JP4948009B2 - Semiconductor device manufacturing method and semiconductor device film forming apparatus - Google Patents

Description

  The present invention is a semiconductor device manufacturing using an X-ray analysis method such as a fluorescent X-ray film thickness measurement method (XRF method), an X-ray reflectance measurement method (XRR method) or an X-ray diffraction measurement method (XRD method). The present invention relates to a method and a film forming apparatus.

  In recent years, in the manufacturing process of semiconductor devices, it is required to measure the film thickness of a thin film formed on a substrate by various vapor deposition methods, plating, or the like for quality control or research and development. As a film thickness measuring method, there are a destructive type and a non-destructive type. As the non-destructive type, for example, a fluorescent X-ray method, a β-ray method, an eddy current method and the like are known. .

  As a nondestructive film thickness measurement method, a film thickness measurement method using fluorescent X-rays (XRF method) has many advantages such as accuracy and ease of operation, and is regarded as a representative one (for example, Japanese Patent Application Laid-Open No. 10-101). No.-221047: refer to Patent Document 1).

  This fluorescent X-ray method is based on the principle that a certain area of a metal film sample is irradiated with X-rays, and the intensity of the generated fluorescent X-ray is proportional to the thickness of the metal film. Using a standard thickness plate with a known thickness, the relationship between the thickness and the intensity of fluorescent X-rays is stored as a calibration curve, and by the intensity and calibration curve of fluorescent X-rays obtained from a sample of unknown thickness, The film thickness was measured.

  The fluorescent X-ray film thickness measurement method is effective when the film thickness is in the range of several nm to several μm. However, as a method that does not require a standard thin film, X-rays are irradiated to a certain area of a thin film sample, An X-ray reflectivity measurement method (XRR method) that can measure the film type classification, film thickness value, etc. of the book film from the surface reflection intensity of the wire is known.

  Furthermore, X-rays that can irradiate X-rays to a certain area of the film sample and read the crystallinity, surface index, etc. of the target substance using X-ray diffracted light generated by the arrangement of atoms of the substance. A diffraction measurement method (XRD method) is also frequently used.

  Thin film analysis by three methods, fluorescent X-ray film thickness measurement method (XRF method), X-ray reflectivity measurement method (XRR method), and X-ray diffraction measurement method (XRD method), each device is divided separately. In order to analyze and analyze film characteristics such as film type classification, film quality, film thickness, and crystallinity using the same sample, it takes a lot of labor on the analysis side. In addition, depending on these measurement methods, there are restriction categories for the film type and the measurement film thickness range, and this also results in shaking the reliability of the measurement values.

  These measurement methods have been used mainly for film deposition equipment and device management technology used in the manufacturing process of semiconductor devices, but instead of measuring the device itself on the premise of product shipment, it is a substitute for the device. As described above, the monitor wafer simply formed on the substrate without the circuit pattern is measured, and the film forming apparatus and the device are managed.

  However, this method does not measure the device itself on the premise that the product is shipped, so using the results from the monitor wafer as device manufacturing management means that regular monitoring work is added to the manufacturing process. This will lead to a decrease in the operating rate of the film forming apparatus and an increase in costs (personnel costs and material costs) associated with the monitoring work. Further, when feeding back these monitoring results to the film forming apparatus, real-time feedback is impossible, and there is a time loss in detecting an abnormality in the film forming apparatus, resulting in outflow of defective devices.

  Further, in the X-ray measurement apparatus disclosed in Patent Document 1, the film thickness measurement method (XRF method) using fluorescent X-rays is applicable to thin film measurement of film thickness in a wide range. The measurement range of the film thickness is expanded in the upper limit direction (3 μm or more) than that of the usual fluorescent X-ray film thickness measurement method (XRF method), and the semiconductor layer is not expanded in the lower limit direction. It is difficult to measure the thin film device itself required in the first half manufacturing process of an integrated circuit or the like.

  Moreover, the X-ray irradiation spot diameter to a board | substrate thin film is 10 mm, When a device measurement is made object, X-rays cannot be irradiated only to a specific area, but the X-ray measurement result only of the specific area can be acquired. This is not possible, and X-ray irradiation is performed in a wide area, resulting in including unnecessary information other than the specific area.

  Furthermore, due to the characteristics of this X-ray measurement device, the pattern recognition function for the device substrate is not installed, and it is impossible to automatically move the X-ray irradiation to a specific area on the substrate for accurate alignment. is there.

Considering these performances, the operation method in the X-ray measurement apparatus disclosed in Patent Document 1 is a measurement for the monitoring substrate only, and the device itself can be measured on the premise of product shipment. First, device management is performed on the monitor wafer.
Japanese Patent Laid-Open No. 10-221047

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device manufacturing method and a film forming apparatus in which the characteristics of the film of the semiconductor device are measured in-line, and a periodic monitoring operation is unnecessary.

In order to solve the above problems, a method for manufacturing a semiconductor device of the present invention includes:
A film forming step of stacking a plurality of films on a substrate;
A pattern formed on the substrate and indicating a position of the specific area on the substrate is recognized as an image, and a position of the specific area is obtained based on the pattern. After moving the X-ray spot to the area, X-rays are irradiated with a spot diameter of 1 μm or more to 50 μm or less on the plurality of films only in this specific area, and the X-ray reflectivity measurement is performed. A measurement process for measuring characteristics;
A management step of managing the film formation state of the plurality of films in the film formation step based on the characteristics of each film ,
Upper Symbol specific area is characterized by being formed into a flat dicing portion of the substrate.

  According to the semiconductor device manufacturing method of the present invention, in the measurement step, a pattern formed on the substrate and indicating a specific area on the substrate is recognized, and X-rays are applied to the plurality of films only in the specific area. Irradiation is performed with a spot diameter of 100 μm or less, and the characteristics of each film are measured by X-ray reflectivity measurement. Therefore, the characteristics of the film of the semiconductor device can be measured inline. Therefore, the quality of each semiconductor device can be improved.

Further, since the film forming states of the plurality of films in the film forming process are managed based on the characteristics of each film measured in-line, the management accuracy is improved. At the same time, periodic monitoring work is not required, so that the productivity of the semiconductor device is improved, and the personnel cost and material cost required for the periodic monitoring are also unnecessary, so that the cost can be greatly reduced.
Further, since the spot diameter of the X-ray is 1 μm or more and 50 μm or less, the X-ray can be reliably irradiated, for example, only to the dicing portion of the substrate. Therefore, the flat X-ray dicing part can be irradiated to obtain a strong reflection signal from the dicing part, and the film characteristics can be reliably measured.
Further, since the specific area is formed in the dicing portion of the substrate, the flat X-ray dicing portion can be irradiated to obtain a strong reflected signal from the dicing portion, The characteristics can be measured reliably.

  In one embodiment of the semiconductor device manufacturing method, the film characteristics include at least one of film type classification, film thickness, film density, roughness state, and crystallinity.

  According to the semiconductor device manufacturing method of this embodiment, the characteristics of the film include at least one of film type classification, film thickness, film density, roughness state, and crystallinity. At least one characteristic can be measured.

  In one embodiment of the semiconductor device manufacturing method, the management step includes controlling film formation conditions of the film in the film formation step based on characteristics of the film.

  According to the semiconductor device manufacturing method of this embodiment, the management step includes controlling the film formation conditions of the film in the film formation step based on the characteristics of the film. The measurement can be fed back to the film forming process in real time, and the accuracy of the manufacturing process can be further improved by automatic correction or the like.

In addition, the manufacturing method of the semiconductor device of the present invention,
A film forming step of forming at least one film on the substrate and performing an annealing process;
A pattern formed on the substrate and indicating a position of the specific area on the substrate is recognized as an image, and a position of the specific area is obtained based on the pattern. After moving the X-ray spot to the area, the film of this specific area is irradiated with X-rays with a spot diameter of 1 μm to 50 μm and the crystallinity of the film is measured by X-ray diffraction measurement. Measuring process to
A management step of managing the annealing state of the film in the film formation step based on the crystallinity of the film ,
Upper Symbol specific area is characterized by being formed into a flat dicing portion of the substrate.

  According to the method for manufacturing a semiconductor device of the present invention, in the measurement step, a pattern formed on the substrate and indicating a specific area on the substrate is recognized, and X-rays of 100 μm or less are applied to the film only in the specific area. Since the crystallinity of the film is measured by X-ray diffraction measurement, the crystallinity of the film of the semiconductor device can be measured in-line. Therefore, the quality of each semiconductor device can be improved.

Further, since the annealing state of the film in the film forming process is managed based on the crystallinity of the film measured in-line, the management accuracy is improved. At the same time, periodic monitoring work is not required, so that the productivity of the semiconductor device is improved, and the personnel cost and material cost required for the periodic monitoring are also unnecessary, so that the cost can be greatly reduced.
Further, since the spot diameter of the X-ray is 1 μm or more and 50 μm or less, the X-ray can be reliably irradiated, for example, only to the dicing portion of the substrate. Therefore, the flat X-ray dicing part can be irradiated to obtain a strong reflection signal from the dicing part, and the film characteristics can be reliably measured.
Further, since the specific area is formed in the dicing portion of the substrate, the flat X-ray dicing portion can be irradiated to obtain a strong reflected signal from the dicing portion, The characteristics can be measured reliably.

In addition, the manufacturing method of the semiconductor device of the present invention,
A film forming step of forming at least one film on the substrate;
A pattern formed on the substrate and indicating a position of the specific area on the substrate is recognized as an image, and a position of the specific area is obtained based on the pattern. After moving the X-ray spot to the area, the film of only this specific area is irradiated with X-rays with a spot diameter of 1 μm or more to 50 μm or less , and the amount of warpage of the substrate is determined by measuring the X-ray reflectivity. Measuring process to measure,
A management step of managing the film formation state of the film in the film formation step based on the amount of warpage of the substrate ,
Upper Symbol specific area is characterized by being formed into a flat dicing portion of the substrate.

  According to the method for manufacturing a semiconductor device of the present invention, in the measurement step, a pattern formed on the substrate and indicating a specific area on the substrate is recognized, and X-rays of 100 μm or less are applied to the film only in the specific area. Since the amount of warpage of the substrate is measured by X-ray reflectivity measurement, the amount of warpage of the substrate of the semiconductor device can be measured in-line. Therefore, the quality of each semiconductor device can be improved.

Further, since the film forming state of the film in the film forming process is managed based on the amount of warpage of the substrate measured in-line, the management accuracy is improved. At the same time, periodic monitoring work is not required, so that the productivity of the semiconductor device is improved, and the personnel cost and material cost required for the periodic monitoring are also unnecessary, so that the cost can be greatly reduced.
Further, since the spot diameter of the X-ray is 1 μm or more and 50 μm or less, the X-ray can be reliably irradiated, for example, only to the dicing portion of the substrate. Therefore, the flat X-ray dicing part can be irradiated to obtain a strong reflection signal from the dicing part, and the film characteristics can be reliably measured.
Further, since the specific area is formed in the dicing portion of the substrate, the flat X-ray dicing portion can be irradiated to obtain a strong reflected signal from the dicing portion, The characteristics can be measured reliably.

In addition, the semiconductor device deposition apparatus of the present invention is
A film forming unit for forming at least one film on the substrate;
The above-mentioned specification that has at least one measurement function of a fluorescent X-ray film thickness measurement function, an X-ray reflectivity measurement function, and an X-ray diffraction measurement function and that indicates the position of a specific area on the substrate that is formed on the substrate A pattern provided at a position different from the area is recognized as an image, the position of the specific area is obtained based on the pattern, an X-ray spot is moved to the specific area, and then only the specific area is A measurement unit that irradiates the film with X-rays with a spot diameter of 1 μm or more and 50 μm or less , and measures the characteristics of the film by the at least one measurement function ;
Upper Symbol specific area is characterized by being formed into a flat dicing portion of the substrate.

  According to the film forming apparatus for a semiconductor device of the present invention, a pattern formed on the substrate and indicating a specific area on the substrate is recognized, and X-rays with a spot diameter of 100 μm or less are applied to the film only on the specific area. Since the measurement unit that irradiates and measures the characteristics of the film by the at least one measurement function is provided, the characteristics of the film of the semiconductor device can be measured in-line. Therefore, the quality of each semiconductor device can be improved.

In addition, since the characteristics of the film can be measured in-line, periodic monitoring work is no longer necessary, and the productivity of semiconductor devices is improved, and the personnel costs and material costs required for periodic monitoring are also eliminated. Cost can be greatly reduced.
Further, since the spot diameter of the X-ray is 1 μm or more and 50 μm or less, the X-ray can be reliably irradiated, for example, only to the dicing portion of the substrate. Therefore, the flat X-ray dicing part can be irradiated to obtain a strong reflection signal from the dicing part, and the film characteristics can be reliably measured.
Further, since the specific area is formed in the dicing portion of the substrate, the flat X-ray dicing portion can be irradiated to obtain a strong reflected signal from the dicing portion, The characteristics can be measured reliably.

  The semiconductor device deposition apparatus according to an embodiment includes a control unit that controls the deposition unit based on the characteristics of the film.

  According to the semiconductor device film forming apparatus of this embodiment, since the control unit that controls the film forming unit based on the characteristics of the film is provided, the measurement of the film characteristics is performed in real time on the film forming unit. Feedback can be provided and the accuracy of the manufacturing process can be further improved by automatic correction or the like.

  In one embodiment of the semiconductor device deposition apparatus, the measurement unit has all the measurement functions of the fluorescent X-ray film thickness measurement function, the X-ray reflectivity measurement function, and the X-ray diffraction measurement function. Have.

  According to the semiconductor device deposition apparatus of this embodiment, the measurement unit has all the measurement functions of the fluorescent X-ray film thickness measurement function, the X-ray reflectivity measurement function, and the X-ray diffraction measurement function. Therefore, even if the film to be measured is any one of a single layer metal film, a multilayer metal film, a single layer insulating film, and a multilayer insulating film, the film can be measured in a flexible manner.

In the semiconductor device deposition apparatus of one embodiment,
A cassette section for storing the substrate;
A transport unit that transports the substrate from the cassette unit to the film forming unit and transports the substrate formed by the film forming unit to the measurement unit.

  According to the semiconductor device film forming apparatus of this embodiment, since the cassette unit and the transfer unit are provided, it is possible to prevent foreign substances and the like from adhering to the substrate when the substrate is transferred. Moreover, since the said conveyance part is provided, the conveyance distance between the said film-forming part and the said measurement part can be shortened, and process time also becomes short.

  According to the method for manufacturing a semiconductor device of the present invention, in the measurement step, a pattern formed on the substrate and indicating a specific area on the substrate is recognized, and X-rays of 100 μm or less are applied to the film only in the specific area. Irradiate with the spot diameter of the above, and measure the characteristics of the film by X-ray reflectivity measurement and X-ray diffraction measurement, so the film characteristics of the semiconductor device is measured in-line, eliminating the need for regular monitoring work Can be.

  According to the film forming apparatus for a semiconductor device of the present invention, a pattern formed on the substrate and indicating a specific area on the substrate is recognized, and X-rays with a spot diameter of 100 μm or less are applied to the film only on the specific area. Irradiation and the measurement unit for measuring the characteristics of the film by the at least one measurement function are provided, so that the characteristics of the film of the semiconductor device can be measured in-line, and periodic monitoring work can be eliminated.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a simplified perspective view showing an embodiment of an X-ray measuring apparatus used in the method for manufacturing a semiconductor device of the present invention. This X-ray measuring apparatus 10 has a stage mechanism 2, an X-ray irradiation optical system 3, an imaging unit 4, an X-ray detector 5, and a fluorescent X-ray detector 6 in a clean atmosphere surrounded by virtual lines. .

  The stage mechanism 2 places a substrate (wafer) 1 thereon. The X-ray irradiation optical system 3 has an X-ray microspot irradiation function. The imaging unit 4 is a CCD or the like, for example, and has a function of recognizing a specific device pattern for X-ray measurement. The X-ray detector 5 has an X-ray reflectivity measurement (XRR) function and an X-ray diffraction measurement (XRD) function. The fluorescent X-ray detector 6 has a fluorescent X-ray film thickness measurement (XRF) function.

  The stage mechanism 2 moves the substrate 1 in the horizontal plane around the Z axis (not shown), a Z axis rotating stage (not shown), an XY stage 22 (shown in FIG. 2), and a Z direction. And a Z stage 23 (shown in FIG. 2).

  Next, the X-ray measurement apparatus 10 will be described more specifically.

  As shown in the simplified configuration diagram of FIG. 2, the stage mechanism 2 includes a sample stage 21 on which the substrate 1 is placed, an XY stage 22 and a Z that move the sample stage 21 with respect to the base 25 in the XY directions. It has a Z stage 23 that moves in the direction.

  The stage mechanism 2 further rotates a Z-axis rotation stage (not shown) that rotates around the Z-axis of the surface of the substrate 1 and an X-axis that rotates around the X-axis of the surface of the substrate 1 (not shown). A rotation stage and a Y-axis rotation stage 24 that rotates around the Y-axis of the surface of the substrate 1 are provided. The Z-axis rotation stage, the X-axis rotation stage, and the Y-axis rotation stage 24 are not essential components.

  The X-ray irradiation optical system 3 includes an X-ray tube 31 that emits primary X-rays B1, a condensing element 32 that converges the primary X-rays B1 of the X-ray tube 31 on the surface of the substrate 1, and the above And a shutter 34 that prevents the circuit pattern portion of the substrate 1 from being irradiated with the primary X-rays B1.

  The X-ray tube 31 has a point-shaped primary X-ray source 31a, and the effective focal spot size (the width expected from the light collecting element 32) is a point-like focal point on the target of the X-ray tube 31. The range is from 1 μm to 100 μm (preferably from 1 μm to 50 μm).

  The condensing element 32 is disposed in an X-ray path between the X-ray tube 31 and the substrate 1, and an irradiation region of the primary X-ray B 1 has a width of 1 μm to 100 μm (preferably from 1 μm or more). (50 μm or less).

  The condensing element 32 is, for example, a mirror or a spectroscopic element, and the reflecting surface 32a of the condensing element 32 is an elliptic cylinder surface or a cylindrical surface as an approximation thereof.

  When the condensing element 32 is a mirror and the incident angle of the X-ray from the X-ray source 31a is very shallow and the reflection at the reflecting surface 32a is totally reflected, the reflecting surface 32a has an elliptical shape. A spherical surface can be used as an approximation of the column surface. Of course, a two-dimensional light collecting element can be used as the light collecting element 32.

  Thus, the beam width W (width of the linear irradiation region) of the primary X-ray B1 from the X-ray source 31a through the condensing element 32 is the focal position, that is, the dicing portion 1b of the substrate 1. Is converged to a width of the effective focal size of the X-ray source 31a. Furthermore, the light condensing element 32 may be configured so that high-resolution measurement can be performed by using a confocal multilayer mirror to change the X-ray emitted from the X-ray source 31a to a single wavelength.

  The shutter 34 is configured to be movable back and forth in the X-ray optical path from the X-ray source 31a, that is, openable and closable. The opening and closing of the shutter 34 is controlled by the control unit 70, and when the dicing unit 1b of the substrate 1 is moved to the measurement position where the primary X-ray B1 is irradiated and the substrate 1 is measured. Only the shutter 34 is opened. Of course, if used for one-chip measurement, the shutter 34 is opened only when the measurement is performed after moving to this chip.

  Although it is conceivable to turn the X-ray tube 31 on and off instead of providing the shutter 34, the primary X-ray B1 becomes unstable each time it rises. preferable. The shutter 34 may be provided between the light condensing element 32 and the substrate 1.

  The X-ray detector 5 having an X-ray reflectivity measurement (XRR) function and an X-ray diffraction measurement (XRD) function includes a light receiving slit 52 and a detection unit 51. The detection unit 51 is, for example, an avalanche photodiode (APD). The X-ray detector 5 is attached to a detector turntable (not shown) that rotates around the rotation axis of the Y-axis rotation stage 24 (having a goniometer).

  The fluorescent X-ray detector 6 having a fluorescent X-ray film thickness measurement (XRF) function includes a detector 61 and a goniometer (not shown).

  Next, a method for measuring the device thin film formed on the dicing portion 1b on the device substrate (wafer) 1 by X-ray reflectivity measurement (XRR) will be described.

  The X-ray B1 is incident on the surface of the substrate 1 at a small incident angle θ, and the X-ray B2 reflected on the surface of the substrate 1 is received at the emission angle θ relative to the surface of the substrate 1. The detection unit (APD) 51 detects through the slit 52. Hereinafter, the light receiving slit 52 and the detecting unit 51 are collectively referred to as a light receiving system.

  The angle formed by the reflected X-ray B2 with respect to the incident X-ray B1 is the scattering angle 2θ. In order to scan the scattering angle 2θ, the X-ray irradiation optical system 3 is rotated clockwise around the center of the goniometer by θ and the light receiving system is moved to the goniometer by a detector turntable (not shown). Rotate θ counterclockwise around the center.

  By the way, the substrate 1 is placed on the sample stage 21 with its center aligned. The imaging unit 4 captures the substrate 1 and obtains an image of the substrate 1. The obtained image is subjected to image processing by the sample recognition unit 71, and the dicing unit 1b between the LSI chips of the substrate 1 is recognized as two-dimensional image data on the XY coordinates. It is also possible to recognize a specific device circuit pattern. Further, the control unit 70 obtains the height data of the substrate 1 measured by the height measuring unit 12.

  Next, the control unit 70 controls the stage mechanism 2 based on the two-dimensional image data of the dicing unit 1b of the substrate 1 recognized by the sample recognition unit 71 and the height data of the substrate 1. Then, the sample stage 21 is moved to a position where the surface of the dicing portion 1b of the substrate 1 is irradiated with the primary X-ray B1 in which the X-ray irradiation region is converged to a width of 100 μm or less. Since the width of the dicing portion 1b of the substrate 1 is about 100 μm, only the dicing portion 1b can be irradiated.

  Next, the substrate 1 is set at a predetermined initial parallel position. The initial setting performed here is performed in order to position the surface of the substrate 1 accurately in parallel with the X-ray beam B1. As described above, after the initial parallel position of the substrate 1 is set, the X-ray incident angle = X-ray detection angle = θ = 0 °, and then the angles θ are accurately synchronized with the determined step angle. The shutter 34 is opened to irradiate a monochromatic X-ray beam, and X-rays are detected by the detection unit (APD) 51 at each θ angle position for a predetermined counting time. Count.

  That is, the irradiated monochromatic (single wavelength) X-ray is reflected by the substrate 1 and the reflected X-ray passes through the light receiving slit 52 and is taken into the detection unit (APD) 51 and counted. Is done. By performing this reflection X-ray counting operation at a series of 2θ angular positions, an X-ray reflectivity curve with respect to 2θ can be obtained.

  In FIG. 3, the outline | summary of the measurement location of the device substrate (wafer) 1 by X-ray microspot irradiation is shown. That is, as a result of irradiating, for example, the dicing portion 1b of the first measurement chip 131, the dicing portion of the second measurement chip 132, and the dicing portion of the third measurement chip 133 with the X-ray beam B1, as shown in FIG. It is possible to obtain an X-ray reflectivity curve with respect to 2θ as shown in the measurement data.

  In such X-ray reflectivity measurement (XRR), the phenomenon that X-rays reflected mainly at each interface of the film interfere with each other is observed as described above. By fitting with the computer included in the control unit 70 or the computer of the analysis unit 72, the density, film thickness, and roughness of each layer can be analyzed. Here, fitting refers to correcting a difference between a theoretical calculated value of spectrum intensity and an actually measured intensity for an X-ray spectrum detected when X-ray measurement is performed.

  FIG. 5 shows fitting at the first measurement chip 131, the second measurement chip 132, and the third measurement chip 133. The density of the thin film on the outermost surface can be calculated from the total reflection critical angle, and the density of the other layers can be calculated from the amplitude of the interference fringes.

  The film thickness of each layer can be calculated from the period of vibration. Further, the roughness can be calculated from the attenuation factor of the entire reflectance measurement data and the attenuation of the interference fringe amplitude on the high angle side, as described in, for example, Japanese Patent Application Laid-Open No. 2001-349849.

  Specifically explaining the fitting process, the physical properties of at least one sample are shown for measurement data obtained by X-ray incidence from an angle near the critical angle with respect to the surface of the film sample composed of a single layer film or a multilayer film. The structure of the film sample is determined by fitting simulation calculation data obtained by simulation calculation performed by changing parameters.

  In addition, as a procedure of the fitting process, for example, analysis by the least square method is used, and the reflectance is calculated while changing the parameter value little by little using the factor for obtaining the X-ray reflectance as a parameter (variable). Then, a set of parameters that best fit the measurement data is determined by minimizing the residual sum of squares with the actual reflectance data.

  As described above, according to the X-ray reflectivity measurement (XRR) function, it is possible to measure the film type classification, film thickness, film density, and roughness state of the formed device thin film.

  In addition, according to the X-ray reflectivity measurement (XRR) function, film characteristics of a device thin film (for example, damascene) formed of a plurality of layers can be measured at a time, and as a result, a plurality of efficiently measured plural Based on the film characteristics of the device thin film composed of layers, the film formation state of the device thin film can be managed.

  Examples of the device thin film formed of a plurality of layers formed by sputtering include a five-layer metal film such as TiN / Ti / Al / TiN / Ti from the upper layer. In this case, after sputtering film formation, the entire surface of the device substrate is covered with a five-layer metal film, and only the device pattern recognition function by the imaging unit 4 detects the density of the wafer surface and performs pattern matching. Is difficult.

  Therefore, as shown in FIG. 4A, pattern matching is performed on the image recognition pattern 41 on the pattern chip boundary line (the scrub line 43) near the specific area on the substrate 1, and as shown in FIG. 4B, By performing an offset movement to the X-ray measurement target 42 as a specific area, measurement can be performed at target measurement points (first to third measurement chips 131, 132, 133 in FIG. 3).

  The image recognition pattern 41 is an alignment mark on the scrub line 43 (the dicing portion 1b). The X-ray measurement target 42 is a flat region portion without an alignment mark on the scrub line 43 (the dicing portion 1b).

  Specifically, as shown in FIGS. 2, 4A, and 4B, the imaging unit 4 uses the image recognition pattern 41 in the dicing unit 1b surrounded by the scrub line 43 as the virtual image in FIG. 4A. An image is captured as indicated by the frame of the line, the image recognition pattern 41 is recognized by the sample recognition unit 71, and the position coordinates are provided to the control unit 70.

  The control unit 70 uses the XY stage 22 of the stage mechanism 2 to offset the X-ray microspot on the X-ray measurement target 42 as a specific area with reference to the position coordinates of the image recognition pattern 41 (see FIG. X, Y coordinate movement). At this time, the imaging unit 4 captures the X-ray measurement target 42 as an image as indicated by a virtual line frame in FIG. 4B. As a result, the X-ray microspot is irradiated onto the X-ray measurement target 42 to enable measurement with the X-ray measurement target 42.

  Then, target measurement points (the first to third measurement chips 131, 132, and 133 in FIG. 3) are measured using the X-ray reflectivity measurement (XRR) function, and the analysis unit 72 in FIG. As a result of the X-ray analysis performed by (or the computer of the control unit 70), an X-ray analysis waveform diagram is obtained as shown in FIG.

  Further, based on the waveform data, the analysis unit 72 (or the computer of the control unit 70) performs a specific area (the first to third measurement chips 131 and 132 in FIG. 3) as shown in FIG. 133), measurement results are obtained for the four types of film type classification, film thickness value, film density, and roughness of the five-layer metal film.

  As described above, by using the X-ray reflectivity measurement (XRR) function of the X-ray measurement apparatus 10 for each of the measurement chips 131, 132, and 133, a device thin film including a plurality of layers formed by sputtering ( It is possible to measure the film characteristics (film type classification, film thickness value, film density, roughness) of the metal film at one time by one measurement.

  And by managing based on the measured film characteristics (particularly film thickness etc.) of each layer, quality control can be performed and monitoring can be substituted.

  In addition, according to the X-ray reflectivity measurement (XRR) function, the amount of warpage of the formed device substrate can also be measured. As a result, the film formation state of the device thin film can be determined based on the amount of warpage of the device substrate. Can be managed.

  Next, a method for measuring the device thin film formed on the dicing portion 1b on the device substrate (wafer) 1 by X-ray diffraction measurement (XRD) will be described.

  The measurement part of the substrate 1 is positioned by using a function of recognizing a specific device pattern as in the case of X-ray reflectance measurement. Then, the surface of the substrate 1 is irradiated with an X-ray B1 composed of parallel X-ray beams at an incident angle α. The diffracted X-rays reflected by the substrate 1 are detected by the X-ray detector 51 through the light receiving slit 52.

  The light receiving system (the light receiving slit 52 and the detecting unit 51) is arranged at an angular position of 2θ0 with respect to the incident X-ray B1. The Bragg angle (depending on the wavelength of the incident X-ray) of the measured grating surface of the substrate 1 is θ0.

  Here, the Bragg angle indicates an X-ray incident angle with respect to the surface of a substance when a substance is irradiated with X-rays to generate a diffracted X-ray unique to the substance.

  The substrate 1 is placed on the stage mechanism 2, and the incident X-ray B1 rotates around the center of the goniometer, and the detection unit 51 also rotates around the center of the goniometer.

  Then, when the measurement surface of the substrate 1 is determined and the wavelength of the X-ray to be used is determined, the Bragg angle θ0 is determined. Therefore, if the incident angle α of the X-ray is set to θ0, the measured grating surface that contributes to diffraction becomes parallel to the surface of the substrate 1.

  Accordingly, diffracted X-rays from the crystallites having the measured lattice plane are detected by the detection unit 51. On the other hand, when the X-ray incident angle α (= θ0 + φ) is satisfied, only crystallites whose measured lattice plane is inclined with respect to the wafer surface by an angle φ will contribute to diffraction.

  In this manner, by fixing the detection unit 51 and changing the incident angle α, diffracted X-ray intensity information from crystallites corresponding to the respective inclination angles φ can be obtained. In the measurement of the diffracted X-ray intensity, the orientation density distribution function ρ that is axially symmetric around the normal direction of the surface of the wafer is assumed, so that the theoretical rocking curve can be compared with the measured rocking curve. . In short, a measurement rocking curve can be obtained by fixing the detection unit 51 and measuring the diffraction X-ray intensity by changing the incident angle α.

  Here, the measurement rocking curve is a graph showing the correlation between the X-ray incident angle and the diffracted X-ray intensity when a substance is irradiated with X-rays and diffracted X-rays specific to the substance are generated. Show.

  In the case of X-ray diffraction measurement, the detection unit 51 may be switched from an APD to a CCD sensor.

  When switching to the CCD sensor in this way, an X-ray diffraction image obtained from the substrate 1 is captured by the CCD sensor and displayed on a display device (not shown) connected to the control unit 70 or the analysis unit 72. Thus, the crystallinity of the device thin film can be evaluated.

  As a result, the annealing state of the device thin film can be managed based on the crystallinity of the device thin film.

  Next, a method for measuring the device thin film formed on the dicing portion 1b on the device substrate (wafer) 1 by fluorescent X-ray film thickness measurement (XRF) will be described.

  The measurement part of the substrate 1 is positioned by using a function of recognizing a specific device pattern as in the case of X-ray reflectance measurement. Then, the shutter 34 is opened, and the dicing part 1b of the substrate 1 is irradiated with the primary X-rays B1 from a relatively high angle, and the fluorescent X-rays B3 generated from the dicing part 1b are irradiated with the fluorescent X-ray detector. 6 is detected.

  Then, based on the detected intensity of the fluorescent X-ray, the analysis unit 72 can measure the film type classification (film composition) and film thickness of the formed device thin film, and this measurement data is managed by the management system 80. Can be provided.

  By the way, the management system 80 may manage a device manufacturing process and connect to the analysis unit 72 or the control unit 70 of the X-ray measurement apparatus 10 via a network 73. Further, the entire control unit of the sputter deposition apparatus (not shown) may be connected to the analysis unit 72 or the control unit 70 via the network 73.

  As described above, the device measured by the X-ray measuring apparatus 10 by connecting the X-ray measuring apparatus 10, the management system 80, and the sputter deposition apparatus (not shown) via the network 73. The film characteristics of the thin film can be provided to the management system 80 and the sputter deposition apparatus, the management system 80 can perform device quality control, and the sputter deposition apparatus can control sputtering conditions including maintenance. .

  The X-ray irradiation optical system 3 includes an optical system for X-ray reflectivity measurement (XRR) and X-ray diffraction measurement (XRD), and an optical system for fluorescent X-ray film thickness measurement (XRF). It may be provided separately. The in-line X-ray measurement apparatus (X-ray monitor apparatus) 10 according to the present invention always requires an X-ray reflectivity measurement (XRR) function and a fluorescent X-ray film thickness measurement (XRF) function. .

  Next, a semiconductor device manufacturing method using the X-ray measuring apparatus 10 having the above-described configuration will be described.

  This semiconductor device manufacturing method includes a film forming process, a measuring process, and a management process. In the film forming step, a plurality of films are stacked on the substrate 1.

  In the measurement step, a pattern formed on the substrate 1 and indicating a specific area on the substrate 1 is recognized, and X-rays of 100 μm or less (micronized) spots are formed on the plurality of films only in the specific area. Irradiate with a diameter and measure the properties of each film (in-line at a time) by X-ray reflectivity measurement. That is, the pattern is the image recognition pattern 41, and the specific area is the X-ray measurement target 42.

  In the management step, the film formation state of the plurality of films in the film formation step is managed based on the characteristics of each film.

  Therefore, the characteristics of the film of the semiconductor device can be measured in-line in the measurement step, and the quality of each semiconductor device can be improved. Moreover, since the film formation state of the plurality of films in the film formation process is managed in the management process based on the characteristics of each film measured in-line, the management accuracy is improved. At the same time, periodic monitoring work is not required, so that the productivity of the semiconductor device is improved, and the personnel cost and material cost required for the periodic monitoring are also unnecessary, so that the cost can be greatly reduced.

  The characteristics of the film may include at least one of film type classification, film thickness, film density, roughness state, and crystallinity, and at least one characteristic can be measured at a time by one measurement. .

  Further, the spot diameter of the X-ray may be 1 μm or more and 50 μm or less, and the X-ray can be reliably irradiated, for example, only to the dicing portion 1 b of the substrate 1. Therefore, the flat X-ray dicing part 1b can be irradiated to obtain a strong reflection signal from the dicing part 1b, and the characteristics of the film can be reliably measured.

  The specific area may be formed in the dicing part 1b of the substrate 1, and the X-ray is irradiated to the flat dicing part 1b to obtain a strong reflected signal from the dicing part 1b. And the characteristics of the film can be reliably measured. However, the film forming characteristics may be confirmed by irradiating the element part instead of the dicing part 1b with X-rays. For example, the crystallinity of the element part may be confirmed by X-ray diffraction measurement. is there.

  The management step may include controlling the film formation conditions of the film in the film formation step based on the characteristics of the film. Feedback can be performed in real time, and the accuracy of the manufacturing process can be further improved by automatic correction or the like.

  In the film formation step, at least one film is formed on the substrate 1 and annealed, and in the measurement step, a pattern is formed on the substrate 1 and indicates a specific area on the substrate 1. The film of only this specific area is irradiated with X-rays with a spot diameter of 100 μm or less, the crystallinity of the film is measured by X-ray diffraction measurement, and in the management step, the film is The annealing state of the film in the film forming process may be managed based on the crystallinity of the film.

  Therefore, the crystallinity of the film of the semiconductor device can be measured in-line in the measurement step, and the quality of each semiconductor device can be improved. Moreover, since the annealing state of the film in the film forming process is managed based on the crystallinity of the film measured in-line in the management process, the management accuracy is improved. At the same time, periodic monitoring work is not required, so that the productivity of the semiconductor device is improved, and the personnel cost and material cost required for the periodic monitoring are also unnecessary, so that the cost can be greatly reduced.

  In the film formation step, at least one film is formed on the substrate 1, and in the measurement step, a pattern formed on the substrate 1 and indicating a specific area on the substrate 1 is recognized. The film only in this specific area is irradiated with X-rays with a spot diameter of 100 μm or less, the amount of warpage of the substrate 1 is measured by X-ray reflectivity measurement, and in the management step, You may make it manage the film-forming state of the said film | membrane in the said film-forming process based on the amount of curvature.

  Therefore, the amount of warpage of the substrate 1 of the semiconductor device can be measured in-line in the measurement step, and the quality of each semiconductor device can be improved. Further, since the film forming state of the film in the film forming process is managed based on the warpage amount of the substrate 1 measured in-line in the management process, the management accuracy is improved. At the same time, periodic monitoring work is not required, so that the productivity of the semiconductor device is improved, and the personnel cost and material cost required for the periodic monitoring are also unnecessary, so that the cost can be greatly reduced.

(Second Embodiment)
FIG. 7 shows an embodiment of a semiconductor device deposition apparatus of the present invention. The film forming apparatus 100 is, for example, a sputter film forming apparatus, and includes a film forming unit 103, the X-ray measuring device 10 of the first embodiment as a measuring unit, a cassette unit 102, and a transport unit 101. . The transport unit 101 and the cassette unit 102 are not essential components.

  The film forming unit 103 forms at least one film on the substrate 1. The film forming unit 103 has a plurality of chambers and annealing chambers around it, and has a handling chamber in and out of the center. The cassette unit 102 accommodates the substrate 1.

  The X-ray measurement apparatus 10 has at least one measurement function of a fluorescent X-ray film thickness measurement function, an X-ray reflectivity measurement function, and an X-ray diffraction measurement function, and is formed on the substrate 1 and the substrate 1 A pattern indicating the upper specific area is recognized, and the film of only the specific area is irradiated with X-rays with a spot diameter of 100 μm or less, and the characteristics of the film are measured by the at least one measurement function.

  The transport unit 101 is formed in a clean atmosphere, transports the substrate 1 from the cassette unit 102 to the film forming unit 103, and the substrate 1 formed by the film forming unit 103 is used as the X-ray measurement apparatus. Transport to 10. In addition, in order to make it intelligible, the casing of the said X-ray measuring apparatus 10 and the said conveyance part 101 is represented by the transparent casing.

  Next, the operation of the film forming apparatus 100 will be described.

  The substrate 1 is transported from the cassette unit 102 to the film forming unit 103 via the transfer unit 101 and sputter film formation is performed on the substrate 1. After the film formation of the substrate 1 is completed, the substrate 1 is unloaded via the transport unit 101 and carried to the X-ray measurement apparatus 10, and at least a multilayer metal film in a specific area on the substrate 1 Measurements are made for four types of film type classification, film thickness, film density, and roughness. Of course, the crystallinity may also be measured.

  Then, the substrate 1 measured by the X-ray measurement apparatus 10 is transported by the transport unit 101 and stored in the cassette unit 102.

  Therefore, the characteristics of the film of the semiconductor device can be measured in-line by the X-ray measuring apparatus 10, and the quality of each semiconductor device can be improved.

  In addition, since the film characteristics can be measured in-line, as shown in FIG. 8, the film characteristics can be measured for each device processing, and periodic monitoring work using a monitoring wafer (substrate) until the next regular maintenance work. This eliminates the need for periodic monitoring work and costs, and as a result, the operating rate can be improved and the cost of semiconductor devices can be reduced.

  In addition, since the cassette unit 102 and the transport unit 101 are provided, it is possible to prevent foreign matters from adhering to the substrate 1 when the substrate 1 is transported. In addition, since the transport unit 101 is provided, the transport distance between the film forming unit 103 and the X-ray measurement apparatus 10 can be shortened, and the process time is also shortened.

  Note that a control unit (for example, the management system 80 in FIG. 2) that controls the film forming unit 103 based on the characteristics of the film may be provided, and measurement of the film characteristics may be performed on the film forming unit. Feedback can be performed in real time, and the accuracy of the manufacturing process can be further improved by automatic correction or the like. For example, it can be developed into an application called an online APC (Advanced Process Control) function.

  The X-ray measurement apparatus 10 may have all the measurement functions of the fluorescent X-ray film thickness measurement function, the X-ray reflectivity measurement function, and the X-ray diffraction measurement function. Whether the film is a single-layer metal film, a multi-layer metal film, a single-layer insulating film, or a multi-layer insulating film can be measured in a flexible manner.

(Third embodiment)
Next, quality control of the film characteristics of the device thin film by in-line measurement using the X-ray measurement apparatus 10 will be described.

  FIG. 9 is a flowchart showing an outline of the device manufacturing process. This device manufacturing process is roughly composed of an insulating film forming process (S81), a photolithography process (S82), an ion implantation process (S83), an etching process (S84), and a subsequent metal pattern forming process (S85 to S89). ).

  The metal pattern forming process includes a resist stripping process (S85), a metal film forming process (S86), an X-ray metal film measuring process (S87) using the X-ray measuring apparatus 10, and a photolithography process (S88). And an etching step (S89).

  As described above, in the metal film forming step (S86), in the case where a plurality of metal films are sequentially laminated and sputtered, the plurality of metal films are formed and then the X-ray metal film measuring step ( S87) may be provided.

  The measurement data acquired by the X-ray measurement apparatus 10 in the X-ray metal film measurement step (S87) is provided to the management system 80 in the management step (S90) to correlate the wafer test and the yield. It is fed back and used for quality control, or provided to the film forming apparatus 100 and used for monitoring management of the film forming apparatus state.

  In addition, this invention is not limited to the above-mentioned embodiment. For example, the semiconductor device manufacturing method of the present invention may be applied to a manufacturing apparatus other than a sputter deposition apparatus, such as a CVD apparatus, an etching apparatus, an ion implantation apparatus, or a CMP apparatus. Furthermore, the semiconductor device manufacturing method of the present invention may be applied not only to a semiconductor integrated circuit manufacturing process but also to a compound semiconductor or liquid crystal panel manufacturing process.

It is a simplified perspective view which shows one Embodiment of the X-ray measuring apparatus used for the manufacturing method of the semiconductor device of this invention. It is a simplified block diagram of an X-ray measuring apparatus. It is a top view which shows an X-ray measurement point. It is an enlarged view which shows an image recognition pattern. It is an enlarged view which shows a X-ray measurement target. It is an X-ray analysis waveform diagram acquired by the X-ray reflectivity measurement (XRR) function. It is explanatory drawing which shows the measurement result of the film | membrane characteristic of each chip | tip measured by the X-ray reflectivity measurement (XRR) function. 1 is a simplified perspective view showing an embodiment of a semiconductor device deposition apparatus of the present invention. It is a flowchart which shows the operation method of a film-forming apparatus. It is a flowchart which shows a device creation process.

DESCRIPTION OF SYMBOLS 1 Substrate 1b Dicing part 2 Stage mechanism 3 X-ray irradiation optical system 4 Imaging part 5 X-ray detector 6 X-ray fluorescence detector 10 X-ray measuring device 21 Sample stage 22 XY stage 23 Z stage 24 Y-axis rotation stage 25 Base 31 X-ray tube 31a X-ray source 32 Condensing element 32a Reflecting surface 34 Shutter 41 Image recognition pattern 42 X-ray measurement target 43 Scrub line 51 Detector (APD)
52 Light-receiving slit 61 Detection unit 70 Control unit 71 Sample recognition unit 72 Analysis unit 73 Network 80 Management system 100 Film formation apparatus 101 Transport unit 102 Cassette unit 103 Film formation unit 131-133 First to third measurement chips

Claims (9)

A film forming step of stacking a plurality of films on a substrate;
A pattern formed on the substrate and indicating a position of the specific area on the substrate is recognized as an image, and a position of the specific area is obtained based on the pattern. After moving the X-ray spot to the area, X-rays are irradiated with a spot diameter of 1 μm or more to 50 μm or less on the plurality of films only in this specific area, and the X-ray reflectivity measurement is performed. A measurement process for measuring characteristics;
A management step of managing the film formation state of the plurality of films in the film formation step based on the characteristics of each film ,
Upper Symbol particular area, a method of manufacturing a semiconductor device characterized by being formed into a flat dicing portion of the substrate. In the manufacturing method of the semiconductor device according to claim 1,
The method of manufacturing a semiconductor device, wherein the characteristics of the film include at least one of film type classification, film thickness, film density, roughness state, and crystallinity. In the manufacturing method of the semiconductor device according to claim 1,
The method of manufacturing a semiconductor device, wherein the managing step includes controlling film forming conditions of the film in the film forming step based on characteristics of the film. A film forming step of forming at least one film on the substrate and performing an annealing process;
A pattern formed on the substrate and indicating a position of the specific area on the substrate is recognized as an image, and a position of the specific area is obtained based on the pattern. After moving the X-ray spot to the area, the film of this specific area is irradiated with X-rays with a spot diameter of 1 μm to 50 μm and the crystallinity of the film is measured by X-ray diffraction measurement. Measuring process to
A management step of managing the annealing state of the film in the film formation step based on the crystallinity of the film ,
Upper Symbol particular area, a method of manufacturing a semiconductor device characterized by being formed into a flat dicing portion of the substrate. A film forming step of forming at least one film on the substrate;
A pattern formed on the substrate and indicating a position of the specific area on the substrate is recognized as an image, and a position of the specific area is obtained based on the pattern. After moving the X-ray spot to the area, the film of only this specific area is irradiated with X-rays with a spot diameter of 1 μm or more to 50 μm or less , and the amount of warpage of the substrate is determined by measuring the X-ray reflectivity. Measuring process to measure,
A management step of managing the film formation state of the film in the film formation step based on the amount of warpage of the substrate ,
Upper Symbol particular area, a method of manufacturing a semiconductor device characterized by being formed into a flat dicing portion of the substrate. A film forming unit for forming at least one film on the substrate;
The above-mentioned specification that has at least one measurement function of a fluorescent X-ray film thickness measurement function, an X-ray reflectivity measurement function, and an X-ray diffraction measurement function and that indicates the position of a specific area on the substrate that is formed on the substrate A pattern provided at a position different from the area is recognized as an image, the position of the specific area is obtained based on the pattern, an X-ray spot is moved to the specific area, and then only the specific area is A measurement unit that irradiates the film with X-rays with a spot diameter of 1 μm or more and 50 μm or less , and measures the characteristics of the film by the at least one measurement function ;
Upper Symbol particular area, deposition apparatus for a semiconductor device characterized by being formed into a flat dicing portion of the substrate. In the film-forming apparatus of the semiconductor device of Claim 6,
A semiconductor device film forming apparatus comprising: a control unit that controls the film forming unit based on characteristics of the film. In the film-forming apparatus of the semiconductor device of Claim 6,
The film forming apparatus for a semiconductor device, wherein the measurement unit has all the measurement functions of the fluorescent X-ray film thickness measurement function, the X-ray reflectivity measurement function, and the X-ray diffraction measurement function. In the film-forming apparatus of the semiconductor device of Claim 6,
A cassette section for storing the substrate;
A semiconductor device film forming apparatus comprising: a transport unit configured to transport the substrate from the cassette unit to the film forming unit and transport the substrate formed by the film forming unit to the measurement unit.

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