CN215680614U - Detection structure of short-circuit defect and detection system for memory - Google Patents

Abstract

The utility model provides a short-circuit defect detection structure and a detection system for a memory. In the detection structure, at least one wire is connected to the grounding port to form a first wire, and at least one wire adjacent to the first wire is set to be not connected to the grounding port to form a second wire, so that the brightness of the first wire and the second wire under the action of electron beams can be directly observed, and whether the second wire and the first wire are short-circuited or not can be judged. The detection structure provided by the utility model can adopt a simpler and more convenient detection means, can quickly and directly obtain a detection result, and can carry out real-time and efficient monitoring on the corresponding preparation process.

Description

Detection structure of short-circuit defect and detection system for memory

Technical Field

The utility model relates to the technical field of semiconductors, in particular to a short-circuit defect detection structure and a detection system for a memory.

Background

In the process of manufacturing a device by using a semiconductor technology, a series of tests are usually performed during or after the manufacturing process of the device in order to determine whether the formed device meets the process requirements. For example, for a plurality of wires in a device, it is necessary to detect and monitor the conditions of the plurality of wires by using corresponding detection structures, which is beneficial to improving the yield of device processing.

With the increasing maturity of semiconductor technology, very large scale integrated circuits are rapidly developed, and integrated circuits with better performance and higher functionality require greater component density, and the pitch size between components is also reduced. For a structure with a small line pitch, short circuit between lines is more likely to occur, and performance is affected. Therefore, it is important to detect the short-circuit defect, but the detection process of the conventional detection structure for detecting the short-circuit defect is complicated.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a short-circuit defect detection structure and a detection system for a memory, so as to simplify the defect detection process.

In order to solve the above technical problem, the present invention provides a short defect detection structure, which has at least one test unit, wherein the test unit includes at least two wires extending in parallel, at least one of the at least two wires is connected to a ground port to form a first wire, and at least one wire adjacent to the first wire is configured to be unconnected to the ground port to form a second wire; and under the action of electron beams, the first lead and the second lead generate brightness to judge whether the second lead and the first lead are short-circuited.

Optionally, the test unit includes a plurality of wires arranged in parallel in sequence, and two wires adjacent to each other on two sides of each first wire are set without being connected to the ground port.

Optionally, the test unit includes a plurality of wires arranged in parallel in sequence, and two wires adjacent to each other on two sides of each second wire are connected to the ground port.

Optionally, the test unit includes a plurality of wires arranged in parallel in sequence, and the wires arranged at intervals are all connected to the ground port.

Optionally, the first wires are all connected to the same interconnection line, and the interconnection line is connected to the ground port.

Optionally, the first wire is correspondingly provided with a contact plug connected with the first wire, and two ends of the contact plug are respectively connected with the first wire and the interconnection line.

Optionally, the material of the conductive line includes tungsten.

Optionally, the detection structure has at least two test units, and the wires located in different test units extend along different directions respectively.

The present invention also provides a detection system for a memory, comprising: the detection structure as described above, comprising a first test unit and a second test unit. The plurality of wires in the first test unit extend in the same direction as the bit lines in the memory, and the plurality of wires in the first test unit generate brightness under the action of electron beams so as to judge whether the wires in the first test unit have short-circuit defects or not, and the judgment result of the first test unit is used for deducing whether the bit lines in the memory have short-circuit defects or not to cause current leakage. And the plurality of wires in the second test unit extend in the same direction as the word line in the memory, and the plurality of wires in the second test unit generate brightness under the action of electron beams so as to judge whether the wires in the second test unit have short-circuit defects or not, and the judgment result of the second test unit is used for deducing whether the word line in the memory has short-circuit defects or not to cause current leakage.

Optionally, the arrangement density of the plurality of wires in the first test unit is the same as the arrangement density of the plurality of bit lines, and the arrangement density of the plurality of wires in the second test unit is the same as the arrangement density of the plurality of word lines.

In the short-circuit defect detection structure provided by the utility model, at least one conducting wire is connected to the grounding port to form a first conducting wire, and at least one conducting wire adjacent to the first conducting wire is set to be not connected to the grounding port to form a second conducting wire, so that whether the second conducting wire is short-circuited with the first conducting wire or not can be judged by directly observing the brightness of the first conducting wire and the second conducting wire under the action of electron beams. Therefore, the detection structure and the detection method correspondingly implemented based on the detection structure provided by the utility model have simple and convenient processes, and can quickly and directly obtain the detection result.

Drawings

FIG. 1 is a diagram illustrating one test unit of a test structure according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a detecting structure under the action of electron beams when there is a short circuit between adjacent conducting wires in the detecting structure according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the brightness of a portion of conductive lines of the detecting structure under the action of electron beams according to an embodiment of the present invention;

FIG. 4 is a diagram of another testing unit of the detecting structure according to an embodiment of the present invention;

fig. 5 is a flowchart illustrating a method for detecting a short defect according to an embodiment of the utility model.

Wherein the reference numbers are as follows:

100 a-a first test unit;

100 b-a second test unit;

110 — a first conductive line;

120-a second wire;

210-an interconnect line;

220-conductive plug.

Detailed Description

The structure for detecting short-circuit defects according to the present invention will be described in further detail with reference to fig. 1 to 5 and the following embodiments. Fig. 1 is a schematic view of one of the test units of the inspection structure in an embodiment of the present invention, fig. 2 is a schematic view of the inspection structure in an embodiment of the present invention under the action of an electron beam when a short circuit exists in a conductive wire, fig. 3 is a schematic view of the inspection structure in an embodiment of the present invention with partial conductive wires under the action of an electron beam, fig. 4 is a schematic view of another test unit of the inspection structure in an embodiment of the present invention, and fig. 5 is a schematic flow chart of the method for detecting a short circuit defect in an embodiment of the present invention. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. It will be understood that relative terms, such as "above," "below," "top," "bottom," "above," and "below," may be used in relation to various elements shown in the figures. These relative terms are intended to encompass different orientations of the elements in addition to the orientation depicted in the figures. For example, if the device were inverted relative to the view in the drawings, an element described as "above" another element, for example, would now be below that element.

Referring to fig. 1 and 4, the detection structure provided in this embodiment has at least one test unit, which may refer to, for example, the first test unit 100a shown in fig. 1, and the test unit may also be the second test unit 100b shown in fig. 4.

Specifically, the test unit includes at least two wires, in this embodiment, the test unit includes a plurality of wires as an example for description, and the plurality of wires in the same test unit extend in parallel along the same direction. For example, the plurality of conductive lines in the first test unit 100a shown in fig. 1 each extend in parallel along the first direction (Y direction), and the plurality of conductive lines in the second test unit 100b shown in fig. 4 each extend in parallel along the second direction (X direction).

Further, in each test unit, at least one of the at least two wires is connected to a ground port to form a first wire 110, and at least one wire adjacent to the first wire 110 is configured to be unconnected to the ground port to form a second wire 120. In this way, the light and dark levels are generated in the first conductive line 110 and the second conductive line 120 under the action of the electron beam to determine whether the second conductive line 120 and the first conductive line 110 are short-circuited. Specifically, whether the second conductive line 120 and the first conductive line 110 are shorted can be determined according to whether the brightness generated by the second conductive line 120 is different from the brightness generated by the first conductive line 110.

Taking the first test unit 100a shown in fig. 1 as an example, fig. 1 illustrates a first conducting line 110 and a second conducting line 120 set according to a predetermined design in the first test unit 100a, that is, a short circuit does not occur between the conducting lines, and fig. 2 illustrates a short circuit occurring between one of the second conducting lines 120 and the first conducting line 110. As shown in fig. 2, the short-circuited second conductive line 120 (i.e., the second conductive line on the right side in fig. 2) has the same brightness generated by the electron beam as the first conductive line 110 and has a different brightness from the non-short-circuited second conductive line 120 (i.e., the second conductive line on the left side in fig. 2). Therefore, whether a short circuit defect exists between adjacent wires can be judged according to different shading degrees presented when each second wire 120 is short-circuited and not short-circuited.

Specifically, when the second conductive line 120 short-circuits the first conductive line 110, the conductive particles in the second conductive line 120 may leak current through the first conductive line 110, so that the short-circuited second conductive line 120 and the first conductive line 110 exhibit the same potential and have the same or similar brightness (e.g., both exhibit brightness or both exhibit darkness) under the action of the electron beam. When the second conductive line 120 is not shorted to the first conductive line 110, the conductive particles in the second conductive line 120 will not generate current leakage, and the second conductive line 120 that is not shorted can maintain its original potential, which is different from the potential of the first conductive line 110, so that the second conductive line 120 that is not shorted will have different brightness (e.g., one of them appears as brightness and the other one appears as darkness) from the first conductive line 110. That is, whether the second conductive line 120 is short-circuited to the first conductive line 110 can be further deduced by determining whether the second conductive line 120 has current leakage by observing the brightness of the second conductive line 120 under the action of the electron beam.

In this embodiment, the material of the wires in the detection structure includes, for example, tungsten (W), that is, the material of the first wire 110 and the second wire 120 includes tungsten. At this time, the grounded wires (e.g., the first wire 110 and the second wire 120 shorted to the first wire 110) may exhibit brightness under the action of the electron beam, for example, while the ungrounded and non-shorted wires (i.e., the non-shorted second wire 120) may exhibit darkness under the action of the electron beam.

Optionally, in the test unit, two adjacent wires on two sides of each first wire 110 are set to be unconnected to the ground port, that is, two sides of each first wire 110 are adjacent to each other and provided with the second wire 120. At this time, the short-circuited area can be determined according to the brightness of the two second conductive lines 120 on both sides of the first conductive line 110.

Optionally, in the test unit, two adjacent wires on two sides of each second wire 120 are connected to the ground port, that is, the first wire 110 is arranged adjacent to two sides of each second wire 120. At this time, the short circuit condition of both sides of the second conductive line 120 can be monitored.

In the test unit provided in this embodiment, the leads disposed at intervals are all connected to the ground port. That is, one first conductive line 110 is disposed every other conductive line, and the second conductive lines 120 and the first conductive lines 110 are alternately arranged. For example, a connection member is additionally provided for a wire arranged at an odd-numbered position to be connected to the ground port, and a connection member is not provided for a wire arranged at an even-numbered position to be not connected to the ground port; alternatively, a connection member is additionally provided for the wires arranged at even-numbered positions to be connected to the ground port, and a connection member is not provided for the wires arranged at odd-numbered positions to be not connected to the ground port. Therefore, the current leakage condition of each second wire 120 can be detected, so that the short circuit condition between each adjacent wires can be monitored, and the detection precision of the detection structure is improved.

It should be noted that the term "a wire connected to a ground port" as used herein refers to: the first wire is correspondingly provided with a connecting piece (such as a conductive plug) aiming at the first wire so as to be connected to the ground port through the connecting piece. And for a wire that is not additionally provided with a connecting member but is connected to the ground port only due to a short circuit between wires, it cannot be defined as "a wire connected to the ground port, i.e., a first wire".

Wherein the connector additionally provided for the wire connected to the ground port includes, for example, an interconnection line. In this embodiment, the first conductive lines 110 connected to the ground ports are all connected to the same interconnect line 210, and the interconnect line 210 is connected to the ground port. Specifically, the material of the interconnection line includes, for example, aluminum and/or copper.

Specifically referring to fig. 1, in the first testing unit 100a, a plurality of conductive wires are sequentially arranged along the second direction (X direction), the interconnection line 210 may extend within a projection area (e.g., an end area or a middle area) of each conductive wire along the arrangement direction (X direction) of the plurality of conductive wires, and a contact plug 220 connected to each first conductive wire 110 is correspondingly disposed on each first conductive wire 110, and two ends of the contact plug 220 are respectively connected to the first conductive wire 110 and the interconnection line 210. And, referring to fig. 4, in the second testing unit 100b, a plurality of conductive lines are sequentially arranged along a first direction (Y direction), the interconnection line 210 may extend within a projection area (e.g., an end area or a middle area) of each conductive line along the arrangement direction (Y direction) of the plurality of conductive lines, and a contact plug 220 connected thereto is correspondingly provided for each first conductive line 110, and both ends of the contact plug 220 are respectively connected to the first conductive line 110 and the interconnection line 210.

In this embodiment, at least two wires in the test unit are arranged side by side in a first structural layer, the interconnect 210 may be arranged in a second structural layer above the first structural layer or below the first structural layer, and two ends of the conductive plug 220 respectively extend to the first structural layer and the second structural layer to respectively connect the first wire 110 and the interconnect 210. It can be considered that the conductive plug 220 is located in a third structural layer, which is located between the first structural layer and the second structural layer, and penetrates the third structural layer so that both ends thereof are connected to the first wire 110 and the interconnection line 210, respectively.

A method for detecting a short-circuit defect based on the above-described detection structure will be described with reference to fig. 5. Specifically, the detection method comprises the following steps: the above-mentioned detection structure is provided, and electron beam scanning is performed on the detection structure, and whether the brightness of each second conductive line 120 is different from the brightness of the first conductive line 110 is observed, so as to determine whether the second conductive line 120 and the first conductive line 110 are short-circuited.

When there are second conductive lines 120 with the same or similar brightness as the first conductive lines 110, for example, all of the second conductive lines are brightness or all of the second conductive lines are darkness, it can be determined that the second conductive lines 120 with the same brightness are short-circuited with the adjacent first conductive lines 110. Conversely, when the brightness of the second conductive line 120 is different from the brightness of the first conductive line 110, for example, one of the first conductive line 110 and the second conductive line 120 is represented as brightness, and the other is represented as darkness, it can be determined that the second conductive line 120 is not shorted with the adjacent first conductive line 110.

In this embodiment, the material of the conductive line includes tungsten (W). At this time, when the electron beam scanning is performed, the first conductive line 110 may exhibit brightness, and if there is a second conductive line 120 with the same brightness, the second conductive line 120 with the same brightness is short-circuited with the adjacent first conductive line 110; if the second conductive line 120 is dark, the second conductive line 120 is not shorted to the adjacent first conductive line 110.

Further, the method for scanning the detection structure with an electron beam includes, for example: scanning the detection structure using one of a Scanning Electron Microscope (SEM) and a Focused Ion Beam (FIB).

It should be noted that the detection structure provided in this embodiment may include only one test unit (e.g., the first test unit 100a or the second test unit 100 b); alternatively, at least two test units may be included, and the wires in different test units extend along different directions (for example, the first test unit 100a and the second test unit 100b are included, and the wires in the first test unit 100a and the wires in the second test unit 100b extend in different directions), so that the short circuit defects of the wires in different directions can be monitored by using the detection structure.

In practical application, the number of the test units in the detection structure and the arrangement mode of each test unit can be correspondingly arranged according to the processed device structure. For example, the structure prepared in the device includes a plurality of wires extending along the first direction, and in this case, the plurality of wires in the test unit may be correspondingly arranged to extend along the first direction; and the structure prepared in the device comprises a plurality of leads extending along the second direction, and the plurality of leads in the test unit can be correspondingly arranged to extend along the second direction; and, the structure prepared in the device includes a plurality of wires extending in a first direction and a plurality of wires extending in a second direction, in which case at least two test cells may be provided, the wires in one of the test cells extending in the first direction and the wires in the other test cell extending in the second direction. Thus, the condition of the wires in the device can be monitored by using the wires arranged in the test unit in the same way.

For example, in a method for manufacturing a memory, it is generally necessary to prepare a plurality of bit lines extending along a first direction and a plurality of word lines extending along a second direction. It should be appreciated that when a short circuit occurs in an adjacent bit line, one of the bit lines will leak current through the shorted other bit line, thereby affecting the performance of the bit line. Similarly, when the adjacent word lines are short-circuited, one word line may generate current leakage through the other short-circuited word line, thereby affecting the performance of the word line. Therefore, corresponding test units can be correspondingly prepared for a plurality of word lines and a plurality of bit lines, whether the bit lines and the word lines in the memory have current leakage hidden dangers or not is deduced by detecting the test units, and effective monitoring of the bit lines and the word lines is realized.

Specifically, the embodiment further provides a detection system for a memory, which includes the detection structure as described above, where the detection structure includes a first test unit and a second test unit.

The plurality of wires in the first test unit and the bit lines in the memory are prepared at the same time and extend in the same direction, the plurality of wires in the first test unit generate brightness under the action of electron beams so as to judge whether the wires in the first test unit have short-circuit defects or not, and the judgment result of the first test unit is used for deducing whether the bit lines in the memory have short-circuit defects or not to cause current leakage. For example, in the fabrication process of a memory, a plurality of bit lines extending along a first direction are fabricated in a device region, and a plurality of conductive lines in a first test cell extending along the first direction are fabricated in a test region. And the arrangement density of the plurality of wires in the first test unit may be the same as the arrangement density of the plurality of bit lines, and the width dimension of the wires in the first test unit may also be the same as the width dimension of the bit lines. Whether the plurality of wires in the first test unit have short-circuit defects is detected by scanning the first test unit through the electron beams, at the moment, the short-circuit conditions of the plurality of bit lines in the device area can be reflected in time according to the detection result of the first test unit, and then whether the hidden danger of current leakage caused by short circuit exists in the plurality of bit lines is deduced, so that the real-time monitoring of the bit line preparation process is realized.

And the plurality of wires in the second test unit extend in the same direction as the word line in the memory, and the plurality of wires in the second test unit generate brightness under the action of electron beams so as to judge whether the wires in the second test unit have short-circuit defects or not, and the judgment result of the second test unit is used for deducing whether the word line in the memory has short-circuit defects or not to cause current leakage. Specifically, during the fabrication of the memory, a plurality of word lines extending along the second direction are fabricated in the device region, and a plurality of conductive lines in a second test unit extending along the second direction are fabricated in the test region. The layout density of the plurality of wires in the second test unit may be the same as the layout density of the plurality of word lines, and the width dimension of the wires in the second test unit is also the same as the width dimension of the word lines. Whether the plurality of wires in the second testing unit have short-circuit defects or not is detected by scanning the second testing unit through the electron beams, at the moment, the short-circuit conditions of the plurality of word lines in the device area can be reflected in time according to the detection result of the second testing unit, and then whether the hidden danger of current leakage caused by short circuit exists in the plurality of word lines or not is deduced, so that the real-time monitoring of the word line preparation process is realized.

In summary, in the short defect detection structure and the detection system for a memory provided in this embodiment, at least one of the conductive lines is connected to the ground port to form a first conductive line, and at least one conductive line adjacent to the first conductive line is not connected to the ground port to form a second conductive line, so that the existence of a short defect between the second conductive line and the first conductive line can be determined by directly observing the brightness of the first conductive line and the second conductive line under the action of the electron beam. That is, it is inferred whether the second wire is short-circuited to the first wire and current leakage occurs through the first wire, based on whether the brightness of the second wire is the same as the brightness of the first wire. It can be considered that, the detection structure provided by this embodiment is to further determine whether the second conducting wire is short-circuited with the first conducting wire by determining whether the second conducting wire has a current leakage. The detection method correspondingly adopted based on the detection structure provided by the embodiment has the advantages that the detection process is simple and convenient, the detection result can be rapidly and directly obtained, and the corresponding preparation process can be efficiently monitored in real time. When the detection structure provided by the embodiment is applied to a detection system of a memory, the detection flexibility of bit lines and word lines in the memory can be correspondingly realized, and the preparation efficiency of the device is improved.

It should be noted that, although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the embodiments. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the utility model without departing from the scope of the utility model. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the content of the technical solution of the present invention is departed from.

It should be further understood that the terms "first," "second," "third," and the like in the description are used for distinguishing between various components, elements, steps, and the like, and are not intended to imply a logical or sequential relationship between various components, elements, steps, or the like, unless otherwise indicated or indicated.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood to have the definition of a logical "or" rather than the definition of a logical "exclusive or" unless the context clearly dictates otherwise.

Claims (10)

1. A short-circuit defect detection structure is characterized in that the detection structure is provided with at least one test unit, and the test unit comprises at least two wires extending in parallel; at least one of the at least two wires is connected to a ground port to form a first wire, and at least one wire adjacent to the first wire is configured to be unconnected to the ground port to form a second wire; and under the action of electron beams, the first lead and the second lead generate brightness to judge whether the second lead and the first lead are short-circuited or not.

2. The short-circuit defect detection structure as claimed in claim 1, wherein said test unit comprises a plurality of wires arranged in parallel in sequence, and two wires adjacent to each other at two sides of each first wire are configured not to be connected to the ground port.

3. The short defect detection structure of claim 1, wherein the test unit comprises a plurality of wires arranged in parallel in sequence, and two wires adjacent to each other on both sides of each second wire are connected to the ground port.

4. The short defect detection structure of claim 1, wherein said test unit comprises a plurality of wires arranged in parallel in sequence, and the wires arranged at intervals are all connected to the ground port.

5. The short defect detection structure of claim 1, wherein said first conductive lines are all connected to the same interconnect line, said interconnect line being connected to said ground port.

6. The short-circuit defect detection structure as claimed in claim 5, wherein the first conductive line is correspondingly provided with a contact plug connected thereto, and two ends of the contact plug are respectively connected with the first conductive line and the interconnection line.

7. The short defect detection structure of claim 1, wherein said wire material comprises tungsten.

8. The short defect detection structure of claim 1, wherein said detection structure has at least two test units, and the conductive lines in different test units extend along different directions, respectively.

9. A detection system for a memory, comprising: the detection structure of any one of claims 1-8, comprising a first test unit and a second test unit;

the plurality of wires in the first test unit extend in the same direction as the bit lines in the memory, and the plurality of wires in the first test unit generate brightness under the action of electron beams so as to judge whether the bit lines in the memory have current leakage or not;

and the plurality of wires in the second test unit extend in the same direction as the word lines in the memory, and the plurality of wires in the second test unit generate brightness under the action of electron beams so as to judge whether the word lines in the memory have current leakage or not.

10. The sensing system for a memory according to claim 9, wherein a layout density of the plurality of conductive lines in the first test unit is the same as a layout density of the plurality of bit lines, and a layout density of the plurality of conductive lines in the second test unit is the same as a layout density of the plurality of word lines.

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