JPH10303268A - Semiconductor manufacturing method and semiconductor inspecting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor inspecting equipment wherein early detection of failure and improvement of yield are realized. SOLUTION: A semiconductor inspecting equipment 9 contains a working part 2 wherein a specified part position on which a pattern of a thin film is formed is bored in an area except for a thin-wall part position which is thinned to be a specified thickness capable of seeing through for analysis from the backside of a wafer, an inspecting part 3 which inspects the thin-wall part position by seeing through for analysis method, and a repairing part 6 for repairing an inspected trace. A wafer wherein a single-layered or multilayered thin film for a component is formed on the surface is extracted from a semiconductor manufacturing line 8 in the course of a manufacturing process and subjected to on-line inspection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor manufacturing method and a semiconductor inspection apparatus in a manufacturing process including a line inspection.

[0002]

2. Description of the Related Art The current state of wafer inspection in a conventional semiconductor manufacturing process will be described below. ULSI (Ult
In order to increase the degree of integration of ra Large Scale Integration), miniaturization of devices has been promoted. U of 64MDRAM
In the LSI example, the gate insulating film thickness of 0.35 μm is about
It has a very fine structure of about 10 nm, and a difference in wiring processing dimensions, a slight displacement of a contact hole, a foreign matter, and the like cause a failure such as disconnection or short circuit. In a mass production line, it is very important to detect the occurrence of such a defect as soon as possible and take a countermeasure. The longer the time from the occurrence of a defect to its discovery, the greater the number of occurrences of the defect and the lower the yield. Therefore, it is essential to promptly remove such a shape defect by an appearance inspection during the process.

[0003] At present, inspection of such a shape defect includes an SEM method using a scanning electron microscope (SEM). SEM is a device that scans the sample surface two-dimensionally with a focused electron beam, detects secondary electrons generated from the surface, and mainly observes the surface shape. In addition to being observable as a thick sample, stereoscopic observation is possible because the depth of focus is much deeper than that of an optical microscope. In particular, a length measuring SEM for a semiconductor line has a feature that the operation is simple and the inspection can be performed on a wafer without processing a sample. Therefore, they are used by being incorporated during the manufacturing process.

On the other hand, in order to measure the size of a finer area and to specify the cause of a defect, a transmission electron microscope (TEM) or a scanning transmission electron microscope (STE) having a higher spatial resolution is required.
M), an energy dispersive X-ray spectrometer (EDX), an electron energy loss spectrometer, etc.
A combination of (EELS) is generally used. In general, a TEM for irradiating a sample with an electron beam, detecting transmitted electrons, and mainly performing a structural analysis of a fine region.
Methods and TEM inspection equipment are used. This TEM
In the method, it is necessary to process a sample to be inspected to a thickness small enough to transmit an electron beam. Therefore, when inspecting a wafer during the manufacturing process, the wafer is first extracted from the line, and a sample for TEM observation is cut out from the line and thinned. This method is mainly used for elucidating a failure mechanism such as analysis of crystal defects and fine foreign matter in a wafer.

[0005]

However, the above S
The EM method and the TEM method have the following problems, respectively. At present, the spatial resolution of the length measuring SEM incorporated in the semiconductor line and used for shape inspection is 5 nm, and the measuring accuracy is ± 1% or about 5 nm. The resolution of the SEM is determined by the size of the probe, but it is considered that the spatial resolution is practically improved to only about 5 nm because the probe is actually spread due to the scattering of the electron beam in the sample.
Probably, it is expected that the shape inspection can be handled with the resolution and length measurement accuracy of SEM from the integration degree of 64M to 256M level.

However, when the integration degree becomes 256M or more, the minimum processing size is expected to be reduced to 0.1 μm or less, and even if processing accuracy is allowed to be 20%, it will be 0.02 μm. Is necessary. In the case of a gate insulating film as an example, the film thickness is expected to be 5 nm or less, and when the control accuracy is 10%, the film thickness is 5 mm. Therefore, the measurement accuracy is required to be 1-2 mm. Therefore, the SEM method has a problem that it is difficult to measure the length of a fine structure because of insufficient spatial resolution and measurement accuracy.

Therefore, it is conceivable to perform inspection using a TEM having a high spatial resolution (up to 1 °) that enables detection of a shape defect with sufficient spatial resolution and length measurement accuracy even when the integration degree becomes 256M or more. However, this TEM method has the following problems. When inspecting by TEM, it is necessary to reduce the thickness of the sample to a thickness that allows electron beams to pass through. Therefore, to inspect a wafer in the middle of the semiconductor manufacturing process, first remove the wafer from the process, and then
Cut out a sample for EM observation (about 5 × 0.2 mm) and reduce the thickness (about 200
nm or less). Since it takes a long time from sample preparation to inspection (at least 2 days), it was difficult to measure by incorporating a TEM into a production line. That is, it was an off-line inspection off the line.

Further, the wafer after being extracted from the process and cutting out the sample for TEM observation is opened to the atmosphere,
The dust generated during cutting adheres and cannot be returned to the original process. Therefore, one wafer was wasted in order to cut out a sample of several mm. Therefore, in order to cope with the miniaturization of elements due to further high integration of semiconductors in the future, a method of inspecting a wafer in the middle of the manufacturing process with higher spatial resolution and high accuracy, and a method of returning the measured wafer to the process again Is needed. Accordingly, an object of the present invention is to provide a semiconductor manufacturing method and a semiconductor inspection apparatus which enable early detection of a shape defect even when the processing dimension of a semiconductor is further miniaturized in the future, and greatly contribute to improvement in yield. is there.

[0009]

A feature of the semiconductor manufacturing method according to the present invention that achieves the above object is that a wafer having a single-layer or multiple-layer element thin film formed on its surface is extracted and the wafer is inspected. In the above, the inspection is an online inspection by a transmission analysis method for a thin portion formed by selecting a local portion of the wafer and reducing the thickness. Further, another feature is that in a semiconductor manufacturing method in which a wafer on which a single-layer or multiple-layer element thin film is formed on the surface is sampled and defects of the wafer are inspected, the inspection includes selecting a local portion of the wafer, The point is that the thin portion is perforated while leaving a thin portion thinned to a predetermined thickness at which the transmission can be analyzed from the back surface of the wafer, and the transmission analysis of the thin portion is performed.

Another feature is a semiconductor manufacturing method in which a wafer having a single-layer or multiple-layer element thin film formed on its surface is withdrawn during a manufacturing process and a line inspection is performed for a defect of the thin film. Aiming at a local portion of the specific pattern of the thin film, at least one of the thin film forming portion or at least one of the wafer portions excluding the thin film forming portion can be subjected to transmission analysis between the holes. This is an inspection in which a thin-walled portion extending vertically on the wafer surface with a thickness is perforated and perforated so as to remain, and an electron beam is transmitted obliquely to the thin-walled portion for analysis. Further, in the line inspection, a predetermined portion on which the pattern of the thin film is formed is left with a thin portion having a predetermined thickness that can avoid the influence of scattering and reflection of irradiation electrons for inspection inside the wafer. The thin portion may be perforated from the back surface of the wafer, and the thin portion may be inspected by a scanning electron microscope.

On the other hand, a semiconductor inspection apparatus for achieving the above object is a semiconductor inspection apparatus for inspecting a wafer having a single-layer or multiple-layer element thin film formed on a surface thereof. A perforation means for perforating the thin portion, leaving a thin portion thinned to a predetermined thickness capable of analyzing the transmission from the back surface of the wafer, an inspection device for inspecting the thin portion by a transmission analysis technique, and a repairing device for repairing the inspection mark. It is a thing.

According to the present invention, since a thinned portion is inspected by selecting a local portion of the wafer and performing transmission analysis, an on-line inspection of a wafer having a miniaturized pattern becomes possible.
Further, since the inspection mark is repaired, early detection of a wafer defect and improvement of the yield can be achieved. Specifically, the wafer in the middle of the manufacturing process is extracted, the thickness is reduced from the back surface of the wafer to the part where the pattern is formed, and the thinned area is inspected by transmission electron microscopy, and the inspection mark is repaired. Since the process returns to the original process, the shape of the wafer during the process can be inspected with high spatial resolution, and the wafer after the measurement can be used, thereby achieving the above object.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a semiconductor manufacturing method according to one embodiment of the present invention.
FIG. 2 is a schematic view showing a wafer having a locally thinned portion for inspection according to an embodiment of the present invention.
FIG. 3 is a diagram showing a semiconductor inspection apparatus according to one embodiment of the present invention. The configuration and operation will be described simultaneously with reference to FIGS.

In FIG. 1, a wafer is taken out from a semiconductor manufacturing line 8 and transported to a semiconductor inspection apparatus 9. First, the wafer is placed in a sample storage case (1) 1. Subsequently, one wafer stored in the sample storage case (1) 1 is extracted and transported to the processing unit 2. Then, in the processing section 2, a predetermined local portion of the thin film (pattern) formed on the surface of the wafer is perforated from the back surface of the wafer to make a thinner portion, thereby forming a thinner portion as an inspection region as described later. The processing section 2 as a drilling means includes a focused ion beam processing apparatus (FI
B) or an ion milling device is used. The back surface of the wafer refers to the surface of the wafer on which the thin film pattern is not formed. In general, a local portion of the wafer where the thin film is formed is inspected, but a local portion of the wafer itself may be inspected as occasion demands. Therefore, the local portion of the wafer to be selected includes the portion of the wafer itself and the portion where the thin film is formed.

The size of the “thinned region 12 in which the plane inspection region 13 as a thinned portion is formed by drilling”, which is local to the large wafer 11 for inspection in FIG. 2, is about 3 mm square. The predetermined thickness of the thin portion 13 left after the thinning of the wafer 11 is set to such a thickness that the transmission analysis can be performed or the spread of the probe due to the scattering of the electron beam inside the sample does not matter. The drilling dimension of the thinning to leave on this wafer is
Inspection of a ULSI pattern of 0.1 μm or less and having a desired degree of integration is sufficiently possible with a local drilled area of 3 mm square. That is, it can be said that the dimension of the thinned portion 13 is a film thickness that allows transmission analysis, and the dimension of the thinned region 12 is a size corresponding to a miniaturized pattern.

After the wafer is thinned for inspection, it is conveyed to the inspection section 3 to inspect the thinned portion 13 as shown in FIG. Inspection unit 3 as inspection means has a transmission electron microscope
(TEM), a scanning transmission electron microscope (STEM), a scanning electron microscope (SEM), or the like. Also, if necessary, TEM, STE
It is also possible to perform elemental analysis using a combination of an elemental analysis function such as an energy dispersive X-ray spectrometer (EDX) or an electron energy loss spectrometer (EELS) with M, SEM, or the like. In this specification, a thinned portion of a wafer is thinned using the above-mentioned transmission electron microscope, scanning transmission electron microscope, scanning electron microscope, energy dispersive X-ray spectrometer, electron energy loss spectrometer, or the like. Is defined as inspection by a transmission analysis method.

The inspected wafer is transported to the sample selection section 4. In the inspection step, when a defective appearance such as a difference in processing dimensions, a positional shift, or a foreign matter is detected on the wafer, the defective wafer is transferred from the sample selection unit 4 to the defective product storage case 5 and is then transferred to the semiconductor manufacturing line. Remove from 8. The non-defective wafer determined to have no problem by the inspection unit 3 is transferred from the sample selection unit 4 to the repair unit 6 as a repair unit. Then, the thinned area 12 remaining as an inspection mark is
For example, repair is performed using a method of embedding W, SiO _2, or the like to prevent a decrease in the strength of the wafer and to prevent foreign matter from being mixed in a later manufacturing process. After the repair, the wafer is once stored in the sample storage case (2) 7 and then returned to the production line 8 again.

As described above, according to the present embodiment, the analysis or the scanning type by the transmission electron microscope or the scanning transmission electron microscope is applied to the predetermined local portion of the wafer having the miniaturized pattern selected to be inspected. Since a thin portion formed by thinning the wafer is formed so as to be able to be inspected by a method such as analysis with an electron microscope, and the local thinned portion is inspected, a line inspection as one process in a series of line operations, that is, In addition, online inspection (or in-line inspection) becomes possible. That is, a wafer in the middle of a manufacturing process can be inspected at a high spatial resolution of 〜1Å, and a wafer that is being miniaturized can be inspected for early detection of a defective wafer appearance in a fine process.
In addition, since the wafer can be effectively used by repairing the inspected wafer and returning to a subsequent process, the yield can be greatly improved.

Next, a semiconductor inspection apparatus using a transmission electron microscope (TEM) as the inspection section 3 will be described with reference to FIG. In addition, a semiconductor manufacturing apparatus incorporating this semiconductor inspection apparatus in a production line offline,
It goes without saying that a semiconductor manufacturing apparatus in which the semiconductor inspection apparatus separately manufactured as a single unit is incorporated in a manufacturing line online is also included in the category of the present invention. In the figure, a wafer 11 is extracted from a semiconductor manufacturing line 8 and transferred to a semiconductor inspection apparatus 9. Then, first, it is stored in the sample storage case (1) 1. Subsequently, the wafer 11 stored in the sample storage case (1) 1
And transport it to the processing unit 2. The processing section 2 as the perforating means of this embodiment performs (performs) perforating processing including (using) processing means using an ion beam. This processing part 2
Then, an electron beam is emitted from the electron gun 201 to the wafer 11, secondary electrons generated from the wafer surface are detected by the secondary electron detector 202, and the surface shape is observed by the secondary electron image monitor 206,
A thinning region is determined as a predetermined local portion on the wafer 11.

Thereafter, the processing region as a predetermined portion determined by the above observation is perforated from the back surface to be thinned by a gallium ion beam emitted from a gallium ion source 203 as a processing means using an ion beam.
Form 13. The irradiation position of the electron beam and the gallium ion beam is adjusted to be the same position across the wafer 11, so that the thin portion 13 (i.e., the processing region) as the inspection region determined by observing the wafer surface is used. Perforation processing can be performed from the back surface. The progress of thinning and the size of the processed region can be observed from the secondary electron detector 204 through the secondary electron image monitor 207. Note that the argon ion gun 205 may be used in combination with the finishing process of the thin portion 13 if necessary.

The size of the thinned region 12 shown in FIG. 2 of the thinned wafer 11 for inspection is about 3 mm square, and the thickness of the thinned portion 13 left on the wafer is a thickness which can be analyzed by transmission. And After that, the wafer 11 is transferred to the inspection unit 3. As the inspection unit 3 of this embodiment, a transmission electron microscope (TEM) is used. An electron gun 301 as a beam irradiation unit for transmission analysis irradiates an electron beam to a sample wafer and transmits the electron beam to a thinned region. The electrons transmitted through the sample are energy filters
It is incident on 302, where the electrons are separated by the difference in energy. By selecting only the electrons (zero-loss electrons) that have passed through the sample with the incident energy by the energy filter 302 and removing the effects of the electrons that have lost energy in the sample (becoming the background), even in relatively thick samples, It is possible to observe a transmitted electron image with high contrast.

Next, the transmitted electrons are detected by a transmitted electron detector 303 and projected on a transmitted electron image monitor 305 to inspect the appearance defects such as differences in processing dimensions, positional deviations, and foreign matter. If necessary, use an energy dispersive X-ray spectrometer for TEM (ED
Elemental analysis can also be performed using X) 304 or energy filter 302. After the inspection, the wafer is transported to the sample selection section 4. When a defect in appearance such as a difference in processing size, a positional shift, or a foreign matter is detected in the inspected wafer, the defective wafer 14 is transferred from the sample selection unit 4 to the defective product storage case 5. The non-defective wafer determined to have no problem by the inspection by the inspection unit 3 is transported from the sample selection unit 4 to the restoration unit 6.

The restoration unit 6 as the restoration means of the present embodiment is
Including (with) processing means using an ion beam, hole repair processing is performed. In the repairing section 6, weak gallium ions are first irradiated on the back surface of the wafer from a gallium ion source 601 as a processing means using an ion beam, and repair is necessary by the secondary electron detector 602 and the secondary electron image monitor 604. Determine the thinning region. While irradiating the thinned region with gallium ions, a W (CO) ₆ gas is introduced from the gas introduction unit 603, and the energy of the gallium ion beam is used to perform tungsten (W) (CO) ₆ → W + 6CO reaction. A film is formed and the inspection mark (processed area) is restored.

The restoration of the inspection trace prevents a decrease in the strength of the wafer and prevents foreign matter from being mixed in a later manufacturing process. The repaired wafer 15 repaired by the repairing means is once stored in the sample storage case (2) 7 and then returned to the semiconductor manufacturing line 8 again. According to this embodiment, a wafer in the middle of the manufacturing process can be inspected with a high spatial resolution of ~ 1 mm, early appearance defects can be detected in a fine process, and the wafer after inspection and measurement can be returned to a subsequent process. , The wafer can be used effectively.
Therefore, it can greatly contribute to improvement in yield.

The above is summarized as follows. The features of the semiconductor manufacturing method and the semiconductor inspection device according to the present invention are as follows.
The advantage is that the disadvantages of TEM are improved while utilizing the high spatial resolution of TEM. That is, the characteristic of the semiconductor manufacturing method (inspection process) of extracting a wafer having a single-layer or multiple-layer element thin film on the surface during the manufacturing process and inspecting the thin film is a transmission analysis method employing local thinning of the wafer. Inspection by. On the other hand, a feature of the semiconductor inspection apparatus is that, in the case of an inspection apparatus using a TEM method, for example, a local thinning processing portion for inspection and an inspected thinned region repairing portion are incorporated in the inspection device using the TEM method. According to the present invention described above, since a portion required for inspection can be processed into a shape for inspection without cutting out the wafer from the wafer, the time required for processing can be greatly reduced. Therefore, early detection of defects and early measures are possible.

Further, by inspecting the wafer in the same shape, the inspected wafer determined to be non-defective after the inspection can be returned to a subsequent process. Part) can be used effectively without wasting. At this time, by repairing the processed inspection area of the wafer after the inspection, it is possible to prevent a decrease in the wafer strength and to prevent the generation of foreign matter in a later manufacturing process. As described above, the yield can be improved by early detection of defects, early measures, and effective use of elements other than the inspection area.

Meanwhile, it is possible to use a wafer in which a specific inspection area is thinned from the beginning or a wafer in which a hole is partially formed in a production line. In this case, a sample is processed for TEM inspection. It is possible to inspect a wafer in the middle of a production line without any trouble, and then return the wafer to the line again. By using this method, the time required for sample processing is reduced, so that a semiconductor inspection apparatus with higher throughput can be provided.

On the other hand, in the above-described embodiment, a processing means using an ion beam is used for the perforating means or the repairing means.
That is, the drilling means provided in the drilling means is a processing means using an ion beam, and the hole repair processing means provided in the repairing means is also a processing means using an ion beam. This is because the irradiation energy of the ion beam is larger than that of the electron beam, and the degree of processing is high (the processing can be performed more quickly and more accurately). However, there is a case where there is a problem in the dual-purpose configuration as shown in this embodiment, and another embodiment described below may be desirable.

Next, another embodiment will be described. FIG. 4 is a diagram showing a semiconductor inspection apparatus according to another embodiment of the present invention. An embodiment in the case where the inspection unit 3 includes a processing area restoration function is shown. Other configurations are almost the same as those of the embodiment of FIG. In the figure, an electron beam is emitted from the electron gun 301 and the inspection unit 3 inspects the electron beam, and when it is determined that the wafer is non-defective, the same electron gun is applied to the non-defective wafer in the same inspection area in the same inspection unit 3. An electron beam is irradiated from 301.
Then, while irradiating, a W (CO) ₆ gas is introduced from the gas introduction unit 603, and a tungsten film is formed by thermal decomposition using the temperature rise of the portion irradiated with the beam to repair a processing area serving as an inspection mark. Aim. The restoration of the processing region can prevent the strength of the wafer from being reduced, and can prevent the generation of foreign matter in a later manufacturing process. The repaired repaired wafer 15 is once stored in the sample storage case (2) 7 and then returned to the semiconductor manufacturing line 8 again. According to the above embodiment, simple and quick inspection of a wafer in the middle of a manufacturing process can be performed, and defective appearance in a fine process can be detected early. Further, by returning the wafer after the measurement to a subsequent process, the wafer can be used effectively, which can greatly contribute to an improvement in yield.

In this embodiment, W (CO) ₆
A gas was introduced, an electron beam was applied from the wafer surface, and the temperature was increased indirectly to form a tungsten film.However, when the processing area was repaired, the front and back sides of the wafer were reversed (the repair area becomes the top), and the repair area It is also possible to form a tungsten film by directly irradiating an electron beam and introducing a W (CO) ₆ gas from above. That is, in FIG. 4, a reversing case 307 (or reversing table 307) indicated by a dotted line for reversing the inspected wafer is provided. This is a means for sharing the electron gun 301 used for inspection and repair, and leads to downsizing and cost reduction of the device.

In other words, in the case where the inspection section includes a step of restoring the inspection mark, by using the same electron gun for the inspection means and the restoration means, it is possible to reduce the size of the apparatus. Note that it is possible to invert the electron gun 301, but inverting the wafer is advantageous in terms of miniaturization and cost reduction of the apparatus. That is, another characteristic of the semiconductor inspection apparatus according to the present invention is that the electron gun 301 as the electron beam irradiating means for repair provided in the repairing means is different from the electron gun 301 as the electron beam irradiating means for transmission analysis provided in the inspecting means. The point is that they are shared. Another feature of the present invention resides in that a reversing case 307 is provided as reversing means for reversing the inspected wafer.

Next, another embodiment will be described. FIG. 5 is a view showing a semiconductor inspection apparatus according to another embodiment of the present invention. An example in which an SEM is used as the inspection unit 3 is shown. In the semiconductor inspection apparatus according to the present embodiment, thinning, inspection, and repair of a processed area are all performed by an inspection unit. In the figure, a wafer 11 is withdrawn from a semiconductor manufacturing line 8 and transported to a semiconductor inspection apparatus 9, and is first placed in a sample storage case (1) 1. Subsequently, one wafer stored in the sample storage case (1) 1 is transported to the sampling inspection unit 3. In the inspection unit 3, an electron beam is emitted from the electron gun 201 to the wafer, secondary electrons generated from the wafer surface are detected by the secondary electron detector 202, and the surface shape is observed through the secondary electron image monitor 206. At this time, a predetermined inspection area that can be inspected with a spatial resolution of about 5 nm is inspected. If a defect is found here, it is sent from the sample selection unit 4 to the defective product storage case 5 and the defective wafer 14 is removed.

Further, the gallium ion beam emitted from the gallium ion source 203 is used to reduce the thickness of a predetermined inspection region requiring inspection with high spatial resolution (1 nm or less) from the back surface. Since the irradiation positions of the electron beam and the gallium ion beam are adjusted so as to be the same position across the wafer, the inspection area determined by observing the wafer surface can be processed from the back surface. The progress of the thinning and the degree of processing can be observed from the secondary electron detector 204 through the secondary electron image monitor 207. The argon ion gun 205 may be used in combination with the finishing process if necessary.

Thereafter, an electron beam is emitted from the electron gun 201 to the thinned region from the back surface, secondary electrons generated from the wafer surface are detected by the secondary electron detector 202, and the surface shape is passed through the secondary electron image monitor 206. Observe the difference in processing dimensions,
Inspect for poor appearance such as displacement or foreign matter. A scanning electron microscope was used to reduce the spread of the incident electron beam inside the wafer by reducing the inspection area to a predetermined thickness to avoid the effects of scattering and reflection of irradiation electrons for inspection inside the wafer. Analytical inspection with high spatial resolution (1 nm or less) becomes possible.

Further, if necessary, elemental analysis can be performed by an energy dispersive X-ray spectrometer (EDX) 214 for SEM. When an appearance defect such as a difference in processing size, a positional shift, or a foreign matter is detected in the inspected wafer, the defective wafer 14 is transferred from the sample selection unit 4 to the defective product storage case 5. The non-defective wafer determined by the inspection by the inspection unit 3 to have no problem with the wafer is irradiated with gallium ions from the gallium ion source 203 to the thinned region serving as the inspection mark in the inspection unit 3 and gaseous. W (C
O) ₆ gases are introduced, and a tungsten film is formed by thermal decomposition using the temperature rise of the part hit by the gallium ion beam, and the processing area is restored. By repairing the inspection trace, it is possible to prevent a decrease in the strength of the wafer and to prevent foreign matter from being mixed in a later manufacturing process. After the repaired wafer 15 is once stored in the sample storage case (2) 7, it is returned to the semiconductor manufacturing line 8 again.

In summary, the electron beam of the scanning electron microscope is applied to a thin portion having a predetermined thickness which can avoid the influence of scattering and reflection of irradiation electrons for inspection inside the wafer. However, since the spread due to electron beam scattering inside the wafer is small, the deterioration of spatial resolution due to beam scattering inside the sample, which has conventionally been a problem with semiconductor inspection equipment using a scanning electron microscope (SEM), has been reduced. Can be avoided. Therefore, it is possible to perform an inspection with high spatial resolution (1 nm or less) by using an SEM for the inspection unit as needed. That is, by using this method, the operation of the inspection unit is simplified, and a semiconductor inspection apparatus with higher throughput can be provided.

In this embodiment, since the gallium ion source 203 is also used as the processing means using the ion beam for the perforation means and the repair means, it is effective in reducing the size of the apparatus. Furthermore, in the present embodiment, processing, inspection, and processing area restoration can be performed by the inspection unit 3 as one means, which is effective in miniaturizing the apparatus. The predetermined thickness at which the effects of scattering and reflection inside the wafer can be avoided depends on the capability of the scanning electron microscope (SEM). For example, if the acceleration voltage is 5 kV, the predetermined thickness is 0.2 (μm)
It can be said that the degree is preferable.

As described above, according to this embodiment, a simple and quick inspection can be performed on a wafer during a manufacturing process.
It is possible to early detect an appearance defect in a fine process, and further, by returning the wafer after the measurement and inspection to a subsequent process, the wafer can be used effectively. Therefore, it can greatly contribute to improvement in yield. Further, since the thinning, inspection, and repair processing can be performed by one apparatus, the size of the semiconductor inspection apparatus can be reduced.

Next, a wafer having a thin portion according to another embodiment will be described. FIG. 6 is a schematic view showing a wafer having a locally thinned portion for inspection according to another embodiment of the present invention. In the embodiment described above,
As the inspection wafer, a wafer 11 thinned from the back surface as shown in FIG. 2 was used. For example, as shown in FIG. 6, a plurality of inspection through-holes 21 are locally formed to reduce the thickness. Wafer 11 having a cross-sectional inspection area 22 as a broken part
a may be used. In the case of the present embodiment, the cross-sectional inspection area 22 as a thin portion extending perpendicular to the wafer surface is set to a predetermined thickness capable of transmission analysis, and the thin cross-sectional inspection area 22 is inspected by transmitting an electron beam obliquely from the oblique direction. It is.

In the above embodiment, the wafer is transported from the production line to the processing section and inspected after the thinning process. However, it is also possible to use a wafer which has already been partially thinned or perforated before entering the production line. Good. When such an existing thin portion or existing through-hole is provided, the processing time required for thinning is shortened, so that a semiconductor inspection device with higher throughput can be provided. By the way, the present invention is also applied to the inspection of a liquid crystal element and a magnetic head element, but a detailed description will be given separately.

[0041]

According to the present invention, a wafer in the middle of a manufacturing process can be inspected with a high spatial resolution of up to 1 mm, so that even if the processing size is further miniaturized, a shape defect can be detected early. . Further, since the wafer after the measurement can be returned to a subsequent process, the wafer can be used effectively. Therefore, it can greatly contribute to improvement in yield.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a semiconductor manufacturing method according to one embodiment of the present invention.

FIG. 2 is a schematic view showing a wafer having a locally thinned portion for inspection according to an embodiment of the present invention.

FIG. 3 is a diagram showing a semiconductor inspection apparatus according to one embodiment of the present invention.

FIG. 4 is a view showing a semiconductor inspection apparatus according to another embodiment of the present invention.

FIG. 5 is a diagram showing a semiconductor inspection apparatus according to another embodiment of the present invention.

FIG. 6 is a schematic view showing a wafer having a locally thinned portion for inspection according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sample storage case (1), 2 ... Processing part, 3 ... Inspection part, 4
... Sample sorting section, 5 ... Reject storage case, 6 ... Repair section, 7
... Sample storage case (2), 8 ... Semiconductor manufacturing line, 9 ... Semiconductor inspection equipment, 11, 11a ... Wafer, 12 ... Thinned area, 13
... plane inspection area (thin part), 14 ... defective wafer, 15 ... repair wafer, 21 ... inspection through hole, 22 ... cross-section inspection area (thin part), 201, 301 ... electron gun, 202, 204, 602 ... secondary electron detector, 203,601: Gallium ion source, 205: Argon ion gun, 206, 207,604: Secondary electron image monitor, 214: Energy dispersive X-ray spectrometer (EDX) for SEM, 302: Energy filter, 303: Transmission electron detector, 304: TEM Energy dispersive X-ray spectrometer (EDX), 305 ... Transmission electron image monitor, 30
7 ... reversing case, 603 ... gas introduction part.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masakazu Saito 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Research Laboratory Co., Ltd. Address Co., Ltd.Hitachi, Ltd.

Claims (10)

[Claims] In a semiconductor manufacturing method for extracting a wafer having a single-layer or multiple-layer element thin film formed on a surface thereof and inspecting the wafer, the inspection is performed by selecting a local portion of the wafer and reducing the thickness. A semiconductor manufacturing method which is an on-line inspection by a transmission analysis method for a thin portion. 2. A semiconductor manufacturing method in which a wafer on which a single-layer or multiple-layer element thin film is formed on a surface is sampled and defects of the wafer are inspected. A method of manufacturing a semiconductor, comprising: perforating a thin portion from a back surface thereof, leaving a thin portion thinned to a predetermined thickness capable of analyzing transmission, and analyzing the transmission of the thin portion. 3. The semiconductor manufacturing method according to claim 1, wherein said transmission analysis is an analysis method using a transmission electron microscope. 4. A semiconductor manufacturing method in which a wafer having a single-layer or multiple-layer element thin film formed on its surface is withdrawn during a manufacturing process and a line inspection is performed for a defect of the thin film. Aiming at a local portion of the pattern, at least one of the thin film forming portion or at least one of the plurality of wafer portions excluding the thin film forming portion is provided with a wafer surface of a predetermined thickness capable of performing transmission analysis between the holes. A semiconductor manufacturing method characterized in that the inspection is performed by penetrating the thin-walled portion so as to leave a thin-walled portion extending vertically, and transmitting an electron beam obliquely to the thin-walled portion. 5. A semiconductor manufacturing method in which a wafer on which a single-layer or multiple-layer element thin film is formed on a surface is withdrawn during a manufacturing process and a line inspection is performed for a defect of the thin film. Is formed through the back surface of the wafer, leaving a thin portion having a predetermined thickness that can avoid the influence of scattering and reflection of irradiation electrons for inspection inside the wafer. A semiconductor manufacturing method characterized by inspecting with a microscope. 6. A semiconductor inspection apparatus for inspecting a wafer on which a single-layer or multiple-layer element thin film is formed on a front surface, wherein a predetermined thickness on which a pattern of the thin film is formed can be analyzed by transmission from a back surface of the wafer. 1. A semiconductor inspection apparatus, comprising: a perforation means for perforating a thinned portion while leaving a thinned portion; an inspection means for inspecting the thinned portion by a transmission analysis technique; and a repairing means for restoring the inspection mark. 7. The semiconductor inspection apparatus according to claim 6, wherein at least one of said perforating means and said repairing means has a processing means using an ion beam. 8. The semiconductor inspection apparatus according to claim 6, wherein the hole punching means provided in the hole punching means and the hole repairing means provided in the repairing means are also used. 9. The semiconductor inspection apparatus according to claim 6, wherein the repairing electron beam irradiating means provided in the repairing means is also used as the transmission analyzing electron beam irradiating means provided in the inspecting means. 10. The semiconductor inspection apparatus according to claim 6, further comprising an inverting means for inverting the inspected wafer.