Bonding layer and process
A method includes providing a first substrate with a first surface including an alkyne moiety. The method includes providing a second substrate with a second surface including an azide moiety. The method further includes bonding the first substrate to the second substrate. The bonding of the first substrate to the second substrate includes making physical contact between the first surface and the second surface at an interface and chemically reacting the alkyne moiety with the azide moiety through a cycloaddition mechanism, thereby forming a triazole moiety-linked layer at the interface.
1 . A method, comprising:
providing a first substrate with a first surface including an alkyne moiety, wherein the provision of the first substrate comprises applying a first self-assembled monolayer (SAM) over the first surface, the first SAM having the alkyne moiety extending from the first surface;
providing a second substrate with a second surface including an azide moiety, wherein the provision of the second substrate comprises applying a second SAM over the second surface, the second SAM having the azide moiety extending from the second surface; and
bonding the first substrate to the second substrate, including making physical contact between the first surface and the second surface at an interface and chemically reacting the alkyne moiety with the azide moiety through a cycloaddition mechanism, thereby forming a triazole moiety-linked layer at the interface,
wherein applying the first SAM and the second SAM include depositing each of the first SAM and the second SAM as a blanket layer and removing portions of the first SAM and the second SAM.
2 . The method of claim 1 , wherein the alkyne moiety is coupled to the first substrate via a first base molecule and the azide moiety is coupled to the second substrate via a second base molecule.
3 . The method of claim 1 , wherein applying the first SAM and the second SAM each include implementing a selective deposition process.
4 . The method of claim 3 , wherein providing the first substrate further includes functionalizing the first surface before applying the first SAM and providing the second substrate further includes functionalizing the second surface before applying the second SAM.
5 . The method of claim 1 , wherein the first surface includes a first conductive feature disposed in a first dielectric layer and the second surface includes a second conductive feature disposed in a second dielectric layer, and wherein the first SAM and the second SAM are selectively formed over the first dielectric layer and the second dielectric layer, respectively.
6 . The method of claim 1 , wherein bonding the first substrate to the second substrate includes applying a thermal treatment to activate the cycloaddition mechanism.
7 . The method of claim 6 , wherein the thermal treatment is implemented at a temperature less than a temperature for forming the first SAM over a first dielectric layer comprising a first conductive feature of the first surface.
8 . A method, comprising:
providing a first substrate with a first bonding surface including a first self-assembled monolayer (SAM) having an alkyne group;
providing a second substrate with a second bonding surface including an azide group;
bonding the first substrate to the second substrate by making physical contact between the first bonding surface and second bonding surface; and
performing a thermal treatment implemented at a temperature less than a temperature for depositing the first SAM over the first bonding surface, thereby allowing a cycloaddition process to occur between the bonded first bonding surface and second bonding surface.
9 . The method of claim 8 , wherein bonding the first substrate to the second substrate includes aligning the first bonding surface with the second bonding surface.
10 . The method of claim 8 , wherein the alkyne group is linked to the first substrate by a first base molecule and the azide group is linked to the second substrate by a second base molecule.
11 . The method of claim 8 , wherein providing the first substrate includes forming a first self-assembled monolayer (SAM) over the first bonding surface, the first SAM including the alkyne group, and providing the second substrate includes forming a second SAM over the second bonding surface, the second SAM including the azide group.
12 . The method of claim 11 , wherein forming the first SAM includes selectively depositing the first SAM over the first bonding surface and forming the second SAM includes selectively depositing the second SAM over the second bonding surface.
13 . The method of claim 8 , wherein performing the thermal treatment causes the alkyne group to covalently bond with the azide group via the cycloaddition process, thereby forming a triazole group in a composite bonding layer.
14 . A semiconductor structure, comprising:
a first substrate;
a second substrate; and
a composite bonding layer covalently coupled to the first substrate and the second substrate, the composite bonding layer including a triazole moiety,
wherein the first substrate includes a first conductive feature disposed in a first dielectric layer and the second substrate includes a second conductive feature disposed in a second dielectric layer, and wherein the composite bonding layer extends between the first dielectric layer and the second dielectric layer.
15 . The semiconductor structure of claim 14 , wherein the composite bonding layer is covalently coupled to a first surface of the first substrate via a first base molecule and to a second surface of the second substrate via a second base molecule.
16 . The semiconductor structure of claim 14 , wherein the composite bonding layer extends to contact a sidewall of each of the first conductive feature and the second conductive feature.