Device packages including redistribution layers with carbon-based conductive elements, and methods of fabrication
View Patent ↗Semiconductor device packages include a redistribution layer (RDL) with carbon-based conductive elements. The carbon-based material of the RDL may have low electrical resistivity and may be thin (e.g., less than about 0.2 μm). Adjacent passivation material may also be thin (e.g., less than about 0.2 μm). Methods for forming the semiconductor device packages include forming the carbon-based material (e.g., at high temperatures (e.g., at least about 550° C.)) on an initial support wafer with a sacrificial substrate. Later or separately, components of a device region of the package may be formed and then joined to the initial support wafer before the sacrificial substrate is removed to leave the carbon-based material joined to the device region.
1. A method for fabricating a semiconductor device package, the method comprising:
forming an initial support wafer comprising a redistribution layer on a sacrificial substrate, the redistribution layer comprising conductive elements comprising a conductive carbon-based material in a passivation material;
bonding the initial support wafer to an additional wafer to form a bonded structure, the additional wafer comprising a device region comprising circuitry comprising semiconductor device components, the device region also comprising vias extending through the circuitry;
after the bonding, inverting the bonded structure and removing the sacrificial substrate to leave the conductive carbon-based material over the additional wafer; and
forming openings extending through the passivation material to the conductive elements, the method forming a semiconductor device package comprising:
the redistribution layer comprising the conductive elements comprising the conductive carbon-based material, the conductive carbon-based material defining a vertical height, between a lower surface and an upper surface of the conductive carbon-based material, of less than about 0.2 μm;
the passivation material laterally between and partially overlapping the upper surface of the conductive elements, the passivation material defining the openings, the openings extending through the passivation material to the conductive elements; and
the device region directly adjacent the conductive carbon-based material of the conductive elements of the redistribution layer, wherein the device region further comprises the vias extending from the lower surface of the conductive carbon-based material and through the circuitry of the device region.
2. The method of claim 1 , wherein forming the initial support wafer comprises forming the redistribution layer so that the conductive carbon-based material and the passivation material each define a height of less than about 0.2 μm.
3. The method of claim 1 , wherein forming the initial support wafer comprises:
forming a sacrificial base material directly on the sacrificial substrate, the sacrificial base material comprising some of the passivation material;
forming a seed material directly on the sacrificial base material; and
forming the conductive carbon-based material directly on the seed material.
4. The method of claim 3 , further comprising, after removing the sacrificial substrate, removing the seed material.
5. The method of claim 3 , further comprising, patterning the conductive carbon-based material to define the conductive elements as discrete structures.
6. The method of claim 3 , wherein forming the initial support wafer further comprises:
patterning the conductive carbon-based material and the seed material to define the conductive elements as discrete structures spaced by additional openings; and
forming more of the passivation material in the additional openings.
7. The method of claim 1 , wherein forming the initial support wafer comprising the redistribution layer comprises:
forming the passivation material on the sacrificial substrate;
forming the conductive carbon-based material on the passivation material;
patterning the conductive carbon-based material to form the conductive elements as discrete structures defining additional openings between the discrete structures; and
filling the additional openings with an additional amount of the passivation material.
8. The method of claim 7 , wherein patterning the conductive carbon-based material precedes inverting the bonded structure.
9. The method of claim 1 , wherein forming the initial support wafer comprising the redistribution layer comprises:
forming the passivation material on the sacrificial substrate;
patterning the passivation material to define other openings; and
forming the conductive carbon-based material in the other openings defined in the passivation material to form the conductive elements comprising the conductive carbon-based material in the passivation material.
10. The method of claim 9 , further comprising, after removing the sacrificial substrate, forming more of the passivation material over the conductive carbon-based material.
11. A method for fabricating a semiconductor device package, the method comprising:
forming an initial support wafer comprising:
forming a conductive carbon-based material in a passivation material on a sacrificial substrate;
bonding a surface of the initial support wafer to another wafer comprising a device region comprising circuitry comprising semiconductor device components, the device region also comprising vias extending through the circuitry;
removing the sacrificial substrate; and
forming openings extending through the passivation material to the conductive carbon-based material,
the method forming a semiconductor device package comprising:
a redistribution layer comprising conductive elements comprising the conductive carbon-based material, the conductive carbon-based material defining a vertical height, between a lower surface and an upper surface of the conductive carbon-based material, of less than about 0.2 μm;
the passivation material laterally between and partially overlapping the upper surface of the conductive elements, the passivation material defining the openings, the openings extending through the passivation material to the conductive elements; and
the device region directly adjacent the conductive carbon-based material of the conductive elements of the redistribution layer, wherein the device region further comprises the vias extending from the lower surface of the conductive carbon-based material and through the circuitry of the device region.
12. The method of claim 11 , wherein forming the conductive carbon-based material in the passivation material on the sacrificial substrate comprises forming graphene in a dielectric material on a semiconductor substrate.
13. The method of claim 11 , wherein forming the conductive carbon-based material comprises forming the conductive carbon-based material at a temperature of at least 550° C. without exposing the other wafer comprising the semiconductor device components to the temperatures.
14. A device package, comprising:
a redistribution layer comprising conductive elements comprising a conductive carbon-based material defining a vertical height, between a lower surface and an upper surface of the conductive carbon-based material, of less than about 0.2 μm;
passivation material laterally between and partially overlapping the upper surface of the conductive elements, the passivation material defining openings extending therethrough to the conductive elements; and
a device region directly adjacent the conductive carbon-based material of the conductive elements of the redistribution layer, wherein the device region further comprises vias extending from the lower surface of the conductive carbon-based material and through circuitry of the device region.
15. The device package of claim 14 , wherein the conductive elements further comprise a seed material on the upper surface of the conductive carbon-based material.
16. The device package of claim 15 , wherein the openings defined by the passivation material extend directly to the seed material of the conductive elements.
17. The device package of claim 15 , wherein the seed material is not horizontally adjacent sidewalls of the conductive carbon-based material.
18. The device package of claim 14 , wherein the passivation material is directly laterally adjacent the conductive carbon-based material of the conductive elements.
19. The device package of claim 14 , wherein the conductive carbon-based material consists essentially of graphene.