SPIN-ON PROTECTIVE COATINGS FOR WET-ETCH PROCESSING OF MICROELECTRONIC SUBSTRATES

• US 20090075087A1
• Filed: 09/13/2007
• Published: 03/19/2009
• Est. Priority Date: 09/13/2007
• Status: Active Grant

• Current Assignee: Brewer Science Inc.
• Original Assignee: Brewer Science Inc.
• Inventors: Yess, Kimberly A., Flaim, Tony D., Xu, Gu
• Granted Patent: US 8,192,642 B2
• Time in Patent Office: Days
• US Class Current: 428/413
• CPC Class Codes: B81C 1/00801 Avoid alteration of functional structures by etching, e.g. using a passivation layer or an etch stop layer B81C1/00595, B81C1/00468 take precedence
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• CPC Class Codes: C08L 63/04 Epoxynovolacs
• CPC Class Codes: C09D 125/12 with unsaturated nitriles
• CPC Class Codes: H01L 21/0271 comprising organic layers
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

New protective coating layers for use in wet etch processes during the production of semiconductor and MEMS devices are provided. The layers include a primer layer, a first protective layer, and an optional second protective layer. The primer layer preferably comprises an organo silane compound in a solvent system. The first protective layer includes thermoplastic copolymers prepared from styrene, acrylonitrile, and compatible compounds such as monomers, oligomers, and polymers comprising epoxy groups; poly(styrene-co-allyl alcohol); and mixtures thereof. The second protective layer comprises a highly halogenated polymer such as a chlorinated polymer which may or may not be crosslinked upon heating.

Claims

1. A composition useful as a protective layer, said composition comprising a first polymer and a compatible compound dissolved or dispersed in a solvent system, wherein:

said first polymer comprises;

wherein;

each R¹ is individually selected from the group consisting of hydrogen and C₁-C₈ alkyls; and

each R² is individually selected from the group consisting of hydrogen, C₁-C₈ alkyls, and C₁-C₈ alkoxys;

said compatible compound is selected from the group consisting of;

monomers, oligomers, and polymers comprising epoxy groups;

poly(styrene-co-allyl alcohol); and

and mixtures thereof; and

said composition is substantially free of photoacid generators.

2. The composition of claim 1, wherein said compatible compound is selected from the group consisting of epoxy phenol novolac resins, epoxy bisphenol A/F resins, epoxy cresol novolac resins, epoxy bisphenol A resins, and epoxy bisphenol A novolac resins.

3. The composition of claim 1, wherein said compatible compound comprises from about 15% to about 30% by weight epoxy groups, based upon the total weight of the compatible compound taken as 100% by weight.

4. A method of forming a microelectronic device, said method comprising contacting a microelectronic structure with an etchant selected from the group consisting of basic etchants and acidic etchants, said microelectronic structure comprising:

a microelectronic substrate having a surface;

a primer layer adjacent said substrate surface; and

a first protective layer adjacent said primer layer, said first protective layer being formed from a composition comprising a first polymer and a compatible compound dissolved or dispersed in a solvent system, wherein;

said first polymer comprises;

wherein;

each R¹ is individually selected from the group consisting of hydrogen and C₁-C₈ alkyls; and

each R² is individually selected from the group consisting of hydrogen, C₁-C₈ alkyls, and C₁-C₈ alkoxys;

said compatible compound is selected from the group consisting of;

monomers, oligomers, and polymers comprising epoxy groups;

poly(styrene-co-allyl alcohol); and

and mixtures thereof; and

said composition is substantially free of photoacid generators.

5. The method of claim 4, wherein said contacting comprises immersing said microelectronic structure in said etchant.

6. The method of claim 4, said structure further comprising a second protective layer adjacent said first protective layer.

7. The method of claim 6, wherein said contacting comprises contacting said structure with one of said basic etchant and said acidic etchant, and further comprising contacting said structure with the other of said basic etchant and said acidic etchant.

8. The method of claim 4, said first protective layer having an average thickness of from about 1-5 μ

m.

9. The method of claim 4, wherein said microelectronic substrate is selected from the group consisting of Si substrates, SiO₂ substrates, Si₃N₄ substrates, SiO₂ on silicon substrates, Si₃N₄ on silicon substrates, glass substrates, quartz substrates, ceramic substrates, semiconductor substrates, and metal substrates.

10. The method of claim 4, said primer layer comprising a silane selected from the group consisting of an aromatic organo silanes, amino silanes, and mixtures thereof.

11. The method of claim 4, wherein said primer and protective layers exhibit less than about 3 mm of lifting when contacted for about 2 hours with a 30-35% by weight aqueous KOH solution having a temperature of about 83-87°

C.

12. The method of claim 4, wherein said primer layer and first protective layer interact to form bonds comprising:

13. A microelectronic structure comprising:

a microelectronic substrate having a surface;

a primer layer adjacent said substrate surface; and

a first protective layer adjacent said primer layer, said first protective layer comprising

a first polymer and a compatible compound dissolved or dispersed in a solvent system, wherein;

said first polymer comprises;

wherein;

each R¹ is individually selected from the group consisting of hydrogen and C₁-C₈ alkyls; and

each R² is individually selected from the group consisting of hydrogen, C₁-C₈ alkyls, and C₁-C₈ alkoxys;

said compatible compound is selected from the group consisting of;

monomers, oligomers, and polymers comprising epoxy groups;

poly(styrene-co-allyl alcohol); and

and mixtures thereof; and

said layer is substantially free of photoacid generators.

14. The structure of claim 13, said structure further comprising a second protective layer adjacent said first protective layer.

15. The structure of claim 13, said first protective layer having an average thickness of from about 1-5 μ

m.

16. The structure of claim 13, wherein said microelectronic substrate is selected from the group consisting of Si substrates, SiO₂ substrates, Si₃N₄ substrates, SiO₂ on silicon substrates, Si₃N₄ on silicon substrates, glass substrates, quartz substrates, ceramic substrates, semiconductor substrates, and metal substrates.

17. The structure of claim 13, said primer layer comprising a silane selected from the group consisting of an aromatic organo silanes, amino silanes, and mixtures thereof.

18. The structure of claim 13, wherein said primer and protective layers exhibit less than about 3 mm of lifting when contacted for about 2 hours with a 30-35% by weight aqueous KOH solution having a temperature of about 83-87°

C.