Methods for fabrication of mmic and rf devices on engineered substrates

Patent metadata

Field	Value
Publication number	US-2025316618-A1
Application number	US-202519240965-A
Country	US
Kind code	A1
Filing date	Jun 17, 2025
Priority date	Oct 14, 2020
Publication date	Oct 9, 2025
Grant date	—

Abstract

A method of fabricating a MMIC system includes providing an engineered substrate including a growth substrate and a device layer coupled to the growth substrate, fabricating a plurality of MMIC device elements using the device layer, and providing a carrier substrate including a plurality of metallic structures. The method also includes bonding the plurality of metallic structures to the plurality of MMIC device elements, removing a portion of the growth substrate, and removing a portion of the carrier substrate. The method further includes forming a ground/power plane coupled to the growth substrate, forming a plurality of vias passing from the ground/power plane to one or more of the plurality of MMIC device elements, and joining a cooling structure to the carrier substrate.

First claim

What is claimed is:

1 . A method of fabricating a MMIC system, the method comprising:
providing an engineered substrate including a growth substrate and a device layer coupled to the growth substrate; fabricating a plurality of MMIC device elements using the device layer; providing a carrier substrate including a plurality of metallic structures; bonding the plurality of metallic structures to the plurality of MMIC device elements; removing a portion of the growth substrate; removing a portion of the carrier substrate; forming a ground/power plane coupled to the growth substrate; forming a plurality of vias passing from the ground/power plane to one or more of the plurality of MMIC device elements; and joining a cooling structure to the carrier substrate.

2 . The method of claim 1 further comprising joining a second cooling structure to the ground/power plane.

3 . The method of claim 1 further comprising, prior to joining the cooling structure to the carrier substrate:
forming a second ground/power plane coupled to the carrier substrate; and
forming a second plurality of vias passing from the second ground/power plane to one or more of the plurality of metallic structures.

4 . The method of claim 3 further comprising joining a second cooling structure to the ground/power plane.

5 . The method of claim 1 wherein a coefficient of thermal expansion (CTE) of the growth substrate substantially matches a CTE of the device layer.

6 . The method of claim 1 wherein the growth substrate comprises a polycrystalline ceramic core.

7 . The method of claim 6 wherein the polycrystalline ceramic core comprises aluminum nitride.

8 . The method of claim 1 wherein a thickness of the device layer is between 1 and 10 μm.

9 . The method of claim 8 wherein the device layer comprises gallium nitride (GaN).

10 . The method of claim 1 wherein the plurality of metallization structures are disposed between the plurality of MMIC device elements and the carrier substrate.

11 . The method of claim 1 wherein each of the plurality of MMIC device elements includes a corresponding metal structure and each of the plurality of metallic structures is joined to one of the corresponding metal structures.

12 . The method of claim 1 wherein bonding the plurality of metallic structures to the plurality of MMIC device elements comprises directly connecting the plurality of metallic structures to the plurality of MMIC device elements.

13 . The method of claim 1 wherein the carrier substrate is directly connected to the plurality of metallization structures.

14 . The method of claim 1 wherein the plurality of MMIC device elements are disposed between the device layer and the plurality of metallization structures.

Assignees

• Qromis Inc

Inventors

• Aktas Ozgur
• Odnoblyudov Vladimir
• Basceri Cem

Classifications

• H10P95/11

  Separation of active layers from substrates · CPC title

• H10W44/251

  for monolithic microwave integrated circuits [MMIC] · CPC title

• H10W70/02

  of conductive package substrates serving as an interconnection, e.g. of metal plates (manufacture or treatment of leadframes H10W70/04) · CPC title

• H10W40/22

  characterised by their shape, e.g. having conical or cylindrical projections · CPC title

• H10W20/427

  Power or ground buses · CPC title