Sacrificial inorganic polymer intermetal dielectric damascene wire and via liner

• US 8,053,901 B2
• Filed: 11/01/2010
• Issued: 11/08/2011
• Est. Priority Date: 01/14/2004
• Status: Active Grant

• Current Assignee: Auriga Innovations, Inc. (Quarterhill Inc. (f/k/a Wi-LAN Inc.))
• Original Assignee: International Business Machines Corporation
• Inventors: Gambino, Jeffrey P., Stamper, Anthony K.
• Primary Examiner(s): Nguyen; Dao
• Assistant Examiner(s): NGUYEN, NIKI HOANG
• Application Number:
  US12/917,154
• Publication Number:
  US 20110042826A1
• Time in Patent Office: 372 Days
• Field of Search: 438/678, 438/638, 438/643, 438/692, 438/618, 438/619, 438622-629, 438/631, 438/633, 438/634, 438/637, 438/639, 257/773, 257/774, 257/785, 257/585, 257/635, 257/637, 257/750, 257/751
• US Class Current: 257/774
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02266 deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/3121 Layers comprising organo-silicon compounds
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/3148 Silicon Carbide layers
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/76811 involving multiple stacked pre-patterned masks
• CPC Class Codes: H01L 21/76813 involving a partial via etch
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76835 Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence
• CPC Class Codes: H01L 2221/1063 Sacrificial or temporary thin dielectric films in openings in a dielectric
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 : Insulating materials
• CPC Class Codes: H01L 23/53295 : Stacked insulating layers
• 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
• CPC Class Codes: H01L 2924/3011 : Impedance

Abstract

The present invention provides a method of forming a rigid interconnect structure, and the device therefrom, including the steps of providing a lower metal wiring layer having first metal lines positioned within a lower low-k dielectric; depositing an upper low-k dielectric atop the lower metal wiring layer; etching at least one portion of the upper low-k dielectric to provide at least one via to the first metal lines; forming rigid dielectric sidewall spacers in at least one via of the upper low-k dielectric; and forming second metal lines in at least one portion of the upper low-k dielectric. The rigid dielectric sidewall spacers may comprise of SiCH, SiC, SiNH, SiN, or SiO₂. Alternatively, the via region of the interconnect structure may be strengthened with a mechanically rigid dielectric comprising SiO₂, SiCOH, or doped silicate glass.

Claims

1. An interconnect structure comprising:

a lower metal wiring level comprising first metal lines positioned within a dielectric stack including a lower low-k dielectric and a first rigid dielectric layer located atop said lower low-k dielectric, wherein each of said first metal lines has an upper surface that is coplanar with an upper surface of the first rigid dielectric layer;

a mechanically rigid dielectric positioned on said lower metal wiring level, said mechanically rigid dielectric comprising a plurality of metal filled vias; and

an upper metal wiring level atop said mechanically rigid dielectric, said upper metal wiring level comprising second metal lines positioned within a dielectric stack including an upper low-k dielectric and a second rigid dielectric layer located atop said upper low-k dielectric, said first and second rigid dielectric layers comprising silicon nitride or silicon carbide, where said plurality of metal vias electrically connect said lower metal wiring level and said upper metal wiring level, wherein said plurality of metal filled vias comprise a set of rigid dielectric sidewall spacers, wherein at least some of the rigid dielectric sidewall spacers have an upper surface that is coplanar with an upper surface of said plurality of metal filled vias, wherein a dielectric material for said rigid dielectric sidewall spacer is selected from the group consisting of SiCH, SiC, SiNH, SiN, and SiO₂.

2. The interconnect structure of claim 1 wherein said plurality of metal filled vias has a coefficient of thermal expansion matched to said mechanically rigid dielectric.

3. The interconnect structure of claim 2 wherein a coefficient of thermal expansion of the mechanically rigid dielectric ranges from about 0.1 ppm/°

C. to about 5 ppm/°

C.

4. The interconnect structure of claim 1 wherein said mechanically rigid dielectric comprises SiO₂, SiCOH, or doped silicate glass.

5. The interconnect structure of claim 1 wherein each of said set of rigid dielectric sidewall spacers have a thickness ranging from about 10 nm to about 100 nm.

6. The interconnect structure of claim 1 wherein said set of rigid dielectric sidewall spacers have an elastic modulus of greater than 10 GPa.

7. The interconnect structure of claim 1 wherein said set of rigid dielectric sidewall spacers have an elastic modulus of greater than 50 GPa.

8. The interconnect structure of claim 1 wherein the material of said rigid dielectric spacers is SiCH.

9. The interconnect structure of claim 1 wherein said first rigid dielectric layer has a thickness of from 5 to 100 nm.

10. The interconnect structure of claim 1 wherein said second rigid dielectric layer has a thickness of from 5 to 100 nm.

11. The interconnect structure of claim 1 further comprising a first etch stop layer located between the first rigid dielectric layer and said mechanically rigid dielectric.

12. The interconnect structure of claim 1 further comprising a second etch stop layer located atop the second rigid dielectric layer.