JP2000323537A - Semiconductor integrated circuit and nondestructive inspection method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a nondestructive inspection method, capable of inspecting in a semiconductor manufacturing process before forming bonding pads and contributing cost cut, the production and reliability improvement of semiconductor devices. SOLUTION: An n-th wiring 34 is formed on a board, at least one of vias 35 for circuits connecting the n-th wiring and (n+1)-th wiring and inspecting vias 305 connected to the n-th wiring 34 but not connected to the (n+1)-th wiring is formed on an insulation layer 32 thereon, and then to form the (n+1)-th wiring, an (n+1)-th wiring conductive film 36 is formed at least on a wider region than the region where the n-th wiring 34 exists, thus forming a semiconductor integrated circuit under manufacturing. This integrated circuit is then irradiated with a beam to cause a thermoelectromagnetic force current in the semiconductor integrated circuit, thereby inducing a magnetic field, and the intensity of this field is detected to inspect defects of the semiconductor integrated circuit from the detected magnetic field strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor integrated circuit and a nondestructive inspection method thereof, and more particularly to a nondestructive inspection method for detecting an electrically active defect in a semiconductor integrated circuit.

[0002]

2. Description of the Related Art Conventionally, this type of non-destructive inspection technology is, for example, "OBIC analysis technology using thermoelectromotive force" (132rd Committee of 132nd Research Meeting of the 132nd Committee of the Application of Charged Particle Beams by the Japan Society for the Promotion of Science Materials, pp. 221-226, 1995
As disclosed in Japanese Patent Application Laid-Open No. 11-31, 1993, it is used for non-destructively detecting a defective portion of a wiring system as a part of a failure analysis and a failure analysis of a semiconductor device.

FIG. 11 is a configuration diagram showing an example of a conventional non-destructive inspection apparatus. In order to inspect a chip using this nondestructive inspection apparatus, a laser beam 3 generated by a laser generator 1 and narrowed down by an optical system 2 is scanned over an observation region of a semiconductor device chip 4. Scanning is a control / image processing system 1
This is performed by deflecting by the optical system 2 under the control of 06. The prober 115-1 probes the current generated at that time to the bonding pad 14-1.
Remove by This current is detected by the current change detector 131, and a change in the current value is displayed as an image on the image display device 7 as a luminance change corresponding to the scanning position under the control of the control / image processing system 106. This image is called a scanning current change image.

FIG. 11 shows a bonding pad 1 different from the bonding pad 14-1 connected to the current change detector 131 so that the generated current flows in a closed circuit.
4-7 shows a configuration example in which the prober 115-2 is probed and the prober 115-2 is grounded.

Next, the operation will be described. The optical system 2 generated by the laser generator 1 under the control of the control / image processing system 106
The laser beam 3 narrowed down by is scanned over the observation region of the semiconductor device chip 4. In response to scanning, for example, the current flowing into the current change detector 131 is bright, and the current in the opposite direction is dark, so that the image display device 7
The scanning current change image is displayed as a luminance on the top. At this time, gradation is displayed for both light and dark.

When a laser beam is irradiated near a defect, such as a portion where heat conduction is deteriorated due to voids or silicon precipitation, a thermoelectromotive force is generated at that moment and a current flows. If you are irradiating a part without defects,
No thermoelectromotive force is generated and no current flows. Therefore, on the image display device 7, an image having a contrast of light and dark (referred to as a scanning current change image) is displayed only in the vicinity of the presence of the defect. When obtaining the scanning current change image, a scanning laser microscope image which is an optical reflection image corresponding to the scanning of the laser beam is taken at the same time or before and after. Thereafter, the scanning current change image and the scanning laser microscope image are combined by a general image processing technique to obtain an image in which the two images are superimposed.
From this composite image, the place where the contrast of light and dark is obtained in the scanning current change image can be clearly recognized, and the defective part can be specified. The detection position accuracy of the defect position by this technique is of the order of submicron.

In order to clearly identify the type of defect and the cause of the non-destructively detected defect, the defect is usually physically destructively analyzed using a focused ion beam method or an electron microscope. Conversely, by clearly confirming the location of the defect with submicron position accuracy in this type of conventional technology, it becomes possible to efficiently perform physical analysis of submicron or smaller minute defects. Thus, the prior art is in an important position in a series of analysis procedures for failure analysis and failure analysis.

[0008]

However, the conventional non-destructive inspection of a chip using a scanning current change image includes:
There are the following problems. The first problem is that a semiconductor device chip to be inspected cannot be inspected until after a pre-process of its manufacturing process is completed and bonding pads are completed. In the prior art, in order to detect a change in current caused by irradiating a laser beam, it is necessary to always electrically connect an inspection device and a semiconductor device chip. Therefore, bonding pads are formed on the semiconductor device chip. Must be.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an inspection method which is not only non-destructive but also non-contact.
The purpose is to enable inspection during a semiconductor manufacturing process before forming a bonding pad. In addition, the current generated by the thermo-electromotive force generated when a beam is irradiated near a defect is extended, thereby facilitating magnetic field detection, thereby reducing costs and improving the productivity of semiconductor devices. It is to contribute to improvement and reliability improvement.

[0010]

According to the nondestructive inspection method of the present invention, an n-th wiring is formed on a substrate, and the n-th wiring and the (n + 1) -th wiring are formed on an insulating layer thereon. And the n-th layer wiring connected to the circuit via connecting the
After forming at least one or more test vias not connected to the (+1) th layer wiring, the (n + 1) th layer wiring is formed in a region wider than at least the region where the (n) th layer wiring exists in order to form the (n + 1) th layer wiring. Irradiating a beam to a semiconductor integrated circuit in the process of manufacturing formed by forming a conductive film, and detecting the intensity of a magnetic field induced by the generation of a thermoelectromotive current in the semiconductor integrated circuit by the irradiation of the beam. The semiconductor integrated circuit is inspected for defects based on the strength of the applied magnetic field.

The semiconductor integrated circuit according to the present invention may further comprise a circuit for connecting an n-th wiring, an (n + 1) -th wiring, and connecting the n-th wiring to the (n + 1) -th wiring on a substrate. It has a via and at least one or more inspection vias provided on the n-th layer wiring, connected to the n-th layer wiring, and not connected to the (n + 1) -th layer wiring.

The present inventor has already applied for a patent (Japanese Patent Application No. 10-272788) concerning a nondestructive inspection apparatus and a nondestructive inspection method. The nondestructive inspection method described in the specification of this patent detects the intensity of a magnetic field induced by the generation of a thermoelectromotive current in a semiconductor device chip by irradiating a laser beam, and detects the intensity of the detected magnetic field. The semiconductor device chip is inspected for the presence or absence of a defect, and a portion where the defect exists is detected.
In this nondestructive inspection method, when a laser beam is applied to a defective portion on a semiconductor device chip and the defective portion is heated, a current flows transiently due to thermoelectromotive force, and as a result,
A magnetic field is formed. By detecting the intensity of the magnetic field, a defect included in the semiconductor device chip can be detected.

That is, in this nondestructive inspection method, the current change detector is not directly measured by the current generated by the thermoelectromotive force, but is measured by the magnetic field induced by the current. There is no need to connect to the chip, and the work of connecting the current change detector to the bonding pad, which has been required conventionally, becomes unnecessary, and the number of steps and costs required for the inspection can be greatly reduced.

Further, at the stage before the bonding pad is formed on the semiconductor device chip, it is possible to detect the defect of the semiconductor device chip. Therefore, it is possible to perform an inspection at a more upstream stage before the completion of the bonding pad in the semiconductor manufacturing process. Inspection results can be fed back at a more upstream stage of the semiconductor manufacturing process, that is, at a stage where the added value is smaller than before.

FIG. 1 is a block diagram showing an example of a non-destructive inspection apparatus used in this non-destructive inspection method. FIG.
In order to inspect the defect of the semiconductor device chip in the course of manufacture shown in FIG. 8 using the non-destructive apparatus shown in FIG. 8, the laser beam 3 generated by the laser generator 1 and narrowed down by the optical system 2 is converted into the semiconductor chip in the course of manufacture. Back side (substrate side) of device chip 40
The semiconductor device chip 40 is irradiated with light from the surface 40b, is focused on the wiring portion near the front surface side 40f, and scans the semiconductor device chip 40 in the process of manufacturing.
Note that the closer the laser irradiation unit, that is, the thermoelectromotive force generation unit and the magnetic field detector 5 are, the better the sensitivity is. Therefore, in general, instead of scanning the laser beam 3, the relative position between the laser irradiation unit and the magnetic field detector 5 Is fixed, and the semiconductor device chip 40 is fixed.
Scanning is more sensitive.

In FIG. 8, reference numeral 31 indicates a silicon substrate, and reference numeral 32 indicates an insulating layer. On the silicon substrate 31, a contact portion 33 is provided,
It is connected to a layer wiring (n-th layer wiring) 34. First
On the layer wiring 34, a circuit via 35 is provided.
It is electrically connected to the layer wiring 34.

FIGS. 9 and 10 are cross-sectional views showing other semiconductor device chips in the course of manufacture. The semiconductor device chip in the process of manufacture shown in FIG. 9 is a state in which the second-layer wiring metal film 36 is further applied on the entire surface of the semiconductor device chip 40 in the process of manufacture shown in FIG. The illustrated semiconductor device chip in the process of manufacture is in a state where the process is further advanced and the second-layer wiring 37 is formed.

The semiconductor device chip in the course of manufacture shown in FIGS. 8 to 10 has a thermoelectromotive force generation defect 41, and when the laser beam 3 is irradiated on the thermoelectromotive generation defect 41, the laser beam 3 A thermo-electromotive force current is generated due to the irradiation heating. By this thermoelectromotive current, FIG.
10 to 10, a transient current flowing in a current path 61 indicated by an arrow flows in an open circuit, and as a result, a magnetic field is generated.

Then, the magnetic field generated by the thermoelectromotive current is detected by the magnetic field detector 5 shown in FIG. The magnetic field detected by the magnetic field detector 5 is transmitted to the control / image processing system 10.
6, an image display device 7 corresponding to the scanning position of the laser.
, A scanning magnetic field image showing the distribution of the magnetic field can be obtained. At the same time as or before or after obtaining the scanning magnetic field image, a scanning laser microscope image which is an optical reflection image corresponding to the scanning of the laser beam 3 or the scanning of the semiconductor device chip is obtained. After acquiring the scanning magnetic field image and the scanning laser microscope image, by obtaining an image in which the two images are superimposed by a normal image processing function, the place where the contrast is obtained in the scanning magnetic field image is displayed on the scanning laser microscope image. It is clearly recognized, and the location of the defect that caused the generation of the thermoelectromotive current can be identified.

However, this nondestructive inspection method includes:
There is a disadvantage that it costs a lot of money. The reason is,
In this non-destructive inspection method, since the thermoelectromotive force current induced by the irradiation heating of the laser beam 3 flows only in an open circuit, the current may flow for a relatively short time.
In that case, a magnetic field detector having a high response speed, that is, an expensive magnetic field detector is required.

The present invention is a non-destructive inspection method for a semiconductor integrated circuit and a semiconductor integrated circuit which can reduce a great cost which is a disadvantage of the non-destructive inspection method. Since the semiconductor integrated circuit of the present invention has an inspection via connected to the n-th wiring and not connected to the (n + 1) -th wiring,
Further, the nondestructive inspection method of the present invention is a method in which a circuit via and an inspection via are provided on the n-th layer wiring, and then the n + 1-th layer wiring conductive film is formed. Detection becomes easy.

That is, according to the semiconductor integrated circuit and the non-destructive inspection method of the present invention, the current generated by the thermoelectromotive force accompanying the non-destructive inspection is transferred to the n-th layer wiring, the circuit via, the inspection via, and the Since the current can flow as a closed circuit current composed of the (n + 1) th layer wiring conductive film, the current may flow for a longer time than the open circuit current. Also,
The path of the current flowing through the n-th wiring is relatively narrow, and the magnetic field induced by the current is also localized along the n-th wiring, and flows through the n + 1-th wiring conductive film. The current path is distributed over a relatively wide range, and the magnetic field induced by the current spreads over a wide range. The directions of the magnetic field generated from the current flowing through the n-th layer wiring and the current flowing through the current flowing through the (n + 1) -th layer wiring conductive film are almost mutually canceling directions. There is no cancellation.

As described above, since the current generated by the thermoelectromotive force can flow as a closed circuit current, the decay time of the current can be prolonged, and the magnetic field generated by the current flowing through the closed circuit can be reduced. By not canceling out so much each other, a strong magnetic field is generated, and the magnetic field can be easily detected. Therefore, while contributing to the improvement of the productivity and reliability of the semiconductor device, a magnetic field detector having a low response speed, that is, a magnetic field detector having a relatively low cost can often detect the thermoelectromotive force-induced magnetic field, which is required for inspection. Costs can be reduced. By making such closed circuits as much as possible, it is possible to increase the possibility of detecting a defect in a semiconductor device chip.

Further, in the above-described semiconductor integrated circuit and the nondestructive inspection method thereof, the inspection via provided to form a closed circuit is connected to the n-th layer wiring and is not connected to the (n + 1) th layer wiring. Therefore, the original circuit function of the semiconductor device chip is not affected.

The inspection via is connected to the n-th layer wiring and is not connected to the (n + 1) -th layer wiring. Therefore, the inspection via can be formed simultaneously with the circuit via in the step of forming the circuit via. At the same time, when the conductive film for the (n + 1) th layer wiring is patterned to form the (n + 1) th layer wiring, it is not connected to the (n + 1) th layer wiring, so it is necessary to add a special step to form an inspection via There is no.
The conductive film for the (n + 1) th layer wiring used as a part of the closed circuit is for forming the (n + 1) th layer wiring, and is conventionally formed in the process of forming the (n + 1) th layer wiring. Therefore, no special process is required to form the (n + 1) th layer conductive film for wiring. Therefore, in the above-described semiconductor integrated circuit and the nondestructive inspection method thereof, the inspection can be easily performed without affecting the manufacturing process of the semiconductor integrated circuit.

In the above nondestructive inspection method,
Preferably, the inspection via is connected to an end of the n-th layer wiring. Further, in the above semiconductor integrated circuit, it is preferable that the inspection via is connected to an end of the n-th layer wiring. The strength of the magnetic field induced by the generation of the thermoelectromotive current increases as the current path increases.
Therefore, by arranging the inspection via so as to be connected to the end of the n-th layer wiring and making the current path of the closed circuit as long as possible, the detection of the magnetic field can be further facilitated. .

Further, according to the non-destructive inspection method of the present invention, an n-th wiring is formed on a substrate, and the n-th wiring is formed on an insulating layer thereon.
After forming at least two or more inspection vias connected to the wiring of the layer and not connected to the wiring of the (n + 1) th layer, the formation vias for forming the wiring of the (n + 1) th layer are formed at least in the region where the wiring of the nth layer exists. (N + 1) th provided in a wide area
A beam is applied to a semiconductor integrated circuit in the process of manufacturing in which the conductive film for the layer wiring is formed, and the intensity of the magnetic field induced by the generation of a thermoelectromotive current in the semiconductor integrated circuit due to the irradiation of the beam is detected. Then, a nondestructive inspection method may be adopted, wherein the defect of the semiconductor integrated circuit is inspected based on the intensity of the detected magnetic field.

The semiconductor integrated circuit according to the present invention may further comprise an n-th wiring, an (n + 1) -th wiring on the substrate, and at least two wirings on the n-th wiring. An inspection via connected to the nth wiring and not connected to the (n + 1) th wiring, and the nth wiring and the (n + 1) th wiring are provided on the nth wiring having the inspection via. The circuit via may not be provided to connect to the wiring.

Since at least two or more such semiconductor integrated circuits are provided, are connected to the n-th wiring, and have an inspection via which is not connected to the (n + 1) -th wiring, Such a nondestructive inspection method is a method in which at least two or more inspection vias are provided, and then the conductive film for the (n + 1) th layer wiring is formed, so that the magnetic field can be easily detected.

That is, according to the semiconductor integrated circuit and the non-destructive inspection method, the current generated by the thermoelectromotive force accompanying the non-destructive inspection is transferred to the n-th wiring, the inspection via, and the n + th wiring.
Since it can be passed as a closed circuit current composed of the first-layer wiring conductive film, a strong magnetic field may be generated similarly to the above-described semiconductor integrated circuit and the nondestructive inspection method thereof, and the magnetic field can be easily detected. More cases. Therefore, while contributing to the improvement of the productivity and reliability of the semiconductor device, a magnetic field detector having a slow response speed, that is, a relatively low-cost magnetic field detector can detect the thermoelectromotive force-induced magnetic field,
The cost required for inspection can be reduced. By making such closed circuits as much as possible, it is possible to increase the possibility of detecting a defect in a semiconductor device chip.

In the semiconductor integrated circuit and the nondestructive inspection method, it is preferable that the inspection via is connected to an end of the n-th layer wiring.
As described above, the strength of the magnetic field induced by the generation of the thermoelectromotive current increases as the current path increases. Therefore,
The test via is connected to the end of the n-th layer wiring, and two or more test vias are arranged so as to be connected to both ends of the n-th layer wiring, and the current path of the closed circuit is changed. By setting the length to be the longest, the detection of the magnetic field can be further facilitated.

In this nondestructive inspection method, the n-th layer wiring may be a wiring having both ends connected to a diffusion layer formed on a substrate. further,
In such a semiconductor integrated circuit, both ends of the n-th layer wiring may be connected to a diffusion layer formed on the substrate.

In the above nondestructive inspection method,
It is preferable that the (n + 1) -th layer wiring conductive film is provided on the entire surface. With such a nondestructive inspection method, the path of the current flowing through the (n + 1) th layer conductive film can be maximized, and the magnetic field induced by the current can be expanded to the widest range. Become. Therefore, the n-th
The difference between the distribution region of the magnetic field generated from the current flowing through the layer wiring and the current flowing through the (n + 1) th layer wiring conductive film can be maximized, a stronger magnetic field can be obtained, and the magnetic field can be more easily detected. It can be.

In the above nondestructive inspection method,
Preferably, the beam is a laser beam. By using a laser beam as the beam, a defective portion can be efficiently heated, and a thermoelectromotive force can be generated with high sensitivity. Therefore, the accuracy of the inspection can be improved.

Further, in the above nondestructive inspection method, it is preferable that the wavelength of the laser beam is longer than 1200 nm. The wavelength of the laser beam is 1
By setting the length to be longer than 200 nm, for example, 1300 nm, it is possible to prevent a photo-induced current from being generated in the silicon portion that causes noise, and to further improve the accuracy of inspection. When the substrate is made of silicon, the laser beam light having the above-mentioned wavelength can be transmitted through silicon, so that the wiring portion near the chip surface can be irradiated and heated from the chip back side. By being able to irradiate the laser beam from the back side of the chip, the magnetic field detector can be arranged on the front side of the chip, and detection can be performed at a position where the intensity of the generated magnetic field is strong, so that the detection sensitivity can be further improved.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The non-destructive inspection method of the present invention will be described below in detail with reference to the drawings. [First Embodiment] Inspection of a defect of a semiconductor device chip 50 in the course of manufacture shown in FIG. 2 using a non-destructive apparatus shown in FIG. 1 is performed by a laser generator 1 and thinned by an optical system 2. The focused laser beam 3 having a wavelength of 1300 nm is applied to the back side (substrate side) 50b of the semiconductor device chip 50 in the course of manufacture.
, And is focused on the wiring portion near the front surface side 50f, and scans the semiconductor device chip 50 in the process of manufacturing.

In FIG. 2, reference numeral 31 indicates a silicon substrate, and reference numeral 32 indicates an insulating layer. On the silicon substrate 31, a contact portion 33 is provided,
It is connected to a layer wiring (n-th layer wiring) 34. First
On the layer wiring 34, a circuit via 35 and an inspection via 30
5 are provided. Circuit via 35 and inspection via 3
05 are connected to different ends of the first-layer wiring 34. On the circuit via 35 and the inspection via 305, the second
A second-layer wiring metal film (conductive film for (n + 1) -th-layer wiring) 36 is provided on the entire surface for forming the second-layer wiring, and is electrically connected thereto.

As shown in FIGS. 3A and 3B, the semiconductor device chip 50 shown in FIG.
When the laser beam 3 is irradiated on the laser beam 1, a thermoelectromotive current is generated which is induced by the irradiation and heating of the laser beam 3. This thermoelectromotive current is supplied to the first layer wiring 34, the circuit via 35, the inspection via 305, and the second layer wiring metal film 36.
And flows through the current path indicated by arrows 611 and 612. As shown in FIGS. 3A and 3B, the current flowing through the current path 611 flows through a narrow area because it flows through the first-layer wiring 34, and the current path 612
Flows through the entire second-layer wiring metal film 36 so as to flow through a wide area. The direction of the current flowing through the first-layer wiring 34 is opposite to the direction of the current flowing through the second-layer wiring metal film 36.

The magnetic field generated by this thermoelectromotive current is
It is detected by the magnetic field detector 5 shown in FIG. The magnetic field detected by the magnetic field detector 5 is displayed in brightness on the image display device 7 by the control / image processing system 106 in correspondence with the scanning position of the laser, whereby a scanning magnetic field image showing the distribution of the magnetic field is obtained. At the same time as or before or after obtaining this scanning magnetic field image, a scanning laser microscope image which is an optical reflection image corresponding to the scanning of the laser beam 3 or the scanning of the semiconductor device chip 50 is obtained. After acquiring the scanning magnetic field image and the scanning laser microscope image, by obtaining an image in which the two images are superimposed by the ordinary image processing function, the place where the contrast of light and dark is obtained in the scanning magnetic field image is displayed on the scanning laser microscope image. It is clearly recognized, and the location of the defect that caused the generation of the thermoelectromotive current can be identified.

According to such a nondestructive inspection method, a semiconductor device chip 50 in the course of manufacture is irradiated with a laser beam 3, and the irradiation of the laser beam 3 generates and induces a thermoelectromotive current in the semiconductor device chip 50. Since the method detects the intensity of the magnetic field and inspects the defect of the semiconductor device chip 50 based on the intensity of the detected magnetic field, there is no need to connect the current change detector to the semiconductor device chip 50, and the number of man-hours required for the inspection and Costs can be significantly reduced. In addition, it is possible to perform an inspection at a more upstream stage than before the completion of the bonding pad in the semiconductor manufacturing process, and it is possible to feed back the inspection result at a stage where the added value is smaller than in the conventional case.

Further, after the circuit via 35 and the inspection via 305 are provided on the first-layer wiring 34, and then the second-layer wiring metal film 36 is formed, the magnetic field is detected. It will be easier. That is, the current generated by the thermoelectromotive force is transferred to the first layer wiring 34, the circuit via 35, and the inspection via 3.
Since the current can flow as a closed circuit current composed of the second circuit wiring 05 and the second-layer wiring metal film 36, the current may flow for a longer time than the open circuit current. Also, the first
The current path 611 flowing through the first-layer wiring 34 is relatively narrow, and the magnetic field induced by the current is also small.
And the second-layer wiring metal film 3
6, the current path 612 flowing through the antenna 6 is distributed over a relatively wide range,
The magnetic field induced by the current also spreads over a wide range. The directions of the magnetic fields generated from the current flowing through the first-layer wiring 34 and the current flowing through the second-layer wiring metal film 36 are directions that cancel each other, but since the magnetic field distribution regions are different as described above, They do not cancel each other out.

As described above, by allowing the current generated by the thermoelectromotive force to flow as a closed circuit current, the decay time of the current can be lengthened in some cases, and the magnetic field generated by the current flowing through the closed circuit can be reduced. By not canceling out so much each other, a strong magnetic field is generated, and the detection of the magnetic field becomes easy. Therefore, the magnetic field detector 5 having a low response speed, that is, the relatively low-cost magnetic field detector 5 can detect the thermoelectromotive force-induced magnetic field in many cases, which contributes to the improvement of the productivity and the reliability of the semiconductor device. Cost can be reduced.

For example, when the laser beam 3 is applied to the semiconductor device chip in the course of manufacture shown in FIGS. 6 and 7, the current generated by the thermoelectromotive force flows through the current path 61 of the first-layer wiring 34. Since there is no path that flows as a closed circuit, it flows only as a transient current determined by the parasitic capacitance, the wiring, and the resistance of the thermal electromotive force generation defect 41. Such a current may flow for only a very short time.
In that case, an expensive magnetic field detector having a very fast response speed is required to detect the magnetic field generated by such a current.

Further, in this non-destructive inspection method, the semiconductor device chip 50 being manufactured in order to form a closed circuit is manufactured.
Are connected to the first layer wiring 34 and are not connected to the second layer wiring, and thus do not affect the original circuit function of the semiconductor device chip. FIG. 4 is a view showing a state after patterning of the second-layer wiring metal film 36 of the semiconductor device chip 50 in the process of manufacturing shown in FIG. As shown in FIG. 4, in the semiconductor device chip in this manufacturing stage, the circuit via 35 is connected to a second-layer wiring 37 disposed so as to be orthogonal to the first-layer wiring 34.
The inspection via 305 is not connected to the second-layer wiring 37. Thus, the inspection via 305 does not affect the original circuit function.

Further, in this nondestructive inspection method,
Circuit via 35 of semiconductor device chip 50 during manufacture
And the inspection via 305 are connected to different ends of the first layer wiring 34, so that the current path can be maximized and the intensity of the magnetic field induced by the generation of the thermoelectromotive current can be reduced. By making it stronger, the detection of the magnetic field can be further facilitated.

In this non-destructive inspection method, a non-destructive inspection method of the semiconductor device chip 50 at the manufacturing stage in which the second-layer wiring metal film 36 is provided on the entire surface is provided.
The path of the current flowing through the second-layer wiring metal film 36 can be maximized, and the magnetic field induced by the current can be widened to the widest range. Therefore, the current flowing through the first-layer wiring 34 and the second-layer wiring metal film 3
6 can maximize the difference in the distribution region of the magnetic field generated from the current flowing through the current 6, thereby obtaining a stronger magnetic field and making it easier to detect the magnetic field.

In this nondestructive inspection method, since a laser beam is used, a defective portion can be efficiently heated, and a thermoelectromotive force can be generated with high sensitivity. Therefore, the accuracy of the inspection can be improved.

Further, in this non-destructive inspection method, since the wavelength of the light of the laser beam 3 is set to 1300 nm, it is possible to prevent the generation of a photo-induced current in the silicon substrate 31 which causes noise, and to improve the accuracy of the inspection. Can be further improved. Further, since the light having a wavelength of 1300 nm can pass through the silicon substrate 31, the laser beam 3 can be emitted from the back surface (substrate side) 50b, and the magnetic field detector 5 can be disposed on the front surface 50f. . Therefore, detection can be performed at a position where the intensity of the generated magnetic field is strong, and the detection sensitivity can be further improved.

[Second Embodiment] Next, another example of the nondestructive inspection method of the present invention will be described. This non-destructive inspection method differs from the above-described non-destructive inspection method in that the structure of the semiconductor device chip in the course of manufacture is different. As shown in FIG. 5, the semiconductor device chip being manufactured has two contact portions 33a and 33b, and the first layer wiring 34 of the semiconductor device chip being manufactured is diffused by the two contact portions 33a and 33b. It is connected between layers. Further, the semiconductor device chip in the course of manufacture does not have the circuit via 35 and is not connected to the second-layer wiring metal film 36. In such a case, as shown in FIG.
a and 305b are provided. At this time, the inspection via 305
a and 305b are arranged so as to be connected to both ends of the first-layer wiring 34, respectively.

As shown in FIG. 5, the semiconductor device chip in the course of manufacture has a thermoelectromotive force generation defect 41, and when the laser beam 3 is irradiated on the thermoelectromotive generation defect 41, the laser beam A thermo-electromotive current induced by the irradiation heating of No. 3 is generated. This thermoelectromotive current is the first
As a closed circuit current including the layer wiring 34, the inspection vias 305a and 305b, and the metal wiring 36 for the second layer, the current flows through current paths indicated by arrows 611 and 612.

Since such a non-destructive inspection method is a method for inspecting the defect of the semiconductor device chip by the intensity of the magnetic field similarly to the above-described non-destructive inspection method, the current change detector is connected to the semiconductor device chip. It is not necessary to perform the inspection, and the man-hour and cost required for the inspection can be greatly reduced. In addition, it is possible to feed back the inspection result at a more upstream stage of the semiconductor manufacturing process, that is, at a stage where the added value is small as compared with the related art.

Further, since the second layer metal film 36 is formed after the inspection vias 305a and 305b are provided, the magnetic field can be easily detected. That is, the current generated by the thermoelectromotive force flows as a closed circuit current including the first-layer wiring 34, the inspection vias 305a and 305b, and the second-layer wiring metal film 36. It may be longer than the case of the circuit current. Further, the current path 611 flowing through the first-layer wiring 34 is relatively narrow, and the magnetic field induced by the current is also localized along the first-layer wiring 34. The current path 612 flowing through the metal film 36 is distributed over a relatively wide range, and the magnetic field induced by the current spreads over a wide range. For this reason, the magnetic field generated from the current flowing through the first-layer wiring 34 and the current flowing through the second-layer wiring metal film 36 have directions that cancel each other out.
Since the distribution regions of the magnetic field are different as described above, they do not cancel each other out so much.

As described above, since the current generated by the thermoelectromotive force flows as a closed circuit current, the decay time of the current can be prolonged, and the magnetic field generated by the current flowing through the closed circuit cancels out so much each other. When they do not match, a strong magnetic field is generated, and the detection of the magnetic field becomes easier. Therefore, while contributing to improved productivity and reliability of semiconductor devices, a magnetic field detector having a slow response speed, that is, a relatively inexpensive magnetic field detector, can detect a thermoelectromotive current-induced magnetic field, thereby reducing inspection costs. it can.

Further, inspection vias 305a and 305b
Are arranged so as to be connected to both ends of the first-layer wiring 34, respectively, so that the current path can be maximized and the intensity of the magnetic field induced by the generation of the thermoelectromotive current can be increased. Thus, the detection of the magnetic field can be further facilitated.

As described above, the nondestructive inspection method of the present invention provides a semiconductor device in the process of manufacturing in which the n-th wiring is the first wiring and the (n + 1) th wiring is the second wiring. It can be used as a method for inspecting a chip, but it can also be used as a method for inspecting wiring of layers other than the above in a semiconductor device chip being manufactured having a multilayer structure of two or more layers,
The wiring to be inspected may be any layer of wiring and is not particularly limited.

Further, as described above, the nondestructive inspection method of the present invention can be a method of inspecting a semiconductor device chip in the course of manufacturing when forming the (n + 1) th layer wiring made of metal. An inspection method for forming the (n + 1) th layer wiring made of polycrystalline silicon or the like can be similarly used, and the material for forming the (n + 1) th layer wiring is not particularly limited.

In the nondestructive inspection method of the present invention, the beam can be a laser beam as described above, but an electron beam or an ion beam may be used instead of the laser beam.

In the nondestructive inspection method of the present invention, as many inspection vias as possible are provided in one semiconductor device chip in order to increase the possibility of detecting a defect in the semiconductor device chip. It is preferable to form many closed circuits.

[0059]

As described above, according to the nondestructive inspection method of the present invention, a semiconductor device chip being manufactured is irradiated with a beam, and the irradiation of the beam generates a thermoelectromotive current in the semiconductor device chip. Since this method detects the intensity of the induced magnetic field and inspects the semiconductor device chip for defects based on the intensity of the detected magnetic field, there is no need to connect a current change detector to the semiconductor device chip, and the number of work steps required for the inspection is reduced. And cost can be significantly reduced. In addition, the inspection can be performed at an upstream stage before the completion of the bonding pad in the semiconductor manufacturing process, and the feedback of the inspection result can be performed at an upstream stage of the semiconductor manufacturing process, that is, at a stage where the added value is smaller than before.

Further, according to the semiconductor integrated circuit and the non-destructive inspection method of the present invention, the current generated by the thermoelectromotive force accompanying the non-destructive inspection is transferred to the n-th layer wiring, the circuit via, the inspection via, and the As a closed circuit current composed of the (n + 1) th layer conductive film, or the nth layer wiring and the inspection via
Since the current can flow as a closed circuit current composed of the first-layer wiring conductive film, the current decay time can be prolonged, and the magnetic field generated by the current flowing through the closed circuit does not cancel each other out so much. As a result, a strong magnetic field is generated, and the case where the magnetic field is easily detected increases. Therefore, while contributing to the improvement of the productivity and reliability of semiconductor devices, a magnetic field detector having a slow response speed, that is, a relatively inexpensive magnetic field detector can detect a thermoelectromotive current-induced magnetic field, thereby reducing inspection costs. it can.

Further, by connecting the inspection via to the end of the n-th layer wiring, the current path can be maximized and the intensity of the magnetic field induced by the generation of the thermoelectromotive current can be increased. And the detection of the magnetic field can be further facilitated.

In the nondestructive inspection method according to the present invention, the path of the current flowing through the (n + 1) th layer conductive film is maximized by providing the (n + 1) th layer conductive film on the entire surface. And the magnetic field induced by the current can be expanded to the widest range. Therefore, the difference between the distribution region of the magnetic field generated from the current flowing through the n-th layer wiring and the current flowing through the n + 1-th layer wiring conductive film can be maximized, and a stronger magnetic field can be obtained. Can be easily detected.

Further, in the nondestructive inspection method of the present invention, by using the beam as a laser beam, a defective portion can be efficiently heated, and a thermoelectromotive force can be generated with high sensitivity. Therefore, the accuracy of the inspection can be improved.

Further, the wavelength of the light of the laser beam is
By setting the length to be longer than 1200 nm, it is possible to prevent a photo-induced current from being generated in the silicon portion, which causes noise, and to further improve the accuracy of inspection. When the substrate is made of silicon, the laser beam light having the above-mentioned wavelength can be transmitted through silicon, so that the wiring portion from the back surface side of the chip to the vicinity of the chip surface can be irradiated and heated. By irradiating the laser beam from the back side of the chip, the magnetic field detector can be arranged on the front side of the chip, and detection can be performed at a position where the intensity of the generated magnetic field is strong, so that the detection sensitivity can be further improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a non-destructive inspection device used in a non-destructive inspection method of the present invention.

FIG. 2 is a cross-sectional view showing an example of a semiconductor device chip in the course of manufacture.

3A and 3B are views for explaining a state in which the semiconductor device chip shown in FIG. 2 is irradiated with a laser beam during manufacturing, and FIG. 3A is a cross-sectional view and FIG. It is.

FIG. 4 is a view showing a state after patterning a second-layer wiring metal film of the semiconductor device chip in the process of manufacturing shown in FIG. 2;

FIG. 5 is a cross-sectional view showing another example of the semiconductor device chip in the course of manufacture.

FIG. 6 is a cross-sectional view showing another example of a semiconductor device chip in the course of manufacture.

FIG. 7 is a cross-sectional view showing another example of a semiconductor device chip in the course of manufacture.

FIG. 8 is a cross-sectional view showing another example of a semiconductor device chip in the course of manufacture.

FIG. 9 is a cross-sectional view showing another example of a semiconductor device chip in the course of manufacture.

FIG. 10 is a cross-sectional view showing another example of a semiconductor device chip in the course of manufacture.

FIG. 11 is a configuration diagram illustrating an example of a conventional nondestructive inspection apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Laser generator 2 Optical system 3 Laser beam 4 Semiconductor device chip 5 Magnetic field detector 7 Image display device 14-1, 14-7 Bonding pad 31 Silicon substrate 32 Insulating layer 33, 33a, 33b Contact part 34 First layer wiring (Nth layer wiring) 35 Circuit via 36 Second layer wiring metal film (n + 1th layer wiring conductive film) 37 Second layer wiring 40, 50 Semiconductor device chip 40b, 50b in the process of manufacturing Back side (Substrate side) 40f, 50f Front side 41 Thermoelectromotive force generation defect 61, 611, 612 Current path 106 Control / image processing system 115-1, 115-2 Prober 131 Current change detector 305, 305a, 305b Inspection via

Claims (11)

[Claims] 1. An n-th layer wiring is formed on a substrate, and a circuit via for connecting the n-th layer wiring and the (n + 1) -th layer wiring is formed in an insulating layer above the n-th layer wiring. Connected to the wiring,
After forming at least one or more inspection vias not connected to the (n + 1) th layer wiring, the (n + 1) th layer is formed in a region wider than at least the region where the (n) th layer wiring exists in order to form the (n + 1) th layer wiring. A beam is irradiated to the semiconductor integrated circuit in the process of manufacturing in which the conductive film for the wiring is formed, and the intensity of the magnetic field induced by the generation of a thermoelectromotive current in the semiconductor integrated circuit by the irradiation of the beam is detected. A non-destructive inspection method, wherein a defect of the semiconductor integrated circuit is inspected based on the intensity of the detected magnetic field. 2. An n-th layer wiring is formed on a substrate, and at least two or more inspection vias connected to the n-th layer wiring and not connected to the (n + 1) -th layer wiring are formed in an insulating layer thereon. After the formation, a semiconductor integrated circuit in the process of forming an (n + 1) th layer wiring conductive film provided in at least a region wider than a region where the (n + 1) th layer wiring exists to form the (n + 1) th layer wiring Irradiating the circuit with a beam, detecting the strength of a magnetic field induced by the generation of a thermoelectromotive force in the semiconductor integrated circuit by the irradiation of the beam, and inspecting the semiconductor integrated circuit for defects based on the detected strength of the magnetic field. Non-destructive inspection method characterized by performing. 3. The nondestructive inspection method according to claim 2, wherein the n-th layer wiring is a wiring having both ends connected to a diffusion layer formed on a substrate. 4. The nondestructive inspection method according to claim 1, wherein the inspection via is connected to an end of the n-th layer wiring. 5. The nondestructive inspection method according to claim 1, wherein the (n + 1) th wiring conductive film is provided on the entire surface. 6. The nondestructive inspection method according to claim 1, wherein the beam is a laser beam. 7. The wavelength of the laser beam is 120.
7. The nondestructive inspection method according to claim 6, wherein the length is longer than 0 nm. 8. An nth layer wiring, an (n + 1) th layer wiring, a circuit via connecting the nth layer wiring and the (n + 1) th layer wiring on a substrate,
A semiconductor integrated circuit, comprising: at least one or more test vias provided on the n-th wiring, connected to the n-th wiring, and not connected to the (n + 1) -th wiring. 9. An n-th wiring, an (n + 1) -th wiring, and at least two or more wirings provided on the n-th wiring on the substrate, connected to the n-th wiring, an inspection via that is not connected to the (n + 1) th layer wiring, and the nth layer wiring having the inspection via is provided on the nth layer wiring.
A semiconductor integrated circuit, wherein a circuit via connecting a layer wiring and the (n + 1) th layer wiring is not provided. 10. The semiconductor integrated circuit according to claim 9, wherein both ends of said n-th layer wiring are connected to a diffusion layer formed on a substrate. 11. The semiconductor integrated circuit according to claim 8, wherein said inspection via is connected to an end of said n-th layer wiring.