Strong, heat stable junction
Provided among other things is an electrical device comprising: a first component that is a semiconductor or an electrical conductor; a second component that is an electrical conductor; and a strong, heat stable junction there between including an intermetallic bond formed of: substantially (a) indium (In), tin (Sn) or a mixture thereof, and (b) substantially nickel (Ni). The junction can have an electrical contact resistance that is small compared to the resistance of the electrical device.
1. An electrical device comprising:
a first component that is a semiconductor or an electrical conductor comprising a layer comprising tin (Sn);
a second component that is an electrical conductor comprising a layer comprising nickel (Ni); and
a conductive strong, heat stable bond formed between the (a) the layer comprising tin (Sn), and (b) the layer comprising nickel (Ni), the bond comprising Ni 3 Sn 2 ,
wherein a transition occurs to the strength and stability of the bond when the first and second components are heated to a range of about 795° C. or higher causing cross-migration of the tin and nickel at the interface of the respective layers of the first and second components forming the Ni 3 Sn 2 .
2. The electrical device of claim 1 , wherein the bond further comprises Sn 3 Ni 2 .
3. The electrical device of claim 1 , wherein the bond is formed of about 35 atomic percent to about 85 atomic percent tin.
4. The electrical device of claim 1 , wherein the bond is formed of about 15 atomic percent to about 65 atomic percent nickel.
5. The electrical device of claim 1 , wherein the bond is thermally and mechanically stable at least up to a temperature of about 750° C.
6. The electrical device of claim 1 , wherein the bond has a resistivity of less than 15 microOhm-cm.
7. The electrical device of claim 1 , wherein the bond has a resistivity of less than 1 microOhm-cm.
8. The electrical device of claim 1 , wherein the first component is a semiconductor.
9. The electrical device of claim 8 , wherein the semiconductor is an n-type or p-type semiconductor.
10. The electrical device of claim 1 , wherein the bond does not comprise indium.
11. A method of forming an electrical device comprising:
a first component that is a semiconductor or an electrical conductor comprising a layer comprising tin (Sn);
a second component that is an electrical conductor comprising a layer comprising nickel (Ni); and
a conductive strong, heat stable bond formed between the (a) the layer comprising tin (Sn), and (b) the layer comprising nickel (Ni), the bond comprising Ni 3 Sn 2 ,
the method comprising:
heating the first component and the second component to a temperature of about 795° C. or higher, thereby forming the conductive strong, heat stable bond formed between the (a) the layer comprising tin (Sn), and (b) the layer comprising nickel (Ni) comprising the Ni 3 Sn 2 ,
wherein a transition occurs to the strength and stability of the bond when the first and second components are heated to said temperature range causing cross-migration of the tin and nickel at the interface of the respective layers of the first and second components forming the Ni 3 Sn 2 .
12. The method of claim 11 , wherein the bond is formed from the layer comprising tin of the first component aligned between the layer comprising nickel of the second component and another layer of nickel.
13. The method of claim 11 , wherein the layer comprising tin (Sn) of the first component comprises a mixture of tin (Sn) and indium (In).
14. The method of claim 11 , wherein the bond is formed of about 35 atomic percent to about 85 atomic percent tin.
15. The method of claim 11 , wherein the bond is formed of about 15 atomic percent to about 65 atomic percent nickel.
16. The method claim 11 , further comprising:
applying a force sufficient to maintain alignment of the first component and the second component while the tin and nickel react during said heating.
17. The method of claim 11 , wherein the bond formed has a resistivity of less than 15 microOhm-cm.
18. The electrical device of claim 1 , wherein the layer comprising tin (Sn) comprises a mixture of tin (Sn) and indium (In), and the bond further comprises (In x Sn (1-x) ) 3 Ni 2 where 0>x>1, where x is wt. %.
19. The method of claim 13 , wherein the mixture of indium and tin in the layer of tin of first component is characterized as x wt. % In: (1−x) wt. % Sn, where 0>x>1.
20. The method of claim 11 , wherein the first component and the second component are heated to a temperature between about 911° C. and about 948° C.