Adhesion promoter apparatus and method
A structure comprises a substrate having a plateau region and a trench region, a reflecting layer formed over a top surface of the trench region, a first adhesion promoter layer formed over the reflecting layer, a bottom cladding layer deposited over the first adhesion promoter layer, a core layer formed over the bottom cladding layer and a top cladding layer formed over the core layer.
1. A device comprising:
a substrate having a plateau region and a trench region, wherein the trench region comprises:
a slope; and
a flat bottom, wherein the slope and the flat bottom form an angle of about 45 degrees, and wherein the substrate comprises a plurality of electrical circuits;
a reflecting layer formed over and in direct contact with a top surface of the trench region;
a first adhesion promoter layer formed over the reflecting layer, wherein the reflecting layer is fully covered by the first adhesion promoter layer;
a first bonding interface formed between the reflecting layer and the first adhesion promoter layer;
a bottom cladding layer deposited over the first adhesion promoter layer;
a second bonding interface formed between the first adhesion promoter layer and the bottom cladding layer, wherein the second bonding interface and the first bonding interface form a chemical structure comprising an oxidized material on a metal layer, a first dielectric material of the first adhesion promoter layer and a second dielectric material of the bottom cladding layer;
a core layer formed over the bottom cladding layer; and
a top cladding layer formed over the core layer.
2. The device of claim 1 , further comprising:
a dielectric layer formed over a top surface of the plateau region;
a redistribution layer formed over the dielectric layer; and
a passivation layer formed over the redistribution layer.
3. The device of claim 2 , further comprising:
a bonding stack formed in an opening of the passivation layer;
an external device formed over the bonding stack; and
an underfill layer formed between the substrate and the external device.
4. The device of claim 1 , further comprising:
a second adhesion promoter layer formed over the bottom cladding layer.
5. The device of claim 1 , further comprising:
a third adhesion promoter layer formed over the core layer.
6. The device of claim 1 , wherein:
the first adhesion promoter layer is formed of APTES.
7. A device comprising:
a silicon substrate having a plateau region and a trench region, wherein the trench region comprises a slope and a flat bottom;
a reflecting layer over a top surface of the trench region;
a first adhesion promoter layer over the reflecting layer;
a bonding interface formed between the first adhesion promoter layer and the reflecting layer, wherein the bonding interface comprises a chemical structure formed by an oxidized material on a metal layer and a dielectric material;
a bottom cladding layer over the first adhesion promoter layer;
a second adhesion promoter layer over the bottom cladding layer; and
a core layer over the second adhesion promoter layer.
8. The device of claim 7 , wherein:
the bonding interface is formed through a chemical reaction between the reflecting layer and the first adhesion promoter layer.
9. The device of claim 7 , further comprising:
the first adhesion promoter layer is formed of the dielectric material.
10. The device of claim 9 , wherein:
the dielectric material is APTES.
11. The device of claim 7 , further comprising:
a top cladding layer formed over the core layer.
12. The device of claim 11 , further comprising:
a third adhesion promoter layer formed between the core layer and the top cladding layer.
13. The device of claim 12 , further comprising:
the third adhesion promoter layer is formed of APTES.
14. The device of claim 7 , wherein:
the first adhesion promoter layer is formed over the slope and the flat bottom of the trench region.
15. A device comprising:
a silicon substrate having a plateau region and a trench region, wherein:
the trench region comprises a slope and a flat bottom;
a dielectric layer on the plateau region;
a redistribution layer on the dielectric layer;
a passivation layer on the redistribution layer;
a metal layer on the passivation layer and a sidewall of the dielectric layer;
a reflecting layer over the slope and the flat bottom of the trench region;
a first adhesion promoter layer over the reflecting layer;
a first bonding interface formed between the first adhesion promoter layer and the reflecting layer, wherein the first bonding interface comprises a chemical structure formed by an oxidized material on a top surface of a conductive layer and a dielectric material;
a bottom cladding layer over the first adhesion promoter layer;
a second adhesion promoter layer over the bottom cladding layer; and
a core layer over the second adhesion promoter layer.
16. The device of claim 15 , wherein:
the reflecting layer and the metal layer are formed of a same conductive material.
17. The device of claim 15 , wherein:
the first adhesion promoter layer is formed of the dielectric material.
18. The device of claim 15 , further comprising:
a second bonding interface formed between the first adhesion promoter layer and the bottom cladding layer, wherein the second bonding interface is a chemical structure formed by a polymer material and the dielectric material.
19. The device of claim 15 , wherein:
the core layer is formed of a photo sensitive polymer; and
the core layer comprises a vertical portion and a horizontal portion, wherein a sidewall of the vertical portion and a top surface of the horizontal portion form a right angle.
20. The device of claim 15 , further comprising:
a bonding stack over the plateau region, wherein:
a lower portion of the bonding stack is surrounded by the metal layer; and
an upper portion of the bonding stack is surrounded by an underfill layer.