JP2009099820A - Inspection device, inspection method, and manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and efficiently detect a defect present in a semiconductor substrate with high sensitivity. <P>SOLUTION: An arm unit connected to a conveyance plate where a semiconductor substrate 11 is disposed is lowered by a conveyance unit to a hollow holding unit 12 having a notch in part of a side surface, and the arm unit passes through the notch of the holding unit 12 to make the holding unit 12 hold the semiconductor substrate 11 from the rear side. Then an irradiation unit 13 irradiates the back of the semiconductor substrate 11 with light 13a, a detection unit 17 detects light 13b emitted from the back of the semiconductor substrate 11, and a measurement unit measures the intensity of the light 13b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inspection apparatus, an inspection method, and a semiconductor device manufacturing method, and more particularly to a semiconductor substrate inspection apparatus, an inspection method, and a semiconductor device manufacturing method.

  In a semiconductor device or the like, various defects such as point defects and dislocations are generated in an insulating film and wiring. Such a defect causes a failure of the semiconductor device and leads to a decrease in reliability. In order to inspect defects in the semiconductor device, various analysis methods using electrons, light, and the like as probes have been devised.

As the most general method, there is an electron microscope observation using electrons as a probe. According to this method, the abnormal part can be observed directly.
On the other hand, methods using light for the probe include an OBIC (Optical Beam Induced Current) method and an OBIRCH (Optical Beam Induced Resistivity CHange) method.

  In the OBIC method, a semiconductor device to which a reverse bias is applied is irradiated with light, and the flow of electrons and holes generated by the light irradiation is observed. And the voltage distribution of a pn junction part is analyzed from the measured electric current value. Here, it is known that if the insulating film in the semiconductor device is defective or a defect exists in the bonding layer, the voltage distribution becomes abnormal. By measuring this voltage distribution, the presence or absence of defects in the semiconductor device can be determined (for example, see Non-Patent Document 1).

  Similar to the OBIC method, the OBIRCH method irradiates light to a semiconductor device to which a reverse bias is applied, and observes a change in resistance from the flow of electrons and holes generated by the light irradiation. Here too, the presence or absence of defects in the semiconductor device can be determined (for example, see Non-Patent Document 2).

As described above, the OBIC method and the OBIRCH method are excellent for detecting minute defects in a semiconductor device, and are used as effective means for failure / failure analysis.
Haraguchi Koshi., “Microscope Optical Beam Induced Current Measurements and their Application”, HYPERLINK "http://ieeexplore.ieee.org/xpl/RecentCon.jsp?punumber=1120" Instrumentation and Measurement Technology Conference, 1994. Conference Proceedings 10th Anniversary Advanced Technologies in I & M., 1994, IEEE, P693-699 Phang JCH, et al., "A review of laser induced techniques for microelectronic failure analysis", Physical and Failure Analysis of Integrated Circuits, 2004, IPFA 2004. Proceedings of 11th International Symposium on the Volume, Issue, 5-8, July, 2004, p255−261

  However, since the OBIC method and the OBIRCH method described above need to apply a reverse bias to the analysis sample (subject), wiring for applying a reverse bias is necessary. For this reason, it is impossible to analyze at any point in the process of manufacturing the semiconductor device. Mainly, semiconductor devices that have been manufactured are subject to analysis. If the defect is detected after the manufacture of the semiconductor device is completed, there is a problem that a large number of defective products are held in the process.

  The present invention has been made in view of such a point, and an inspection apparatus, an inspection method, and a semiconductor device manufacturing method for detecting a defect existing in a semiconductor substrate easily, efficiently, and with high sensitivity. The purpose is to provide.

  In the present invention, in order to solve the above-mentioned problem, as shown in FIG. 1, a hollow holding part 12 having a notch in a part of a side surface and an arm part connected to a transport plate on which a semiconductor substrate 11 is arranged are lowered. Then, the arm part passes through the notch of the holding part 12, and the holding part 12 holds the semiconductor substrate 11 from the back side, and the light 13a is applied to the back surface of the semiconductor substrate 11 held by the holding part 12 from the back side. An irradiation unit 13 that irradiates, a detection unit 17 that detects light 13b emitted from the back surface of the semiconductor substrate 11 by irradiation with light 13a, and a measurement unit that measures the intensity of light 13b detected by the detection unit 17 The inspection apparatus 10 characterized by this is provided.

  According to such a detection apparatus, the arm unit connected to the transport plate on which the semiconductor substrate is disposed is lowered by the transport unit to the hollow holding unit having a cutout on a part of the side surface, and the arm unit is retained. The semiconductor substrate is held from the back side by the holding part through the notch of the part. Then, the irradiation unit irradiates light on the back surface of the semiconductor substrate, the detection unit detects light emitted from the back surface of the semiconductor substrate, and the measurement unit measures the light intensity.

  In order to solve the above problem, the arm portion connected to the transfer plate on which the semiconductor substrate is disposed is lowered, and the arm portion passes through the notch of the hollow holding portion having a notch in a part of the side surface. A transporting step of holding the semiconductor substrate from the back side by the holding unit, an irradiation step of irradiating the back surface of the semiconductor substrate held by the holding unit from the back side, and irradiation of the semiconductor substrate by the light irradiation. There is provided an inspection method comprising a detection step of detecting light emitted from the back surface, and a measurement step of measuring the intensity of the light detected by the detection step.

  According to such an inspection method, the arm part connected to the transport plate on which the semiconductor substrate is arranged is lowered, and the arm part passes through the notch of the hollow holding part having a notch on a part of the side surface. The semiconductor substrate is held by the holding unit from the back side, the back surface of the semiconductor substrate is irradiated with light, the light emitted from the back surface of the semiconductor substrate by light irradiation is detected, and the light intensity is measured.

  In order to solve the above problem, the arm portion connected to the transfer plate on which the semiconductor substrate is disposed is lowered, and the arm portion passes through the notch of the hollow holding portion having a notch in a part of the side surface. A transporting step of holding the semiconductor substrate from the back side by the holding unit, an irradiation step of irradiating the back surface of the semiconductor substrate held by the holding unit from the back side, and irradiation of the semiconductor substrate by the light irradiation. There is provided a method for manufacturing a semiconductor device, comprising: an inspection step having a detection step of detecting light emitted from the back surface and a measurement step of measuring the intensity of light detected by the detection step.

  According to such a method of manufacturing a semiconductor device, the arm portion connected to the transport plate on which the semiconductor substrate is disposed is lowered, and the arm portion passes through the notch of the hollow holding portion having a notch on a part of the side surface. Then, the semiconductor substrate is held by the holding portion from the back side, the light is irradiated on the back surface of the semiconductor substrate, the light emitted from the back surface of the semiconductor substrate is detected by the light irradiation, and the light intensity is measured.

  In the present invention, the conveyance unit lowers the arm unit connected to the conveyance plate on which the semiconductor substrate is disposed, and the arm unit passes through the notch of the holding unit to the hollow holding unit having a cutout on a part of the side surface. Then, the holding part holds the semiconductor substrate from the back side. The irradiation unit irradiates light on the back surface of the semiconductor substrate, the detection unit detects light emitted from the back surface of the semiconductor substrate, and the measurement unit measures the light intensity. Thereby, defects existing in the semiconductor substrate can be detected easily, efficiently and with high sensitivity.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments.
First, the first embodiment will be described.

FIG. 1 is a schematic diagram of a main part of the inspection apparatus according to the first embodiment.
The inspection apparatus 10 includes a holding unit 12 that holds the semiconductor substrate 11, an irradiation unit 13 that irradiates the semiconductor substrate 11 with light 13 a, and a detection unit 17 that detects the light 13 b emitted from the semiconductor substrate 11 through the slit 15 and the filter 16. And an apparatus control unit 18.

  The semiconductor substrate 11 is, for example, a semiconductor device in a wafer state before being singulated as a semiconductor chip. Further, in a semiconductor device, semiconductor elements composed of transistors, capacitors, multilayer wirings and the like are formed vertically and horizontally on a semiconductor substrate (wafer substrate) composed of silicon (Si), gallium arsenide (GaAs), or the like. For example, a semiconductor substrate 11 having a diameter of 300 nm is installed on the holding unit 12.

  The holding | maintenance part 12 has comprised the hollow cylinder shape, and the notch is formed in a part of side surface. And the holding | maintenance part 12 hold | maintains the semiconductor substrate 11 which is a test object from the back side as mentioned above. Further, the holding unit 12 can freely move in a three-dimensional range in a direction facing the light 13a (Z direction in the drawing) and a direction perpendicular to the Z direction (X and Y directions in the drawing). It has become. Details of the holding unit 12 will be described later.

The irradiation unit 13 has, for example, an argon (Ar) ion laser (wavelength: about 364 nm) or a YAG (Yttrium Aluminum Garnet) laser (wavelength: about 1064 nm) as a light source, and a wavelength of about 473 nm. Semiconductor lasers of about 532 nm, about 527 nm, about 648 nm, about 1047 nm, and about 1053 nm are used. Moreover, the irradiation part 13 can comprise several irradiation systems as needed. For example, an Ar ion laser and a YAG laser, and semiconductor lasers having wavelengths of about 473 nm, about 532 nm, about 527 nm, about 648 nm, about 1047 nm, and about 1053 nm can be provided. And the light 13a radiate | emitted from the irradiation part 13 is reflected by the reflecting plate 14 installed as needed. Further, as shown in Non-Patent Document 2, the transmittance varies depending on the impurity concentration doped into Si and the thickness of Si (described later in FIG. 4). It is possible to control the penetration of light into Si by selecting the wavelength of light to be irradiated with reference to this known transmittance change. One example is described below. When the penetration depth of light into Si doped with an impurity of about 1 × 10 ¹⁵ atoms / cm ^{3 is} determined from the transmittance, it is about 1 μm (the wavelength of the irradiated light is about 500 nm), about 100 μm (the wavelength of the irradiated light is About 967 nm), about 200 μm (the wavelength of irradiated light is about 1018 nm), and about 500 μm (the wavelength of irradiated light is about 1057 nm). Considering the penetration depth of the light and the substrate thickness, by selecting a plurality of lasers having different wavelengths as described above, it is possible to determine the depth position of the defect determined from the change in scattering or the intensity of photoluminescence.

  The reflecting plate 14 can be freely rotated in a three-dimensional range around any of the X, Y, and Z axes, and the incident angle of the light 13a with respect to the semiconductor substrate 11 can be varied. The light 13 a reflected by the reflecting plate 14 is irradiated to the back surface of the semiconductor substrate 11 held from the back side by the holding unit 12. In addition, not only semiconductor elements but also a large number of metal wirings are disposed on one main surface (front surface side) of the semiconductor substrate 11. Therefore, the light irradiated to the surface side of the semiconductor device cannot pass through the semiconductor substrate 11, and the detection sensitivity of defects in the semiconductor device is lowered. For this reason, the back surface of the semiconductor substrate 11 is irradiated with light 13a.

  In the semiconductor substrate 11 irradiated with the light 13a, photoluminescence, scattering of the irradiated light, and reflection of the irradiated light occur according to the wavelength of the light 13a. Then, light 13b is emitted from the back surface of the semiconductor substrate 11 (details will be described later). The light 13 b is detected by the detection unit 17 through the slit 15 and the filter 16. In addition, the slit 15 and the filter 16 can be installed as appropriate. Further, the detection unit 17 may be provided with a spectral function as needed to detect the dispersed light.

  The intensity of light such as photoluminescence or scattered light of the semiconductor device detected by such a method is measured in the device controller 18. Then, the data measured in the device control unit 18 is processed, and displayed as an image, for example, as a two-dimensional distribution and output. If the detection unit 17 has a spectroscopic function, the device control unit 18 displays an image of the intensity of light of a specific wavelength such as photoluminescence or scattered light.

Furthermore, the apparatus control unit 18 not only performs the data processing as described above, but also controls the entire inspection apparatus 10.
For example, in the apparatus control unit 18, the irradiation unit control unit 18 a that controls the irradiation unit 13, the detection unit control unit 18 b that controls the slit 15, the filter 16 and the detection unit 17, and the light emission data detected by the detection unit 17 are processed. A data processing unit 18c for detecting defects, a storage unit 18d for storing data, and an input / output unit 18e serving as a user interface are provided.

Now, the light emission of the holding unit 12 and the semiconductor substrate 11 will be described below.
First, the detail of the holding | maintenance part 12 is demonstrated with reference to drawings.
FIG. 2 is a schematic perspective view of the holding portion according to the first embodiment. In FIG. 2, for convenience of explanation, the holding unit 12 is enlarged, and the holding unit 12 and the semiconductor substrate 11 are not shown in contact with each other.

  FIG. 2 shows a part of the inspection apparatus 10. The holding unit 12 that holds the semiconductor substrate 11, the irradiation unit 13 that irradiates the semiconductor substrate 11 with light 13 a, the light 13 b emitted from the semiconductor substrate 11, the slit 15 and A detection unit 17 for detecting via the filter 16 and a device control unit (not shown) are provided. However, in FIG. 2, a reflector 14a is newly installed so that the light 13b emitted from the semiconductor substrate 11 is reflected by the reflector 14a. Further, similarly to the reflector 14, the reflector 14a is configured to rotate in a three-dimensional range around any of the X, Y, and Z axes, and to change the incident angle of the light 13b with respect to the slit 15. Since other configurations are the same as those in FIG. 1, detailed description of each configuration is omitted.

As described above, the holding portion 12 has a hollow cylindrical shape, and the cutout region 12a is formed in a part of the side surface. And the holding | maintenance part 12 hold | maintains the semiconductor substrate 11 which is a test object from the back side. The material of the holding part 12 is preferably quartz (SiO ₂ ) or silicon carbide (SiC) used in the manufacturing process of the semiconductor device. In consideration of the formation region of the semiconductor element or the like on the semiconductor substrate 11, the holding unit 12 is preferably held within about 3 mm from the outer periphery of the semiconductor substrate 11. The holding unit 12 can move in a three-dimensional range in a direction facing the light 13a (Z direction in the drawing) and a vertical direction (X, Y direction) with respect to the Z direction.

In the inspection apparatus 10 including the holding unit 12 having such a shape, a process of transporting the semiconductor substrate 11 will be described below.
3A and 3B are schematic perspective views showing the main part of the semiconductor substrate transfer process according to the first embodiment, wherein FIG. 3A is an arrangement of the semiconductor substrate on the transfer plate, and FIG. 3B is a holding part of the semiconductor substrate. (C) shows installation to the holding part of the semiconductor substrate.

  First, as shown in FIG. 3A, the semiconductor substrate 11 is placed on the transport plate 19a by the transport device 19 including the transport plate 19a and an arm portion 19b formed integrally with the transport plate 19a. Deploy. At the time of arrangement, the arrangement surface of the transport plate 19a and the back surface of the semiconductor substrate 11 are opposed to each other. Note that FIG. 3A illustrates just before the semiconductor substrate 11 is arranged on the transport plate 19a.

Next, as illustrated in FIG. 3B, the semiconductor substrate 11 is transported onto the holding unit 12 by the transporter 19. At this time, the arm portion 19b is arranged on the cutout region 12a.
Next, the transporter 19 on which the semiconductor substrate 11 is disposed is moved downward so that the arm portion 19b passes through the cutout region 12a. Then, as shown in FIG. 3C, the semiconductor substrate 11 is held by the holding unit 12 from the back side.

  Thereafter, as described above, the back side of the semiconductor substrate 11 is irradiated with the light 13a by the irradiation unit 13, and the intensity of the light 13b emitted from the semiconductor substrate 11 generated by the irradiated light 13a is detected to inspect the defect. Do. In addition, conveyance and movement of the conveyance device 19 are realized by, for example, installing conveyance means (not shown).

  In the inspection apparatus 10, the semiconductor substrate 11 can be held by the holding unit 12 through the above-described transfer process. Therefore, such a transfer process can be easily incorporated into a semiconductor device manufacturing process line. For example, the semiconductor substrate 11 may be transported to the holding unit 12 by the transporter 19 during or during manufacture by the semiconductor device manufacturing apparatus. Or you may make it manufacture the semiconductor substrate 11 on the conveyance board 19a previously.

Next, the light 13b emitted from the back surface of the semiconductor substrate 11 will be described.
4A and 4B show the wavelength dependence of the transmittance of the silicon wafer substrate, where FIG. 4A is a graph regarding the doping amount, and FIG. 4B is a graph regarding the film thickness of the silicon wafer substrate.

  FIG. 4 irradiates the silicon wafer substrate with light of various wavelengths, and further shows the amount of doping to the silicon wafer substrate and the light transmittance for each film thickness. The horizontal axis represents wavelength (nm), and the vertical axis represents transmittance (arbitrary unit).

  As shown in FIG. 4A, the transmittance of light having a wavelength of 800 nm or less with respect to the silicon wafer substrate is approximately 0 (%). However, at 800 nm or more, the transmittance changes according to the doping amount. For example, in the silicon wafer substrate with the lowest doping amount (highest resistance), the transmittance increases up to about 1150 nm corresponding to the band gap of Si. Thereafter, the transmittance shows a substantially constant value. Further, in a silicon wafer substrate having a high doping amount (low resistance), the transmittance increases to about 1150 nm. However, after the transmittance reaches the maximum value, it tends to decrease.

  As shown in FIG. 4B, similarly to FIG. 4A, the transmittance of light having a wavelength of 800 nm or less with respect to the silicon wafer substrate is substantially 0 (%). However, at 800 nm or more, the transmittance changes according to the film thickness. For example, in the case of a silicon wafer substrate, the transmittance tends to increase until the wavelength is around 1150 nm, and thereafter the transmittance tends to decrease. It is shown that the maximum value is larger as the film thickness of the silicon wafer substrate is thinner.

Therefore, from FIG. 4, the light near the wavelength of the band edge emission (about 1150 nm) can be regarded as transparent to the silicon wafer substrate.
Therefore, the emission spectrum of the semiconductor substrate 11 when the back surface of the semiconductor substrate 11 is irradiated with a YAG laser (wavelength: about 1064 nm) having a wavelength close to band edge emission will be described.

  The irradiated YAG laser light enters the semiconductor substrate 11. In particular, the wavelength of the YAG laser (about 1064 nm) has a high transmittance with respect to the silicon wafer substrate as described above, and therefore reaches the active layer of the semiconductor element formed on the semiconductor substrate 11. Since the energy of the light of the YAG laser irradiated to the semiconductor substrate 11 is larger than the band gap of Si (corresponding to a wavelength of about 1150 nm), electrons in the valence band are excited to the conduction band. With the excitation of electrons, holes are generated in the valence band. The electrons and holes generated in this way are then recombined to emit light, and photoluminescence having a wavelength unique to the crystal is generated.

  Further, the irradiated YAG laser light causes generation and recombination of electrons and holes as described above. However, if there is a defect in the recombination process of electrons and holes, this defect forms a unique electronic level in the band gap and affects the recombination process. As a result, the semiconductor substrate 11 emits light having an energy (wavelength) different from that of the photoluminescence unique to the crystal.

And the case where the 2nd harmonic of YAG laser or Ar ion laser is used for irradiation part 13 is explained.
The energy corresponding to these wavelengths is larger than the band gap of Si energy. For this reason, photoluminescence occurs as in the case of the YAG laser described above. However, as shown in FIG. 4, at these wavelengths, it cannot penetrate to the deep part in the semiconductor substrate 11 and can penetrate only to the vicinity of the back surface of the semiconductor substrate 11. For this reason, photoluminescence occurs near the back surface of the semiconductor substrate 11.

  Accordingly, when the semiconductor substrate 11 is irradiated with a wavelength that transmits through the semiconductor substrate 11 and a wavelength that does not transmit through the semiconductor substrate 11, light having different intensities is emitted from the semiconductor substrate 11. This difference in light intensity is detected by the detection unit 17 so that it is possible to easily, efficiently, and highly sensitively identify whether the defect is on the circuit surface or inside the substrate. At this time, the detection unit 17 may be provided with a spectroscopic function as necessary to detect the spectroscopic specific wavelength.

Furthermore, the case where the light of a YAG laser is scattered by a defect is demonstrated.
FIG. 5 shows an emission spectrum of the semiconductor substrate irradiated with the YAG laser. The horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit).

FIG. 5 shows an emission spectrum detected by the inspection apparatus 10 using a YAG laser as the irradiation unit 13.
Incidentally, a phenomenon called Rayleigh scattering in which irradiated light is scattered by fine particles is known. In FIG. 5, a large peak can be confirmed at a wavelength substantially equal to that of the YAG laser (about 1064 nm). That is, it is considered that the YAG laser light irradiated on the semiconductor substrate 11 regards defects in the semiconductor substrate 11 as fine particles and is scattered by the defects. Therefore, by irradiating the semiconductor substrate 11 with the YAG laser and detecting the intensity of scattered light emitted from the semiconductor substrate 11, it becomes possible to easily identify defects in the semiconductor substrate 11.

Next, the basic principle of the inspection method of the semiconductor device by the inspection apparatus 10 using such a configuration and the light emission principle will be described.
FIG. 6 is a flowchart of the inspection method.

The inspection apparatus 10 performs inspection of defects in the semiconductor device according to the flowchart of FIG. Hereinafter, description will be made with reference to FIG. 6 together with FIG.
[Step S31] A measurement condition is input to the apparatus control unit 18 of the inspection apparatus 10.

[Step S <b> 32] On the holding unit 12, for example, the semiconductor substrate 11 in a wafer state is placed so that the back side thereof is exposed from the holding unit 12.
[Step S33] The irradiation unit 13 is controlled by the irradiation unit control means 18a to irradiate the light 13a from the irradiation unit 13, and irradiate the light 13a to an arbitrary position of the semiconductor substrate 11 from the back side.

  [Step S34] The detection unit 17 is controlled by the detection unit control means 18b, and the detection unit 17 detects photoluminescence, scattered light, and reflected light emitted from the semiconductor substrate 11.

  [Step S35] The data of the photoluminescence / scattered light / reflected light detected in step S34 is processed and held by the data processing means 18c and the storage means 18d.

  [Step S36] The input / output means 18e displays, for example, an emission spectrum or an image display as a detection result. In particular, in image display, for example, the detected light intensity of a specific wavelength is displayed as a two-dimensional distribution.

  In the above description, only the method for inspecting the semiconductor substrate 11 has been described. When the inspection apparatus 10 as shown in FIG. 3 is incorporated in the manufacturing process line of the semiconductor device, for example, the following process can be performed in step S32 (see FIG. 3).

[Step S32a] The semiconductor substrate 11 is laid on the transport plate 19a by the transport means.
[Step S32b] The transporter 19 on which the semiconductor substrate 11 is arranged is moved onto the holding unit 12 by the transporting means. At this time, the arm portion 19b is arranged on the cutout region 12a.

  [Step S <b> 32 c] The transfer unit 19 on which the semiconductor substrate 11 is disposed is moved downward so that the arm unit 19 b passes through the cutout region 12 a by the transfer unit, and the semiconductor substrate 11 is placed on the holding unit 12.

  According to such an inspection flow, the back surface of the semiconductor substrate 11 is irradiated with the light 13a, the light 13b emitted from the back surface of the semiconductor substrate 11 is detected by the irradiation of the light 13a, and the intensity of the light 13b obtained by the detection is detected. Is measured. Further, the measured light intensity is displayed as an image such as a two-dimensional distribution, so that it is possible to identify whether the defect is on the circuit surface or inside the substrate.

Next, a second embodiment will be described.
In the first embodiment, the case has been described in which defects are inspected by displaying an image of the intensity of light emitted from the semiconductor substrate 11. In the second embodiment, a case will be described in which a reference value of light intensity is introduced, a difference between the intensity of light emitted from the semiconductor substrate 11 and the reference value is displayed as an image, and a defect is inspected.

  FIG. 7 is a schematic diagram of a main part of the inspection apparatus according to the second embodiment. In the inspection apparatus 10a of the second embodiment, the apparatus control unit 20 is installed in place of the apparatus control unit 18 in the inspection apparatus 10 of FIG. Therefore, description of the details of other components of the inspection apparatus 10a is omitted.

  In the apparatus control unit 20, similarly to the apparatus control unit 18, an irradiation unit control unit 18 a that controls the irradiation unit 13, a detection unit control unit 18 b that controls the slit 15, the filter 16, and the detection unit 17, and the detection unit 17. Data processing means 18c for detecting the defect by processing the detected light emission data, storage means 18d for storing data, and input / output means 18e serving as a user interface are provided. Further, the device control unit 20 includes a light emission reference data storage unit 20a and a characteristic measurement unit 20b.

  The light emission reference data storage means 20a holds data obtained by measuring in advance the intensity of light emitted from a defect-free semiconductor device, the electrical characteristics of the defect-free semiconductor device, and the like. Note that the acquisition of data related to a defect-free semiconductor device may be measured by the inspection apparatus 10 or another measurement apparatus.

The characteristic measuring unit 20 b measures the electric characteristics of the semiconductor substrate 11 held by the holding unit 12.
An inspection method of the inspection apparatus 10a having the apparatus control unit 20 having such a configuration will be described.

  First, as described above, the irradiation unit controller 18 a controls the irradiation unit 13 using, for example, a YAG laser, and irradiates the light 13 a from the irradiation unit 13 to the back side of the semiconductor substrate 11.

Next, the detection unit 17 detects the intensity of the light 13 b from the semiconductor substrate 11 through the slit 15 and the filter 16.
Next, the intensity of the light 13b detected by the data processing means 18c is converted into data and stored in the storage means 18d.

  Next, the data processing unit 18c refers to the light intensity data of the defect-free semiconductor device acquired in advance from the light emission reference data storage unit 20a, and acquires the difference from the light intensity data of the light 13b.

Finally, the input / output means 18e displays an image of the difference in intensity between the light of the defect-free semiconductor device and the light 13b.
After detecting the defect of the semiconductor substrate 11, the electric characteristic of the semiconductor substrate 11 is measured by the characteristic measuring unit 20b. Then, the data processing means 18c refers to the difference between the electrical characteristics of the semiconductor substrate 11 and the electrical characteristics data of the defect-free semiconductor device from the light emission reference data storage means 20a and the above-described defect data. As a result, it is possible to grasp the defect that affects the electrical characteristics.

Note that the inspection apparatus 10a can also be incorporated into a manufacturing process line of a semiconductor device manufacturing apparatus, as in the first embodiment.
As described above, the inspection apparatus 10 illustrated in FIG. 1 includes an irradiation unit 13 that irradiates the back surface of the semiconductor substrate 11 with the light 13a and a detection unit that detects the light 13b emitted from the back surface of the semiconductor substrate 11 by the irradiation of the light 13a. 17 and an apparatus control unit 18 that measures the intensity of the light 13b obtained by the detection and controls the entire inspection apparatus 10.

Then, the inspection apparatus 10 inspects the semiconductor substrate 11 for defects near the active region of the semiconductor element formed by the wafer process.
In particular, in the inspection apparatus 10, as shown in FIG. 3, the holding portion 12 has a hollow cylindrical shape and a notch region 12 a is formed in a part of the side surface. The substrate 11 can be easily held by the holding unit 12. Therefore, the inspection apparatus 10 can be easily incorporated into a manufacturing process line of a semiconductor device, and irradiates light from the back surface of the semiconductor device, emits light from the substrate by light irradiation, scatters from the substrate, or semiconductor device. The reflected light from the active layer can be detected from the back surface of the semiconductor device, and the detected data can be analyzed to detect defects generated in the semiconductor device with high sensitivity and ease.

  Further, in the inspection apparatus 10 a shown in FIG. 7, a light emission reference data storage unit 20 a having new data on the light intensity and electrical characteristics of a defect-free semiconductor device in the apparatus control unit 18 in the inspection apparatus 10 and the semiconductor substrate 11. And a characteristic measuring means 20b for measuring the electric characteristics.

  According to the inspection apparatus 10a, the defect can be image-displayed by the difference in intensity between the light of the defect-free semiconductor device and the light 13b, so that the defect can be clearly revealed. It is also possible to identify defects that affect electrical characteristics.

  As described above, according to the present embodiment, defects existing in a wafer scale or chip scale semiconductor device can be detected efficiently and with high sensitivity, and an inspection apparatus can be easily incorporated into a semiconductor device manufacturing process. it can.

It is a principal part schematic diagram of the test | inspection apparatus in 1st Embodiment. It is a perspective schematic diagram of the holding | maintenance part in 1st Embodiment. It is a principal part perspective schematic diagram which shows the conveyance process of the semiconductor substrate in 1st Embodiment, (A) is arrangement | positioning of the semiconductor substrate on a conveyance board, (B) is conveyance to the holding part of a semiconductor substrate, (C) shows the installation of the semiconductor substrate on the holding part. It is the wavelength dependence of the transmittance | permeability of a silicon wafer board | substrate, Comprising: (A) is about a doping amount, (B) is a graph about the film thickness of a silicon wafer substrate. It is an emission spectrum of a semiconductor substrate irradiated with a YAG laser. It is a flowchart figure of an inspection method. It is a principal part schematic diagram of the inspection apparatus in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inspection apparatus 11 Semiconductor substrate 12 Holding part 13 Irradiation part 13a, 13b Light 14 Reflector 15 Slit 16 Filter 17 Detection part 18 Device control part 18a Irradiation part control means 18b Detection part control means 18c Data processing means 18d Storage means 18e Input / output means

Claims (5)

A hollow holding part having a notch in a part of the side surface;
A transport unit that lowers the arm portion connected to the transport plate on which the semiconductor substrate is disposed, and the arm portion passes through the notch of the holding unit, and the holding unit holds the semiconductor substrate from the back side;
An irradiation unit for irradiating light to the back surface of the semiconductor substrate held from the back side by the holding unit;
A detector for detecting light emitted from the back surface of the semiconductor substrate by the light irradiation;
A measurement unit for measuring the intensity of light detected by the detection unit;
An inspection apparatus comprising:   The inspection apparatus according to claim 1, wherein a semiconductor element is formed on the semiconductor substrate. It further has a storage unit that holds the light intensity of the defect-free semiconductor substrate measured in advance,
The inspection apparatus according to claim 1, wherein a difference between the light intensity measured by the measurement unit and the light intensity of the defect-free semiconductor substrate is acquired. The arm portion connected to the transfer plate on which the semiconductor substrate is disposed is lowered, and the arm portion passes through the notch of the hollow holding portion having a notch on a part of the side surface, and the semiconductor substrate is placed on the holding portion. A transport step to be held from the back side;
An irradiation step of irradiating light to the back surface of the semiconductor substrate held from the back side by the holding unit;
A detection step of detecting light emitted from the back surface of the semiconductor substrate by the light irradiation;
A measurement step for measuring the intensity of light detected by the detection step;
An inspection method characterized by comprising:   The arm portion connected to the transport plate on which the semiconductor substrate is disposed is lowered, and the arm portion passes through the notch of the hollow holding portion having a notch on a part of the side surface, and the semiconductor substrate is placed on the holding portion. A transporting step of holding from the back side, an irradiating step of irradiating light on the back surface of the semiconductor substrate held from the back side by the holding unit, and a detecting step of detecting light emitted from the back surface of the semiconductor substrate by the light irradiation And a measuring step for measuring the intensity of the light detected by the detecting step. A method for manufacturing a semiconductor device, comprising:

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