Bonded structure having diffused metal oxide material surrounding misaligned bond pads or bond pads of different sizes and method of manufacturing thereof
View Patent ↗Embodiments of present invention provide a semiconductor structure. The semiconductor structure includes a first copper pad embedded in a first dielectric layer; a second copper pad embedded in a second dielectric layer; and an oxygen-containing inter-layer, where a portion of the oxygen-containing inter-layer is directly between the first copper pad and the second dielectric layer and includes a first alloy element of manganese, aluminum, zirconium, titanium, tin, or a combination thereof. A method of forming the same is also provided.
1 . A semiconductor structure comprising:
a first bond pad embedded in a first dielectric layer in a first substrate;
a second bond pad embedded in a second dielectric layer in a second substrate; and
an oxygen-containing inter-layer bonding the first substrate with the second substrate,
wherein at least a first portion of the oxygen-containing inter-layer vertically fully and directly contacts the first bond pad in the first substrate and the second dielectric layer in the second substrate and horizontally fully and directly contacts the second bond pad and a third portion of the oxygen-containing inter-layer, the first portion of the oxygen-containing inter-layer including a first alloy element such that it is materially different from the third portion of the oxygen-containing inter-layer.
2 . The semiconductor structure of claim 1 , wherein a second portion of the oxygen-containing inter-layer is vertically directly between the first dielectric layer in the first substrate and the second bond pad in the second substrate and horizontally directly between the first bond pad and a fourth portion of the oxygen-containing inter-layer, the second portion of the oxygen-containing inter-layer being materially different from the fourth portion of the oxygen-containing inter-layer to include a second alloy element.
3 . The semiconductor structure of claim 2 , wherein the first and the second bond pad are made of copper to be a first and a second copper pad respectively, and the first copper pad is directly bonded to the second copper pad.
4 . The semiconductor structure of claim 2 , wherein the first and the second alloy element are an alloy element selected from a group consisting of manganese, aluminum, zirconium, titanium, tin, or a combination thereof.
5 . The semiconductor structure of claim 2 , wherein the first and the second portion of the oxygen-containing inter-layer include manganese-oxide, aluminum-oxide, zirconium-oxide, titanium-oxide, or tin-oxide.
6 . The semiconductor structure of claim 1 , wherein the third portion of the oxygen-containing inter-layer is a layer of silicon-oxynitride, or a bilayer of silicon-nitride and oxygen doped silicon-carbide.
7 . The semiconductor structure of claim 1 , wherein the third portion of the oxygen-containing inter-layer is vertically directly between the first dielectric layer in the first substrate and the second dielectric layer in the second substrate.
8 . A semiconductor structure comprising:
a first copper pad embedded in a first dielectric layer;
a second copper pad embedded in a second dielectric layer; and
an oxygen-containing inter-layer,
wherein a portion of the oxygen-containing inter-layer vertically directly contacts the first copper pad and the second dielectric layer and horizontally directly contacts another portion of the oxygen-containing inter-layer that is directly between and contacts the first dielectric layer and the second dielectric layer, the portion of the oxygen-containing inter-layer is materially different from the another portion of the oxygen-containing inter-layer and includes a first alloy element of manganese, aluminum, zirconium, titanium, tin, or a combination thereof.
9 . The semiconductor structure of claim 8 , wherein the portion of the oxygen-containing inter-layer is a first portion of the oxygen-containing inter-layer, further comprising a second portion of the oxygen-containing inter-layer, the second portion of the oxygen-containing inter-layer is directly between the first dielectric layer and the second copper pad, is materially different from the another portion of the oxygen-containing inter-layer, and includes a second alloy element.
10 . The semiconductor structure of claim 8 , wherein the another portion of the oxygen-containing inter-layer that is directly between the first dielectric layer and the second dielectric layer horizontally surrounds a portion of the first copper pad and a portion of the second copper pad.
11 . The semiconductor structure of claim 8 , wherein the another portion of the oxygen-containing inter-layer is a layer of silicon-oxynitride, or a bilayer of silicon-nitride and oxygen doped silicon-carbide.
12 . The semiconductor structure of claim 8 , wherein a majority of the first copper pad is bonded directly to the second copper pad.
13 . A method comprising:
providing a first and a second substrate;
forming a first oxygen-containing inter-layer on the first substrate and forming a second oxygen-containing inter-layer on the second substrate;
forming a first copper pad with a first alloy element in the first substrate and forming a second copper pad with a second alloy element in the second substrate;
attaching the first substrate to the second substrate by bonding the first copper pad with the second copper pad and bonding the first oxygen-containing inter-layer with the second oxygen-containing inter-layer, wherein at least a portion of the first copper pad is bonded directly with the second oxygen-containing inter-layer in a first region of the second oxygen-containing inter-layer; and
annealing the first and the second substrate to segregate the first alloy element from the first copper pad into the first region, causing the first region to be materially different from another region of the second oxygen-containing inter-layer that directly contacts the first region but is not directly bonded with the first copper pad, wherein the first region directly contacts the first copper pad and the second substrate.
14 . The method of claim 13 , wherein attaching the first substrate to the second substrate further comprises subjecting the first and the second substrate to a first temperature of about 25 to 50 degrees Celsius for a duration between about 10 seconds to about 120 seconds while bonding the first copper pad with the second copper pad and bonding the first oxygen-containing inter-layer with the second oxygen-containing inter-layer.
15 . The method of claim 14 , wherein annealing the first and the second substrate comprises subjecting the first and the second substrate to a second temperature between 350 and 400 degrees Celsius for a duration between about 1 minute and about 120 minutes.
16 . The method of claim 13 , wherein the first and the second oxygen-containing inter-layers are a layer of silicon-oxynitride or a bilayer of silicon-nitride and oxygen doped silicon-carbide.
17 . The method of claim 13 , wherein the first and the second alloy element are manganese, aluminum, zirconium, titanium, tin, or a combination thereof and are materially different from each other.
18 . The method of claim 13 , wherein forming the first copper pad with the first alloy element comprises forming an alloy seed layer containing the first alloy element in an opening in the first substrate and performing an electroplating of copper on top of the alloy seed layer.
19 . The method of claim 13 , wherein at least a portion of the second copper pad is bonded directly with the first oxygen-containing inter-layer in a second region, and at least some of the second alloy element is segregated from the second copper pad into the second region.
20 . The method of claim 19 , wherein the first region is between the first copper pad and the second substrate surrounding the second copper pad wherein the second copper pad partially protrudes from the second substrate, and the second region is between the first substrate surrounding the first copper pad and the second copper pad wherein the first copper pad partially protrudes from the first substrate.