MULTI COMPONENT DIELECTRIC LAYER

• US 20120032311A1
• Filed: 08/09/2010
• Published: 02/09/2012
• Est. Priority Date: 08/09/2010
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Gates, Stephen M., Grill, Alfred, Nguyen, Son V., Nitta, Satyanarayana V.
• Granted Patent: US 8,357,608 B2
• Time in Patent Office: Days
• US Class Current: 257/635
• 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 21/02167 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 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 21/76832 Multiple layers
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 2221/1047 the air gaps being formed by pores in the dielectric
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/53295 Stacked insulating layers
• CPC Class Codes: H01L 23/538 the interconnection structure between a plurality of semiconductor chips being formed on, or in, insulating substrates H05K takes precedence; manufacture or treatment H01L21/4846 ; mountings per se H01L23/12; materials H01L23/49866
• CPC Class Codes: H01L 29/06 characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
• 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 in-situ process is described incorporating plasma enhanced chemical vapor deposition comprising flowing at least one of a Si, Si+C, B, Si+B, Si+B+C, and B+C containing precursor, and a N containing precursors at first times and removing the N precursor at second times and starting the flow of an oxidant gas and a porogen gas into the chamber. A dielectric layer is described comprising a network having inorganic random three dimensional covalent bonding throughout the network which contains at least one SiCN, SiCNH, SiN, SiNH, BN, BNH, CBN, CBNH, BSiN, BSiNH, SiCBN and SiCBNH as a first component and a low k dielectric as a second component adjacent thereto.

Claims

1. A method for forming a dielectric structure comprising:

placing a substrate in a chamber for performing one of plasma enhanced chemical vapor deposition and plasma enhanced atomic layer deposition,

flowing a vapor including at least one of a Si, Si+C, B, Si+B, Si+B+C, and B+C containing precursor, a N containing precursor, and an inert gas into said chamber,

heating said substrate in said chamber in the range from 100°

C. to 450°

,

initiating a plasma in said chamber to form a first component comprising at least one of SiCN, SiCNH, SiN, SiNH, BN, BNH, CBN, CBNH, BSiN, BSiNH, SiCBN and SiCBNH on said substrate,

while maintaining said plasma, reducing the flow of said N containing precursor to substantially zero while maintaining said flow of said at least one of a Si, Si+C, B, Si+B, Si+B+C, and B+C containing precursor and said inert gas, and

flowing an oxidant gas into said chamber to form a second component adjacent said first component, said second component comprising at least one of SiCOH, p-SiCOH, p-SiCNH, p-BN, p-BNH, p-CBN and p-CBNH.

2. The method of claim 1 wherein said N containing precursor comprises

ammonia, and said Si and C containing precursor is selected from the group consisting of trimethylsilane, tetramethylsilane, dimethylsilacyclopentane (DMSCP) and disilacyclobutane.

3. The method of claim 1 wherein said flowing a vapor further comprises flowing a B containing precursor selected from the group consisting of borane, diborane, liquid borazine (B₃N₃H₆), ammonia borane (NH₃—

BH₃), and other gas/liquid/vapor containing B, N and H elements only.

4. The method of claim 1 wherein said flowing a vapor further comprises

flowing a B containing precursor selected from the group consisting of borane, diborane, liquid borazine (B₃N₃H₆), ammonia borane (NH₃—

BH₃), other gas/liquid/vapor containing B, N and H elements only and flowing a hydrocarbon selected from the group consisting of ethylene, propylene, ethane, other gas/liquid/vapor containing N,N′

,N″

trimethyl borazine, other gas/liquid/vapor precursors containing B,B′

,B″

triethynyl borazine and other gas/liquid/vapor precursors containing B, N, C and H elements only.

5. The method of claim 1 wherein said flowing a vapor further comprises flowing a B containing precursor selected from the group consisting of borane, diborane, liquid borazine (B₃N₃H₆), ammonia borane (NH₃—

BH₃), and other gas/liquid/vapor containing B, N and H elements only and flowing a silane based precursor selected from the group consisting of SiH₄ and Si₂H₆.

6. The method of claim 1 wherein said flowing a vapor further comprises flowing a B containing precursor selected from the group consisting of borane, diborane, liquid borazine (B₃N₃H₆), ammonia borane (NH₃—

BH₃), and other gas/liquid/vapor containing B, N and H elements only, flowing a hydrocarbon selected from the group consisting of ethylene, propylene, ethane, and other gas/liquid/vapor containing N,N′

,N″

trimethyl borazine, other gas/liquid/vapor containing B,B′

,B″

triethynyl borazine and other gas/liquid/vapor precursors containing B, N, C and H elements only and flowing at least one of a silane based precursor selected from the group consisting of SiH₄ and Si₂H₆ and an alkylsilane precursor.

7. The method of claim 1 wherein said oxidant gas is selected from the group consisting of N₂O and O₂.

8. The method of claim 1 further including flowing a porogen vapor into said chamber.

9. The method of claim 8 wherein said porogen vapor comprises a vapor of a hydrocarbon, preferably selected from the group consisting of bicycloheptadiene (BCHD), hexadiene, limonene and alphaterpinene.

10. The method of claim 2 while maintaining said plasma and said flow further including adjusting flows of said Si and C containing precursor and said oxidant and further including flowing a porogen vapor to provide a second component having a final dielectric constant k value less than 3.2.

11. The method of claim 1 further including exposing said dielectric structure to at least one of ultraviolet radiation, electron beam and thermal treatment to form a porosity in said second component.

12. A dielectric structure comprising:

a first component comprising at least one of SiCN, SiCNH, SiN, SiNH, BN, BNH, CBN, CBNH, BSiN, BSiNH, SiCBN and SiCBNH and a second component adjacent said first component wherein said second component has a dielectric constant less than 3.2.

13. The dielectric structure of claim 12 wherein said first component comprises at least one multilayer of SiN/SiCN, BN/CBN and SiN/BN—

CBN.

14. The dielectric structure of claim 12 wherein said second component comprises a porous component.

15. The dielectric structure of claim 12 wherein said second component comprises at least one of SiCOH, p-SiCOH, p-SiCNH, p-BN, p-BNH, p-CBN and p-CBNH.

16. The dielectric structure of claim 12 wherein said first component comprises a random three dimensional covalently bonded network.

17. The dielectric structure of claim 12 wherein said second component comprises a random three dimensional covalently bonded network.

18. An interconnect structure comprising at least one wiring level in an integrated circuit chip having conductors in said wiring level and a dielectric comprising a first component of at least one of SiCN, SiCNH, SiN, SiNH, BN, BNH, CBN, CBNH, BSiN, BSiNH, SiCBN and SiCBNH and a second component adjacent said first component, said second component comprising at least one of SiCOH, p-SiCOH, p-SiCNH, p-BN, p-BNH, p-CBN and p-CBNH.

19. The interconnect structure of claim 18 wherein said first and second components do not have a discrete interface between said first and second components.

20. The interconnect structure of claim 18 wherein said first and second components have one continuous random three dimensional network spanning both said first and second components.

21. The interconnect structure of claim 18 wherein said first and second components are separated by a transition region in contact with said first and second components.

22. The interconnect structure of claim 21 wherein said transition region comprises substantially one or more atoms of Si, C, N, O and H and wherein the concentration of N decreases and O increases in said transition region as a function of distance from said first component to said second component.

23. The interconnect structure of claim 22 wherein said first component comprises Si, CN, SiCNH, CBN, CBNH, SiCBN and SiCBNH and wherein the concentration of C decreases in said transition region as a function of distance from said first component to said second component.

24. The interconnect structure of claim 21 wherein said first component comprises Si, CN, SiCNH, CBN, CBNH, SiCBN and SiCBNH and wherein said transition region comprises substantially one or more atoms of Si, C, N, O and H and wherein the concentration of C decreases and O increases in said transition as a function of distance from said first component to said second component.