# US 12,007,435 B2 · Method of copper hillock detecting

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- Number: US 12,007,435 B2
- Document ID: US12007435B2
- Status: Granted
- Kind: B2
- Application number: 17/114,515
- Filed: 2020-12-08
- Published: 2022-06-09
- Granted: 2024-06-11
- Earliest claimed: 2020-12-08
- Assignees: United Microelectronics Corp.
- Applicants: United Microelectronics Corp.
- Inventors: Ching-Chih Chang; Yi-Hsiu Chen; Yuan-Fu Ko; Chih-Sheng Chang
- Web page: https://patentgrep.com/patent/US12007435B2

## CPC

- G01R 31/2884: {using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence)}
- G01R 31/2894: {Aspects of quality control [QC] (G01R31/31718 takes precedence; program control for QC G05B19/41875)}
- H10P 74/207: {Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics}
- H10P 74/277: {Circuits for electrically characterising or monitoring manufacturing processes, e.g. circuits in tested chips or circuits in testing wafers}
- Y10T 29/49004: including measuring or testing of device or component part
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method of copper hillock detecting includes the following steps. A testkey structure is disposed on a substrate, wherein the testkey structure includes a lower metallization layer, an upper metallization layer, and a dielectric layer between the lower metallization layer and the upper metallization layer. A force voltage difference is applied to the lower metallization layer and the upper metallization layer under a test temperature and stress time. A changed sensing voltage difference to the lower metallization layer and the upper metallization layer is detected for detecting copper hillock.

## Claims

### Claim 1

A method of copper hillock detecting, comprising:
disposing a testkey structure on a substrate, wherein the testkey structure comprises:
a lower metallization layer, an upper metallization layer, and a dielectric layer between the lower metallization layer and the upper metallization layer, wherein the lower metallization layer comprises a plurality of first metal lines parallel to each other, and the upper metallization layer comprises a plurality of second metal lines parallel to each other;
applying a force voltage difference to the lower metallization layer and the upper metallization layer under a test temperature and stress time, wherein a part of the second metal lines are connected to a first voltage, the other part of the second metal lines are connected to a second voltage, and the first metal lines are connected to ground; and
detecting a changed sensing voltage difference to the lower metallization layer and the upper metallization layer for detecting copper hillock.

### Claim 2 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the testkey structure is disposed in a scribe line of the substrate.

### Claim 3 (depends on 1)

The method of copper hillock detecting according to claim 1, further comprising:
performing a regular integrated circuit fabricating process on the substrate.

### Claim 4 (depends on 3)

The method of copper hillock detecting according to claim 3, further comprising:
processing a mass production after the changed sensing voltage difference is detected within a pre-determined voltage range.

### Claim 5 (depends on 3)

The method of copper hillock detecting according to claim 3, further comprising:
optimizing the regular integrated circuit fabricating process after the changed sensing voltage difference is detected out of a pre-determined voltage range.

### Claim 6 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the force voltage difference is at a range of 0-400V.

### Claim 7 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the test temperature is at a range of 25-300° C.

### Claim 8 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the stress time is at a range of 0.001-60 s.

### Claim 9 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the force voltage difference comprises a three-step voltage of a first step voltage, a second step voltage and a third step voltage.

### Claim 10 (depends on 9)

The method of copper hillock detecting according to claim 9, wherein the second step voltage is higher than the first step voltage and the third step voltage.

### Claim 11 (depends on 10)

The method of copper hillock detecting according to claim 10, wherein the first step voltage and the third step voltage is 40V, and the second step voltage is 400V.

### Claim 12 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the first metal lines and the second metal lines are crossly arranged.

### Claim 13 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the first metal lines and the second metal lines extend along a same direction.

### Claim 14 (depends on 13)

The method of copper hillock detecting according to claim 13, wherein the second metal lines vertically overlap the first metal lines.

### Claim 15 (depends on 1)

The method of copper hillock detecting according to claim 1, wherein the part of the second metal lines and the other part of the second metal lines are alternatively arranged.