Wafer processing apparatus

Abstract

To provide a wafer processing device that can perform appropriate processing according to the semiconductor wafer standards without registering the processing order of lots with different standards or requiring user intervention when processing semiconductor wafers with different standards.SOLUTION: A sensor obtains shape information of at least a portion of a semiconductor wafer to be processed. A processing unit performs processing on the semiconductor wafer. A control unit analyzes shape information of at least a portion of the semiconductor wafer acquired by the sensor, and causes the processing unit to perform different processing according to the analysis result.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a wafer processing apparatus.

Background Art

[0002] As an annealing method for activating a dopant doped in a semiconductor wafer, a laser annealing method is known in which a pulsed laser beam is incident on the wafer and the beam spot is moved within the wafer surface (for example, Patent Document 1, etc.). Generally, wafers of the same wafer size are processed continuously.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There are a plurality of standards for semiconductor wafers, and the length of the orientation flat may differ depending on the standard. For example, silicon wafers have two standards, JEITA and SEMI. For example, the length of the orientation flat of a 6-inch silicon wafer is 47.5 mm according to the JEITA standard, whereas it is 57.5 mm according to the SEMI standard. When the length of the orientation flat 11 is different, the shape and area of the upper surface of the semiconductor wafer are different.

[0005] For example, when annealing is performed by scanning the surface of a semiconductor wafer with a laser beam, the size of the area to be scanned is different between a wafer conforming to the JEITA standard and a wafer conforming to the SEMI standard. For example, when a lot conforming to the JEITA standard and a lot conforming to the SEMI standard are mixed in the semiconductor wafers to be processed, in order to perform appropriate processing on a plurality of lots with different standards, the processing order of the lots with different standards must be registered in advance. Or, when the standard of the lot to be processed next is different from the standard of the lot processed immediately before, user intervention is required to perform appropriate processing according to the standard.

[0006] An object of the present invention is to provide a wafer processing apparatus capable of performing appropriate processing according to the standard of a semiconductor wafer without registering the processing order of lots with different standards or requiring user intervention when processing semiconductor wafers with different standards.

Means for Solving the Problems

[0007] According to one aspect of the present invention, a sensor that acquires information on the shape of at least a part of a semiconductor wafer to be processed, a processing unit that performs processing on the semiconductor wafer, a control unit that controls the processing unit are provided, the control unit analyzes the shape information acquired by the sensor and causes the processing unit to execute different processing according to the analysis result 、 The sensor is a camera that images at least a part of a semiconductor wafer to be processed. The semiconductor wafer to be processed includes at least two types of semiconductor wafers with different lengths of orientation flats. The field of view of the camera is sized such that the entire orientation flat of the semiconductor wafer to be processed does not fit within it. Furthermore, a positioning mechanism is provided for positioning the semiconductor wafer with respect to the field of view of the camera. With the semiconductor wafer positioned with respect to the field of view of the camera, the detection area is set such that the end of the orientation flat of one type of semiconductor wafer enters a part of the detection area of the field of view of the camera, and the end of the orientation flat of the other type of semiconductor wafer does not enter the detection area. The control unit analyzes the image of the semiconductor wafer acquired by the camera and determines the type of the semiconductor wafer based on whether the end of the orientation flat is detected in the detection area. a wafer processing apparatus is provided.

Effects of the Invention

[0008] The processing unit analyzes an image of a semiconductor wafer and executes different processes on the processing unit according to the analysis result, so that it is possible to register the processing order of lots with different specifications and perform appropriate processing according to the difference in the shape of the semiconductor wafer without requiring user intervention.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] A wafer processing apparatus according to an embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a schematic diagram of a wafer processing apparatus according to the present embodiment. The wafer processing apparatus includes a processing unit 30, a camera 20, and a control unit 40.

[0011] The processing unit 30 includes a laser oscillator 31, a beam expander 32, a beam shaping optical element 33, a folding mirror 34, an XY stage 35, and a chuck table 36. A semiconductor wafer 10 to be processed is held and fixed on the chuck table 36. The chuck table 36 is movable in two directions in a horizontal plane by the XY stage 35.

[0012] The laser oscillator 31 outputs a pulsed laser beam. The pulsed laser beam output from the laser oscillator 31 is incident on the semiconductor wafer 10 via the beam expander 32, the beam shaping optical element 33, and the folding mirror 34. In addition, an aperture, a lens, etc. may be arranged as necessary. For example, a dopant is ion-implanted into the semiconductor wafer 10, and activation annealing of the dopant is performed by the incidence of the pulsed laser beam.

[0013] As the laser oscillator 31, for example, a fiber laser oscillator, a laser diode, a solid-state laser oscillator, etc. can be used. The beam expander 32 adjusts the beam size at the incidence position of the laser beam to the beam shaping optical element 33. The beam shaping optical element 33 shapes the beam spot on the surface of the semiconductor wafer 10 and equalizes the intensity distribution. As the beam shaping optical element 33, for example, a diffractive optical element is used.

[0014] The control unit 40 controls the XY stage 35 and the laser oscillator 31. For example, the control unit 40 controls the XY stage 35 so that the pulsed laser beam is incident on the target position on the surface of the semiconductor wafer 10. Further, the output timing of the pulsed laser beam from the laser oscillator 31 is controlled. By moving the semiconductor wafer 10 in two directions perpendicular to the path of the pulsed laser beam while irradiating the semiconductor wafer 10 with the pulsed laser beam, a predetermined region of the semiconductor wafer 10 can be annealed.

[0015] A camera 20 is arranged above the chuck table 36. The camera 20 images at least a part of the semiconductor wafer 10 held by the chuck table 36. The image data of the semiconductor wafer 10 obtained by imaging with the camera 20 is input to the control unit 40. The control unit 40 discriminates the type of the semiconductor wafer 10 by performing image analysis.

[0016] FIG. 2 is a diagram showing the planar positional relationship of the components of the wafer processing apparatus according to the embodiment. The wafer processing apparatus according to the embodiment includes a processing chamber 58 and a robot chamber 55. In the robot chamber 55, a robot arm 50, two wafer cassettes 51, and an aligner 52 are accommodated. In the processing chamber 58, an XY stage 35 (FIG. 1), a chuck table 36, and a camera 20 are accommodated.

[0017] In a plan view, two wafer cassettes 51 and an aligner 52 are arranged around the robot arm 50. An unprocessed semiconductor wafer 10 is stored in one of the wafer cassettes 51, and a processed semiconductor wafer 10 is stored in the other wafer cassette 51. Note that a transfer method may be adopted in which the unprocessed semiconductor wafer 10 is processed without distinguishing the wafer cassette 51 for unprocessed and processed wafers, and the processed semiconductor wafer 10 is returned to the original position of the wafer cassette 51.

[0018] Next, the functions of the wafer processing apparatus will be described. By being controlled by the control unit 40, the robot arm 50 transfers the semiconductor wafer 10 between the wafer cassette 51, the aligner 52, and the chuck table 36. The aligner 52 positions the semiconductor wafer 10 in the rotational direction by detecting the orientation flat of the semiconductor wafer 10.

[0019] The field of view of the camera 20 is sized to accommodate the entire semiconductor wafer 10. The XY stage 35 moves the semiconductor wafer 10 so that the semiconductor wafer 10 fits within the field of view of the camera 20. Further, during annealing, the semiconductor wafer 10 is moved in two directions perpendicular to the path of the laser beam. The camera 20 images the semiconductor wafer 10 to generate image data. The generated image data is input to the control unit 40. The control unit 40 discriminates the type of the semiconductor wafer 10 by performing image analysis, and operates the laser oscillator 31 and the XY stage 35 (FIG. 1) to perform annealing processing according to the type of the semiconductor wafer 10.

[0020] FIGS. 3A and 3B are plan views showing the positional relationship among the chuck table 36, the imaging boundary 21 of the camera 20 (FIGS. 1 and 2), and the semiconductor wafers 10S and 10J. The entire semiconductor wafers 10S and 10J are within the imaging boundary 21. The semiconductor wafers 10S and 10J shown in FIGS. 3A and 3B are of 6-inch SEMI standard and JEITA standard, respectively. In the SEMI standard, the length L of the orientation flat 11 is 57.5 mm, and in the JEITA standard, the length L of the orientation flat 11 is 47.5 mm. Thus, the length L of the orientation flat 11 varies according to the standard.

[0021] The control unit 40 (FIGS. 1 and 2) analyzes an image in which the entire semiconductor wafer 10 is reflected and measures the length L of the orientation flat 11. Based on the measured value of the length L of the orientation flat 11, it is determined whether the semiconductor wafer 10 is of SEMI standard or JEITA standard.

[0022] FIG. 4 is a flowchart showing the procedure of the wafer processing method according to this embodiment. These procedures are executed by the control unit 40 controlling the robot arm 50, the aligner 52 (FIG. 2), the XY stage 35, the laser oscillator 31 (FIG. 1), and the camera 20 (FIGS. 1 and 2).

[0023] First, the robot arm 50 takes out an unprocessed semiconductor wafer 10 from the unprocessed wafer cassette 51 (step S1). The taken-out semiconductor wafer 10 is transferred to the aligner 52 (FIG. 2), and alignment in the rotational direction is performed by the aligner 52 (step S2). When the alignment in the rotational direction is completed, the robot arm 50 takes out the semiconductor wafer 10 from the aligner 52, transfers it into the processing chamber 58, and holds it on the chuck table 36 (FIGS. 1 and ) (step S3). At this time, the semiconductor wafer 10 is positioned and held at a predetermined position on the chuck table 36.

[0024] The XY stage 35 is driven so that the semiconductor wafer 10 fits within the imaging field 21 of the camera 20. The camera 20 (Figs. 1 and 2) images the semiconductor wafer 10 and generates image data. The control unit 40 acquires the generated image data (step S4). Further, the control unit 40 measures the length L (Figs. 3A and 3B) of the orientation flat 11 of the semiconductor wafer 10 by analyzing the image data (step S5). Based on the measured value of the length L of the orientation flat 11, the control unit 40 determines whether the semiconductor wafer 10 conforms to the SEMI standard or the JEITA standard, and causes the processing unit 30 (Fig. 1) to execute different processes according to the determined result (step S6). "Different processes" are, for example, processes in which the action exerted on the semiconductor wafer 10 to be processed (such as annealing) is the same, but at least one of the shape and area of the region where the action is exerted on the semiconductor wafer 10 to be processed is different.

[0025] If the semiconductor wafer 10 conforms to the SEMI standard, a process corresponding to the SEMI standard is executed (step S7), and if the semiconductor wafer 10 conforms to the JEITA standard, a process corresponding to the JEITA standard is executed (step S8). Specifically, the size of the region on the surface of the semiconductor wafer 10 to be annealed is different between the SEMI standard and the JEITA standard. The control unit 40 controls the processing unit 30 to anneal a region of a size corresponding to each standard.

[0026] When the processing of the semiconductor wafer 10 is completed, the robot arm 50 picks up the processed semiconductor wafer 10 from the chuck table 36 and returns it to the wafer cassette 51 (step S9). Note that it may be passed through the aligner 52 before returning it to the wafer cassette 51. In this case, the aligner 52 adjusts the posture of the semiconductor wafer 10 in the rotational direction so that the orientation flat 11 of the semiconductor wafer 10 returned to the wafer cassette 51 is aligned in a predetermined direction.

[0027] Next, the excellent effects of the above embodiment will be described. In the above-described embodiment, before annealing the semiconductor wafer 10, an image of the semiconductor wafer 10 is analyzed, and different processes are performed on the semiconductor wafer 10 according to the analysis result (step S6). For this reason, appropriate processes can be performed for each type without registering in advance the type (standard) of the semiconductor wafer 10 to be processed. Further, even when the type of the semiconductor wafer 10 to be processed changes, user intervention is not required.

[0028] Next, a modified example of the above-described embodiment will be described. In the above-described embodiment, the type is discriminated for each semiconductor wafer 10. However, when a plurality of semiconductor wafers 10 of the same type are continuously processed as one lot, for each lot, the type of the first semiconductor wafer 10 to be processed is discriminated, and for the other semiconductor wafers 10 within the same lot, the type may not be discriminated. For example, it is preferable that a plurality of semiconductor wafers 10 within one wafer cassette be regarded as one lot. The control unit 40 may identify the first semiconductor wafer 10 for each lot by detecting that the wafer cassette 51 (FIG. 2) has been replaced. Since the type discrimination process is performed only for the first semiconductor wafer 10 to be processed for each lot, the processing time can be shortened.

[0029] In the above-described embodiment, as examples of the type of the semiconductor wafer 10, a 6-inch wafer of the SEMI standard and a 6-inch wafer of the JEITA standard are cited. In addition, it is also possible to discriminate a plurality of types of semiconductor wafers 10 having different lengths L (FIGS. 3A and 3B) of the orientation flat 11. For example, the wafer size is not limited to 6 inches. Further, it is not limited to the SEMI standard and the JEITA standard, and the types of semiconductor wafers of various standards having different other shapes can be discriminated. Further, the semiconductor wafer to be discriminated is not limited to a silicon wafer, and the types of wafers made of various other semiconductors can also be discriminated.

[0030] In the above embodiment, before holding the semiconductor wafer 10 on the chuck table 36, alignment in the rotational direction is performed by the aligner 52 (step S2), but it is not always necessary to perform alignment in the rotational direction. Since the entire semiconductor wafer 10 is within the field of view 21 of the camera 20, the length L of the orientation flat 11 can be measured by image analysis without being affected by the orientation of the semiconductor wafer 10 in the rotational direction.

[0031] The wafer processing apparatus according to the above embodiment performs laser annealing processing on a semiconductor wafer, but the above embodiment can also be applied to an apparatus that performs other processes, such as film formation, polishing, and the like.

[0032] In the above embodiment, the camera 20 that acquires a two-dimensional image of the semiconductor wafer 10 to be processed is used, but in addition, a sensor that acquires information on the shape of at least a part of the semiconductor wafer 10 may be used. For example, a shape measurement sensor that measures the shape with line light, a three-dimensional profile measuring instrument that measures the three-dimensional profile of an object, an ultrasonic camera, a multispectral camera, etc. can be used.

[0033] Next, with reference to FIG. 5, a wafer processing apparatus according to another embodiment will be described. Hereinafter, description of the configurations common to the wafer processing apparatus according to the embodiment described with reference to FIGS. 1 to 4 will be omitted.

[0034] FIG. 5 is a plan view showing the positional relationship among the chuck table 36 of the wafer processing apparatus according to the present embodiment, the field of view 21 of the camera 20 (FIGS. 1 and 2), and the semiconductor wafers 10S and 10J. In FIG. 5, the semiconductor wafer 10S conforming to the SEMI standard is represented by a solid line, and the semiconductor wafer 10 conforming to the JEITA standard is represented by a dashed line. In the embodiment shown in FIGS. 3A and 3B, the field of view 21 of the camera 20 is wider than the semiconductor wafer 10. In contrast, in the embodiment shown in FIG. 5, the field of view 21 of the camera 20 is sized such that the entire area of the orientation flat 11 of the semiconductor wafer 10 does not fit within it.

[0035] In this embodiment, the XY stage 35 (FIG. 1), the robot arm 50, and the aligner 52 (FIG. 2) position the semiconductor wafer 10 in a predetermined posture and at a predetermined position with respect to the chuck table 36, and place it on the chuck table 36. By driving the XY stage 35 by the control unit 40, the semiconductor wafer 10 is positioned with respect to the imaging field 21 of the camera 20. The robot arm 50, the aligner 52, and the XY stage 35 have a function as a positioning mechanism for positioning the semiconductor wafer 10 with respect to the imaging field 21 of the camera 20. A detection area 22 is defined in a part of the imaging field 21.

[0036] With the semiconductor wafer 10 positioned with respect to the imaging field 21 of the camera 20, one end of each of the orientation flats 11 of the SEMI-standard semiconductor wafer 10S and the JEITA-standard semiconductor wafer 10J is within the imaging field 21. The detection area 22 is set such that one end of the orientation flat 11 of the JEITA-standard semiconductor wafer 10 enters the detection area 22, but the end of the orientation flat 11 of the SEMI-standard semiconductor wafer 10 does not enter the detection area 22.

[0037] In step S5 (FIG. 4), the control unit 40 determines whether or not the end of the orientation flat 11 is detected within the detection area 22, instead of measuring the length L of the orientation flat 11. If the end of the orientation flat 11 is detected within the detection area 22, the semiconductor wafer 10 is of the JEITA standard, and if not detected, the semiconductor wafer 10 is of the SEMI standard.

[0038] Next, the excellent effects of this embodiment will be described. Also in this embodiment, similar to the embodiments shown in FIGS. 1 to 4, the type of the semiconductor wafer 10 can be automatically discriminated, and appropriate processing can be performed according to the type. Further, in this embodiment, even when the imaging field 21 of the camera 20 is smaller than the semiconductor wafer 10, the type of the semiconductor wafer 10 can be discriminated.

[0039] Next, with reference to FIG. 6, a wafer processing apparatus according to still another embodiment will be described. Hereinafter, descriptions of configurations common to the wafer processing apparatus according to the embodiment described with reference to FIG. 5 will be omitted.

[0040] FIG. 6 is a plan view showing the positional relationship among a chuck table 36 of the wafer processing apparatus according to the present embodiment, a field 21 of a camera 20 (FIGS. 1 and 2), and semiconductor wafers 10S and 10J. In FIG. 6, a semiconductor wafer 10S conforming to the SEMI standard is represented by a solid line, and a semiconductor wafer 10 conforming to the JEITA standard is represented by a broken line.

[0041] In the embodiment shown in FIG. 5, one end of the orientation flat 11 of both types of semiconductor wafers 10S and 10J enters the field 21 of the camera 20. In contrast, in the present embodiment, one end of the orientation flat 11 of the semiconductor wafer 10J conforming to the JEITA standard enters the field 21, but the end of the orientation flat 11 of the semiconductor wafer 10S conforming to the SEMI standard does not enter the field 21.

[0042] In step S5 (FIG. 4), the control unit 40 determines whether or not an end of the orientation flat 11 is detected within the field 21, instead of measuring the length L of the orientation flat 11. If an end of the orientation flat 11 is detected within the field 21, the semiconductor wafer 10 is of the JEITA standard, and if not detected, the semiconductor wafer 10 is of the SEMI standard.

[0043] Next, the excellent effects of the present embodiment will be described. Also in the present embodiment, similar to the embodiment shown in FIG. 5, the type of the semiconductor wafer 10 can be automatically discriminated, and processing according to the type can be performed. Further, in the present embodiment, even when the field 21 of the camera 20 is smaller than that in the embodiment shown in FIG. 5, the type of the semiconductor wafer 10 can be discriminated.

[0044] Next, modifications of the various embodiments shown in FIGS. 1 to 6 will be described. In the above embodiment, the type of the semiconductor wafer 10 is determined by paying attention to the difference in the dimensions of the orientation flat 11 of the semiconductor wafer 10. However, the type of the semiconductor wafer 10 may also be determined by paying attention to other differences in shape. For example, in semiconductor wafers 10 of the same size, when two types, one using an orientation flat for specifying the crystal orientation and the other using a notch, are mixed, the type of the semiconductor wafer 10 may be determined by detecting the difference in the shapes of the orientation flat and the notch.

[0045] Each of the above-described embodiments is illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. Regarding the same operational effects due to the same configurations of multiple embodiments, they will not be sequentially described for each embodiment. Furthermore, the present invention is not limited to the above-described embodiments. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

Explanation of Reference Numerals

[0046] 10 Semiconductor wafer 10J Semiconductor wafer according to JEITA standard 10S Semiconductor wafer according to SEMI standard 11 Orientation flat 20 Camera 21 Field of view of the camera 22 Detection area 30 Processing unit 31 Laser oscillator 32 Beam expander 33 Beam shaping optical element 34 Fold mirror 35 XY stage 36 Chuck table 40 Control unit 50 Robot arm 51 Wafer cassette 52 Aligner 55 Robot chamber 58 Processing chamber

Claims

1. A sensor that acquires information on the shape of at least a part of a semiconductor wafer to be processed, a processing unit that performs processing on the semiconductor wafer, and a control unit that controls the processing unit are provided, the control unit analyzes the shape information acquired by the sensor and causes the processing unit to execute different processing according to the analysis result, the sensor is a camera that images at least a part of the semiconductor wafer to be processed, the semiconductor wafer to be processed includes at least two types of semiconductor wafers with different lengths of the orientation flat, the field of view of the camera is sized such that the entire orientation flat of the semiconductor wafer to be processed does not fit within it, further, a positioning mechanism for positioning the semiconductor wafer with respect to the field of view of the camera is provided, with the semiconductor wafer positioned with respect to the field of view of the camera, the detection area is set such that the end of the orientation flat of one type of semiconductor wafer enters a part of the detection area of the field of view of the camera, and the end of the orientation flat of the other type of semiconductor wafer does not enter the detection area, the control unit analyzes the image of the semiconductor wafer acquired by the camera and discriminates the type of the semiconductor wafer based on whether the end of the orientation flat is detected in the detection area. A wafer processing apparatus.

2. A sensor that acquires information on the shape of at least a part of a semiconductor wafer to be processed, a processing unit that performs processing on the semiconductor wafer, and a control unit that controls the processing unit are provided, the control unit analyzes the shape information acquired by the sensor and causes the processing unit to execute different processing according to the analysis result, the sensor is a camera that images at least a part of the semiconductor wafer to be processed, The semiconductor wafer to be processed includes at least two types of semiconductor wafers with different lengths of the orientation flats. The field of view of the camera is sized such that the entire orientation flat of the semiconductor wafer to be processed does not fit within it. Furthermore, it is provided with a positioning mechanism for positioning the semiconductor wafer with respect to the field of view of the camera. With the semiconductor wafer positioned with respect to the field of view of the camera, the positional relationship between the field of view of the camera and the semiconductor wafer after alignment is set such that the end of the orientation flat of one type of semiconductor wafer enters the field of view of the camera, and the end of the orientation flat of the other type of semiconductor wafer does not enter the field of view of the camera. The control unit analyzes the image of the semiconductor wafer acquired by the camera, and is a wafer processing apparatus that discriminates the type of the semiconductor wafer based on whether the end of the orientation flat is detected within the field of view of the camera.

3. The different processes executed by the control unit on the processing unit are processes in which the action exerted on the semiconductor wafer to be processed is the same, and at least one of the shape and area of the region exerting the action on the semiconductor wafer to be processed is different. The wafer processing apparatus according to claim 1 or 2.

Images