Redistribution layers with carbon-based conductive elements, methods of fabrication and related semiconductor device packages and systems

Patent metadata

Field	Value
Publication number	US-10854549-B2
Application number	US-201816236681-A
Country	US
Kind code	B2
Filing date	Dec 31, 2018
Priority date	Dec 31, 2018
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

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.

First claim

What is claimed is:

1. A semiconductor device package, comprising:
a redistribution layer including conductive elements comprising a conductive carbon-based material and a conductive seed material on the conductive carbon-based material, the conductive elements of the redistribution layer defining a vertical height of less than about 0.2 μm, the vertical height being a maximum total vertical thickness of the conductive carbon-based material and the conductive seed material of the conductive elements of the redistribution layer;
a passivation material vertically adjacent the conductive seed material and between the conductive elements of the redistribution layer, the passivation material defining another vertical height of less than about 0.2 μm, the other vertical height being a maximum vertical thickness of the passivation material vertically adjacent the conductive seed material of the conductive elements of the redistribution layer; and
a device region of a semiconductor die comprising circuitry connected to the conductive elements of the redistribution layer, conductive plugs of the device region being in direct contact with the conductive carbon-based material of the redistribution layer,
the conductive seed material being directly vertically between the conductive carbon-based material and at least one portion of the passivation material.

2. The semiconductor device package of claim 1 , wherein the conductive carbon-based material exhibits an electrical resistivity of about 10 −6 Ω·m or less.

3. The semiconductor device package of claim 1 , wherein the conductive carbon-based material comprises graphene.

4. The semiconductor device package of claim 3 , wherein the conductive carbon-based material consists of graphene.

5. The semiconductor device package of claim 1 , wherein the conductive seed material is vertically thinner than the conductive carbon-based material.

6. The semiconductor device package of claim 1 , wherein the conductive seed material comprises a bi-layer of copper (Cu) and nickel (Ni) or comprises nickel (Ni).

7. The semiconductor device package of claim 1 , wherein the passivation material comprises an insulative nitride material.

8. A method for fabricating a semiconductor device package, the method comprising:
forming a conductive carbon-based material on a conductive seed material on a sacrificial substrate;
inverting the sacrificial substrate;
bonding the sacrificial substrate to a wafer comprising a device region of a semiconductor die comprising circuitry;
after the bonding, removing the sacrificial substrate to leave the conductive carbon-based material and the conductive seed material over the wafer;
forming conductive elements from the conductive carbon-based material and the conductive seed material; and
forming a passivation material vertically adjacent the conductive seed material and between the conductive elements,
the method forming the semiconductor device package comprising:
a redistribution layer including the conductive elements comprising the conductive carbon-based material and the conductive seed material on the conductive carbon-based material, the conductive elements of the redistribution layer defining a vertical height of less than about 0.2 μm, the vertical height being a maximum total vertical thickness of the conductive carbon-based material and the conductive seed material of the conductive elements of the redistribution layer;
the passivation material vertically adjacent the conductive seed material and between the conductive elements of the redistribution layer, the passivation material defining another vertical height of less than about 0.2 μm, the other vertical height being a maximum vertical thickness of the passivation material vertically adjacent the conductive seed material of the conductive elements of the redistribution layer; and
the device region of the semiconductor die comprising the circuitry connected to the conductive elements of the redistribution layer, conductive plugs of the device region being in direct contact with the conductive carbon-based material of the redistribution layer,
the conductive seed material being directly vertically between the conductive carbon-based material and at least one portion of the passivation material.

9. The method of claim 8 , wherein forming the passivation material vertically adjacent the conductive seed material and between the conductive elements comprises forming the passivation material above the conductive carbon-based material.

10. The method of claim 8 , further comprising, before forming the conductive carbon-based material on the conductive seed material on the sacrificial substrate:
forming a sacrificial base material directly on the sacrificial substrate, the sacrificial base material comprising a dielectric material; and
forming the conductive seed material directly on the sacrificial base material,
wherein forming the conductive carbon-based material on the conductive seed material on the sacrificial substrate comprises forming the conductive carbon-based material directly on the conductive seed material.

11. The method of claim 8 , wherein forming the conductive elements from the conductive carbon-based material and the conductive seed material comprises, after removing the sacrificial substrate, patterning the conductive carbon-based material and the conductive seed material to define the conductive elements, the conductive elements being discrete structures spaced by openings.

12. The method of claim 8 , wherein:
forming the conductive elements from the conductive carbon-based material and the conductive seed material comprises patterning the conductive carbon-based material to form the conductive elements as discrete structures defining openings between the discrete structures; and
forming the passivation material vertically adjacent the conductive seed material and between the conductive elements comprises over filling the openings with the passivation material.

13. The method of claim 8 , wherein forming the conductive elements from the conductive carbon-based material and the conductive seed material precedes inverting the sacrificial substrate.

14. The method of claim 8 , wherein forming the conductive elements from the conductive carbon-based material and the conductive seed material follows inverting the sacrificial substrate.

15. The method of claim 8 , wherein forming the conductive elements from the conductive carbon-based material and the conductive seed material and forming the passivation material vertically adjacent the conductive seed material and between the conductive elements comprise:
forming the passivation material on the sacrificial substrate;
patterning the passivation material to define openings; and
forming the conductive seed material and the conductive carbon-based material in the openings defined in the passivation material.

16. The method of claim 15 , further comprising, after removing the sacrificial substrate, forming another passivation material over the conductive carbon-based material.

17. A method for fabricating a semiconductor device package, the method comprising:
forming an initial support wafer comprising:
forming a conductive seed material on a sacrificial substrate; and
forming a conductive carbon-based material on the conductive seed material;

bonding a surface of the initial support wafer to another wafer comprising a device region of a semiconductor die comprising circuitry;
removing the sacrificial substrate; and
forming conductive elements from the conductive carbon-based

Assignees

• Micron Technology Inc

Inventors

• Nakano Eiichi

Classifications

• H10W90/401

  characterised by multiple insulating or insulated package substrates, interposers or RDLs · CPC title

• H10W90/00

  Package configurations · CPC title

• H10W70/65 Primary

  Shapes or dispositions of interconnections · CPC title

• H10W20/4462 Primary

  Carbon or carbon-containing materials, e.g. graphene · CPC title

• H10W20/4446

  Refractory-metal alloys · CPC title