Analysis apparatus, and analysis method

Abstract

This invention provides an analytical apparatus and method capable of analyzing even minute defects on the surface of a semiconductor substrate. The analytical apparatus includes: a surface defect measuring unit that measures the presence or absence of defects on the surface of the semiconductor substrate and obtains positional information on the surface of the semiconductor substrate regarding the defects; and an analytical unit that irradiates the defects on the surface of the semiconductor substrate with laser light based on the positional information of the defects, recovers the analytical sample obtained by irradiation using a carrier gas, and performs inductively coupled plasma mass spectrometry analysis.

Description

Technical Field

[0001] This invention relates to an analytical apparatus and method for analyzing defects on the surface of a semiconductor substrate using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Prior Technology

[0002] Currently, silicon substrates and other semiconductor substrates are used to manufacture various semiconductor devices. If defects such as foreign objects exist on the surface of the semiconductor substrate, the formation of the transistor gate will be insufficient during the manufacturing process, or wiring may break, sometimes resulting in defective semiconductor devices. Thus, defects such as foreign objects on the surface of the semiconductor substrate affect the yield of semiconductor devices.

[0003] Regarding defects in semiconductor substrates, for example, the method for evaluating residual metal impurities inside the silicon crystal of a silicon wafer, as described in Patent Document 1, can be used for evaluation. In the method for evaluating residual metal impurities inside the silicon crystal of a silicon wafer in Patent Document 1, heat treatment is performed to collect the metal impurities inside the silicon crystal on the surface of the silicon wafer. Subsequently, vapor phase decomposition inductively coupled plasma mass spectrometry (VPD-ICP-MS) is performed to determine the concentration of the metal impurities collected on the surface of the silicon wafer. The number of surface defects on the silicon wafer is determined using a SurfScan SP5 manufactured by KLA Corporation.

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-195020 [Patent Document 2] Japanese Patent Application Publication No. 2020-027920

[0005] The inductively coupled plasma mass spectrometry analysis using the gas phase decomposition method in the aforementioned patent document 1 melts away the silicon wafer, making it impossible to evaluate defects in the semiconductor substrate in a non-destructive manner. As an evaluation method for non-destructive evaluation of defects in semiconductor substrates, there is a method for evaluating metal contamination in wafers as described in Patent Document 2.

[0006] Patent Document 2 describes a method for evaluating metal contamination on a wafer, which includes the following as a foreign object inspection device: a particle counter (e.g., the SurfScanSP5 manufactured by KLA Corporation) that detects the light scattering pattern of foreign objects by scanning the wafer surface with laser light and measuring the light scattering intensity from the foreign object, and a laser microscope with a confocal optical system (e.g., the MAGICS manufactured by Lasertec Corporation) that detects foreign objects by detecting the difference in reflected light from the wafer surface. Patent Document 2 also describes the following: SEM (Scanning Electron Microscope) observation of a bright spot is performed based on the coordinates obtained in the first step, and EDX (Energy Dispersive X-ray Spectroscopy) analysis is performed based on the characteristic X-rays generated by electron beam irradiation.

[0007] As mentioned above, when defects such as foreign matter exist on the surface of a semiconductor substrate, especially with the miniaturization and hyper-integration of semiconductor devices, the impact of these surface defects on the production of defective semiconductor devices and consequently reduced yield becomes increasingly significant. Therefore, measuring surface defects on semiconductor substrates is extremely important, and the measurement of minute foreign matter among these defects becomes even more crucial. However, when using the wafer metal contamination evaluation method described in Patent Document 2 to analyze minute foreign matter of approximately 20 nm on the surface of a semiconductor substrate, elemental analysis using EDX is highly likely to be impossible. Currently, there is a desire to be able to analyze minute foreign matter of approximately 20 nm on the surface of semiconductor substrates. Summary of the Invention

[0008] The purpose of this invention is to provide an analytical apparatus and method capable of analyzing even smaller defects on the surface of a semiconductor substrate.

[0009] To achieve the above objectives, one aspect of the present invention provides an analysis apparatus that uses location information of defects on the surface of a semiconductor substrate. The analysis apparatus includes an analysis unit that irradiates the defects on the surface of the semiconductor substrate with laser light based on the location information of the defects on the surface of the semiconductor substrate. The analysis sample obtained by irradiation is recovered using a carrier gas and subjected to inductively coupled plasma mass spectrometry analysis. One aspect of the present invention provides an analytical apparatus comprising: a surface defect measuring device for measuring the presence or absence of defects on the surface of a semiconductor substrate and obtaining position information of the defects on the surface of the semiconductor substrate; and a mass spectrometry analysis device for irradiating the defects on the surface of the semiconductor substrate with laser light based on the position information of the defects on the surface of the semiconductor substrate obtained by the surface defect measuring device, and recovering the analytical sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis. A surface defect measuring device is better if it has a storage unit for storing location information. The surface defect measuring device has: an incident section that allows incident light to be incident on the surface of a semiconductor substrate; and a light receiving section that receives the emitted light that is reflected or scattered by the incident light due to defects on the surface of the semiconductor substrate. One aspect of the present invention provides an analytical apparatus comprising: a surface defect measuring unit for measuring the presence or absence of defects on the surface of a semiconductor substrate and obtaining positional information on the surface of the semiconductor substrate regarding the defects; and an analytical unit for irradiating the defects on the surface of the semiconductor substrate with laser light based on the positional information of the defects on the surface of the semiconductor substrate, and recovering the analytical sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis.

[0010] It is preferable for the surface defect measurement unit to have a storage unit that stores location information. The surface defect measuring unit preferably includes: an incident section that allows incident light to be incident on the surface of a semiconductor substrate; and a light receiving section that receives the emitted light that is reflected or scattered by the incident light due to defects on the surface of the semiconductor substrate. It is preferable to have a container section for storing the semiconductor substrate to be measured, and to perform the analysis of the semiconductor substrate based on the analysis section within the container section. It has: a cleaning gas supply section for supplying cleaning gas into the container section; and an outlet section for allowing the cleaning gas to flow out of the container section. It has: an inlet section, which is provided with a container for storing a semiconductor substrate that is to be measured; and a conveying device, which preferably conveys the semiconductor substrate from the inlet section to the surface defect measurement section.

[0011] One aspect of the present invention provides an analysis method that uses the location information of defects on the surface of a semiconductor substrate. The analysis method includes the following steps: irradiating the defects on the surface of the semiconductor substrate with laser light based on the location information of the defects on the surface of the semiconductor substrate; recovering the analysis sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis. One aspect of the present invention provides an analytical method comprising the following steps: determining the presence or absence of defects on the surface of a semiconductor substrate; obtaining positional information on the surface of the semiconductor substrate regarding the defects; irradiating the defects on the surface of the semiconductor substrate with laser light based on the positional information of the defects on the surface of the semiconductor substrate; and recovering the analytical sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis.

[0012] The preferred water content of the carrier gas is above 0.00001 ppm by volume and below 0.1 ppm by volume. The analysis step is performed in a container that houses the semiconductor substrate to be measured. It is preferable to clean the container with a cleaning gas before the analysis step. [Invention Effects]

[0013] According to the present invention, it is possible to analyze even smaller defects on the surface of a semiconductor substrate. Simple Explanation of the Diagram

[0014] Figure 1 is a schematic diagram showing a first example of an analytical apparatus according to an embodiment of the present invention. Figure 2 is a schematic diagram of an example of the analysis unit of the first embodiment of the analysis apparatus of the present invention. Figure 3 is a schematic diagram illustrating the first example of the analysis method of an embodiment of the present invention. Figure 4 is a schematic cross-sectional view illustrating the first example of the analytical method of an embodiment of the present invention. Figure 5 is a schematic diagram showing a second example of an analytical apparatus according to an embodiment of the present invention. Figure 6 is a schematic diagram showing a third example of an analysis apparatus according to an embodiment of the present invention. Figure 7 is a schematic diagram showing a modified example of the analysis section of the analysis apparatus according to an embodiment of the present invention. Implementation

[0015] The analytical apparatus and analytical method of the present invention will now be described in detail with reference to the preferred embodiments shown in the accompanying drawings. Furthermore, the figures described below are for illustrative purposes only and the invention is not limited to the figures shown below. Additionally, the "~" sign indicating a range includes the values ​​on both sides. For example, ε for the value εa ~ εb means that the range of ε includes both the values ​​εa and εb. In mathematical notation, this would be εa ≤ ε ≤ εb. "Angles expressed in specific numerical values", "parallel", "perpendicular" and "orthogonal" angles, unless otherwise specified, include the generally permissible error range in this technical field. Furthermore, "same" encompasses the generally permissible range of error in this technical field. Also, "comprehensive," etc., encompass the generally permissible range of error in this technical field.

[0016] [Example of an analytical apparatus] Figure 1 is a schematic diagram showing a first example of an analysis apparatus according to an embodiment of the present invention, and Figure 2 is a schematic diagram showing an example of an analysis unit of the first example of an analysis apparatus according to an embodiment of the present invention. The analysis apparatus 10 shown in Figure 1 includes a surface defect measurement unit 20 and an analysis unit 30, which will be described in detail later. The analysis apparatus 10 measures the presence or absence of defects on the surface 50a of the semiconductor substrate 50 and analyzes the defects on the surface 50a of the semiconductor substrate 50, taking the semiconductor substrate 50 as the measurement object. The analytical apparatus 10 has a first transport chamber 12a, a measurement chamber 12b, a second transport chamber 12c, and an analysis chamber 12d, arranged sequentially in the order of the first transport chamber 12a, the measurement chamber 12b, the second transport chamber 12c, and the analysis chamber 12d. The first transport chamber 12a, the measurement chamber 12b, the second transport chamber 12c, and the analysis chamber 12d are each divided by a wall 12h, but are provided with doors (not shown) to allow the semiconductor substrate 50, which is the object of measurement, to move. The doors can be opened when the semiconductor substrate 50 passes through.

[0017] In the analysis apparatus 10, a semiconductor substrate 50 is transported from outside the analysis apparatus 10 to a first transport chamber 12a, and then from the first transport chamber 12a to a measurement chamber 12b, where surface defects of the semiconductor substrate 50 are measured. Next, the semiconductor substrate 50 with measured surface defects is transported from the measurement chamber 12b to a second transport chamber 12c, and further to the analysis chamber 12d. The analysis unit 30 analyzes the surface defects of the semiconductor substrate 50 based on the measurement results of the presence or absence of defects on the surface 50a of the semiconductor substrate 50 in the surface defect measurement unit 20. In the analysis apparatus 10, to prevent the semiconductor substrate 50 from being exposed to the outside air, the interiors of the first delivery chamber 12a, the measuring chamber 12b, the second delivery chamber 12c, and the analysis chamber 12d can be configured into specific environments. For example, a vacuum pump can be installed to exhaust the gas inside the first delivery chamber 12a, the measuring chamber 12b, the second delivery chamber 12c, and the analysis chamber 12d to create a reduced-pressure environment. Alternatively, an inert gas such as nitrogen can be supplied to the interiors of the first delivery chamber 12a, the measuring chamber 12b, the second delivery chamber 12c, and the analysis chamber 12d to create an inert gas environment.

[0018] As described above, the first delivery chamber 12a delivers the semiconductor substrate 50, which is transported from outside the analytical apparatus 10, to the measuring chamber 12b. The first delivery chamber 12a has an inlet portion 12g on its side. A receiving container 13 is provided at the inlet portion 12g. To maintain an airtight seal with the receiving container 13, a sealing member (not shown) is provided at the inlet portion 12g. The storage container 13, for example, is arranged in a shelf-like manner inside and houses a plurality of semiconductor substrates 50. The semiconductor substrates 50 are, for example, disc-shaped substrates. The receiving container 13 is, for example, a FOUP (Front Opening Unified Pod). By using the receiving container 13, the semiconductor substrate 50 can be transported to the analysis device 10 in a sealed state without being exposed to the outside air. This helps to suppress contamination of the semiconductor substrate 50.

[0019] In the first transport chamber 12a, a transport device 14 is provided inside. The transport device 14 transports the semiconductor substrate 50 in the receiving container 13 from the first transport chamber 12a to the adjacent measuring chamber 12b. The conveying device 14 is not particularly limited as long as it can remove the semiconductor substrate 50 from the storage container 13 and convey it to the stage 22 of the measuring chamber 12b. The transport device 14 shown in Figure 1 has a transport arm 15 that holds the outer side of the semiconductor substrate 50 and a drive unit (not shown) that drives the transport arm 15. The transport arm 15 is mounted on the mounting part 14a and can rotate freely about the rotation axis C1. In addition, as long as the transport arm 15 can hold and transport the semiconductor substrate 50, its configuration is not particularly limited to holding the outer side of the semiconductor substrate 50, and it can also be appropriately used for transport between processes of semiconductor wafers. In the conveying device 14, the mounting part 14a is movable along the height direction V, and the conveying arm 15 is movable along the height direction V, which is parallel to the rotation axis C1. By moving the mounting part 14a along the height direction V, the position of the conveying arm 15 in the height direction V can be changed.

[0020] (Surface Defect Measurement Department) As described above, surface defects of the semiconductor substrate 50 are measured inside the measuring chamber 12b. A surface defect measuring unit 20 is provided inside the measuring chamber 12b. The surface defect measurement unit 20 measures the presence or absence of defects on the surface 50a of the semiconductor substrate 50, and obtains position information on the surface 50a of the semiconductor substrate 50 regarding the defects on the surface 50a of the semiconductor substrate 50. The surface defect measurement unit 20 includes a stage 22 for placing a semiconductor substrate 50, an incident part 23 for incident light Ls onto the surface 50a of the semiconductor substrate 50, and a focusing lens 24 for focusing the incident light Ls onto the surface 50a of the semiconductor substrate 50. The stage 22 on which the semiconductor substrate 50 is placed can rotate freely around the rotation axis C2, and can change the position of the semiconductor substrate 50 in the height direction V, and can also change the position in the direction H which is orthogonal to the height direction V. Using the stage 22, the irradiation position of the incident light Ls on the surface 50a of the semiconductor substrate 50 can be changed. In this way, the incident light Ls can be sequentially irradiated onto a specific area or the entire surface of the semiconductor substrate 50a to detect defects such as foreign objects on the surface 50a of the semiconductor substrate 50.

[0021] The wavelength of the incident light Ls irradiated by the incident section 23 is not particularly limited. The incident light Ls may be ultraviolet light, but it may also be visible light or other light. Here, ultraviolet light refers to light in the wavelength region below 400 nm, and visible light refers to light in the wavelength region of 400 to 800 nm. Regarding the incident angle of the incident light Ls, all directions horizontal to the surface 50a of the semiconductor substrate 50 are set to 0°, and the directions perpendicular to the surface 50a of the semiconductor substrate 50 are set to 90°. In this case, if the incident angle of the incident light Ls is defined from a minimum of 0° to a maximum of 90°, then the incident angle of the incident light Ls is more than 0° and less than 90°, preferably more than 0° and less than 90°.

[0022] The surface defect measurement unit 20 has a light-receiving section for receiving emitted light that is reflected or scattered by the incident light Ls from the surface 50a of the semiconductor substrate 50. In the surface defect measurement unit 20 shown in FIG. 1, for example, two light-receiving sections 25 and 26 are provided. When the emitted light is received by either of the light-receiving sections 25 and 26, it is assumed that a defect exists on the surface 50a of the semiconductor substrate 50; when no emitted light is generated, it is assumed that no defect exists on the surface 50a of the semiconductor substrate 50. Thus, the presence or absence of a defect on the surface 50a of the semiconductor substrate 50 is determined. A light-receiving portion 25 is disposed around the semiconductor substrate 50. A light-receiving portion 26 is disposed above the surface 50a of the semiconductor substrate 50. A condensing lens 27 is provided between the surface 50a of the semiconductor substrate 50 and the light-receiving portion 26. The emitted light generated by the incident light Ls is focused onto the light-receiving portion 26 by the condensing lens 27. By using the condensing lens 27, the emitted light can be focused onto the light-receiving portion 26 with high efficiency. In addition, the number of light-receiving portions is not limited to two. The surface defect measuring unit 20 can be configured with either the light-receiving portion 25 or the light-receiving portion 26, or it can be configured with three or more light-receiving portions. The light-receiving part 25 receives the emitted light at a low angle. "Low angle" refers to receiving light within a range of 0° to 80° of the aforementioned incident angle. The light-receiving part 26 receives the emitted light at a high angle. "High angle" refers to receiving light within a range exceeding 80° but less than 90° of the aforementioned incident angle. The light-receiving part 25 and the light-receiving part 26 are, for example, composed of a light sensor such as a photomultiplier tube. Furthermore, both the light-receiving part 25 and the light-receiving part 26 are capable of receiving unpolarized light or polarized light.

[0023] The surface defect measurement unit 20 has a calculation unit 28 and a storage unit 29. The arithmetic unit 28 calculates the location information and size of the detected defect based on the information of the emitted light received by the light receiving units 25 and 26. The location information of the defect refers to the location coordinate information of the defect on the surface 50a of the semiconductor substrate 50. The location coordinates are, for example, set by using a reference position shared by a plurality of semiconductor substrates 50 as the origin after pre-setting the reference position.

[0024] The light-receiving units 25 and 26 receive incident light Ls irradiated by the incident light unit 23, which is reflected or scattered by defects on the surface 50a of the semiconductor substrate 50 and emitted as radiation. In the light-receiving units 25 and 26, the emitted light is detected as a bright spot. In the calculation unit 28, based on the size of the bright spot containing information about the emitted light caused by defects in the light-receiving units 25 and 26, the size of the defect that generated the bright spot, i.e., the detection size, is calculated based on the size of a standard particle. The calculation of the detection size based on the size of the standard particle is performed using a calculation device included in a commercially available surface inspection apparatus or a known calculation method. The calculation unit 28 obtains position information of the irradiation position of the incident light Ls from the control unit 42, for example, based on information about the emitted light caused by defects in the light-receiving units 25 and 26, to obtain position information and size information of defects on the surface 50a of the semiconductor substrate 50. The obtained position information and size information of defects on the surface 50a of the semiconductor substrate 50 are stored in the storage unit 29. The storage unit 29 is not particularly limited as long as it can store the location and size information of defects such as foreign objects on the surface 50a of the semiconductor substrate 50. For example, it can use various storage media such as volatile memory, non-volatile memory, hard disk or SSD (Solid State Drive).

[0025] Here, in the surface defect measuring unit 20, the stage 22 and the incident unit 23 are controlled by the control unit 42. Also, the calculation unit 28 is controlled by the control unit 42. The control unit 42 acquires position information of the incident light Ls irradiated by the incident unit 23 on the surface 50a of the semiconductor substrate 50. In order to irradiate the area on the surface 50a of the semiconductor substrate 50 that is not irradiated with incident light Ls, the control unit 42 drives the stage 22 and changes the irradiation position of the surface 50a of the semiconductor substrate 50. In the surface defect measurement unit 20, incident light Ls is irradiated onto the entire area of ​​the surface 50a of the semiconductor substrate 50. For example, based on the information of the emitted light received by the two light-receiving units 25 and 26, the location information and size information of defects on the surface 50a of the semiconductor substrate 50 at each irradiation position are obtained. In this way, comprehensive location information and size information of defects on the surface 50a of the semiconductor substrate 50 can be obtained. That is, the location information and size information of two-dimensional defects on the surface 50a of the semiconductor substrate 50 can be obtained. When the surface defect measuring unit 20 is used for measurement, the environment of the measuring chamber 12b is not particularly limited. As mentioned above, it can be a depressurized environment or a nitrogen environment. Additionally, as the surface defect measuring unit 20, a surface inspection device (SurfScan SP5; manufactured by KLA Corporation) can be used, for example.

[0026] In the second transport chamber 12c, a transport device 16 is installed inside. The transport device 16 is used to transport the semiconductor substrate 50, whose surface defects have been measured by the surface defect measuring unit 20, from the measuring chamber 12b to the analysis chamber 12d. The conveying device 16 can use the same components as the conveying device 14 described above. The conveying device 16 has a conveying arm 15 that holds the outer side of the semiconductor substrate 50 and a drive unit (not shown) that drives the conveying arm 15. The conveying arm 15 is mounted on the mounting part 16a and can rotate freely about the rotation axis C1. In the conveying device 16, the mounting portion 16a is movable along the height direction V, and is also movable along the height direction V, which is parallel to the rotation axis C1. The position of the conveying arm 15 in the height direction V is changed by the movement of the mounting portion 16a on which the conveying arm 15 is mounted along the height direction V.

[0027] (Analysis Department) The analysis chamber 12d contains an analysis unit 30. The analysis unit 30 uses LA-ICP-MS (Laser Ablation-Inductively Coupled Plasma Mass Spectrometer) for analysis. ICP-MS (Inductively Coupled Plasma Mass Spectrometer) utilizes plasma generated by inductive coupling at approximately 10,000°C in argon gas to ionize elements in liquid samples for mass spectrometry analysis. LA-ICP-MS involves irradiating defects 51 on the surface 50a of a semiconductor substrate 50 with laser light in the laser ablation section (LA section). The sample obtained through irradiation is then introduced into the ICP-MS section (Inductively Coupled Plasma Mass Spectrometry section) using a carrier gas for quantitative analysis of the elements contained in the sample.

[0028] The analysis unit 30 has a stage 32 for placing a semiconductor substrate 50 and a container 33 for storing the semiconductor substrate 50 placed on the stage 32. An analysis unit 36 ​​is connected to the container section 33 via a pipe 39. The semiconductor substrate 50 is analyzed while being housed entirely within the container section 33. The stage 32 on which the semiconductor substrate 50 is placed can rotate freely around the rotation axis C3, and can change the position of the semiconductor substrate 50 in the height direction V, and can also change the position in the direction H orthogonal to the height direction V. The stage 32 is controlled by the control unit 42. The control unit 42 drives the stage 32 and changes the irradiation position on the surface 50a of the semiconductor substrate 50 in order to irradiate the defect 51 on the surface 50a of the semiconductor substrate 50 with laser light La.

[0029] The analysis unit 30 has a light source 34 that irradiates laser light La onto defects 51 on the surface 50a of the semiconductor substrate 50 measured by the surface defect measurement unit 20. A focusing lens 35 is provided between the light source 34 and the surface 50a of the semiconductor substrate 50 to focus the laser light La onto the defects 51 on the surface 50a of the semiconductor substrate 50. The light source 34 and the condenser lens 35 are disposed on the outside of the container 33. A window (not shown) through which laser light La can be transmitted is provided on the container 33 so that the laser light La can be transmitted into the interior. The light source unit 34 uses femtosecond lasers, nanosecond lasers, picosecond lasers, or attosecond lasers. For example, a Ti:sapphire laser can be used as a femtosecond laser.

[0030] The analysis unit 30 has a carrier gas supply unit 38 that supplies carrier gas into the container unit 33. The carrier gas supply unit 38 includes a gas supply source (not shown) such as a gas cylinder for storing carrier gas, a regulator (pressure regulator) connected to the gas supply source, and an adjustment valve (not shown) for controlling the supply amount of carrier gas. For example, the regulator and the adjustment valve are connected by a hose, and the adjustment valve and the container unit 33 are connected by a pipe. The carrier gas may be, for example, helium or argon. Furthermore, the analysis unit 30 includes a cleaning gas supply unit 40 that supplies cleaning gas to the container unit 33. The cleaning gas supply unit 40 includes a gas supply source (not shown) such as a gas cylinder for storing cleaning gas, a regulator (pressure regulator) connected to the gas supply source, and an adjustment valve (not shown) for controlling the amount of cleaning gas supplied. For example, the regulator and the adjustment valve are connected by a hose, and the adjustment valve and the container unit 33 are connected by a pipe. The cleaning gas used may be, for example, helium or argon.

[0031] Furthermore, an outlet 41 is provided in the container section 33 to allow cleaning gas to flow out from inside the container section 33 to the outside. The outlet 41 is, for example, composed of a pipe and a valve. By opening the valve, cleaning gas can flow out from inside the container section 33 to the outside. For rinsing, a heater (not shown) can be installed in the container section 33. By heating the container section 33 with cleaning gas while it is being supplied, foreign matter such as eroded deposits or adsorbed gases can be removed. This improves the cleanliness of the container section 33 and suppresses contamination of the semiconductor substrate 50. The heater may be, for example, an infrared lamp or a xenon flash lamp. Furthermore, in addition to the cleaning gas, a carrier gas can also be used in the rinsing process.

[0032] <Analysis Unit> The analysis unit 36 ​​utilizes the aforementioned ICP-MS to irradiate the defects 51 on the surface 50a of the semiconductor substrate 50 with laser light La. The analytical sample obtained by irradiation is recovered using a carrier gas and analyzed by inductively coupled plasma mass spectrometry. Furthermore, ICP is an abbreviation for inductively coupled plasma. In the analysis unit 36, the analyte is ionized using a high-temperature plasma maintained by high-frequency electromagnetic induction, and the ions are detected using a mass spectrometer to measure the types of atoms and their concentrations. For example, as shown in FIG2, the analysis unit 36 ​​has a plasma torch 44 that generates plasma to ionize the analytical sample introduced from the piping 39 along with the carrier gas, and a mass spectrometry analysis unit 46 having an ion introduction section located near the front end of the plasma torch 44.

[0033] The plasma torch 44 may be a triple-tube structure, for example, with a carrier gas introduced through piping 39. Additionally, plasma gas for plasma formation is introduced into the plasma torch 44. Argon gas may be used as an example of the plasma gas. A high-frequency coil (not shown) connected to a high-frequency power supply (not shown) is provided in the plasma torch 44. Plasma is formed inside the plasma torch 44 by applying a high-frequency current of about 1~2KW, such as 27.12MHz or 40.68MHz, to the high-frequency coil.

[0034] In the mass spectrometry analysis section 46, ions generated by the plasma torch 44 are introduced into the ion lens section 46a and the mass spectrometer section 46b via the ion introduction section. The vacuum pressure in the ion lens section 46a and the mass spectrometer section 46b is reduced by a vacuum pump (not shown) to make the ion lens section 46a on the plasma torch 44 side a low vacuum and the mass spectrometer section 46b a high vacuum.

[0035] The ion lens section 46a is provided with a plurality of ion lenses 47, for example, three. The ion lenses 47 are used to separate ions into the mass spectrometer section 46b. Within the ion lens section 46a of the mass spectrometry analysis section 46, the light and ions of the plasma are separated by the ion lens 47, and only the ions are allowed to pass through.

[0036] The mass spectrometer section 46b separates ions according to their mass-to-charge ratio and detects them using detector 49. The mass spectrometer section 46b includes a reflection electric field mass spectrometer 48 for detecting ions that have passed through the ion lens section 46a and a detector 49 for detecting the ions. The reflection electric field mass spectrometer 48, referred to as an ion mirror, is a device that uses an electrostatic field to reverse the flight direction of charged particles. By using the reflection electric field mass spectrometer 48, charged particles with different kinetic energies at the same mass-to-charge ratio can converge on the time axis and arrive at detector 49 in approximately the same time. Using the reflection electric field mass spectrometer 48, errors can be compensated for, and mass resolution can be improved. The reflection electric field mass spectrometer 48 can be a known device for time-of-flight mass spectrometry (TOF-MS).

[0037] The detector 49 is not particularly limited as long as it can detect ions and identify elements, and can use any known method for time-of-flight mass spectrometry (TOF-MS). Using the analysis unit 36, for example, the signal (not shown) of the detected element ions can be displayed as a graph (not shown) at each time interval. The concentration of the detected element corresponds to the signal intensity.

[0038] As shown in Figure 1, the analysis apparatus 10 includes a control unit 42. The control unit 42 uses the location and size information of foreign matter or other defects on the surface 50a of the semiconductor substrate 50, stored in the storage unit 29 of the surface defect measurement unit 20, to drive the stage 32 of the analysis unit 30, or to change the irradiation position of the laser light La to irradiate the defects 51 on the surface 50a of the semiconductor substrate 50. This allows for the analysis of the defects 51 on the surface 50a of the semiconductor substrate 50. Furthermore, by configuring the analysis apparatus 10 to perform inductively coupled plasma mass spectrometry analysis based on the analysis unit 30 while the semiconductor substrate 50 is entirely housed within the container section 33, contamination of the surface 50a of the semiconductor substrate 50 can be suppressed.

[0039] In the analysis apparatus 10, carrier gas and cleaning gas are supplied in different systems, but it is not limited to this. Since the supply times of carrier gas and cleaning gas are different, they can also share a single configuration to supply to container section 33. For example, it can be configured to not provide cleaning gas supply section 40, but only provide carrier gas supply section 38. Furthermore, it is preferable that the water content of the carrier gas is above 0.00001 ppm by volume and below 0.1 ppm by volume.

[0040] If the moisture content of the carrier gas is 0.00001 ppm or more and 0.1 ppm or less, contamination on the surface 50a of the semiconductor substrate 50 during analysis within the container section 33 can be reduced. For example, when the moisture content of the carrier gas is high, impurities dissolve in trace amounts of moisture adhering to the piping surface of the carrier gas or the inner surface of the container section 33. Sometimes, the number of defects increases because these impurities re-adhere to the semiconductor substrate 50. However, if the moisture content of the carrier gas is within the above-mentioned range, these impurities can be suppressed. Furthermore, when the moisture content is low, the surface 50a of the semiconductor substrate 50 is easily charged when the carrier gas passes near the semiconductor substrate 50. As a result, charged particles floating in the container section 33 are easily attracted to the surface 50a of the semiconductor substrate 50, or particles floating nearby during transport in the transport system are attracted to the surface 50a of the semiconductor substrate 50. Also, re-adhesion of products resulting from laser ablation is likely to occur, but this can be suppressed if the moisture content of the carrier gas is within the aforementioned range. The water content in the carrier gas can be determined using an atmospheric pressure ionization mass spectrometer (API-MS). More specifically, the water content in the carrier gas can be determined, for example, using a device manufactured by NIPPON API CO.,LTD. The method for adjusting the moisture content is not particularly limited; it can be achieved through a gas purification step that removes water (water vapor) contained in the feed gas. In particular, the moisture content in the carrier gas can be adjusted by changing the number of purification cycles or the filter. In addition, the flow rate of the carrier gas is preferably 1.69×10⁻³~1.69 Pa·m³ / sec (1~1000 sccm (standard cubic centimeter per minute)).

[0041] [Example of an analytical method] The analytical method comprises the following steps: determining the presence or absence of defects on the surface of a semiconductor substrate, obtaining information on the location of these defects on the semiconductor substrate; irradiating the defects on the surface of the semiconductor substrate with laser light based on the location information of the defects; recovering the analytical sample obtained through irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis. The analytical method is described in detail below. Figure 3 is a schematic diagram illustrating the first example of the analysis method of the embodiment of the present invention, and Figure 4 is a schematic cross-sectional view illustrating the first example of the analysis method of the embodiment of the present invention. In addition, in Figures 3 and 4, the same symbols are used to mark the same components as those in the analysis apparatus 10 shown in Figure 1, and their detailed descriptions are omitted.

[0042] In the analysis method, for example, a storage container 13 (see Figure 1) containing a plurality of semiconductor substrates 50 is connected to the inlet portion 12g on the side of the first delivery chamber 12a of the analysis apparatus 10 shown in Figure 1. The lid of the storage container 13 is opened, so that the semiconductor substrates 50 are removed from the storage container 13. Next, the semiconductor substrate 50 is removed from the storage container 13 using the transport device 14 of the first transport chamber 12a and transported to the stage 22 of the measurement chamber 12b. By transporting the semiconductor substrate 50 from the storage container 13 to the stage 22 of the measurement chamber 12b, contamination of the semiconductor substrate 50 can be suppressed even when transported from outside the analysis apparatus 10. With contamination of the semiconductor substrate 50 suppressed, surface defects of the semiconductor substrate 50 can be measured using the surface defect measurement unit 20.

[0043] Next, within the measurement chamber 12b, the surface defects of the semiconductor substrate 50 are measured using the surface defect measurement unit 20. This allows for the detection of the location and size of defects such as foreign objects on the surface 50a of the semiconductor substrate 50. For example, as shown in FIG3, a defect 51 can be represented on the surface 50a of the semiconductor substrate 50. Representing the defect 51 on the surface 50a of the semiconductor substrate 50 is called mapping. The location and size information of the defect 51 on the surface 50a of the semiconductor substrate 50 are stored in the storage unit 29. This location and size information of the defect 51 on the surface 50a of the semiconductor substrate 50 is called mapping information.

[0044] Next, the semiconductor substrate 50 with measured surface defects is transported from the measurement chamber 12b to the analysis chamber 12d using the transport device 16 of the second transport chamber 12c shown in FIG1. Next, within the analysis chamber 12d, the analysis unit 30 performs analysis based on the position and size information, i.e., mapping information, of the defect 51 on the surface 50a of the semiconductor substrate 50. As shown in FIG4, the analysis is performed with the semiconductor substrate 50 entirely housed within the container 33 and a carrier gas (not shown) supplied into the container 33 from the carrier gas supply unit 38. During the analysis, the position of the defect 51 is determined based on the mapping information, for example, by using the stage 32 to move the semiconductor substrate 50 to a position where the defect 51 is located under the irradiation of the laser light La. Next, as shown in FIG4, laser light La is irradiated onto the defect 51 on the surface 50a of the semiconductor substrate 50. The analytical sample 51a obtained by irradiating the defect 51 with laser light La is moved to the analysis unit 36 ​​via piping 39 using a carrier gas (not shown). The analytical sample 51a from the defect 51, moved by the carrier gas, is subjected to inductively coupled plasma mass spectrometry analysis in the analysis unit 36 ​​to determine the elemental composition of the defect 51.

[0045] In the analytical method, it is preferable to perform a step of cleaning the container section 33 with a cleaning gas before the analytical step. Specifically, the cleaning step involves supplying cleaning gas into the container section 33 before conveying the semiconductor substrate 50 into the container section 33, and using a heater to heat the container section 33 to perform a rinsing process. Through the cleaning step, foreign matter such as etched deposits or adsorbed gases are removed from the container section 33.

[0046] Furthermore, in the analysis apparatus 10, the position information of the defects 51 on the surface 50a of the semiconductor substrate 50 can be obtained by measuring the defects 51 on the surface 50a of the semiconductor substrate 50 using another device different from the analysis apparatus 10, such as the surface defect measuring device 70 (see Figure 1). The position information of the defects 51 on the surface 50a of the semiconductor substrate 50 is, for example, the mapping information shown in Figure 3. In this case, the mapping information obtained by the surface defect measuring device 70 is supplied to the storage unit 29. Then, the semiconductor substrate 50, on which the defects 51 on the surface 50a have been measured in the surface defect measuring device 70, is stored, for example, in the storage container 13 and transported to the analysis apparatus 10. The semiconductor substrate 50 is transported to the analysis chamber 12d through the first transport chamber 12a, the measuring chamber 12b, and the second transport chamber 13c. Next, the control unit 42 reads the mapping information from the storage unit 29 and determines the position of the defect 51 on the surface 50a of the semiconductor substrate 50 based on the mapping information. Then, the semiconductor substrate 50 is moved using the stage 32 to a position where the defect 51 is located for irradiation by laser light La. Next, laser light La is irradiated onto the defect 51 on the surface 50a of the semiconductor substrate 50. The analytical sample 51a obtained by irradiating the defect 51 with laser light La is moved to the analysis unit 36 ​​using a carrier gas. The analytical sample 51a from the defect 51, moved using a carrier gas, is subjected to inductively coupled plasma mass spectrometry analysis in the analysis unit 36 ​​to determine the elemental composition of the defect 51.

[0047] As described above, when analyzing defect 51 using the mapping information shown in FIG3 measured by the surface defect measuring device 70 (see FIG1), it is not necessary to measure the surface defects of the surface defect measuring unit 20 and the semiconductor substrate 50. Alternatively, the analysis device 10 may be configured without the surface defect measuring device 70 shown in FIG1. Furthermore, the location information of the defects 51 on the surface 50a of the semiconductor substrate 50 supplied to the storage unit 29 is not particularly limited to those measured by the surface defect measuring device 70 (see Figure 1). The surface defect measuring device 70 may, for example, have a storage unit (not shown) for storing location information. Also, the surface defect measuring device 70 may have the same configuration as the surface defect measuring unit 20 (see Figure 1). Therefore, the surface defect measuring device 70 may, for example, have an incident portion 23 that allows incident light Ls to be incident on the surface 50a of the semiconductor substrate 50 and a light receiving portion 26 that receives the emitted light emitted by the incident light Ls due to reflection or scattering by the defects 51 on the surface 50a of the semiconductor substrate 50.

[0048] [Example of an analytical apparatus] Figure 5 is a schematic diagram showing a second example of an analytical apparatus according to an embodiment of the present invention. Furthermore, in Figure 5, components identical to those in the analytical apparatus 10 shown in Figure 1 are labeled with the same symbols, and their detailed descriptions are omitted. Compared to the analysis apparatus 10 shown in FIG1, the analysis apparatus 10a shown in FIG5 is different in that it does not have a second transport chamber 12c and a transport device 16; the surface defect measuring unit 20 and the analysis unit 30 are arranged in a processing chamber 12e, and the other configuration is the same as that of the analysis apparatus 10 shown in FIG1.

[0049] In the analysis apparatus 10a, surface defect measurement and analysis are performed with the semiconductor substrate 50 entirely housed within the container section 33. In the analysis unit 30, the light source unit 34 is configured such that the optical axis of the laser light La is tilted relative to the surface 50a of the semiconductor substrate 50. In the analysis apparatus 10a, by placing the surface defect measuring unit 20 and the analysis unit 30 in a processing chamber 12e, the apparatus can be miniaturized compared to the analysis apparatus 10 shown in FIG1. Furthermore, by configuring the semiconductor substrate 50 to be housed entirely within the container section 33, the measurement of surface defects based on the surface defect measurement section 20 and the inductively coupled plasma mass spectrometry analysis based on the analysis section 30 are performed. This reduces the transport of the semiconductor substrate 50, further suppressing contamination of the surface 50a of the semiconductor substrate 50. Consequently, the accuracy of surface defect measurement of the semiconductor substrate 50a can be further improved, and contamination within the processing chamber 12e of the analysis apparatus 10a can be further suppressed.

[0050] [Example of an analytical method] The second example of the analysis method is basically the same as the first example of the analysis method described above. The difference between the second example and the first example of the analysis method is that the surface defect measurement based on the surface defect measurement unit 20 is performed while the semiconductor substrate 50 is completely housed in the container 33; after the surface defect measurement, the semiconductor substrate 50 with the measured surface defects is not transported from the measurement chamber 12b (see Figure 1) to the analysis chamber 12d (see Figure 1) using the transport device 16 (see Figure 1). Other than this, the steps are the same as the first example of the analysis method. In the second example of the analysis method, by performing the surface defect measurement based on the surface defect measurement unit 20 and the inductively coupled plasma mass spectrometry analysis based on the analysis unit 30 while the semiconductor substrate 50 is completely housed in the container unit 33, it is possible to further suppress contamination on the surface 50a of the semiconductor substrate 50 and suppress contamination in the processing chamber 12e of the analysis device 10a. Furthermore, as described above, by performing surface defect measurement based on the surface defect measurement unit 20 and inductively coupled plasma mass spectrometry analysis based on the analysis unit 30 while the semiconductor substrate 50 is entirely housed within the container section 33, the semiconductor substrate 50 does not need to be transported between steps, thus shortening the analysis time compared to the first example of the analysis method. Moreover, as described above, contamination of the surface 50a of the semiconductor substrate 50 can be further suppressed.

[0051] Furthermore, in the analysis apparatus 10a, similarly to the analysis apparatus 10, it is also possible to use another device different from the analysis apparatus 10a, such as the surface defect measuring device 70 (see Figure 5), to measure the defects 51 on the surface 50a of the semiconductor substrate 50, and obtain the mapping information shown in Figure 3. In this case, the mapping information acquired by the surface defect measuring device 70 is supplied to the storage unit 29. Then, the semiconductor substrate 50 on which the defects 51 on the surface 50a have been measured in the surface defect measuring device 70 is, for example, stored in the storage container 13 and transported to the analysis apparatus 10a. In the analysis apparatus 10a, based on the mapping information, as described above, in the processing chamber 12e, the analysis unit 30 performs inductively coupled plasma mass spectrometry analysis on the analysis sample 51a from the defect 51 in the analysis unit 36d to determine the elements of the defect 51. In this case, when using the mapping information measured by the surface defect measuring device 70 (see Figure 5), it is not necessary to measure the surface defects of the surface defect measuring unit 20 and the semiconductor substrate 50. Furthermore, in the analysis device 10a, similar to the analysis device 10, it is also possible to have a configuration without the surface defect measuring device 70 shown in Figure 5. Also, the location information of the defects 51 on the surface 50a of the semiconductor substrate 50 supplied to the storage unit 29 is not particularly limited to those measured by the surface defect measuring device 70 (see Figure 5).

[0052] [The third example of an analytical device] As described above, when using mapping information measured by a device other than the analysis device, such as the surface defect measuring device 70, the analysis device does not necessarily need a surface defect measuring unit, and the analysis device can be configured without a surface defect measuring unit. In this case, the analysis device becomes a configuration that only has the analysis unit 30 (see Figure 1). Figure 6 is a schematic diagram showing a third example of an analytical apparatus according to an embodiment of the present invention. Furthermore, in Figure 6, components identical to those in the analytical apparatus 10 shown in Figure 1 and the analytical apparatus 10a shown in Figure 5 are labeled with the same reference numerals, and their detailed descriptions are omitted. Compared to the analytical apparatus 10 shown in FIG. 1, the analytical apparatus 10b shown in FIG. 6 is configured without the first transport chamber 12a, transport device 14, measuring chamber 12b, surface defect measuring unit 20, second transport chamber 12c, and transport device 16. Furthermore, the analytical apparatus 10b incorporates the analytical unit 30 (see FIG. 1) as a mass spectrometry analytical apparatus 72, and includes both the aforementioned surface defect measuring device 70 and the mass spectrometry analytical apparatus 72. The mass spectrometry analytical apparatus 72 has the same configuration as the analytical unit 30 (see FIG. 1), therefore a detailed description of the mass spectrometry analytical apparatus 72 is omitted.

[0053] In the analysis apparatus 10b, the surface defect measuring device 70 and the mass spectrometry analysis device 72 are independent devices, not integrated. In this case, the mapping information acquired by the surface defect measuring device 70 is supplied to the storage unit 29. Furthermore, the semiconductor substrate 50, on which the surface defect 51 of the surface 50a has been measured in the surface defect measuring device 70, is stored, for example, in the storage container 13 and transported to the mass spectrometry analysis device 72. The semiconductor substrate 50 is transported to the analysis chamber 12d via the first transport chamber 12a. Next, in the mass spectrometry analysis apparatus 72, the control unit 42 reads the mapping information from the storage unit 29. Based on the mapping information, in the analysis chamber 12d, as described above, in the analysis unit 36d, inductively coupled plasma mass spectrometry analysis is performed on the analysis sample 51a from the defect 51 to determine the element of the defect 51. Furthermore, the position information of the defect 51 on the surface 50a of the semiconductor substrate 50 supplied to the storage unit 29 can also be obtained using position information other than that measured by the surface defect measuring apparatus 70 (see Figure 6).

[0054] The analytical apparatus 10, the analytical section 30 of analytical apparatus 10a, and the mass spectrometry analytical apparatus 72 of analytical apparatus 10b are not limited to the configuration of the analytical section 30. Here, FIG7 is a schematic diagram showing a modified example of the analytical section of the analytical apparatus according to an embodiment of the present invention. In addition, in FIG7, the same reference numerals are used to mark the same components as those in the analytical apparatus 10 shown in FIG1, and their detailed descriptions are omitted. As shown in Figure 7, the analysis unit 30 may be provided with an imaging unit 60 for observing the surface 50a of the semiconductor substrate 50 and a display unit 62 for displaying the image obtained by the imaging unit 60. Using the camera unit 60, it is possible to observe the location of the laser light La irradiation on the surface 50a of the semiconductor substrate 50, i.e., the location of the defect 51. Examples of camera units 60 include CCD (Charge Coupled Device) sensors and CMOS (Complementary Metal Oxide Semiconductor) sensors. Examples of display units 62 include liquid crystal displays and organic EL (Electro Luminescence) displays. The light source unit 34 and the camera unit 60 are configured, for example, to have their optical axes (not shown) orthogonal. The camera unit 60 is configured to face the surface 50a of the semiconductor substrate 50. A semi-reflective mirror 64 is disposed at the intersection of the optical axis of the light source unit 34 and the optical axis of the imaging unit 60. The laser light La emitted from the light source unit 34 is reflected by the semi-reflective mirror 64 and then irradiates the surface 50a of the semiconductor substrate 50 through the condenser lens 35.

[0055] (Semiconductor substrate) Semiconductor substrates are not particularly limited and can be various types of semiconductor substrates, such as silicon (Si) substrates, sapphire substrates, SiC substrates, GaP substrates, GaAs substrates, InP substrates, or GaN substrates. Silicon semiconductor substrates are frequently used as semiconductor substrates.

[0056] The present invention is essentially constructed as described above. The analytical apparatus and analytical method of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Various modifications or alterations can be made without departing from the spirit of the present invention. [Example]

[0057] The present invention will now be described in further detail with reference to embodiments. The materials, amounts, proportions, processing contents, and processing steps shown in the following embodiments can be appropriately modified without departing from the spirit of the invention. Therefore, the scope of the present invention should not be limited by the embodiments shown below. Hereinafter, Examples 1 to 29 and Comparative Examples 1 to 3 will be described.

[0058] (Examples 1-20) In this embodiment, a dispersion containing Fe nanoparticles of 10-20 nm in size was prepared. The dispersion was diluted and adjusted on a 300 mm diameter silicon substrate to a particle size of approximately 1 particle / cm². The adjusted dispersion was then applied to the 300 mm diameter silicon substrate using an electrostatic spraying device. The silicon substrate coated with the dispersion liquid is placed in a storage container that can hold the entire silicon substrate and transported to the surface defect measurement unit. The surface defect measurement unit uses a surface inspection device (SurfScan SP5; manufactured by KLA Corporation). In the surface inspection device, laser light is incident on the surface of a silicon substrate, and the scattered light is measured. This allows the determination of the location and size of defects on the silicon substrate, obtaining defect location information and defect size information, which are then stored in a storage unit. Next, the silicon substrate for which surface defects have been measured is transported to the analysis unit. The analysis unit uses a laser ablation ICP-MS (LA-ICP-MS) instrument. Furthermore, when transporting the silicon substrate from the surface defect measurement unit to the analysis unit, the silicon substrate is transported in a state of isolation from external air. For those using the aforementioned storage container, the silicon substrate is always kept isolated from external air whenever it is transported.

[0059] Based on the obtained defect location and size information, elemental analysis of the defects based on laser ablation was performed using a laser ablation ICP mass spectrometry analysis device, and it was confirmed that Fe could be detected at the predetermined location of laser ablation. Laser ablation was performed with the silicon substrate housed within a container and a carrier gas supplied. The analytical samples obtained by laser ablation were recovered using the carrier gas and analyzed by inductively coupled plasma mass spectrometry. A femtosecond laser was used in the laser ablation. Subsequently, the contamination status of the silicon substrate was confirmed again in the surface defect measurement section, that is, whether the silicon substrate was contaminated and whether defects were etched during the analysis. In addition, the moisture concentration in the carrier gas is shown in Tables 1 and 2 below. Argon was used as the carrier gas. The flow rate of the carrier gas was set to 1.69 × 10⁻² Pa·m³ / sec (10 sccm). Furthermore, in Examples 1-14, the container was cleaned by rinsing with a carrier gas before performing elemental analysis based on defects from laser ablation. In Examples 15-20, the container was not cleaned by rinsing with a carrier gas.

[0060] (Examples 21-29) Compared to Example 1, Examples 21-26 are the same as Example 1 except that the silicon substrate is transported without using a storage container for the semiconductor substrate. In Examples 21-26, the silicon substrate is transported from the surface defect measurement unit to the analysis unit while exposed to the outside air. Compared to Example 1, Examples 27-29 are the same as Example 1 except that the silicon substrate is transported without using a container for storing the semiconductor substrate and the cleaning of the container section using a carrier gas is not performed. In Examples 27-29, the silicon substrate is transported in a state of being exposed to the outside air when transporting it from the surface defect measurement section to the analysis section.

[0061] The storage container for the semiconductor substrate uses a FOUP (Front Opening Unified Pod). When a storage container is used, it is marked "Yes" in the semiconductor substrate storage container column of Tables 1 and 2 below. On the other hand, when a storage container is not used, it is marked "No" in the semiconductor substrate storage container column of Tables 1 and 2 below.

[0062] (Comparative Examples 1-3) In Comparative Examples 1 to 3, a surface inspection device (SurfScan SP5; manufactured by KLA Corporation) was used to incident a laser onto the surface of a silicon substrate and measure the scattered light, thereby determining the location and size of defects on the silicon substrate, obtaining defect location information and defect size information, and storing them in the storage unit. Next, based on the obtained defect location and size information, qualitative elemental analysis of the defects on the silicon substrate was attempted using a defect analysis apparatus (SEMVision G6 (manufactured by Applied Materials, Inc.)). In the qualitative elemental analysis of the defects on the silicon substrate in Comparative Examples 1-3, SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) was utilized. In Comparative Examples 1 to 3, as described above, SEM-EDS was used for qualitative elemental analysis of defects on the silicon substrate. SEM-EDS is performed using an electron beam under vacuum, therefore no carrier gas is used. Therefore, for Comparative Examples 1 to 3, the "Moisture content of carrier gas" column in Table 2 below is recorded as "-". In Comparative Examples 1 to 3, there was no container section, so the "Cleaning steps for the container section" column in Table 2 below is recorded as "-".

[0063] [Table 1] Semiconductor substrate Storage containers Before analysis Semiconductor substrate Surface defects (unit / substrate) carrier gas type Container Department Washing steps carrier gas Moisture content (volume ppm) element Detection After analysis Semiconductor substrate Surface defects (unit / substrate) Example 1 have 695 Ar have 0.1 Can 14 Example 2 have 707 Ar have 0.01 Can 9 Example 3 have 658 Ar have 0.001 Can 13 Example 4 have 679 He have 0.1 Can 20 Example 5 have 750 He have 0.01 Can 11 Example 6 have 773 He have 0.001 Can 15 Example 7 have 787 Ar have 1000 Can 151 Example 8 have 549 Ar have 100 Can 109 Example 9 have 659 Ar have 10 Can 94 Example 10 have 788 Ar have 0.000005 Can 99 Example 11 have 639 He have 1000 Can 168 Example 12 have 731 He have 100 Can 138 Example 13 have 745 He have 10 Can 108 Example 14 have 744 He have 0.000005 Can 113 Example 15 have 695 Ar none 0.1 Can 56 Example 16 have 707 Ar none 0.01 Can 35

[0064] [Table 2] Semiconductor substrate Storage containers Before analysis Semiconductor substrate Surface defects (unit / substrate) carrier gas type Container Department Washing steps carrier gas Moisture content (volume ppm) element Detection After analysis Semiconductor substrate Surface defects (unit / substrate) Example 17 have 658 Ar none 0.001 Can 77 Example 18 have 679 He none 0.1 Can 46 Example 19 have 750 He none 0.01 Can 27 Example 20 have 773 He none 0.001 Can 44 Example 21 none 2016 Ar have 0.1 Can 133 Example 22 none 1870 Ar have 0.01 Can 95 Example 23 none 1901 Ar have 0.001 Can 161 Example 24 none 2108 He have 0.1 Can 155 Example 25 none 2060 He have 0.01 Can 75 Example 26 none 1790 He have 0.001 Can 172 Example 27 none 2016 Ar none 0.1 Can 198 Example 28 none 1870 Ar none 0.01 Can 167 Example 29 none 1901 Ar none 0.001 Can 203 Comparative Example 1 have 790 Ar - - No 808 Comparative Example 2 have 635 Ar - - No 655 Comparative Example 3 have 689 Ar - - No 701

[0065] As shown in Tables 1 and 2, in Examples 1 to 29, the target Fe particles were etched away through the analysis steps, and Fe was detected by elemental analysis. In Examples 1-29, the number of defects on the silicon substrate decreased after analysis, and the number of defects on the silicon substrate did not increase, thus confirming that the etching was successfully performed. Furthermore, the number of defects on the silicon substrate after analysis was not zero, which is believed to be due to the inability to reduce contamination during analysis to zero. On the other hand, in Comparative Examples 1 to 3, no laser ablation ICP mass spectrometry analysis device was used, and the sensitivity of elemental analysis by SEM-EDS was insufficient, so qualitative elemental analysis of the defects could not be performed, and Fe could not be detected.

[0066] Furthermore, according to Examples 1-29, it was confirmed that by setting the impurity concentration of the carrier gas to 0.00001 ppm or more and 0.1 ppm or less, contamination of the silicon substrate surface during analysis can be reduced. That is, by adjusting the moisture content of the carrier gas, cleaning can be performed simultaneously with analysis. A comparison of Examples 1-6 with Examples 15-20 confirmed that the contamination of the silicon substrate during analysis was further reduced by incorporating a cleaning step. Based on the comparison of Examples 1-20 and Examples 21-29, it was confirmed that when a storage container for storing semiconductor substrates is used, contamination is less likely to occur in the silicon substrate before analysis.

[0067] 10, 10a, 10b: Analytical apparatus 12a: First transport chamber 12b: Measurement Chamber 12c: Second transport chamber 12d: Analytical Laboratory 12e: Processing Room 12g: Import section 12h: wall 13: Storage Containers 14: Conveying device 14a: Installation Department 15: Conveyor Arm 16: Conveying device 16a: Installation Department 20: Surface Defect Measurement Department 22,32: Stage 23: Entrance section 24: Condensing Lens 25, 26: Light-receiving parts 27: Condensing Lens 28: Arithmetic Department 29: Storage Department 30: Analysis Department 33: Container Department 34: Light Source Section 35: Condensing Lens 36: Analysis Unit 38: Carrier Gas Supply Section 39:Piping 40: Cleaning Gas Supply Department 41:Outflow department 42: Control Department 44: Plasma torch 46: Mass Spectrometry Analysis Department 46a: Ion Lens Section 46b: Mass Spectrometer Section 47: Ion Lens 48: Reflection electric field mass spectrometer 49: Detector 50: Semiconductor substrate 50a: Surface 51: Defect 51a: Analytical Sample 70: Surface Defect Measurement Device 72: Mass spectrometry analysis device C1, C2, C3: Rotation axes H: Direction La: Laser light Ls: Incident light V: Height direction

Claims

1. An analytical apparatus comprising: a surface defect measuring device for measuring the presence or absence of defects on the surface of a semiconductor substrate and obtaining position information of the defects on the surface of the semiconductor substrate; and a mass spectrometry analysis device for irradiating the defects on the surface of the semiconductor substrate with laser light based on the position information of the defects on the surface of the semiconductor substrate obtained by the surface defect measuring device, recovering the analytical sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis, wherein the moisture content of the carrier gas is 0.00001 ppm by volume or more and 0.1 ppm by volume or less, wherein the surface defect measuring device comprises: an incident section for incident light onto the surface of the semiconductor substrate; a light receiving section for receiving emitted light due to reflection or scattering of the incident light by the defects on the surface of the semiconductor substrate; and a focusing lens, wherein the light receiving section comprises: a first light receiving section disposed around the semiconductor substrate; and a second light receiving section disposed above the surface of the semiconductor substrate. The aforementioned focusing lens is disposed between the aforementioned surface of the aforementioned semiconductor substrate and the aforementioned second light-receiving portion.

2. The analysis apparatus as described in claim 1, wherein the aforementioned surface defect measuring apparatus has a storage unit for storing the aforementioned location information.

3. An analytical apparatus comprising: a surface defect measuring unit for measuring the presence or absence of defects on the surface of a semiconductor substrate, and obtaining position information on the surface of the semiconductor substrate regarding the defects; and an analytical unit for irradiating the defects on the surface of the semiconductor substrate with laser light based on the position information of the defects, recovering the analytical sample obtained by irradiation using a carrier gas, and performing inductively coupled plasma mass spectrometry analysis, wherein the moisture content of the carrier gas is 0.00001 ppm by volume or more and 0.1 ppm by volume or less, the surface defect measuring unit comprising: an incident unit for incident light onto the surface of the semiconductor substrate; a light receiving unit for receiving emitted light due to reflection or scattering of the incident light by the defects on the surface of the semiconductor substrate; and a focusing lens, the light receiving unit comprising: a first light receiving unit disposed around the semiconductor substrate; and a second light receiving unit disposed above the surface of the semiconductor substrate. The aforementioned focusing lens is disposed between the aforementioned surface of the aforementioned semiconductor substrate and the aforementioned second light-receiving portion.

4. The analysis apparatus as described in claim 3, wherein the aforementioned surface defect measuring unit has a storage unit for storing the aforementioned location information.

5. The analytical apparatus as described in claim 3 or claim 4, having a container section for receiving the aforementioned semiconductor substrate as the object of measurement, and performing analysis based on the aforementioned semiconductor substrate within the container section.

6. The analytical apparatus as claimed in claim 5, comprising: a cleaning gas supply unit for supplying cleaning gas into the aforementioned container unit; and an outlet unit for allowing the cleaning gas to flow out of the aforementioned container unit.

7. The analytical apparatus as described in claim 3 or claim 4, comprising: an inlet section having a receiving container for receiving the aforementioned semiconductor substrate as the object of measurement; and a conveying device for conveying the aforementioned semiconductor substrate from the inlet section to the aforementioned surface defect measuring section.

8. An analytical method that uses location information of defects on the surface of a semiconductor substrate, wherein the analytical method comprises the following steps: irradiating the defects on the surface of the semiconductor substrate with laser light based on the location information of the defects on the surface of the semiconductor substrate; recovering the analytical sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis, wherein the moisture content of the carrier gas is 0.00001 ppm or more and 0.1 ppm or less.

9. An analytical method comprising the following steps: determining the presence or absence of defects on the surface of a semiconductor substrate; obtaining position information on the surface of the semiconductor substrate regarding the defects on the aforementioned surface of the semiconductor substrate; irradiating the aforementioned defects on the aforementioned surface of the semiconductor substrate with laser light based on the position information of the aforementioned defects on the aforementioned surface of the semiconductor substrate; recovering the analytical sample obtained by irradiation using a carrier gas and performing inductively coupled plasma mass spectrometry analysis, wherein the moisture content of the aforementioned carrier gas is 0.00001 ppm by volume or more and 0.1 ppm by volume or less.

10. The analytical method as described in claim 8 or claim 9, wherein the aforementioned analytical step is performed in a container housing the aforementioned semiconductor substrate as the object of measurement, and prior to the aforementioned analytical step, a step of cleaning the aforementioned container housing with a cleaning gas is provided.

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