JP2013044644A - Inspection and manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection and manufacturing method of a semiconductor device which enable accurate detection of attachments on a sample surface.SOLUTION: The surface of a sample 11 where a reflection coating 13 and a thin film 14 are formed in order on a substrate 12 is irradiated with an incident X-ray 82a at an incident angle θ shallower than a critical angle θc of the reflection coating 13, and the irradiation of the incident X-ray 82a is used to detect a fluorescent X-ray 83 emitted from attachments 86 on the thin film 14 surface, thereby detecting the attachments 86 on the sample 11 surface.

Description

  The present invention relates to a semiconductor device inspection method and a semiconductor device manufacturing method.

  The total reflection fluorescent X-ray method is used for the inspection of the contamination state of the surface of a silicon wafer or a silicon oxide film. In this total reflection X-ray fluorescence method, the sample surface is irradiated with X-rays at a small incident angle to totally reflect the X-rays on the sample surface, and at that time, the fluorescent X-rays emitted from the adhered substance on the sample surface are detected. To assess the state of contamination.

  However, in the conventional total reflection fluorescent X-ray method, when it is difficult to totally reflect the X-rays on the sample surface, the detection sensitivity of the adhering substance is lowered.

JP-A-5-206240 Japanese Patent Laid-Open No. 9-43171

  In view of the above, an object of the present invention is to provide a method for inspecting a semiconductor device and a method for manufacturing a semiconductor device that can detect a substance adhering to a sample surface with high sensitivity.

  According to one aspect of the following disclosure, a surface of a sample formed by sequentially forming a reflective film and a thin film above a substrate is irradiated with X-rays at an incident angle smaller than the critical angle of the reflective film; A method for inspecting a semiconductor device, comprising: detecting fluorescent X-rays emitted from an attached substance on the surface of the thin film by X-ray irradiation.

  According to another aspect, the step of sequentially forming a reflective film and a thin film above the substrate, and the step of irradiating the surface of the thin film with X-rays at an incident angle smaller than the critical angle of the reflective film And a step of detecting fluorescent X-rays emitted from the attached substance on the surface of the thin film by the X-ray irradiation.

  In the semiconductor device inspection method and the semiconductor device manufacturing method according to the above aspect, a reflective film is disposed under the thin film of the sample, and X-rays are irradiated at an incident angle smaller than the critical angle of the reflective film. At this time, X-rays that could not be reflected by the thin film are totally reflected by the reflective film, so that X-ray irradiation to the substrate is prevented. For this reason, it is possible to prevent the detection sensitivity of the fluorescent X-rays from the attached substance from being lowered due to the emission of fluorescent X-rays having a wavelength overlapping with the fluorescent X-rays of the attached substance from the substrate. Further, since the adhering substance on the surface of the thin film is further irradiated with the X-rays totally reflected by the reflecting film, the emission amount of the fluorescent X-rays of the adhering substance increases. Thereby, the adhered substance on the sample surface can be detected with high sensitivity.

FIG. 1 is a diagram illustrating an example of a transmission electron microscope image of an organic insulating film. FIG. 2 is a diagram showing measurement results of the organic insulating film and the silicon oxide film of FIG. 1 using an optical particle counter. FIG. 3 is a graph showing the relationship between the incident angle of X-rays and the reflectance. FIG. 4 is a cross-sectional view illustrating the total reflection fluorescent X-ray method. FIG. 5 is a table showing critical angles of various materials with respect to Cr—Kα rays. FIG. 6 is a cross-sectional view illustrating a problem that occurs when the total reflection X-ray fluorescence method is applied to an organic insulating film. FIG. 7 is a view showing an inspection apparatus used in the semiconductor device inspection method according to the first embodiment. FIG. 8 is a cross-sectional view of a sample used in the semiconductor device inspection method according to the first embodiment. FIG. 9A is a cross-sectional view of a sample according to the experimental example of the first embodiment, and FIG. 9B is a graph showing the measurement result of the sample in FIG. 9A. 10A is a cross-sectional view of the sample according to Comparative Example 1, and FIG. 10B is a graph showing the measurement result of the sample in FIG. 10A. FIG. 11 is a graph showing measurement results by XPS (X-ray Photoelectron Spectroscopy) according to Comparative Example 2. 12A and 12B are a plan view and a cross-sectional view of a semiconductor wafer used in the method for manufacturing a semiconductor device according to the second embodiment. 13A and 13B are a plan view and a cross-sectional view of a semiconductor wafer used in the method for manufacturing a semiconductor device according to the third embodiment.

  Prior to the description of the embodiment, preliminary items as a basis will be described.

  Materials such as porous materials and organic materials have been proposed as materials for insulating films used in semiconductor devices. Among these, since the organic insulating film using the photosensitive resin can form a pattern by exposure and development processing, development aiming at cost reduction of the semiconductor device is being advanced.

  In the manufacturing process of a semiconductor device using an organic insulating film, it is desired to verify the state of contamination on the surface of the organic insulating film from the viewpoint of preventing the generation of defective products. For example, when a wiring is formed on the organic insulating film by a damascene process, polishing using a slurry is performed in a CMP (Chemical Mechanical Polishing) process. If the slurry used in the CMP process or the particles of the wiring material generated by polishing remain on the surface of the organic insulating film, problems such as leakage between wirings and peeling between the organic insulating films occur.

  For detecting particles on the surface of a silicon wafer or a silicon oxide film, an optical particle counter using light scattering by an attached substance is used. In view of this, it is conceivable to use a particle counter for the detection of the adhered substance on the surface of the organic insulating film.

  FIG. 1 is an example of a transmission electron microscope image of an organic insulating film.

  As shown in FIG. 1, an organic insulating film used in a semiconductor device is blended with rubber particles 91 containing an elastic material such as rubber in a matrix 90 of an organic material in order to ensure the required mechanical strength. There is a case.

  The surface of the organic insulating film containing such rubber particles 91 has a large number of irregularities derived from the rubber particles 91. Even if there is no unevenness on the surface, the light that has entered the organic insulating film is irregularly reflected by particles in the organic insulating film. Therefore, when the surface of the organic insulating film is measured using a particle counter, the rubber particles 91 are erroneously detected as an adhering substance.

  FIG. 2A shows the result of measuring the surface of the organic insulating film with an optical particle counter, and FIG. 2B shows the result of measuring the surface of the silicon thermal oxide film with the optical particle counter. . The black dots in the figure represent the positions of adhered substances having a size of 0.3 μm to 1 μm detected by the particle counter.

  As shown in FIG. 2 (b), in the case of a silicon thermal oxide film, almost no adhering substance is detected. In contrast, as shown in FIG. 2A, in the case of the organic insulating film, it can be seen that a large number of irregularities derived from the rubber particles 91 are erroneously detected as adhered substances.

  As described above, it is difficult for the optical particle counter to identify the adhered substance on the surface of the organic insulating film.

  There is a total reflection fluorescent X-ray method as another method for detecting the adhered substance on the sample surface.

  FIG. 3 is a graph showing an example of the relationship between the incident angle θ of X-rays and the reflectance for a thin film having a flat surface. Here, the incident angle θ is an angle formed between the thin film surface and the incident X-ray.

  As the incident angle θ of X-rays is decreased, the reflectivity of the thin film surface gradually increases as shown in the reflectivity curve of FIG. When the incident angle becomes smaller than the predetermined incident angle θ, the incident X-rays are totally reflected on the surface of the thin film. The largest incident angle at which this total reflection occurs is called the critical angle θc.

  In the total reflection fluorescent X-ray method, a substance adhering to the sample surface is detected using the total reflection of the X-ray.

  FIG. 4 is a cross-sectional view illustrating the total reflection fluorescent X-ray method. Here, a case where an adhering substance on the surface of the substrate 80 on which the thin film 81 is formed is detected will be described as an example.

  As shown in FIG. 4, in the total reflection fluorescent X-ray method, the surface of the thin film 81 is irradiated with incident X-rays 82a at an incident angle θ smaller than the critical angle θc of the thin film 81, and the incident X-rays 82a are irradiated on the surface of the thin film 81. Is totally reflected. At this time, the element contained in the adhering substance 86 attached to the surface of the thin film 81 is excited by the incident X-ray 82a and the reflected X-ray 82b, and emits the fluorescent X-ray 83 peculiar to the element. In the total reflection fluorescent X-ray method, the type and amount of the adhering substance 86 are specified by detecting the peak wavelength and the intensity of the fluorescent X-ray 83 peculiar to the element contained in the adhering substance 86.

  Here, the critical angle θc of the thin film 81 varies depending on the material of the thin film 81.

  FIG. 5 represents the critical angle θc of various materials relative to the Cr—Kα line (5.411 keV).

  As shown in FIG. 5, the critical angle θc increases as the material density increases. Among these, the density of the organic insulating film is as low as about 1, and the critical angle θc with respect to the Cr—Kα line is as small as about 0.21 °. The critical angle θc decreases as the X-ray energy increases. For example, in the case of tungsten W-Lβ line (9.67 keV), the critical angle θc of the organic insulating film is about 0.12 °.

  Thus, when the thin film 81 is an organic material, it is necessary to make the X-rays incident at an incident angle θ smaller than that of silicon or silicon oxide in order to totally reflect the X-rays. However, as a result of the investigation by the inventors of the present application, it has been found that an organic insulating film that requires X-ray irradiation from a small incident angle θ cannot obtain sufficient accuracy for evaluating the contamination state for the following reasons. .

  FIG. 6A is a diagram for explaining a problem caused by the unevenness of the organic insulating film.

  The organic insulating film 81 is formed by a spin coating method or the like, but large unevenness is generated on the surface of the film formed by the spin coating method compared to a silicon wafer, a thermally oxidized silicon film, or the like. As described with reference to FIG. 1, when rubber particles 91 are blended in the organic insulating film 81, many irregularities are generated on the surface of the organic insulating film 81.

As described above, when the incident X-ray 82a is irradiated to the organic insulating film 81 having the unevenness on the surface at the incident angle θ which is equal to or less than the critical angle θc, as shown in FIG. Although reflected, the incident angles θ ₂ and θ _{3 of} the incident X-ray 82a incident on the uneven inclined surface or the like may exceed the critical angle θc. Since the organic insulating film 81 has a smaller critical angle θc than other materials, the incident angles θ ₂ and θ ₃ exceed the critical angle θc even with smaller irregularities.

  As a result, part of the incident X-rays 82a enters the thin film 81, and the substrate 80 is irradiated with the incident X-rays 82a, whereby the substrate 80 is excited and fluorescent X-rays 84 are emitted. A part of the peak wavelength of the fluorescent X-ray 84 overlaps the peak wavelength of the fluorescent X-ray 83 from the adhering substance 86, so that the detection sensitivity of the adhering substance 86 using the fluorescent X-ray 83 is lowered.

  Further, even if the surface of the organic insulating film 81 is flat, there arises a problem due to the parallelism of incident X-rays as described below.

  FIG. 6B is a diagram for explaining a problem caused by the parallelism of the beam of the incident X-ray 82a.

  As shown in FIG. 6B, the beam of the incident X-ray 82a is not completely parallel to the optical axis c and has a variation of about ± 0.05 °, for example. Therefore, even if the incident X-ray 82a is incident on the thin film 81 at an incident angle θ smaller than the critical angle θc, the high-angle component of the incident X-ray 82a exceeds the critical angle θc, and a part of the incident X-ray 82a May enter the thin film 81. Also in this case, the fluorescent X-ray 84 is emitted from the substrate 80, and a part of the peak wavelength of the fluorescent X-ray 84 overlaps the peak wavelength of the fluorescent X-ray 83 of the adhering substance 86, so that the detection sensitivity of the adhering substance 86 is detected. Will fall.

  For the reasons described above, when the thin film 81 is an organic material, sufficient sensitivity cannot be obtained for the detection of the adhered substance on the surface of the thin film 81 even if the total reflection fluorescent X-ray method is used. Similar to the organic insulating film, such a problem also occurs in an insulating film made of a porous material having a low density and a lot of irregularities on the surface.

  Further, even when a material having a high density is used, the same applies to the case where a substance adhering to the surface such as a semiconductor film or a metal film that cannot totally reflect the incident X-rays 82a due to irregularities on the surface is detected.

  The inventors of the present application have conceived the embodiment described below based on the above findings.

(First embodiment)
FIG. 7 is a diagram of an inspection apparatus used in the semiconductor device inspection method according to the first embodiment.

  As shown in FIG. 7, the inspection apparatus 10 includes an X-ray source 1 that generates X-rays 82, a spectral crystal 2, a slit plate 3, a sample stage 4, and an X-ray detector 5. Among these, the X-ray source 1 generates X-rays 82 by causing electrons emitted from the cathode filament 1a to collide with the anode target 1b.

  Here, Cr (chromium) is used as the material of the target 1b. In addition to Cr, Ag (silver), Cu (copper), W (tungsten), or the like may be used as the material of the target 1b.

  The X-rays 82 emitted from the X-ray source 1 are irradiated onto the spectral crystal 2, and only the incident X-rays 82 a made of Cr—Kα rays are reflected by the spectral crystal 2 toward the sample 11 and pass through the slit plate 3. . X-rays 82 other than Cr—Kα rays are removed by the spectral crystal 2. Further, the opening angle (high angle component) of the incident X-ray 82 a is limited by the slit plate 3.

  In addition, as the incident X-ray 82a, a W-Lβ ray may be used, and other than this, it may be appropriately selected from wavelengths that do not overlap with the peak wavelength of the fluorescent X-ray of the element contained in the adhered substance.

  The incident X-rays 82 a that have passed through the slit plate 3 enter the surface of the sample 11 placed on the sample table 4. The sample stage 4 changes the direction of the sample 11 so that X-rays enter the sample 11 at a predetermined incident angle θ. The X-ray incident angle θ may be adjusted by moving the position of the sample stage 4 in the vertical direction.

  A part of the incident X-ray 82a incident on the sample 11 is reflected by the sample 11 to become a reflected X-ray 82b. Further, a part of the incident X-ray 82a excites an element contained in an adhering substance such as particles or contaminants on the surface of the sample 11 to generate fluorescent X-rays 83.

  The X-ray detector 5 is disposed above the sample 11, and the spectrum of the fluorescent X-ray 83 emitted from the adhering substance 86 on the surface of the sample 11 is detected by the X-ray detector 5.

  FIG. 8 is a cross-sectional view of the sample 11 according to the first embodiment.

  As shown in FIG. 8, the sample 11 includes a substrate 12 using a semiconductor material such as a silicon single crystal or an organic material, a reflective film 13 formed on the substrate 12, and a reflective film 13. And the formed thin film 14. In the illustrated example, the reflective film 13 is formed on the substrate 12, but the present embodiment is not limited to this, and an insulating film or a plurality of layers are provided between the substrate 12 and the reflective film 13. Wiring or the like may be provided.

  The reflective film 13 is a film having a flat surface and is made of a material having a peak wavelength of fluorescent X-rays at a wavelength that does not overlap with the peak wavelength of fluorescent X-rays from the adhering substance 86. In order to more reliably reflect the incident X-rays 82a, it is preferable to use a material having a larger density and critical angle θc than that of the thin film 14 for the reflective film 13.

  As the material of the reflective film 13, a material containing an element having an atomic number smaller than that of Na and having a higher density than the organic insulating film can be used. This is because fluorescent X-rays that hinder the detection of Si, Al and the like are not emitted from an element having an atomic number smaller than that of Na. Examples of such materials include diamond, diamond-like carbon, carbon, boron nitride, lithium fluoride, and beryllium.

  Further, even if the element has an atomic number larger than that of Na, the peak wavelength of fluorescent X-rays does not overlap with the peak wavelength of fluorescent X-rays such as Si and Al, and oxides of Cr and Ti , Nitrides, borides, and the like may be used as the material of the reflective film 13.

Among the materials listed above, Cr has a density of 8.1 g / cm ³ which is larger than that of the organic insulating film and has a larger critical angle θc. Furthermore, since Cr has a small crystal grain size, the reflective film 13 having a flat surface can be easily formed by sputtering, and thus is suitable as a material for the reflective film 13.

  When it is desired to detect contamination due to Si or Al with higher sensitivity, it is preferable to reduce the contents of Si, Al, Sn (tin), Co (cobalt), and W in the reflective film 13 as much as possible. When these elements are contained, fluorescent X-rays having a wavelength that overlaps the peak wavelength of Si or Al fluorescent X-rays are emitted from the reflective film 13, and fluorescent X-rays from Si or Al contained in the adhered substance 86 are emitted. This is because the detection sensitivity is lowered.

  The thickness of the reflective film 13 may be at least about 10 nm. Since the penetration depth of X-rays under the total reflection condition is about 10 nm, if the thickness of the reflective film 13 is 10 nm or more, irradiation of the incident X-rays 82a to the substrate 12 can be prevented, and Si or It is possible to prevent the emission of fluorescent X-rays that hinder the detection of Al or the like.

  On the other hand, the material of the thin film 14 is not particularly limited. For example, an organic insulating film using an organic material or a porous insulating film using a porous material can be used. The material of the thin film 14 is not limited to an insulating material, and may be a conductive material or a semiconductor material.

  In the present embodiment, incident X-rays 82 a are incident on the surface of the sample 11 as described above at an incident angle θ smaller than the critical angle θc of the reflective film 13. For example, the incident angle θ when the incident X-ray 82a is a Cr—Kα ray may be 0.58 ° or less if the material of the reflective film 13 is Cr, and 0.46 ° or less if Ti is Ti. That's fine. In addition, the incident angle θ when the incident X-ray 82a is a W-Lβ ray may be 0.32 ° or less if the material of the reflective film 13 is Cr, or 0.26 ° or less if Ti is Ti. .

  Thereby, even if the incident X-ray 82a enters the thin film 14, the incident X-ray 82a is totally reflected by the reflective film 13, so that the irradiation of the incident X-ray 82a onto the substrate 12 can be prevented. Therefore, the emission of fluorescent X-rays from the substrate 12 can be prevented, and the fluorescent X-rays of the adhering substance 86 can be detected without being disturbed by the fluorescent X-rays from the substrate 12.

  Further, the adhering substance 86 adhering to the surface of the thin film 14 is excited not only by the incident X-ray 82 a but also by the reflected X-ray 82 b totally reflected by the reflecting film 13, so that the fluorescent X emitted from the adhering substance 86 is emitted. The line increases.

  Therefore, according to the inspection method of the present embodiment, the fluorescent X-ray 83 from the adhering substance 86 on the surface of the thin film 14 can be detected with high sensitivity, and is included in the adhering substance 86 based on the spectrum of the detected fluorescent X-ray 83. Elements can be detected with high sensitivity. Thereby, the state of contamination on the surface of the thin film 14 can be more accurately evaluated.

(Experimental example and comparative example)
Hereinafter, experimental examples and comparative examples evaluated by the present inventors will be described.

  FIG. 9A is a cross-sectional view of a sample according to an experimental example of this embodiment, and FIG. 9B is a graph showing a result of measuring the sample 21 of FIG. 9A with the inspection apparatus 10 of FIG. It is.

  As shown in FIG. 9A, in this experimental example, a silicon wafer 22 is first prepared, and the surface of the silicon wafer 22 is thermally oxidized to form a silicon oxide film 23 having a thickness of about 100 nm.

  Next, a Cr film 24 having a thickness of about 500 nm was formed as a reflective film on the silicon oxide film 23 by sputtering.

  Then, a photosensitive organic insulating film 25 (JSR WPR5100) having a thickness of about 5 μm was formed on the Cr film 24 by a spin coating method, and a sample 21 of this experimental example was obtained.

  Next, the sample 21 in FIG. 9A is placed on the sample stage 4 of the measuring apparatus 10 (see FIG. 7), and the incident angle smaller than the critical angle θc of the Cr film 24 is formed on the surface of the sample 21. The spectrum of fluorescent X-rays was measured by injecting Cr-Kα rays at 0.09 °.

  The voltage and current between the filament 1a and the target 1b of the X-ray source 1 (see FIG. 7) were set to 35 kV and 35 mA, respectively. The sample 21 was irradiated with incident X-rays for 500 seconds, and during this time, the fluorescent X-rays emitted from the sample were integrated to obtain a spectrum.

  As a result, the spectrum shown in FIG. 9B was obtained. In this spectrum, the peak of S (sulfur) -Kα is a peak derived from sulfur (S) contained in the organic insulating film, and Cr-Kα is a peak derived from incident X-rays 82a. On the other hand, Cl (chlorine), K (potassium), Ca (calcium), and Ti (titanium) are peaks due to fluorescent X-rays of the adhered substances. From this result, it can be seen that many kinds of impurities are detected.

  In addition, the Si peak contained in the underlying silicon oxide film 23 and the substrate 22 does not appear, and it can be seen that the chromium film 24 prevents the emission of fluorescent X-rays from the silicon oxide film 23 and the substrate 22.

The measurement limits of Si and Al obtained from the result of FIG. 9B were both 1 × 10 ¹¹ atoms / cm ² .

  When the sample 21 shown in FIG. 9A is irradiated with X-rays at an incident angle θ larger than the critical angle θc of the reflective film 23, it is derived from Si contained in the underlying silicon oxide film 23 or the substrate 22. A peak appeared and Cl, K, Ca, and Ti could not be detected.

  Next, a comparative example will be described.

  FIG. 10A is a cross-sectional view of a sample according to Comparative Example 1, and FIG. 10B is a graph showing a result of measuring the sample 26 in FIG. 10A with the measuring apparatus 10 in FIG.

  In the sample 26 of Comparative Example 1 in FIG. 10A, unlike the sample 21 in FIG. 9A, the photosensitive organic insulating film 25 is formed on the silicon oxide film 23 without forming the Cr film 24. .

  Next, the sample 26 was placed on the sample stage 4 of the inspection apparatus 10 (see FIG. 7), and the spectrum of the fluorescent X-ray of the sample 26 in FIG. 10A was measured under the same conditions as in the experimental example. As a result, the spectrum shown in FIG. 10B was obtained. As shown in FIG. 10B, a peak derived from Si appears in the fluorescent X-ray spectrum of the sample 26 of Comparative Example 1. This is because the sample 26 does not have a reflective film, so that the incident X-rays that have entered the photosensitive organic insulating film 25 reach the underlying silicon oxide film 23 and the substrate 22, and the fluorescent X from Si contained in them. A line is emitted.

  As described above, in the case of Comparative Example 1, the peak of Si contained in the underlying silicon oxide film 23 and the substrate 22 appears in the fluorescent X-ray spectrum. The peak wavelength of the fluorescent X-rays of Si contained in the silicon oxide film 23 and the substrate 22 not only overlaps the peak wavelength of the fluorescent X-rays of Si on the surface of the photosensitive organic insulating film 25 but also the fluorescent X-rays from Al. Is close to the peak wavelength. Therefore, the detection sensitivity of elements such as Si and Al contained in the adhered substance on the surface is lowered.

In Comparative Example 1, the detection limit of Si in the adhered substance adhering to the surface of the photosensitive organic insulating film 25 was 2.4 × 10 ¹³ atoms / cm ² , which was two orders of magnitude worse than the experimental example. Moreover, the detection limit of Al in Comparative Example 1 was 1.7 × 10 ¹² atoms / cm ² , which was an order of magnitude worse than the experimental example.

  FIG. 11 is a graph showing measurement results according to Comparative Example 2.

  In Comparative Example 2, measurement by XPS (X-ray photoelectron spectroscopy), which is known as a measurement method sensitive to the sample surface, was performed using Sample 21 of Experimental Example 1 (see FIG. 9A). As shown in FIG. 11, in the measurement by XPS of Comparative Example 2, elements having relatively small atomic numbers such as O (oxygen), F (fluorine), C (carbon), and N (nitrogen) that cannot be detected in the experimental example are used. It can be detected. However, the peak of metal elements such as Al, Si, Ca, Ti, etc. could not be confirmed.

  From this, it has been confirmed that according to the present embodiment, contamination by elements such as Al, Si, Ca, Ti and the like generated in the manufacturing process of the semiconductor device can be detected with much higher sensitivity than XPS.

  As described above, according to the method for inspecting a semiconductor device according to the present embodiment, contamination on the surface of a thin film such as an organic insulating film can be evaluated with high sensitivity.

(Second Embodiment)
In the second embodiment, a semiconductor device manufacturing method using the above-described semiconductor device inspection method will be described.

  FIG. 12A is a plan view of a semiconductor wafer according to the second embodiment, and FIG. 12B is a cross-sectional view taken along line II of the sample in FIG.

  As shown in the plan view of FIG. 12A, a chip region 31 and a monitor region 32 are provided on the surface of the semiconductor wafer 30 of the present embodiment.

  As shown in FIG. 12B, a plurality of semiconductor chips 33 such as a CPU and a memory are attached on the semiconductor wafer 30 in the chip region 31 of the semiconductor wafer 30. On the semiconductor chip 33, a plurality of layers of organic insulating films 35, vias 36 and wirings 37 embedded therein are formed. Such a wiring 37 formed on the semiconductor chip 33 is also called a rewiring, and a package in which a connection terminal (not shown) is formed on the surface of the organic insulating film 35 through this rewiring is a WLP (Wafer Level Package). Called.

  On the other hand, a reflection film such as Cr is formed as a monitor pattern 34 in the monitor region 32. The monitor pattern 34 is formed, for example, by attaching a rectangular Cr plate to the semiconductor wafer 30. The monitor pattern 34 may be formed by forming a Cr film or the like on the semiconductor wafer 30 by sputtering or the like.

  The size of the monitor pattern 34 may be a size sufficient for evaluation by the inspection apparatus 10, and may be a square shape having a side length of about 10 mm, for example. Here, the size of the monitor pattern 34 is a square with a side of 20 mm with a margin.

  On the monitor pattern 34 as described above, the same organic insulating film 35 as that formed in the chip region 31 is formed.

  In the manufacturing method of the semiconductor device of this embodiment, the vias 36 and the wirings 37 formed in the chip region 31 are formed by a damascene process. After performing the polishing step and the cleaning step by this damascene process, the semiconductor wafer 30 is placed on the sample stage 4 of the inspection apparatus 10 in FIG.

  Then, incident X-rays 82a are made incident on the monitor region 32 at an incident angle θ smaller than the critical angle θc of Cr, and fluorescent X-rays from the adhered substance on the surface of the organic insulating film 35 are detected. Thereafter, based on the detected spectrum of fluorescent X-rays, the amount of the elements and the amount of adhering substances contained in the adhering substances on the surface of the organic insulating film 35 is specified.

  As a result, when the amount of the adhering substance on the organic insulating film 35 in the monitor region 31 is less than the specified value, the semiconductor chip 33 and the monitor pattern 34 formed in the chip region 31 are subjected to various processes thereafter. To complete the semiconductor device.

  As described above, according to the manufacturing method of the semiconductor device of the present embodiment, the adhered substance on the surface of the organic insulating film 35 can be detected with high sensitivity. Thereby, the adhered substance on the surface of the organic insulating film 35 can be set to a certain value or less, and a semiconductor device having excellent reliability can be manufactured.

(Third embodiment)
FIG. 13A is a plan view of a semiconductor wafer used in the method for manufacturing a semiconductor device according to the third embodiment, and FIG. 13B is a cross-sectional view taken along the line II-II in FIG. is there.

  In the semiconductor wafer 40 according to the present embodiment, as shown in FIGS. 13A and 13B, the entire upper surface of the semiconductor wafer 40 is covered with a reflective film 41 such as Cr, and an organic insulation is formed on the reflective film 41. A film 42 is formed.

  In the semiconductor device manufacturing method of this embodiment, every time a predetermined number of semiconductor wafers are processed in the semiconductor device manufacturing line, the semiconductor wafer 40 shown in FIGS. 13A and 13B is supplied to the manufacturing line. To do.

  Thereafter, the semiconductor wafer 40 processed in the production line is placed on the sample stage 4 of the test apparatus 10 of FIG. Then, the fluorescent X-rays from the adhered substance on the surface of the organic insulating film 42 are detected by the semiconductor device inspection method described with reference to FIGS. Then, based on the detected fluorescent X-ray spectrum, the type of the element contained in the adhering substance and the amount of the adhering substance are specified, and whether or not the amount of the adhering substance on the surface of the organic insulating film 42 is equal to or less than the specified value. evaluate.

  Here, if an adhering substance exceeding the specified value is detected, the cause of the adhering substance is identified based on the elements contained in the adhering substance, and the production line is controlled so that the adhering substance is below the specified value. I do.

  Thus, according to the semiconductor device manufacturing method of the present embodiment, a semiconductor device having excellent reliability can be manufactured by managing the manufacturing line based on the contamination state of the surface of the organic insulating film.

  Regarding the above embodiments, the following additional notes are disclosed.

(Appendix 1) A step of irradiating the surface of a sample formed by sequentially forming a reflective film and a thin film above a substrate with an incident angle smaller than the critical angle of the reflective film;
Detecting fluorescent X-rays emitted from the adhered substance on the surface of the thin film by irradiation with the X-rays;
A method for inspecting a semiconductor device, comprising:

  (Additional remark 2) The said thin film is a film | membrane whose density is lower than the said reflecting film, The inspection method of the semiconductor device of Additional remark 1 characterized by the above-mentioned.

  (Supplementary note 3) The method for inspecting a semiconductor device according to Supplementary note 1 or 2, wherein a peak wavelength of fluorescent X-rays of the reflective film is different from a peak wavelength of fluorescent X-rays of an element contained in the attached substance.

  (Supplementary note 4) The semiconductor device inspection method according to any one of supplementary notes 1 to 3, wherein a material of the reflective film is the same material as a target of the X-ray source that generates the X-rays.

  (Supplementary note 5) The semiconductor device inspection method according to any one of supplementary notes 1 to 4, wherein the material of the thin film is an organic material or a porous material.

  (Supplementary note 6) The method for inspecting a semiconductor device according to any one of supplementary notes 1 to 5, wherein the X-ray is a Kα ray of Cr (chromium).

  (Supplementary note 7) The semiconductor device inspection method according to any one of supplementary notes 1 to 6, wherein an element contained in the adhering substance is detected based on a spectrum of the fluorescent X-ray.

(Appendix 8) A step of sequentially forming a reflective film and a thin film above the substrate;
Irradiating the surface of the thin film with X-rays at an incident angle smaller than the critical angle of the reflective film;
Detecting fluorescent X-rays emitted from the adhered substance on the surface of the thin film by irradiation of the X-rays;
A method for manufacturing a semiconductor device, comprising:

  (Additional remark 9) The said board | substrate is provided with the semiconductor chip covered with the said thin film, The said reflective film is provided beside the said semiconductor chip, The manufacturing method of the semiconductor device of Additional remark 8 characterized by the above-mentioned.

(Appendix 10) The reflective film and the thin film cover the entire upper surface of the substrate,
A step of supplying the substrate to the production line every time processing of a predetermined number of semiconductor wafers is completed in the production line of the semiconductor device;
9. The method of manufacturing a semiconductor device according to appendix 8, wherein the manufacturing line is managed based on a detection result of the fluorescent X-rays of the substrate processed in the manufacturing line.

  DESCRIPTION OF SYMBOLS 1 ... X-ray source, 1a ... Filament, 1b ... Target, 2 ... Spectral crystal, 3 ... Slit plate, 4 ... Sample stand, 5 ... X-ray detector, 10 ... Inspection apparatus, 11, 21, 26 ... Sample, 12 , 22, 80 ... substrate, 13, 24, 41 ... reflective film, 14, 25, 35, 42, 81 ... thin film (organic insulating film), 23 ... silicon oxide film, 30, 40 ... semiconductor wafer, 31 ... chip region , 32 ... monitor region, 33 ... semiconductor chip, 34 ... monitor pattern, 36 ... via, 37 ... wiring, 82 ... X-ray, 82a ... incident X-ray, 82b ... reflected X-ray, 83, 84 ... fluorescent X-ray, 86 ... adhesive substances, 90 ... matrix, 91 ... rubber particles.

Claims (5)

Irradiating the surface of the sample formed by sequentially forming a reflective film and a thin film above the substrate with X-rays at an incident angle smaller than the critical angle of the reflective film;
Detecting fluorescent X-rays emitted from the adhered substance on the surface of the thin film by irradiation with the X-rays;
A method for inspecting a semiconductor device, comprising:   2. The semiconductor device inspection method according to claim 1, wherein the thin film is a film having a density lower than that of the reflective film.   3. The semiconductor device inspection method according to claim 1, wherein a peak wavelength of fluorescent X-rays of the reflective film is different from a peak wavelength of fluorescent X-rays of elements contained in the contaminant. Forming a reflective film and a thin film in order above the substrate;
Irradiating the surface of the thin film with X-rays at an incident angle smaller than the critical angle of the reflective film;
Detecting fluorescent X-rays emitted from the adhered substance on the surface of the thin film by irradiation of the X-rays;
A method for manufacturing a semiconductor device, comprising:   The method of manufacturing a semiconductor device according to claim 4, wherein the substrate includes a semiconductor chip covered with the thin film, and the reflective film is provided beside the semiconductor chip.

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