# US 10,319,518 B2 · Method of manufacturing a vertical inductor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,319,518 B2 - Document ID: US10319518B2 - Status: Granted - Kind: B2 - Application number: 15/963,033 - Filed: 2018-04-25 - Published: 2018-08-30 - Granted: 2019-06-11 - Earliest claimed: 2014-04-22 - Assignees: Semiconductor Manufacturing International (Shanghai) Corporation - Applicants: Semiconductor Manufacturing International (Shanghai) Corporation - Inventors: Dekui Qi; Haifang Zhang; Xuanjie Liu; Zheng Chen; Xin Li - Web page: https://patentgrep.com/patent/US10319518B2 ## CPC - H01F 41/041: {Printed circuit coils (apparatus or processes for manufacturing printed circuits in general H05K3/00)} - H01F 5/00: Coils (superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00) - H01F 17/0013: {with stacked layers} - H01F 2017/002: {Details of via holes for interconnecting the layers} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract A method of fabricating a spiral inductor includes providing a substrate having a top surface and a bottom surface, forming a plurality of through holes aligned in a vertical plane and spaced apart from each other, forming a metal interconnect structure having at least one top metal layer on the top surface of the substrate, the metal interconnect structure configured to connect to a top portion of the through holes, and forming a redistribution layer having at least a bottom layer on the bottom surface of the substrate. The redistribution layer is configured to connect to a bottom portion of the through holes to form a spiral structure. ## Claims ### Claim 1 A method of fabricating a spiral inductor, the method comprising: providing a substrate having a top surface and a bottom surface; forming a plurality of through holes aligned in a same vertical plane and spaced apart from each other; forming a metal interconnect structure having at least one top metal layer on the top surface of the substrate, the metal interconnect structure configured to connect to a top portion of the through holes; forming a redistribution layer having at least a bottom layer on the bottom surface of the substrate, the redistribution layer configured to connect to a bottom portion of the through holes to form a spiral structure in the same vertical plane. ### Claim 2 (depends on 1) The method of claim 1, further comprising, after forming the metal interconnect structure, forming a protective layer on the metal interconnect structure. ### Claim 3 (depends on 2) The method of claim 2, further comprising, after forming the redistribution layer, removing the protective layer. ### Claim 4 (depends on 1) The method of claim 1, further comprising: forming a plurality of bottom vias in the redistribution layer. ### Claim 5 (depends on 1) The method of claim 1, wherein the plurality of through holes comprises a first through hole, a second through hole, a third through hole, and a fourth through hole; the method further comprising: forming a first top metal layer having a plurality of spaced apart portions; forming a plurality of top vias on the first top metal layer; forming a second top metal layer on the plurality of top vias, the second top metal layer having at least three portions, wherein a first portion connects the first through hole with the third through hole through first and second top vias. ### Claim 6 (depends on 5) The method of claim 5, further comprising: connecting a second portion of the second top metal layer with the second through hole through a third top via to form a first connecting terminal; and connecting a third portion of the second top metal layer with the fourth through hole through a fourth top via to form a second connecting terminal. ### Claim 7 (depends on 1) The method of claim 1, wherein the plurality of through holes comprises a first through hole, a second through hole, a third through hole, and a fourth through hole; the method further comprising: removing a portion of the bottom surface of the substrate to expose the bottom portion of the through holes; forming a first bottom metal layer having a plurality of spaced apart portions, one of the spaced apart portion connecting the second and third through holes; forming a plurality of bottom vias on the first bottom metal layer; and forming a second bottom metal layer on the bottom vias connecting the first and fourth through holes. ### Claim 8 A method of fabricating a spiral inductor, the method comprising: providing a substrate having a top surface and a bottom surface; forming a first set of through holes and a second set of through holes spaced apart from each other by a first distance, the through holes in the first set of the through holes and the through holes in the second set of through holes being spaced apart from each other by a second distance that is smaller than the first distance; forming a metal interconnect structure having at least one top metal layer on the top surface of the substrate, the metal interconnect structure configured to connect to a top portion of the through holes; and forming a redistribution layer having at least a bottom layer on the bottom surface of the substrate, the redistribution layer configured to connect to a bottom portion of the through holes to form a spiral structure in a same vertical plane. ### Claim 9 (depends on 8) The method of claim 8, wherein forming the metal interconnect structure comprises: forming a dielectric layer on the top surface of the substrate; forming a patterned photoresist layer on the dielectric layer; etching the dielectric layer using the patterned photoresist layer as a mask to form a trench exposing the through holes; and filling the trench with a metal material to form the metal interconnect structure. ### Claim 10 (depends on 8) The method of claim 8, further comprising, after forming the metal interconnect structure, forming a protective layer on the metal interconnect structure. ### Claim 11 (depends on 10) The method of claim 10, further comprising, after forming the redistribution layer, removing the protective layer. ### Claim 12 (depends on 8) The method of claim 8, further comprising, after forming the metal interconnect structure and prior to forming the redistribution layer: removing portion of the bottom surface of the substrate to expose the bottom portion of the through holes. ### Claim 13 (depends on 8) The method of claim 8, wherein forming the redistribution layer comprises: forming a first redistribution layer having a first bottom metal layer; and forming a second redistribution layer over the first redistribution layer and having a second bottom metal layer. ### Claim 14 (depends on 8) The method of claim 8, wherein the metal interconnect layer comprises a plurality of top vias. ### Claim 15 (depends on 8) The method of claim 8, wherein the redistribution layer comprises a plurality of bottom vias. ### Claim 16 (depends on 8) The method of claim 8, wherein the at least one top metal layer comprises: a first top metal layer including first, second, third, and fourth top portions spaced apart from each other, each of the top portions being directly connected to one of the through holes; and a second top metal layer including a first portion, a second portion, and a third portion spaced apart from each other, wherein the first portion of the second top metal layer is connected to the first and third top portions of the first top metal layer, the second portion of the second top metal layer is connected to the second top portion of the first top metal layer and a first terminal of the spiral inductor, and the third portion of the second top metal layer is connected to the fourth portion of the first top metal layer and a second terminal of the spiral inductor. ### Claim 17 (depends on 16) The method of claim 16, wherein the first terminal and the second terminal are disposed at opposite ends of the spiral inductor. ### Claim 18 (depends on 8) The method of claim 8, wherein each of the through holes comprises a liner layer on an inner surface, a barrier layer on the liner layer, and a conductive layer on the barrier layer. ### Claim 19 (depends on 18) The method of claim 18, wherein the barrier layer comprises a stack of TiN and Ti layers. ### Claim 20 (depends on 18) The method of claim 18, wherein the conductive layer comprises one of Pt, Au, Ti, and W, or a combination thereof.