IP Library Granted Patent US 8,972,922
Granted Patent B2
US 8,972,922 · App. 14/096,051 · Granted Mar 3, 2015

Method for forming an electrical connection between metal layers

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Quick Facts
Patent No.
US 8,972,922
App. No.
14/096,051
Granted
Mar 3, 2015
Kind
B2
Abstract

A method includes forming a connection between a first metal layer and a second metal layer. The second metal layer is over the first metal layer. A via location for a first via between the first metal layer and the second metal layer is identified. Additional locations for first additional vias are determined. The first additional vias are determined to be necessary for stress migration issues. Additional locations necessary for second additional vias are determined. The second additional vias are determined to be necessary for electromigration issues. The first via and the one of the group consisting of (i) the first additional vias and second additional vias (ii) the first additional vias plus a number of vias sufficient for electromigration issues taking into account that the first additional vias, after taking into account the stress migration issues, still have an effective via number greater than zero.

Claims (11)

1. A method of forming a connection between a first metal layer and a second metal layer overlying the first metal layer, comprising:

determining a first number of vias between the first metal layer and the second metal layer to achieve a first effective via number, wherein the first effective via number sufficiently takes into account stress migration effects;

determining a second effective via number for connecting between the first metal layer and the second metal layer, wherein the second effective via number is sufficient for addressing electromigration;

if the second effective via number does not exceed the first effective via number, forming, between the first metal layer and the second metal layer, the first number of vias;

if the second effective via number is greater than the first effective via number, forming, between the first metal layer and the second metal layer, a second number of vias in addition to forming the first number of vias to at least achieve the second effective via number; and

manufacturing an integrated circuit comprising the first number of vias, and, if the second number of vias are formed in addition to the first number of vias, the integrated circuit further comprises the second number of vias.

2. The method of claim 1 , wherein the second number of vias is the least number that achieves the second effective via number.

3. The method of claim 1 wherein the step of determining the first number of vias takes into account radii of the vias.

4. The method of claim 1 , wherein the step of determining the first number of vias takes into account expected vacancies from the first metal layer and expected vacancies from the second metal layer.

5. The method of claim 1 , wherein the step of determining the first number of vias includes determining an effective resistance for each via of the first number of vias based on expected vacancies from the first metal layer and the second metal layer.

6. The method of claim 5 , wherein the first effective via number is determined based on all of the effective resistances being in parallel.

Assignments (30)
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 11759915 AND REPLACE IT WITH APPLICATION 11759935 PREVIOUSLY RECORDED ON REEL 040925 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE RELEASE OF SECURITY INTEREST. Recorded Feb 17, 2020
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP, B.V. F/K/A FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 052917/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 11759915 AND REPLACE IT WITH APPLICATION 11759935 PREVIOUSLY RECORDED ON REEL 040928 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE RELEASE OF SECURITY INTEREST. Recorded Jan 17, 2020
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP B.V.
Reel/Frame 052915/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12298143 PREVIOUSLY RECORDED ON REEL 042985 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded Oct 22, 2019
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 051029/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12298143 PREVIOUSLY RECORDED ON REEL 042762 FRAME 0145. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded Oct 22, 2019
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 051145/0184 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12298143 PREVIOUSLY RECORDED ON REEL 038017 FRAME 0058. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded Oct 22, 2019
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 051030/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12298143 PREVIOUSLY RECORDED ON REEL 039361 FRAME 0212. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded Oct 22, 2019
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 051029/0387 →
RELEASE OF SECURITY INTEREST Recorded Sep 10, 2019
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP B.V.
Reel/Frame 050744/0097 →
RELEASE OF SECURITY INTEREST Recorded Sep 10, 2019
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP B.V.
Reel/Frame 050745/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE NATURE OF CONVEYANCE PREVIOUSLY RECORDED AT REEL: 040632 FRAME: 0001. ASSIGNOR(S) HEREBY CONFIRMS THE MERGER AND CHANGE OF NAME. Recorded Sep 21, 2017
From: FREESCALE SEMICONDUCTOR INC.
To: NXP USA, INC.
Reel/Frame 044209/0047 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12681366 PREVIOUSLY RECORDED ON REEL 038017 FRAME 0058. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded May 9, 2017
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 042985/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12681366 PREVIOUSLY RECORDED ON REEL 039361 FRAME 0212. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded May 9, 2017
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 042762/0145 →
CHANGE OF NAME Recorded Nov 8, 2016
From: FREESCALE SEMICONDUCTOR, INC.
To: NXP USA, INC.
Reel/Frame 040632/0001 →
RELEASE OF SECURITY INTEREST Recorded Nov 7, 2016
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP B.V.
Reel/Frame 040928/0001 →
RELEASE OF SECURITY INTEREST Recorded Sep 21, 2016
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP, B.V., F/K/A FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 040925/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 12092129 PREVIOUSLY RECORDED ON REEL 038017 FRAME 0058. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY AGREEMENT SUPPLEMENT. Recorded Jul 14, 2016
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 039361/0212 →
SUPPLEMENT TO THE SECURITY AGREEMENT Recorded Jun 16, 2016
From: FREESCALE SEMICONDUCTOR, INC.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 039138/0001 →
SECURITY AGREEMENT SUPPLEMENT Recorded Mar 7, 2016
From: NXP B.V.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 038017/0058 →
CORRECTIVE ASSIGNMENT TO CORRECT THE FILING AND REMOVE APPL. NO. 14085520 REPLACE IT WITH 14086520 PREVIOUSLY RECORDED AT REEL: 037515 FRAME: 0390. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS. Recorded Mar 1, 2016
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From: CITIBANK, N.A.
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CORRECTIVE ASSIGNMENT TO CORRECT THE INCORRECT APPL. NO. 14/085,520 PREVIOUSLY RECORDED AT REEL: 037515 FRAME: 0420. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS. Recorded Feb 11, 2016
From: CITIBANK, N.A.
To: MORGAN STANLEY SENIOR FUNDING, INC.
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CORRECTIVE ASSIGNMENT OF INCORRECT APPL. NO. 14/085,520 PREVIOUSLY RECORDED AT REEL: 037515 FRAME: 0390. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS. Recorded Feb 11, 2016
From: CITIBANK, N.A.
To: MORGAN STANLEY SENIOR FUNDING, INC.
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CORRECTIVE ASSIGNMENT OF INCORRECT PATENT APPLICATION NUMBER 14085520 ,PREVIOUSLY RECORDED AT REEL: 037458 FRAME: 0399. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS. Recorded Feb 11, 2016
From: CITIBANK, N.A.
To: MORGAN STANLEY SENIOR FUNDING, INC.
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From: CITIBANK, N.A.
To: MORGAN STANLEY SENIOR FUNDING, INC.
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CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE NAME PREVIOUSLY RECORDED ON REEL 037458 FRAME 0399. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS. Recorded Jan 14, 2016
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ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS Recorded Jan 7, 2016
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ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS Recorded Jan 7, 2016
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To: MORGAN STANLEY SENIOR FOUNDING, INC.
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PATENT RELEASE Recorded Dec 21, 2015
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To: FREESCALE SEMICONDUCTOR, INC.
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From: FREESCALE SEMICONDUCTOR, INC.
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From: FREESCALE SEMICONDUCTOR, INC.
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