Metal etching method for an interconnect structure and metal interconnect structure obtained by such method
View Patent ↗A metal interconnects structure, comprises a substrate ( 11 ), a dielectric layer ( 12 ) lying above the substrate, a stop layer ( 13 ) for metal etching lying above the dielectric layer, a metal layer ( 15 ′) lying above the stop layer, said metal layer being patterned according to a desired pattern.
1. Subtractive method of manufacturing a metal interconnects structure on a substrate using a metal etching process, comprising the steps of:
depositing a dielectric layer above the substrate;
depositing a stop layer above the dielectric layer, the stop layer exhibiting a lower etch rate compared to an etch rate of the dielectric layer using the metal etching process;
depositing a first resist layer above the stop layer;
patterning the first resist layer according to a first desired pattern;
etching the stop layer through the patterned first resist layer;
after etching the stop layer, removing the patterned first resist layer;
etching the dielectric layer for forming contact or via holes using the patterned stop layer as a hard mask;
depositing a metal layer above the stop layer;
depositing a second resist layer above the metal layer;
patterning the second resist layer according to a second desired pattern; and
etching the metal layer through the patterned second resist layer up to the stop layer.
2. The method of claim 1 , further comprising, before depositing the metal layer, the steps of:
depositing a layer of Ti or TiN in the contact holes; and
filling the remaining portions of the contact holes with tungsten.
3. The method of claim 1 , wherein etching the metal layer includes plasma etching using a gas mixture that includes at least one of BCl 3 , HCl, HBr, HI and SF 6 .
4. The method of claim 1 , wherein the metal layer includes at least one of Al, W, Cu, Ti, TIN, Ta and TaN.
5. The method of claim 1 , further comprising, before depositing the metal layer, the steps of:
filling the contacts holes with metal for forming contacts; and,
planarizing the contacts by etch back or chemical-mechanical polishing and using the patterned stop layer as a stop layer.
6. The method of claim 1 , wherein the stop layer material is selected from the group comprising SiC, SiCN, SiBC, SiBCN, and combinations thereof.
7. The method of claim 1 , wherein the metal layer is copper.
8. Metal interconnect structure comprising:
a substrate;
a dielectric layer lying above the substrate;
a stop layer for metal etching, lying above the dielectric layer, the stop layer exhibiting a lower etch rate compared to an etch rate of the dielectric layer for the metal etching, and the stop layer containing at least one of SiC, SiCN, SiBC, and SiBCN;
a metal layer lying above the stop layer, said metal layer being patterned according to a first desired pattern.
9. The metal interconnect structure of claim 8 , wherein said dielectric layer and said stop layer are both patterned according to a second desired pattern.
10. The metal interconnect structure of claim 9 , wherein the patterned dielectric layer and the patterned stop layer define contacts holes filled with metal.
11. The metal interconnect structure of claim 10 , wherein the metal filling the contacts holes is at least one metal selected from the group comprising Al, W, Cu, Ti, TIN, Ta, TaN and combinations thereof.
12. The metal interconnect structure of claim 10 , wherein the metal filling the contacts holes tungsten and Ti or TiN.
13. The metal interconnect structure of claim 8 , wherein the metal layer material is at least one metal selected from the group comprising Al, W, Cu, Ti, TIN, Ta, TaN and combinations thereof.
14. Semiconductor device comprising an interconnect structure according to claim 8 .
15. Electronic apparatus comprising a semiconductor device according to claim 14 .
16. Integrated circuit chip comprising an interconnect structure according to claim 8 .
17. Electronic apparatus comprising an integrated circuit chip according to claim 16 .
18. Electronic apparatus comprising an interconnect structure according to claim 8 .
19. The metal interconnect structure of claim 8 , wherein the metal layer is copper.
20. A metal interconnect structure comprising:
a substrate;
a dielectric layer lying above the substrate;
a stop layer for metal etching, lying above the dielectric layer, the stop layer exhibiting a lower etch rate compared to an etch rate of the dielectric layer for the metal etching, and the stop layer containing at least one of SiC, SiCN, SiBC, and SiBCN;
a metal layer lying above the stop layer, said metal layer being patterned according to a first desired pattern,
wherein the metal interconnect structure is obtained by a method that includes,
depositing the dielectric layer above the substrate;
depositing the stop layer above the dielectric layer;
depositing a the metal layer above the stop layer;
depositing a first resist layer above the metal layer;
patterning the first resist layer according to the first desired pattern; and
etching the metal layer through the patterned first resist layer up to the stop layer.