Integrated circuit shield structure
View Patent ↗Embodiments of the invention provide an integrated circuit structure comprising: a substrate; a shield structure comprising a shield member and a ground strap formed on the substrate, wherein the shield member comprises a non-metallic portion, and the ground strap comprises a metallic portion.
1. An integrated circuit structure comprising:
a substrate; and
a shield structure comprising a shield member and a ground strap formed on the substrate,
wherein the shield member comprises a non-metallic portion, and the ground strap comprises a metallic portion.
2. A structure as claimed in claim 1 wherein the shield member comprises at least one conductive region.
3. A structure as claimed in claim 2 wherein said at least one conductive region is arranged substantially to inhibit an inducement of eddy current in the shield structure by a current in an inductor associated with the shield structure.
4. A structure as claimed in claim 3 wherein said at least one conductive region comprises a comb pattern of a plurality of conductive line elements.
5. A structure as claimed in claim 3 wherein the inductor has an inductor axis, the inductor axis being arranged to be substantially normal to a plane of the shield structure, the inductor axis passing through a centre of the inductor.
6. A structure as claimed in claim 5 wherein the at least one conductive region is oriented at an angle of at least substantially 30° to corresponding conductive track portions of the inductor, said corresponding conductive track portions being located directly above or below the at least one conductive region with respect to a direction parallel to the inductor axis.
7. A structure as claimed in claim 5 wherein said at least one conductive region is arranged not to pass through said inductor axis.
8. A structure as claimed in claim 1 wherein the shield member and ground strap are formed in the substrate.
9. A structure as claimed in claim 1 wherein the substrate comprises a dielectric material.
10. A structure as claimed in claim 1 wherein the shield member comprises doped polysilicon, undoped high resistivity polysilicon, or salicided doped polysilicon.
11. A structure as claimed in claim 1 wherein the shield member comprises at least one diffusion region in the substrate, or at least one polysilicon region or a combination thereof.
12. A structure as claimed in claim 1 wherein the shield structure extends from an inductor axis beyond a periphery of an inductor.
13. The structure as claimed in claim 1 wherein the ground strap is disposed around a periphery of the shield structure.
14. The structure as claimed in claim 1 wherein:
the shield member comprises first and second shield elements comprising different materials, and the second shield elements comprising doped diffusion regions.
15. The structure as claimed in claim 14 wherein the first and second shield elements are arranged in vertical overlap.
16. The structure as claimed in claim 1 wherein:
the shield member comprises first and second shield elements, the first shield elements comprising undoped polysilicon, doped polysilicon or salicided doped polysilicon and the second shield elements comprising doped diffusion regions.
17. The structure as claimed in claim 1 wherein the shield member comprises polysilicon having a resistance in the range of megaohms.
18. The structure as claimed in claim 1 further comprising an inductor with an operational frequency and wherein at least a portion of the shield member has a thickness less than the skin depth of the portion of the shield member at the operational frequency.
19. An integrated circuit structure comprising:
a substrate; and
a shield member and a ground strap formed on the substrate,
wherein the shield member comprises a plurality of conductive regions formed from a non-metallic material and arranged substantially to inhibit an inducement of eddy current in the shield member by a current in an inductor disposed adjacent to a shield portion, and the ground strap comprises a metallic portion.
20. An integrated circuit structure comprising:
a substrate;
shield elements formed on the substrate, the shield elements comprise a first material; and
a shield strap coupled to the shield elements, the shield strap comprises a second material, wherein the second material comprises a metallic material and is different from the first material.
21. The structure of claim 20 wherein the first material comprises undoped polysilicon, doped polysilicon or salicided doped polysilicon and the second material comprises aluminum or copper.