阅读说明：本技术 电迁移可靠性测试结构及电迁移可靠性测试方法 (Electromigration reliability test structure and electromigration reliability test method ) 是由 马琼 曹巍 陈雷刚 于 2019-09-23 设计创作，主要内容包括：本申请公开了一种电迁移可靠性测试结构及电迁移可靠性测试方法,该测试结构包括：测试线,测试线为集成电路中的互连线；第一通孔,第一通孔的第一端和测试线的第一端连接；第一引线,第一引线与第一通孔的第二端以及第一电流线连接,第一引线和第一通孔的第二端的连接位置和至少一对电压感测线连接；第二通孔,第二通孔的第一端和测试线的第二端连接；第二引线,第二引线与第二通孔的第二端以及第二电流线连接,第二引线和第二通孔的第二端的连接位置和至少一根电压感测线连接。本申请通过在通孔附近连接至少一对电压感测线,能够增加捕捉到测试线电阻变化的几率,提高了电迁移可靠性测试的精确度；同时,当通孔附近设置有一对以上的电压感测线时,能够进一步增加捕捉到测试线电阻变化的几率。(The application discloses electromigration reliability test structure and electromigration reliability test method, this test structure includes: the test line is an interconnection line in the integrated circuit; the first end of the first through hole is connected with the first end of the test line; the first lead is connected with the second end of the first through hole and the first current line, and the connection position of the first lead and the second end of the first through hole is connected with at least one pair of voltage sensing lines; the first end of the second through hole is connected with the second end of the test line; and the second lead is connected with the second end of the second through hole and the second current line, and the connection position of the second lead and the second end of the second through hole is connected with at least one voltage sensing line. According to the electromigration reliability testing device, at least one pair of voltage sensing lines are connected near the through hole, so that the probability of capturing resistance change of the testing lines can be increased, and the electromigration reliability testing accuracy is improved; meanwhile, when more than one pair of voltage sensing lines are arranged near the through hole, the probability of capturing the resistance change of the testing line can be further increased.)

1. An electromigration reliability test structure, wherein the electromigration reliability test structure is used for detecting electromigration reliability of an interconnect line in an integrated circuit, comprising:

the test line is an interconnection line in the integrated circuit;

a first through hole, a first end of which is connected with a first end of the test line;

a first lead connected to a second end of the first via and a first current line, a connection position of the first lead and the second end of the first via being connected to at least one pair of voltage sensing lines;

a second through hole, a first end of the second through hole being connected to a second end of the test line;

and the second lead is connected with the second end of the second through hole and the second current line, and the connection position of the second lead and the second end of the second through hole is connected with at least one voltage sensing line.

2. The electromigration reliability test structure of claim 1, wherein the connection location of the test line and the first end of the first via is further connected to at least one pair of voltage sense lines;

the connection position of the test line and the first end of the second through hole is also connected with at least one voltage sensing line.

3. The electromigration reliability test structure of claim 2, wherein the connection location of the second lead and the second end of the second via is further connected to at least one pair of voltage sense lines.

4. The electromigration reliability test structure of claim 3, wherein the connection location of the test line and the first end of the second via is further connected to at least one pair of voltage sense lines.

5. The electromigration reliability test structure of claim 4, wherein when the electromigration reliability test structure is in operation, a current is passed to the electromigration reliability test structure through the first current line and the second current line; measuring at least one of the following voltages:

a voltage between either voltage sense line of each pair of voltage sense lines at a connection location of the first lead and the second end of the first via and either voltage sense line at a connection location of the second lead and the second end of the second via;

a voltage between the test line and any one of the pair of voltage sensing lines at the connection position of the first end of the first via and any one of the pair of voltage sensing lines at the connection position of the test line and the first end of the second via;

a voltage between either voltage sense line of each pair of voltage sense lines at a connection location of the second lead and the second end of the second via and either voltage sense line of each pair of voltage sense lines at a connection location of the first lead and the second end of the first via;

a voltage between the test line and any one of the pair of voltage sensing lines at the connection location of the first end of the first via and the test line.

6. The electromigration reliability test structure of any of claims 1 to 4, wherein the width of the test line, the first via, the second via, the first lead, and the second lead is less than 130 nm.

7. The electromigration reliability test structure of claim 6, wherein the widths of the first current line, the second current line, and the voltage sense line are less than 130 nanometers.

8. The electromigration reliability test structure of claim 7, wherein a distance between each of the first current line, the second current line, and the voltage sense line is less than 130 nm.

9. The electromigration reliability test structure of any of claims 1 to 4, wherein the test line comprises copper and tantalum, and the first via and the second via comprise copper and tantalum.

10. The electromigration reliability test structure of any of claims 1 to 4, wherein the test line comprises aluminum and titanium, and the first via and the second via comprise tungsten.

11. An electromigration reliability test method, which is used for testing the electromigration reliability of an interconnection line in an integrated circuit, and comprises the following steps:

applying a current to the electromigration reliability test structure of any of claims 1 to 10;

monitoring voltage, and when the voltage is monitored, taking out a test wire, and carrying out failure physical analysis on the test wire so as to capture a site for forming a cavity; or

Monitoring voltage, and when the voltage is monitored, starting to record time until the voltage is not changed any more so as to record the time for obtaining the cavity formation; and analyzing the failure physical property of the test line according to the time for forming the cavity.

12. The electromigration reliability test method of claim 11 wherein a current density passing into the electromigration reliability test structure has a value in a range of 1 ma/cm to 10 ma/cm.

13. The electromigration reliability test method of claim 11 or 12, wherein a test temperature of the electromigration reliability test method is in a range of 150 degrees celsius to 450 degrees celsius.

Technical Field

The application relates to the technical field of reliability assessment in the field of semiconductor manufacturing, in particular to an electromigration reliability test structure and an electromigration reliability test method.

Background

The electromigration phenomenon refers to a phenomenon that when an integrated circuit in a semiconductor device works, current flows through a metal wire, and metal ions generate substance transportation under the action of the current. Therefore, some portions of the metal lines may be broken due to voids (Void) caused by the electromigration phenomenon, and some portions may be shorted due to hillocks (Hillock) caused by the electromigration phenomenon.

In the integrated circuit process development stage, reliability evaluation is an important part of successful evaluation of process development, and an electromigration reliability test for the electromigration phenomenon is an essential test in the later stage of process evaluation.

Referring to fig. 1, an electromigration reliability test structure provided in the related art is shown. The electromigration reliability test structure includes a test line 110, a first via 121, a second via 122, a first lead 131, and a second lead 132. The first lead 131 is connected to the first through hole 121, the first through hole 121 is connected to one end of the test line 110, the second through hole 122 is connected to the other end of the test line 110, and the second through hole 122 is connected to the second lead 132.

During testing, the first lead 131 is connected to the first voltage sensing line and the first current line, the second lead 132 is connected to the second voltage sensing line and the second current line, the first voltage sensing line, the second voltage sensing line, the first current line and the second current line are connected to the corresponding pads, current is supplied to the test structure through the first current line and the second current line, and the resistance of the voltage monitoring test line of the test line is measured through the first voltage sensing line and the second voltage sensing line.

In the test process of the test structure, because the through hole has a small volume, the time required for generating the cavity (such as the cavity 101 in fig. 1) by pushing the metal ions is short, the test line is generally wide and thick, the forming range of the cavity is large, and adjacent atoms supplement in the cavity accumulation process, when the resistance completely jumps, the cavity is formed at the bottom or the upper part of the through hole, so that the jump moment of the resistance of the test line is difficult to capture in time.

Disclosure of Invention

The application provides an electromigration reliability test structure and an electromigration reliability test method, which can solve the problem that the electromigration reliability test structure provided in the related technology is difficult to capture the change of the resistance of a test line.

In one aspect, an embodiment of the present application provides an electromigration reliability test structure, where the electromigration reliability test structure is used to detect electromigration reliability of an interconnection line in an integrated circuit, and includes:

the test line is an interconnection line in the integrated circuit;

a first through hole, a first end of which is connected with a first end of the test line;

a first lead connected to a second end of the first via and a first current line, a connection position of the first lead and the second end of the first via being connected to at least one pair of voltage sensing lines;

a second through hole, a first end of the second through hole being connected to a second end of the test line;

and the second lead is connected with the second end of the second through hole and the second current line, and the connection position of the second lead and the second end of the second through hole is connected with at least one voltage sensing line.

Optionally, the connection position of the test line and the first end of the first through hole is further connected with at least one pair of voltage sensing lines;

the connection position of the test line and the first end of the second through hole is also connected with at least one voltage sensing line.

Optionally, the connection position of the second lead and the second end of the second via is further connected to at least one pair of voltage sensing lines.

Optionally, the connection position of the test line and the first end of the second via is further connected to at least one pair of voltage sensing lines.

Optionally, when the electromigration reliability test structure works, current is introduced to the electromigration reliability test structure through the first current line and the second current line; measuring at least one of the following voltages:

a voltage between any one voltage sensing line of each pair of voltage sensing lines at a connection location of the first lead and the second end of the first via and any one voltage sensing line at a connection location of the second lead and the second end of the second via;

a voltage between any one voltage sensing line of each pair of voltage sensing lines at a connection location of the test line and the first end of the first via and any one voltage sensing line at a connection location of the test line and the first end of the second via;

a voltage between either voltage sense line of each pair of voltage sense lines at a connection location of the second lead and the second end of the second via and either voltage sense line of each pair of voltage sense lines at a connection location of the first lead and the second end of the first via;

a voltage between any one of the voltage sensing lines of each pair of voltage sensing lines at a connection location of the test line and the first end of the second via and any one of the voltage sensing lines of each pair of voltage sensing lines at a connection location of the test line and the first end of the first via.

Optionally, the widths of the test line, the first through hole, the second through hole, the first lead, and the second lead are less than 130 nm.

Optionally, the widths of the first current line, the second current line, and the voltage sensing line are less than 130 nanometers.

Optionally, a distance between each of the first current line, the second current line, and the voltage sensing line is less than 130 nm.

Optionally, the test line includes copper and tantalum, and the first via and the second via include copper and tantalum.

Optionally, the test line includes aluminum and titanium, and the first via hole and the second via hole include tungsten.

In another aspect, the present application provides an electromigration reliability test method, for detecting electromigration reliability of an interconnection line in an integrated circuit, including:

introducing current to any one of the electromigration reliability test structures;

monitoring the voltage value between each pair of voltage sensing lines, taking out the test line when the voltage is monitored between any one pair of voltage sensing lines in at least one pair of voltage sensing lines, and carrying out failure physical analysis on the test line to capture a site for cavity formation; or

Monitoring the voltage value between each pair of voltage sensing lines, and when the voltage is monitored between any one pair of voltage sensing lines in at least one pair of voltage sensing lines, starting to record time until the voltage does not change any more so as to record the time for obtaining the formation of the cavity; and analyzing the failure physical property of the test line according to the time for forming the cavity.

Optionally, the value of the current density introduced into the electromigration reliability test structure ranges from 1 milliampere/square centimeter to 10 milliampere/square centimeter.

Optionally, the testing temperature range of the electromigration reliability testing method is 150 to 450 ℃.

The technical scheme at least comprises the following advantages:

at least one pair of voltage sensing lines are connected near the first through hole, and the holes are usually generated near the through holes, so that the probability of capturing resistance change of the testing lines can be increased, and the accuracy of electromigration reliability testing is improved; meanwhile, when more than one pair of voltage sensing lines are arranged near the through hole, the probability of capturing the resistance change of the testing line can be further increased.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of an electromigration reliability test structure provided in the related art;

FIG. 2 is a schematic diagram illustrating a top view of an electromigration reliability test structure provided in accordance with an exemplary embodiment of the present application;

FIG. 3 is a flowchart of a method for electromigration reliability testing as provided by an exemplary embodiment of the present application.

Detailed Description

The technical solutions in the present application will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection can be mechanical connection or electrical connection; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

In the embodiment of the application, the direction in which the length of the test line is defined is an X axis, the direction in which the length of the through hole is defined is a Z axis, and the directions perpendicular to the X axis and the Z axis are defined as Y axes.