PACKAGE STRUCTURES TO IMPROVE ON-CHIP ANTENNA PERFORMANCE

• US 20140145884A1
• Filed: 11/27/2012
• Published: 05/29/2014
• Est. Priority Date: 11/27/2012
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Dang, Bing, Liu, Duixian, Marnat, Loc, Shamim, Atif, Tsang, Cornelia K.-I.
• Granted Patent: US 8,917,210 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device antennas per se H01Q
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/13025 the bump connector being disposed on a via connection of the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73215 Layer and wire connectors
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01Q 1/2283 mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

A radio frequency integrated circuit (RFIC) chip package is provided having an RFIC chip and an integrated antenna structure. The integrated antenna structure includes an on-chip antenna having one or more radiator elements formed as part of a back-end-of-line structure of the RFIC chip. The antenna structure further includes a superstrate structure disposed on the back-end-of-line structure of the RFIC chip. The superstrate structure includes at least one substrate layer and a focusing metal element. The focusing metal element has a structure that is complementary to the on-chip radiator elements and which is configured to focus electromagnetic radiation to and from the planar antenna structure. The superstrate structure improves the performance (e.g., antenna gain and bandwidth) of the on-chip antennas for millimeter-wave applications.

Claims

1. A package structure, comprising:

an RFIC (radio frequency integrated circuit) chip comprising a semiconductor substrate having an active surface and an inactive surface, and a BEOL (back end of line) structure formed on the active surface of the semiconductor substrate; and

an antenna structure comprising;

a planar antenna having one or more radiator elements formed as part of the BEOL structure of the RFIC chip; and

a superstrate structure disposed on a surface of the BEOL structure adjacent planar antenna, the superstrate structure comprising at least one substrate layer and a focusing metal element disposed on a surface of the at least one substrate and aligned to the one or more radiator elements of the planar antenna, wherein the focusing metal element has a structure that is complementary to the one or more radiator elements of the planar antenna and configured to focus electromagnetic radiation to and from the planar antenna structure.

2. The package structure of claim 1, wherein the at least one substrate of the superstrate structure is formed of a low loss semiconductor material.

3. The package structure of claim 2, wherein the low loss semiconductor material comprises high resistivity silicon, silica, quartz, or borofloat.

4. The package structure of claim 1, wherein the at least one substrate of the superstrate structure is formed of a low loss glass material.

5. The package structure of claim 1, wherein a total thickness of the at least one substrate layer of the superstrate structure is less than ¼

wavelength of an operating frequency of the planar antenna.

6. The package structure of claim 1, wherein the at least one substrate layer of the superstrate structure comprises a first substrate layer and a second substrate layer, wherein the focusing metal element is disposed on a surface of the second substrate layer and the first substrate layer is disposed between the BEOL structure and the second substrate layer.

7. The package structure of claim 6, wherein the first substrate layer is formed on high resistivity silicon, and wherein the second substrate layer is formed of borofloat.

8. The package structure of claim 1, wherein the planar antenna comprises a planar rectangular patch radiator element, and wherein the focusing metal element of the superstrate structure comprises a planar rectangular structure with a rectangular cutout feature that is aligned to the planar rectangular patch radiator element.

9. The package structure of claim 8, wherein the rectangular cutout feature of the focusing metal element is larger an area of the planar rectangular patch radiator element.

10. The package structure of claim 1, wherein the planar antenna comprises a planar rectangular fractal-patch radiator element, and wherein the focusing metal element of the superstrate structure comprises a planar rectangular structure with a rectangular cutout feature that is aligned to the planar rectangular fractal patch radiator element.

11. The package structure of claim 10, wherein the rectangular cutout feature of the focusing metal element is larger in area that an area of the planar rectangular fractal-patch radiator element.

12. The package structure of claim 1, wherein a footprint of the superstrate structure is smaller than a footprint of the RFIC chip.

13. The package structure of claim 1, wherein the superstrate structure and the RFIC chip have substantially a same size footprint.

14. The package structure of claim 1, further comprising an antenna feed line formed as part of the BEOL structure of the RFIC chip.

15. The package structure of claim 1, further comprising an antenna ground plane formed as part of the BEOL structure of the RFIC chip.

16. An apparatus, comprising;

an RFIC (radio frequency integrated circuit) chip comprising a semiconductor substrate having an active surface and an inactive surface, and a BEOL (back end of line) structure formed on the active surface of the semiconductor substrate; and

an antenna structure comprising;

a planar antenna having one or more radiator elements formed as part of the BEOL structure of the RFIC chip; and

a superstrate structure disposed on a surface of the BEOL structure adjacent planar antenna, the superstrate structure comprising at least one substrate layer and a focusing metal element disposed on a surface of the at least one substrate and aligned to the one or more radiator elements of the planar antenna, wherein the focusing metal element has a structure that is complementary to the one or more radiator elements of the planar antenna and configured to focus electromagnetic radiation to and from the planar antenna structure.

a circuit board, wherein the RFIC chip is mounted to the circuit board; and

electrical interconnect structures providing DC supply, ground, control and I/O baseband signal lines between the RFIC chip and the circuit board.

17. The apparatus of claim 16, wherein a footprint of the superstrate structure is smaller than a footprint of the RFIC chip, and wherein the electrical interconnect structures comprise:

contact pads formed as part of the BEOL structure and exposed on a peripheral surface region of the BEOL structure;

contact pads formed on the surface of the circuit board;

wire bonds formed between contacts pads on the surface of the BEOL structure and the circuit board; and

conductive vias and metal traces formed in the BEOL structure connecting the contact pads on the surface of the BEOL structure to one or more metal layers of the BEOL structure.

18. The apparatus of claim 16, wherein the superstrate structure and the RFIC chip have substantially a same size footprint, and wherein the electrical interconnect structures comprise:

conductive vias that are formed through the semiconductor substrate of the RFIC chip from the active surface to the inactive surface; and

contact pads on the inactive surface of the semiconductor subset of the RFIC chip forming electrical bonds to contact pads on the circuit board.

19. The apparatus of claim 16, wherein the superstrate structure is fabricated separately from the RFIC chip and bonded to the BEOL structure of the RFIC chip.

20. The apparatus of claim 16, wherein the superstrate structure is fabricated as part of a fabrication process of the RFIC chip using wafer scale fabrication.

21. The apparatus of claim 16, wherein the at least one substrate of the superstrate structure is formed of a low loss semiconductor material.

22. The apparatus of claim 21, wherein the low loss semiconductor material comprises high resistivity silicon, silica, or quartz.

23. The apparatus of claim 16, wherein the at least one substrate of the superstrate structure is formed of a low loss glass material.

24. The apparatus of claim 16, wherein a total thickness of the at least one substrate layer of the superstrate structure is less than ¼

wavelength of an operating frequency of the planar antenna.

25. The apparatus of claim 16, wherein the at least one substrate layer of the superstrate structure comprises a first substrate layer and a second substrate layer, wherein the focusing metal element is disposed on a surface of the second substrate layer and the first substrate layer is disposed between the BEOL structure and the second substrate layer.

26. The apparatus of claim 25, wherein the first substrate layer is formed of high resistivity silicon and wherein the second substrate layer is formed of borofloat.

27. The apparatus of claim 16, wherein the planar antenna comprises a planar rectangular patch radiator element, and wherein the focusing metal element of the superstrate structure comprises a planar rectangular structure with a rectangular cutout feature that is aligned to the planar rectangular patch radiator element.

28. The apparatus of claim 27, wherein the rectangular cutout feature of the focusing metal element is larger in area than an area of the planar rectangular patch radiator element.

29. The apparatus of claim 16, wherein the planar antenna comprises a planar rectangular fractal-patch radiator element, and wherein the focusing metal element of the superstrate structure comprises a planar rectangular structure with a rectangular cutout feature that is aligned to the planar rectangular fractal patch radiator element.

30. The apparatus of claim 29, wherein the rectangular cutout feature of the focusing metal element is larger in area that an area of the planar rectangular fractal-patch radiator element.