Substrate processing apparatus and calibration method

Abstract

To provide a substrate processing apparatus and a calibration method of a light receiving device which are capable of determining a level of the output of the light receiving device.SOLUTION: A substrate processing apparatus is provided with: a chamber containing a stage; light receiving devices to receive light inside the chamber; a shaft; and a rotation arm to rotate with rotation of the shaft. The substrate processing apparatus can supply a plurality of light beams having different amounts of light to at least one of the light receiving devices.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing apparatus and a calibration method. [Background technology]

[0002] For example, in an ALD process, plasma emission is detected by a Si photodiode sensor to monitor the synchronicity of the RF-ON indication output and plasma emission, or to monitor the intensity of plasma emission. However, there is no defense system to diagnose the state of the photodiode sensor, and since there are individual differences in the photodiode sensor output, it is not possible to judge the level based on the output value of the photodiode sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-163433 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a substrate processing apparatus capable of determining the level of the output of a light-receiving element, and a method for calibrating the light-receiving element. [Means for solving the problem]

[0005] The substrate processing apparatus according to the present disclosure has a chamber housing a stage, a light receiving element that receives light inside the chamber, a shaft, and a rotation arm that rotates in conjunction with the rotation of the shaft, and provides multiple beams of light with different intensities to the light receiving element.

[0006] Other features of the present disclosure are set forth below. Effect of the Invention

[0007] According to the present disclosure, the level of the output from the light receiving element can be determined. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a substrate processing apparatus. [Diagram 2] FIG. 4 is a diagram illustrating an example of characteristics of a light receiving element. [Diagram 3] FIG. 2 is a partial cross-sectional view of the substrate processing apparatus. [Figure 4A] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 4B] FIG. 11 is a cross-sectional view of a shaft according to another example. [Diagram 5] 1 is a flowchart illustrating an example of a calibration method. [Figure 6A] FIG. 13 is a diagram illustrating an example of an output from a light receiving element. [Figure 6B] FIG. 13 is a diagram illustrating an example of an output from a light receiving element. [Figure 6C] FIG. 13 is a diagram illustrating an example of an output from a light receiving element. [Figure 7A] FIG. 13 is a diagram showing outputs from a plurality of light receiving elements before calibration. [Figure 7B] FIG. 13 is a diagram showing outputs from a plurality of light receiving elements after calibration. [Figure 8] FIG. 13 is a diagram showing light from a rotation arm to a light receiving element. [Figure 9] FIG. 2 is a diagram showing a light-emitting wafer. [Figure 10] FIG. 2 illustrates a dual chamber module and a light emitting wafer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The substrate processing apparatus and the calibration method will be described with reference to the drawings. The same or corresponding components are designated by the same reference numerals, and the repeated description may be omitted.

[0010] Embodiment FIG. 1 is a diagram showing a configuration example of a substrate processing apparatus. This substrate processing apparatus configures a Quad Chamber Module (QCM) having four chamber modules in a chamber 10. The number of chamber modules is not particularly limited. According to one example, four chambers 12, 14, 16, and 18 are provided in the chamber 10. The chambers 12, 14, 16, and 18 can be provided as, for example, reactor chambers. According to one example, each chamber is a plasma processing apparatus.

[0011] The chambers 12, 14, 16, and 18 each include a stage 12a, 14a, 16a, and 18a. These stages are, for example, susceptors. The chambers 12, 14, 16, and 18 each include a light receiving element 12b, 14b, 16b, and 18b on the outside thereof. According to an example, a plurality of light receiving elements are provided in a one-to-one correspondence with a plurality of chambers. For example, the light receiving elements 12b, 14b, 16b, and 18b can receive light from the inside of the chambers 12, 14, 16, and 18, respectively, through a viewport of the chamber. According to an example, the light receiving elements 12b, 14b, 16b, and 18b are silicon photodiode sensors.

[0012] A substrate transfer device 20 is provided in the chamber 10. According to one example, the substrate transfer device 20 has a shaft 20a and a rotation arm 20b that rotates with the rotation of the shaft 20a. In the example of Fig. 1, four rotation arms 20b fixed to the shaft 20a rotate with the rotation of the shaft 20a extending in the direction perpendicular to the paper surface. The substrate transfer device 20 allows the substrate to be moved between the stages.

[0013] A wafer handling chamber (WHC) 30 is connected to the chamber 10. A wafer transfer arm in the WHC 30 places a substrate on the stage 12a, 14a and removes the substrate from the stage 12a, 14a.

[0014] According to one example, a process module controller (PMC) 40 receives outputs from the light receiving elements 12b, 14b, 16b, and 18b, controls the light receiving elements 12b, 14b, 16b, and 18b, and controls the substrate transport device 20. In this example, a unique platform controller (UPC) 42 instructs the PMC 40 to operate each module, and the PMC 40 controls each module based on the instructions. According to another example, each module can be controlled by a controller other than the UPC 42 and the PMC 40.

[0015] Figure 2 shows an example of the relationship between the amount of light incident on the light receiving element and the output voltage. According to this example, when the amount of light incident on the light receiving element is 160 nW, the output of the light receiving element varies by about 20% due to individual differences. In addition, a linearity error of about 5% occurs in each light receiving element. Therefore, if the light receiving elements 12b, 14b, 16b, and 18b are used as they are, their outputs cannot be used to judge the level or to understand the difference between chambers.

[0016] 3 is a partial cross-sectional view of the substrate processing apparatus of FIG. 1. The shaft 20a is a rotation axis extending long in the z direction. The substrate transport device 20 can be moved in the z positive direction and the z negative direction by a driving mechanism provided inside or outside the chamber 10. For example, holes 20c and 20d are formed in the shaft 20a. The hole 20c is a hole that extends substantially parallel to the z axis in the shaft 20a. The hole 20d is a hole that extends substantially perpendicular to the z axis in the shaft 20a and is connected to the hole 20c. According to one example, a plurality of holes 20d can be provided on the side surface of the shaft 20a.

[0017] In this example, the light source 50 is provided outside the chamber 12. Although the light source 50 may be provided inside the chamber 10, providing the light source 50 outside the chamber 12 facilitates the maintenance of the light source 50. The light source 50 is turned on and off under the control of, for example, the PMC 40. The light source 50 provides light to the holes 20c and 20d. According to one example, the light source 50 and the shaft 20a can be connected by an optical fiber to provide light to the holes 20c and 20d. According to another example, a cavity that allows the light source to be inserted and removed can be provided in a part of the shaft, and the light source can be provided in the cavity to provide light to the holes 20c and 20d. According to yet another example, the light source can be provided at any position.

[0018] When the light source 50 is turned on, the light passes through the holes 20c and 20d and enters the light receiving element. By turning on the light source 50 while rotating the shaft 20a, or by repeating the rotation of the shaft 20a and the emission of light from the light source 50, the light can be made to enter the light receiving elements 12b, 14b, 16b, and 18b.

[0019] FIG. 4A is a cross-sectional view taken along line AA in FIG. 3. A plurality of holes 20d are provided on the side of the shaft 20a to transmit light from the light source. In this example, a plurality of holes 20d with different cross-sectional areas are provided. Light with high light intensity is emitted from a hole with a large cross-sectional area, and light with low light intensity is emitted from a hole with a small cross-sectional area. In FIG. 4A, arrows indicate the light La, Lb, Lc, and Ld emitted from the four holes 20d. The thickness of the arrow indicates the magnitude of the light intensity. The cross-sectional areas increase in the order of the cross-sectional area of ​​the optical path of light La, the cross-sectional area of ​​the optical path of light Lb, the cross-sectional area of ​​the optical path of light Lc, and the cross-sectional area of ​​the optical path of light Ld, so that the light intensity is light La<light Lb<light Lc<light Ld.

[0020] 4B is a cross-sectional view of a shaft according to another example. In this example, the cross-sectional areas of the four holes 20d are substantially the same. The four holes 20d are provided with light-transmitting materials 20e, 20f, 20g, and 20h having different light transmittances. The light-transmitting materials 20e, 20f, 20g, and 20h are, for example, ceramics. The light-transmitting materials 20e, 20f, 20g, and 20h have the lowest light transmittances in this order. As a result, the light intensities are as follows: light La<light Lb<light Lc<light Ld.

[0021] In the example of Figures 4A and 4B, light emitted from one light source passes through the inside of shaft 20a, is split into multiple light beams with different light intensities, and is provided to the light receiving element. By adjusting the shape or material of the shaft in a manner different from that of Figures 4A and 4B, multiple light beams with different light intensities can be provided.

[0022] According to one example, a method for calibrating a plurality of light receiving elements includes, in this order, making light incident on the plurality of light receiving elements from one light source, and performing system calibration so that outputs of the plurality of light receiving elements become the same when the plurality of light receiving elements receive the same amount of light from the one light source. The system calibration can also be called scaling.

[0023] 5 is a flow chart showing an example of a method for calibrating a light receiving element. First, in step S1, a plurality of lights having different amounts of light or light intensities are incident on the light receiving elements 12b, 14b, 16b, and 18b from the side of the shaft 20a in the manner described above. According to one example, the shaft 20a is rotated continuously or intermittently while providing light, so that a plurality of lights having different light intensities are incident sequentially on all the light receiving elements. For example, the lights La, Lb, Lc, and Ld are incident sequentially on the light receiving element 12b, the lights La, Lb, Lc, and Ld are incident sequentially on the light receiving element 14b, the lights La, Lb, Lc, and Ld are incident sequentially on the light receiving element 16b, and the lights La, Lb, Lc, and Ld are incident sequentially on the light receiving element 18b.

[0024] Then, as described above, due to the error of the light receiving elements, the outputs of the light receiving elements vary even though the light La, Lb, Lc, and Ld of the same light intensity are incident on all the light receiving elements. Figure 6A is a diagram showing an example of the outputs of the light receiving elements 12b, 14b, 16b, and 18b obtained in step S1. As is clear from this figure, the outputs for the same light input vary due to the characteristic variation of the light receiving elements.

[0025] If such output variations are found in step S1, the process proceeds to step S2. In step S2, in a controller exemplified by PMC 40 and UPC 42, system calibration is performed so that the outputs of multiple light receiving elements that receive the same amount of light from one light source become the same. FIG. 6B is a diagram showing that the outputs of multiple light receiving elements are made the same by system calibration. The calibration in step S2 makes it possible to make the outputs of multiple light receiving elements that receive light of the same light intensity the same.

[0026] On the other hand, if the relationship shown in FIG. 6B, for example, is obtained in step S1, then such system calibration is obviously not necessary.

[0027] Next, the relationship between the optical input and the output of the light receiving element, obtained with or without calibration, is stored as an initial log in step S3, for example, in the controller or an external storage device.

[0028] Thereafter, after a certain period of time has elapsed, for example by processing the substrate using a substrate processing apparatus or transporting the substrate, the process proceeds to step S4. In step S4, light is irradiated from one light source to the multiple light receiving elements with the same amount of light as that during system calibration. For example, light La, Lb, Lc, and Ld are sequentially received by all the light receiving elements. Then, it is confirmed whether the outputs of the multiple light receiving elements are maintained the same. This confirmation can be made by comparing the obtained output of the light receiving elements with the initial log saved in step S3.

[0029] If at least one of the outputs of the light receiving elements obtained in step S4 does not match the initial log, the process proceeds to step S5. FIG. 6C is a diagram showing an example of such a mismatch. In this example, when the same amount of light as that at the time of system calibration is received, the outputs of the light receiving elements 12b, 14b, and 16b match the initial log, but the output of the light receiving element 18b does not match the initial log. A light receiving element whose output is not maintained the same as the initial log is called an output variable element. If there is an output variable element, it is determined whether the difference between the output of the output variable element and the initial log exceeds a threshold value. In other words, it is determined whether the output change amount of the output variable element exceeds a threshold value. For example, in the example of FIG. 6C, it is determined whether the output of the output variable element is between the upper limit value UL and the lower limit value LL. If the output of the output variable element is between the upper limit value UL and the lower limit value LL, the process proceeds to step S6, and the system is recalibrated so that the outputs of the multiple light receiving elements are the same. For example, the output of the output variable element is calibrated so that it matches the initial log.

[0030] On the other hand, if the output change amount of the output variable element exceeds the threshold value, an alarm is issued in step S7. In the example of Fig. 6C, the output of the light receiving element 18b, which is the output variable element, is lower than the lower limit LL, so an alarm is issued.

[0031] In step S4, if the latest output values ​​of the multiple light receiving elements match the initial log, the process ends without recalibration. Steps S4-S7 can be performed periodically or after a specific process is completed. Periodically checking whether recalibration or an alarm is necessary makes it possible to prevent the output of the light receiving elements from changing over time for a certain input. The calibration and recalibration process can be performed automatically by the controller.

[0032] Calibrating the outputs of the multiple light receiving elements in this manner allows for the determination of the output level of the light receiving elements, for example, in substrate processing involving plasma emission. For example, it is possible to investigate whether substantially the same plasma is generated in multiple chambers, or whether plasma with a predetermined range of emission intensity is generated in multiple chambers. If plasma with an intended emission intensity is not generated in a specific chamber, the process conditions of that chamber can be changed to achieve plasma with the intended emission intensity. For example, the high frequency power can be adjusted, or the gas provided to the chamber can be adjusted. According to another example, the output of the light receiving element can be fed back to the process conditions of the substrate.

[0033] 7A and 7B are diagrams simply illustrating how the outputs of multiple light receiving elements are unified by calibration or recalibration. RC# stands for the reactor chamber number.

[0034] In the example of Fig. 3, the light from the light source 50 is split into multiple beams by the shaft 20a. However, according to another example, the light from the light source can be split in any part of the substrate transport apparatus to provide multiple beams of different light intensity to the light receiving element. For example, the light from the light source may be provided to the light receiving element from a rotation arm.

[0035] 8 is a diagram showing how light is provided to a light receiving element from a rotation arm. The rotation arms 20b are made of a light-transmitting material that transmits light. Quartz or a light-transmitting ceramic can be used as the light-transmitting material.

[0036] The shaft 20a is provided with a hole 20c extending in a direction substantially parallel to the z-axis, and multiple holes 20d extending from the side surface of the shaft 20a to the hole 20c. The multiple holes 20d provided on the side surface of the shaft 20a can be holes with different cross-sectional areas, as illustrated in Fig. 4A. According to another example, the multiple holes 20d can be provided with light-transmitting materials with different light transmittances, as illustrated in Fig. 4B.

[0037] The multiple rotation arms 20b can be provided in one-to-one correspondence with the multiple holes 20d. For example, one rotation arm is provided adjacent to the outlet of one hole 20d. Light from the light source passes through the hole 20c and the multiple holes 20d, and the multiple rotation arms emit light, providing the light to the multiple light receiving elements.

[0038] According to another example, the light for calibration or recalibration can be provided to the light receiving element from a light emitting wafer. FIG. 9 is a cross-sectional view of the light emitting wafer 60. According to one example, the light emitting wafer 60 emits light by being provided with a fluorescent material, a battery and a light emitting device, or an LED. According to another example, the light emitting wafer 60 may be an LED-equipped teaching wafer used in the Auto teaching system provided by Cyber ​​Optics. According to one example, the light emitting wafer 60 provides a plurality of lights with different light intensities to a plurality of light receiving elements. The light emitting wafer 60 can be provided to and removed from the chamber by the same transport system as the product wafer.

[0039] The light-emitting wafer 60 is placed on a stage in a certain chamber, and light is provided to a light-receiving element that monitors the inside of that chamber. After that, the light-emitting wafer 60 is placed on a stage in another chamber, and light is provided to a light-receiving element that monitors the inside of that chamber. In this manner, the movement of the light-emitting wafer and the provision of the reference light to the light-receiving element are repeated, whereby the reference light is provided to all the light-receiving elements from one light-emitting wafer 60.

[0040] According to another example, a light emitting wafer 60 is placed on a rotation arm, and light is made incident from the light emitting wafer onto a plurality of light receiving elements by utilizing the rotation of the rotation arm.

[0041] 10 is a diagram showing a dual chamber module (DCM) 51 and a light emitting wafer 60. In the case of the DCM 51, the light emitting wafer 60 is placed on a stage 52a in a chamber 52, and reference light is provided from the light emitting wafer 60 to a light receiving element 52b. Furthermore, the light emitting wafer 60 is placed on a stage 54a in a chamber 54, and reference light is provided from the light emitting wafer 60 to a light receiving element 54b.

[0042] For example, the process for calibrating or recalibrating the light receiving element in FIG. 5 is the same whether the reference light is applied to the light receiving element from the substrate transport device or from the light emitting wafer. [Explanation of symbols]

[0043] 20 substrate transport device, 20a shaft, 20b rotation arm, 12b, 14b, 16b, 18b light receiving element

Claims

1. A chamber housing a plurality of stages; a light receiving element that receives light from inside the chamber; a substrate transport device having a shaft and a rotation arm that rotates in association with the rotation of the shaft, and configured to move a substrate between the plurality of stages; A light source; A plurality of holes are provided on the side of the shaft, The substrate processing apparatus, wherein the substrate transport device is configured to split light from the light source and provide a plurality of light beams with different light intensities to the light receiving element through the plurality of holes.

2. The substrate processing apparatus of claim 1 , wherein the plurality of holes have different cross-sectional areas.

3. The substrate processing apparatus according to claim 1 , further comprising: a light transmitting material having different light transmittances provided in the plurality of holes.

4. The substrate processing apparatus according to claim 1 , wherein the light source is provided outside the chamber.

5. A chamber housing a plurality of stages; a light receiving element that receives light from inside the chamber; a substrate transport device having a shaft and a plurality of rotation arms that rotate in association with the rotation of the shaft, the substrate transport device moving the substrate between the plurality of stages; A light source; the plurality of rotation arms are formed of a light-transmitting material that transmits light; A plurality of holes are provided on a side surface of the shaft to allow light from the light source to pass therethrough, the plurality of rotation arms are provided in one-to-one correspondence with the plurality of holes, The substrate processing apparatus, wherein the substrate transport device is configured to split light from the light source and provide a plurality of light beams with different light intensities to the light receiving element through the plurality of holes.

6. The substrate processing apparatus of claim 5 , wherein the plurality of holes have different cross-sectional areas.

7. The substrate processing apparatus according to claim 5 , further comprising: a light transmitting material having different light transmittances provided in the plurality of holes.

8. The substrate processing apparatus according to claim 5 , wherein the light source is provided outside the chamber.

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