interconnects and inductors, as well as, in the field of bio-sensors for mini- or micro-columns in gas or liquid separation, gas/liquid chromatography, and in capillary separation techniques. In addition, special techniques are described to deposit by atomic layer deposition, ALD, a copper barrier layer and seed layer for electroless copper plating, filling trench and channel or tunnel openings in a type of damascene process, to form copper interconnects and inductors.

Claims

1. A method of forming trench and channel, or tunnel, openings for an inductor comprising the following steps:

(a) providing an insulating layer overlying a substrate;

(b) forming a patterned first silicon nitride sacrificial layer, for subsequent channel formation, over the insulating layer;

(c) providing a first dielectric layer, overlying said patterned first silicon nitride sacrificial layer;

(d) forming a patterned second silicon nitride sacrificial layer over the first dielectric layer;

(e) forming a second dielectric layer, over said patterned second silicon nitride sacrificial layer and planarizing the second dielectric layer, by chemical mechanical polishing;

(f) forming via openings in the second dielectric layer, by patterning and selectively removing regions of the second dielectric layer, by a reactive ion etch, stopping on the patterned second silicon nitride sacrificial layer, while exposing portions of the underlying first silicon nitride sacrificial layer;

(g) changing plasma etching chemistry to etch through exposed regions of the underlying second silicon nitride sacrificial layer, and while continuing to pattern the first dielectric layer, forming vertical channels of the inductor by reactive ion etching, stopping on the patterned first silicon nitride sacrificial layer;

(h) selectively wet etching away the underlying first and second silicon nitride sacrificial layers, thus forming both top and bottom horizontal channels or tunnels.

2. The method of claim 1, wherein said substrate includes a semiconductor substrate or silicon oxide substrate with semiconductor device structures comprising gate electrodes and source/drain regions.

3. The method of claim 1, wherein said substrate includes a semiconductor substrate with semiconductor device structures comprising gate electrodes, source/drain regions and multiple levels of metal interconnections.

4. The method of claim 1, wherein multilevel interconnected vertical channels and horizontal channels or tunnels are fabricated by repeating steps (b) through (h).

5. The method of claim 1, wherein said first and second dielectric layers are low dielectric constant material or materials comprising PECVD, plasma enhanced chemical vapor deposition of TEOS, tetraethoxysilane deposition with O₃, halogenated SiO, FSG, fluorinated silicate glass, PECVD with silane for SiO₂, carbon-rich silicate glass, porous low-K polymer deposition, in a thickness range from 2,000 to 10,000 Angstroms deposited by chemical vapor deposition or spun-on.

6. The method of claim 1, wherein said sacrificial layers of first and second silicon nitride are comprised of SiN in a thickness range from 200 to 800 Angstroms deposited by plasma enhanced chemical vapor deposition.

7. The method of claim 1, wherein said underlying first and second sacrificial silicon nitride layers, are selectively wet etched away forming both vertical channels and horizontal channels or tunnels in the dielectric layers by the following highly selective wet etching method comprised of hot phosphoric acid in a temperature range of from 160 to 200°

C.

8. The method of claim 1, wherein multilevel interconnected vertical channels and horizontal channels or tunnels, fabricated by repeating steps (b) through (h), comprise a list of broad applications in semiconductors, and bio-sensors comprised of:

mini- or micro-columns for gas or liquid separation, gas/liquid chromatography, and capillary separation techniques.

9. A method of forming trench and channel, or tunnel, openings and then coating the surface of trench and channel or tunnel, openings with a copper barrier layer and a copper seed layer, in the fabrication of interconnects and inductors, comprising the following steps:

(a) providing an insulating layer overlying a substrate;

(b) forming a patterned first silicon nitride sacrificial layer, for subsequent channel formation, over the insulating layer;

(c) providing a first dielectric layer overlying said patterned first silicon-nitride sacrificial layer;

(d) forming a patterned second silicon nitride sacrificial layer over the first dielectric layer;

(e) forming a second dielectric layer over said patterned second silicon nitride and planarizing the second dielectric layer by chemical mechanical polishing;

(f) forming via openings in the second dielectric layer by patterning and selectively removing regions of the second dielectric layer by a reactive ion etch, stopping on the patterned second silicon nitride sacrificial layer, while exposing portions of underlying first silicon nitride sacrificial layer;

(g) changing plasma etching chemistry to etch through exposed regions of the underlying second silicon nitride sacrificial layer, and while continuing to pattern the first dielectric layer forming vertical channels of the inductors by reactive ion etching, stopping on the patterned first silicon nitride sacrificial layer;

(h) selectively wet etching away the underlying patterned first and second silicon nitride sacrificial layers, forming both top and bottom horizontal channel or tunnel openings;

(i) depositing said copper barrier layer coating both vertical channels and horizontal channels or tunnels in the first and second dielectric layers, by atomic layer deposition;

(j) depositing said copper seed layer overlying said copper barrier layer, by atomic layer deposition, thus coating the surface of trench and channel or tunnel, openings with said copper barrier layer and said copper seed layer, in the fabrication of interconnects and inductors.

10. The method of claim 9, wherein said substrate includes a semiconductor substrate or silicon oxide substrate with semiconductor device structures comprising gate electrodes and source/drain regions.

11. The method of claim 9, wherein said substrate includes a semiconductor substrate with semiconductor device structures comprising gate electrodes, source/drain regions and multiple levels of metal interconnections.

12. The method of claim 9, wherein said first and second dielectric layers are low dielectric constant material or materials comprising PECVD, plasma enhanced chemical vapor deposition of TEOS, tetraethoxysilane deposition with O₃, halogenated SiO, FSG, fluorinated silicate glass, PECVD with silane for SiO₂, carbon-rich silicate glass, porous low-K polymer deposition, in a thickness range from 2,000 to 10,000 Angstroms deposited by chemical vapor deposition or spun-on.

13. The method of claim 9, wherein said sacrificial layers of first and second silicon nitride are comprised of SiN in a thickness range from 200 to 800 Angstroms deposited by plasma enhanced chemical vapor deposition.

14. The method of claim 9, wherein said underlying first and second sacrificial silicon nitride layers, are selectively wet etched away forming both vertical channels and horizontal channels or tunnels in the insulating layers by the following highly selective wet etching method comprised of hot phosphoric acid in a temperature range of from 160 to 200°

C.

15. The method of claim 9, wherein said copper barrier layer is selected from the group consisting of TiN, TiSiN, tantalum nitride, (Mo₂N and MoN), NbN, and tungsten nitride, deposited by atomic layer deposition, to a thickness ranging from 20 to 200 Angstroms.

16. The method of claim 9, wherein said copper seed layer is comprised of copper deposited by atomic layer deposition, thickness range from 20 to 200 Angstroms, with atomic layer deposition conditions of:

approximate temperature range from 200 to 300°

C., pressure range from 10 to 200 mTorr, deposition rate ranging from 0.01 to 0.05 nm per cycle, and pulse time varying from 0.05 to 0.5 seconds.

17. A method of forming trench and channel, or tunnel openings and then coating the surface of trench and channel or tunnel openings with a copper barrier layer and a copper seed layer, filling the tunnel openings by electroless plating of copper, in the fabrication of interconnects and inductors, comprising the following steps:

(a) providing an insulating layer overlying a substrate;

(b) forming a patterned first silicon nitride sacrificial layer, for subsequent channel formation, over the insulating layer;

(c) providing a first dielectric layer overlying said patterned first silicon nitride sacrificial layer;

(d) forming a patterned second silicon nitride sacrificial layer over the first dielectric layer;

(e) forming a second dielectric layer over said patterned second silicon nitride and planarizing the second dielectric layer by chemical mechanical polishing;

(f) forming via openings in the second dielectric layer by patterning and selectively removing regions of the second dielectric layer by a reactive ion etch, stopping on the second silicon nitride sacrificial layer, while exposing portions of the underlying first silicon nitride sacrificial layer;

(g) changing plasma etching chemistry to etch through exposed regions of the underlying second silicon nitride sacrificial layer, and while continuing to pattern the first dielectric layer forming vertical channels of the inductors by reactive ion etching, stopping on the first silicon nitride sacrificial layer;

(h) selectively wet etching away the underlying first and second silicon nitride sacrificial layers, forming both top and bottom horizontal channel or tunnel openings;

(i) depositing a bottom copper barrier layer, first barrier, coating both vertical channels and horizontal channels or tunnels in the first and second dielectric layers, by atomic layer deposition;

(j) depositing said copper seed layer overlying said bottom copper barrier layer, by atomic layer deposition, coating surface of trench and channel or tunnel openings with said bottom copper barrier layer and said copper seed layer;

(k) performing electroless copper plating copper on said copper seed layer filling trench and channel or tunnel openings with an excess of copper;

(l) removing said excess of copper and planarizing back the excess copper by chemical mechanical polishing;

(m) depositing a top blanket copper barrier layer, second barrier, thus completing the fabrication of inlaid copper interconnects and inductors.

18. The method of claim 17, wherein multilevel inlaid copper interconnects and inductors are fabricated by repeating steps (b) through (m).

19. The method of claim 17, wherein said substrate includes a semiconductor substrate or silicon oxide substrate with semiconductor device structures comprising gate electrodes and source/drain regions.

20. The method of claim 17, wherein said substrate includes a semiconductor substrate with semiconductor device structures comprising gate electrodes, source/drain regions and multiple levels of metal interconnections.

21. The method of claim 17, wherein said first and second dielectric layers are low dielectric constant material or materials comprising PECVD, plasma enhanced chemical vapor deposition of TEOS, tetraethoxysilane deposition with O₃, halogenated SiO, FSG, fluorinated silicate glass, PECVD with silane for SiO₂, carbon-rich silicate glass, porous low-K polymer deposition, in a thickness range from 2,000 to 10,000 Angstroms deposited by (CVD,) chemical vapor deposition or spun-on.

22. The method of claim 17, wherein said sacrificial layers of first and second silicon nitride are comprised of SiN in a thickness range from 200 to 800 Angstroms deposited by plasma enhanced chemical vapor deposition.

23. The method of claim 17, wherein said underlying first and second sacrificial silicon nitride layers, are selectively wet etched away forming both vertical channels and horizontal channels or tunnels in the insulating layers by the following highly selective wet etching method comprised of hot phosphoric acid in a temperature range of from 160 to 200°

C.

24. The method of claim 17, wherein said bottom copper barrier layer is selected from the group consisting of TiN, TiSiN, tantalum nitride, (Mo₂N and MoN), NbN, and tungsten nitride deposited by atomic layer deposition, in a thickness ranging from 20 to 200 Angstroms.

25. The method of claim 17, wherein said copper seed layer overlying the bottom copper barrier layer, is comprised of copper deposited by atomic layer deposition, thickness range from 20 to 200 Angstroms, with atomic layer deposition conditions of:

approximate temperature range from 200 to 300°

C., pressure range from 10 to 200 mTorr, deposition rate ranging from 0.01 to 0.05 nm per cycle, and pulse time varying from 0.05 to 0.5 seconds.

26. The method of claim 17, wherein said electroless plated copper on the copper seed layer, filling channel or tunnel openings with an excess of copper, comprising the following deposition conditions;

a liquid plating bath mixture comprising CuSO₄, HF, HCl and CH₂O with heat in a temperature range from 25 to 65°

C., yielding a copper plating thickness ranging from 2,000 to 10,000 Angstroms.

27. The method of claim 17, wherein said excess copper is planarized back by chemical mechanical polishing, forming inlaid copper interconnect wiring and inductors.

28. The method of claim 17, wherein said top blanket copper barrier layer, second barrier, overlying the copper, is comprised of SiN deposited by PECVD, plasma-enhanced chemical vapor deposition, in a thickness ranging from 200 to 800 Angstroms.