Silicon carbide device and method for forming a silicon carbide device
A silicon carbide device includes a silicon carbide substrate, a contact layer located on the silicon carbide substrate and including nickel and silicon, a barrier layer structure including titanium and tungsten, and a metallization layer comprising copper, wherein the contact layer is located between the silicon carbide substrate and at least a part of the barrier layer structure, wherein the barrier layer structure is located between the silicon carbide substrate and the metallization layer, wherein the metallization layer is configured as a contact pad of the silicon carbide device.
1 . A silicon carbide device, comprising:
a silicon carbide substrate;
a contact layer located on the silicon carbide substrate and comprising nickel and silicon;
a barrier layer structure comprising titanium and tungsten; and
a metallization layer comprising copper,
wherein the contact layer is located between the silicon carbide substrate and at least a part of the barrier layer structure,
wherein the barrier layer structure is located between the silicon carbide substrate and the metallization layer,
wherein the metallization layer is configured as a contact pad of the silicon carbide device,
wherein silicon is present within the contact layer throughout a vertical thickness of the contact layer,
wherein the barrier layer structure forms a direct interface with the contact layer.
2 . The silicon carbide device of claim 1 , wherein the barrier layer structure comprises a TiW layer.
3 . The silicon carbide device of claim 2 , wherein the TiW layer contacts the metallization layer.
4 . The silicon carbide device of claim 1 , wherein the barrier layer structure comprises a TiWN layer.
5 . The silicon carbide device of claim 4 , wherein the TiWN layer contacts the metallization layer.
6 . The silicon carbide device of claim 1 , wherein the barrier layer structure contacts the contact layer.
7 . The silicon carbide device of claim 1 , wherein the barrier layer structure comprises a Ti/TiN layer, and/or a TiW layer, and/or a TiWN layer, and/or a MON layer.
8 . The silicon carbide device of claim 1 , wherein the barrier layer structure comprises a Ti/TiN layer.
9 . The silicon carbide device of claim 8 , wherein the Ti/TiN layer contacts the contact layer.
10 . The silicon carbide device of claim 8 , wherein the barrier layer structure further comprises a TiW layer and/or a TiWN layer.
11 . The silicon carbide device of claim 8 , wherein a titanium layer of the Ti/TiN layer contacts the contact layer.
12 . The silicon carbide device of claim 1 , wherein a vertical thickness of the barrier layer structure is at least 100 nm and at most 600 nm.
13 . The silicon carbide device of claim 1 , wherein the contact layer comprises at least 1% and at most 20% silicon by volume.
14 . The silicon carbide device of claim 1 , wherein the contact layer comprises at most 10% carbon inclusions by volume.
15 . The silicon carbide device of claim 1 , wherein the contact layer is in ohmic contact with a first doping region of the silicon carbide substrate and/or with a second doping region of the silicon carbide substrate, wherein the first doping region has a first conductivity type, and wherein the second doping region has a second conductivity type.
16 . The silicon carbide device of claim 1 , wherein the metallization layer comprises at least 60% copper by volume.
17 . The silicon carbide device of claim 1 , wherein the metallization layer is at least 5 times thicker than each of the contact layer and the barrier layer structure.
18 . The silicon carbide device of claim 1 , further comprising a bondwire bonded to the metallization layer.
19 . The silicon carbide device of claim 18 , wherein the bondwire has a diameter of at most 100 μm.
20 . The silicon carbide device of claim 18 , wherein the bondwire is a copper bondwire.
21 . The silicon carbide device of claim 1 , further comprising a gate contact pad or a sense contact pad at least partially formed by the metallization layer, wherein a lateral surface area of the gate contact pad or sense contact pad is at most 200 μm by 200 μm.
22 . The silicon carbide device of claim 1 , wherein at least one of a transistor structure and/or a diode structure of the silicon carbide device has a breakdown voltage of more than 100V.
23 . The silicon carbide device of claim 1 , wherein a lateral dimension of the contact pad is at least 100 μm, and wherein a vertical thickness of the of the contact pad is at most 100 μm.
24 . The silicon carbide device of claim 1 , wherein an atomic ratio of Ni and Si within the contact layer varies at most by 5% in a vertical direction throughout the vertical thickness of the contact layer.