Detection system and method for detecting ripple marks on quartz wafers

Abstract

To provide a detection system and a detection method which have detection capability for ripple defects of a quartz wafer.SOLUTION: A detection system includes a light source device, a coaxial imaging device, and a dimmer. The coaxial imaging device is used to irradiate a quartz wafer with illumination light, after receiving the illumination light and allowing the illumination light to pass through an objective lens set in the form of coaxial illumination. The illumination light passing through the objective lens set has an oblique component that is incident obliquely on the quartz wafer and a vertical component that is incident vertically on the quartz wafer. The illumination light is defined to have an axis. The dimmer partially blocks the illumination light and is used to make the oblique component asymmetric with respect to the axis. Thus, ripple defects on the quartz wafer can be appeared in a detection image.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technical field of the present disclosure relates to optical detection technology, and particularly to a detection system and a detection method capable of detecting ripple marks on a quartz wafer.

Background Art

[0002] Quartz materials are used in various electronic products due to their own characteristics (low loss, small thermal expansion coefficient, piezoelectric effect, etc.). For example, crystal oscillators are widely used in communication products such as mobile phones and network devices.

[0003] In the manufacturing process of quartz wafers, defects may occur during the formation of the crystal lattice, and these defects are likely to lead to ripple marks (ripple defect) on the manufactured quartz wafers. Ripple marks cause the etching rate of the quartz wafer to vary in all directions during the etching process, which affects the performance of the manufactured quartz chips and may cause them to fail inspection, resulting in a decrease in yield. For thinner quartz chips, the impact of ripple marks is even greater, making it more difficult to improve the yield.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the detection system and detection method of some embodiments of the present disclosure, the detection ability of ripple marks on a quartz wafer is improved.

[0005] In the detection system and detection method of some embodiments of the present disclosure, by solving the problem that ripple marks are difficult to detect, the effect of improving the yield is achieved.

[0006] By improving the ability to detect ripple marks on quartz wafers, it is possible to check for ripple marks on the quartz wafers before they enter the downstream process and are fabricated into individual quartz chips. This prevents defective wafers from flowing into the downstream process and reducing the yield of the final product. [Means for solving the problem]

[0007] According to several embodiments, a detection system capable of detecting ripple marks on a quartz wafer is provided, comprising a light source device, a coaxial imaging device, and a dimming device. The light source device is used to emit illumination light. The coaxial imaging device is used to receive the illumination light, pass the illumination light through an objective lens set in the form of coaxial illumination, and then irradiate the quartz wafer. The coaxial imaging device is also used to acquire a detection image of the quartz wafer. The dimming device is positioned between the light source device and the coaxial imaging device and is used to partially block the illumination light. The illumination light that has passed through the objective lens set consists of an oblique component incident obliquely on the quartz wafer and a perpendicular component incident perpendicularly on the quartz wafer, and the illumination light is defined as having an axis, and the dimming device is used to make the oblique component appear asymmetrical with respect to the axis.

[0008] According to some embodiments, the dimming device includes a blocking section that blocks illumination light and a light-transmitting section that allows illumination light to pass through, and the area of ​​the blocking section can be configured to be larger than that of the light-transmitting section.

[0009] According to some embodiments, the illumination light incident on the dimming device defines a cross-sectional region through which the light passes along its axis, and this cross-sectional region is defined to have four quadrant regions, and the dimming device may be configured to shield at least two of the four quadrant regions of the cross-sectional region.

[0010] According to some embodiments, the illumination light incident on the dimming device defines a cross-sectional region through which the light passes along the axis, and this cross-sectional region is defined to have four quadrant regions, and the dimming device may be configured to shield three of the four quadrant regions of the cross-sectional region.

[0011] According to some embodiments, the dimming device may be configured to include a movable shielding member for selectively and partially shielding the illumination light incident on the dimming device.

[0012] According to some embodiments, the shielding member may have two working parts, one of which may be used to allow all of the illumination light incident on the dimmer to pass through, and the other working part may be used to partially shield the illumination light incident on the dimmer.

[0013] According to some embodiments, the other working part is defined to have a blocking part that blocks illumination light and a light-transmitting part that allows illumination light to pass through, with the area of ​​the blocking part being larger than that of the light-transmitting part. In some embodiments, the light-transmitting part may be configured as a fan-shaped opening with an opening angle of 90 degrees or less.

[0014] According to several embodiments, a method for detecting ripple marks on a quartz wafer is provided for use in a coaxial imaging apparatus for acquiring a detection image by focusing illumination light onto a quartz wafer after it has passed through an objective lens set. The detection method is characterized by partially shielding the illumination light such that the illumination light that has passed through the objective lens set has an oblique component that is incident on the quartz wafer at an angle and a perpendicular component that is incident on the quartz wafer perpendicularly, wherein the illumination light is defined as having an axis and the oblique component is asymmetric with respect to the axis. [Effects of the Invention]

[0015] Therefore, the configuration of the coaxial imaging device makes it possible to make ripple marks on a quartz wafer visible in the detection image under specific detection conditions (specific lighting conditions). This allows for confirmation of whether ripple marks are present on the quartz wafer before it enters the subsequent process and is fabricated into individual quartz chips. This prevents defective wafers from flowing into subsequent processes and improves the overall yield of the process. [Brief explanation of the drawing]

[0016] [Figure 1] Schematic diagram of a detection system for a quartz wafer according to some embodiments. [Figure 2] Partial schematic diagram of illumination light on an optical path according to some embodiments. [Figure 3] Schematic diagram of an optical path through which illumination light that is not partially blocked passes through an objective lens set according to some embodiments. [Figure 4] Schematic diagram of an optical path through which partially blocked illumination light passes through an objective lens set according to some embodiments. [Figure 5] Detection image of a quartz wafer obtained under the irradiation conditions (without shielding) of FIG. 3. [Figure 6] Detection image of a quartz wafer obtained under the irradiation conditions (the oblique component is asymmetric) of FIG. 4. [Figure 7] Detection image of a quartz wafer obtained under irradiation conditions where only symmetric oblique component irradiation light is incident on the quartz wafer. [Figure 8] Schematic diagram of a dimming device according to Example 1. [Figure 9] Schematic diagram of a dimming device according to Example 2. <{ [Figure 10] Schematic diagram of a dimming device according to Example 3. [Figure 11] Schematic diagram of a dimming device according to Example 4.

Mode for Carrying Out the Invention

[0017] In order to fully understand the object, features, and effects of the present invention, the present invention will be described in detail below in combination with the drawings attached to specific embodiments.

[0018] As used herein, the term "a" or "an" is used to describe a unit, member, structure, device, module, system, part or region, etc. This is done merely for convenience and to give a general meaning to the scope of the present invention. This description should be read as including one or at least one, and the singular includes the plural unless it is clear that it means otherwise.

[0019] As used herein, the term "comprising", "including", "having" or any other variation thereof is not necessarily limited to only those components, and can also include other components not explicitly listed for such units, members, structures, devices, modules, systems, parts or regions, or inherent thereto.

[0020] The coaxial imaging device can integrate illumination light into the imaging path, that is, the coaxial imaging device irradiates the test object with illumination light in the form of coaxial illumination by making the axis of the illumination light (for example, the central axis) coaxial with the imaging axis, and obtains a detection image of the illuminated test object. The coaxial imaging device is suitable for many detection environments that require uniform illumination and has been widely used in various optical detection systems.

[0021] FIG. 1 is a schematic diagram of a detection system for a quartz wafer according to some embodiments. The detection system includes a light source device 100, a coaxial imaging device 200, and a light control device 300.

[0022] The light source device 100 is used to emit illumination light L1. The light control device 300 is used to adjust the illumination light L1 emitted by the light source device 100. The coaxial imaging device 200 receives the adjusted illumination light L2 and irradiates the quartz wafer 400 in the form of coaxial illumination. The coaxial imaging device 200 includes an objective lens set 210, and after the illumination light L2 passes through the objective lens set 210, an illumination light L3 that converges on the quartz wafer 400 is formed. In some other embodiments, the light control device 300 can also be integrated with the coaxial imaging device 200 to achieve the same adjustment effect.

[0023] As shown in Figure 1, the illumination light L1 emitted by the light source device 100 is partially shielded based on the adjustment action provided by the dimming device 300 to form adjusted illumination light L2. After passing through the reflective member 201 and the spectral member 202, the adjusted illumination light L2 illuminates the quartz wafer 400 on the imaging path of the imaging unit 220, creating coaxial illumination conditions. After passing through the objective lens set 210, the adjusted illumination light L2 forms focused illumination light L3 on the quartz wafer 400. The reflected light L and R from the illuminated quartz wafer 400 pass through the objective lens set 210 and the spectral member 202 and enter the imaging unit 220 to generate a detection image. In some other embodiments, the reflective member 201 may be omitted, for example, the light source device 100 may be configured to be incident on the coaxial imaging device 200 from the side, and the illumination light L1 may be emitted to irradiate in the direction of the spectral member 202.

[0024] Next, Figure 2 is a schematic partial view of illumination light in the optical path according to several embodiments. The illumination light L1 emitted from the light source device 100 defines a light point formed on an arbitrary plane whose normal vector is the direction of light propagation, for example, on the plane of the real object. The illumination light L1 emitted from the light source device 100 can be defined as having an axis C perpendicular to the plane to which the cross-sectional area A belongs, for example, the central axis or the optical axis of the objective lens set 210. Axis C can be used as a reference for comparison to show the relative pattern (e.g., symmetrical or asymmetrical) of the light irradiated toward the object under examination. In the example in Figure 2, the illumination light L1 emitted from the light source device 100 exhibits a pattern symmetrical with respect to axis C.

[0025] Next, referring to Figures 3 and 4, Figure 3 is a schematic diagram of the optical path through which partially unblocked illumination light passes the objective lens set according to several embodiments, and Figure 4 is a schematic diagram of the optical path through which partially blocked illumination light passes the objective lens set according to several embodiments. For ease of explanation, Figures 3 and 4 are simplified by omitting optical elements for reflection or spectroscopy that do not affect the optical path focused on the quartz wafer 400. Whether the illumination light is partially blocked or not is expressed by the amount of illumination light.

[0026] As shown in Figure 3, the illumination light L11, L12, and L13 emitted from the light source device 100 are not shielded and, after passing through the objective lens set 210, each form corresponding parallel light and are focused onto the quartz wafer 400. These lights focused onto the quartz wafer 400 include a vertical component L12' that is incident perpendicular to the quartz wafer 400 and oblique components L11' and L13' that are incident obliquely to the quartz wafer 400, respectively. As can be seen from Figure 3, the partially unshielded illumination light, after passing through the objective lens set, exhibits a symmetrical pattern with respect to axis C, regardless of whether it is a vertical or oblique component incident on the quartz wafer 400.

[0027] As shown in Figure 4, the illumination light L13 emitted from the light source device 100 is shielded (not shown), and the illumination light L12 is partially shielded. After the remaining light passes through the objective lens set 210, it forms corresponding parallel light beams, which are focused onto the quartz wafer 400. These beams focused onto the quartz wafer 400 include a vertical component L12' that is incident perpendicular to the quartz wafer 400 and an oblique component L11' that is incident obliquely to the quartz wafer 400. As can be seen from Figure 4, after the remaining light of the partially shielded illumination passes through the objective lens set, the oblique component incident on the quartz wafer 400 exhibits a clearly asymmetric pattern with respect to axis C (the oblique component L13' is blocked and cannot be incident on the quartz wafer 400).

[0028] Next, referring to Figures 5 to 7, Figure 5 is a detection image of a quartz wafer obtained under the irradiation conditions based on Figure 3 (no shielding), Figure 6 is a detection image of a quartz wafer obtained under the irradiation conditions of Figure 4 (the oblique component is asymmetrical), and Figure 7 is a detection image of a quartz wafer obtained under irradiation conditions in which only symmetrical oblique component irradiation light is incident on the quartz wafer (as further explained in Figure 3, the illumination light L12 is blocked). The object used for testing was a quartz wafer with ripple marks. As can be seen from Figures 5 to 7, if the oblique component of the irradiation light incident on the quartz wafer 400 is asymmetrical, and the irradiation light incident on the quartz wafer 400 also has a vertical component, the ripple marks will become apparent (Figure 6). Note that the ripple marks cannot be shown in Figures 5 and 7. Therefore, in order for the detection image to show the ripple marks, the oblique component of the irradiation light incident on the quartz wafer 400 must be asymmetrical, and at the same time, it must also have a vertical component. The vertical component is asymmetric under the irradiation conditions shown in Figure 4, but in some other embodiments, the vertical component can also be configured as symmetric.

[0029] (Example 1) Next, referring to Figure 8, which is a schematic diagram of the dimming device of Embodiment 1, the dimming device 300 includes a light-transmitting section 310 and a light-blocking section 320. The light-transmitting section 310 is for transmitting illumination light and is configured, for example, as a through hole or a light-transmitting member with a light transmittance of more than 90%. The light-blocking section 320 is for blocking illumination light and is configured, for example, as a non-light-transmitting member or a light-transmitting member with a light transmittance of less than 10%. The adjustment area 301 of the dimming device may correspond to, for example, the cross-sectional area A shown in Figure 2. The area of ​​the light-blocking section 320 is configured to be larger than that of the light-transmitting section 310. In the example of Figure 8, the light-transmitting section 310 is a fan-shaped opening with an opening angle of more than 90 degrees.

[0030] (Example 2) Next, referring to Figure 9, which is a schematic diagram of the dimming device of Embodiment 2. The illumination light L1 incident on the dimming device 300 defines a cross-sectional region A through which the light passes along axis C. The cross-sectional region A is defined as having four quadrant regions, and the dimming device 300 is used to shield at least two of the four quadrant regions of the cross-sectional region A. As shown in the example in Figure 9, the dimming device 300 is used to shield three of the four quadrant regions of the cross-sectional region A (where the shielding section 320 is located), leaving only one quadrant region (where the light-transmitting section 310 is located) and allowing the remaining illumination light L1 to pass through. Alternatively, the dimming device 300 can be configured to shield a larger area, leaving only an area smaller than one quadrant region so that the remaining illumination light L1 can pass through. In the example in Figure 9, the light-transmitting section 310 is a fan-shaped aperture with an opening angle equal to 90 degrees.

[0031] (Example 3) Next, referring to Figure 10, which is a schematic diagram of the dimming device of Embodiment 3, the dimming device 300 includes a movable shielding member 302. The shielding member 302 is provided with two working parts A1 and A2. Working part A1 is for allowing all of the illumination light incident on the dimming device 300 to pass through, and working part A2 is for partially shielding the illumination light incident on the dimming device 300. The movable shielding member 302 can provide operational flexibility, that is, it can be operated to selectively position working part A1 or working part A2 on the optical path region B according to the detection requirements, thereby adjusting the illumination light incident on the dimming device 300. Since this type of detection system equipped with a coaxial imaging device can simultaneously provide various other detection functions, the movable shielding member 302 provides high flexibility and convenience to the detection system and maximizes the use of the space occupied by the detection system.

[0032] The working part A1 is defined as having a light-transmitting section 312 that allows all of the illumination light to pass through. The working part A2 is defined as having a light-transmitting section 311 (for example, configured as a through hole or a light-transmitting member with a light transmittance of more than 90%) that allows most or all of the illumination light to pass through, and a blocking section 321 (for example, configured as a non-light-transmitting member or a light-transmitting member with a light transmittance of less than 10%) that prevents most or all of the illumination light from passing through. Furthermore, the light-transmitting section 311 can be configured as a fan-shaped opening with an opening angle of 90 degrees or less or at least less than 180 degrees, and the light-transmitting section 311 shown in Figure 10 is a fan-shaped opening with an opening angle of less than 90 degrees.

[0033] In the embodiments described above, examples are shown where the cross-sectional area A of the light spot, the working portion A1, and the working portion A2 are all circular (for example, the light source of the light source device 100 is provided by LEDs arranged in a circle), but light sources that form light spots of other shapes are also applicable to each embodiment. The size of the aperture angle of each light-transmitting portion (310, 311) with respect to axis C can be selected according to the actual illumination requirements and the incident light source (light spot shape). When the light spot is circular or approximately circular, the aperture angle of the light-transmitting portion (310, 311) can be configured to be at least less than 180 degrees, under the condition that the oblique components of the illumination light incident on the quartz wafer 400 are arranged asymmetrically. On the other hand, when the light spot has a shape other than circular, the size of the light-transmitting portion (310, 311) can be configured based on the purpose of asymmetrically arranging the oblique components of the illumination light incident on the quartz wafer 400.

[0034] (Example 4) Next, referring to Figure 11, which is a schematic diagram of the dimming device of Embodiment 4. The illumination light L1 incident on the dimming device 300 is defined as having a cross-sectional region A through which light passes along axis C. A sector-shaped region (i.e., light-transmitting portion 310) is defined in the cross-sectional region A with the axis as its vertex, and the dimming device 300 is used to shield the non-sector-shaped region within the cross-sectional region A. Compared with the embodiment in Figure 9, in the embodiment shown in Figure 11, the dimming device 300 can adjust the sector-shaped region (i.e., light-transmitting portion 310) to cover both the first quadrant region and the fourth quadrant region in order to further improve the contrast of defect display, and the adjusted illumination light L2 is formed by passing the illumination light L1 through the sector-shaped region (i.e., light-transmitting portion 310). In addition, the sector-shaped region (i.e., light-transmitting portion 310) can be adjusted to cover regions of other quadrants as needed, that is, the sector-shaped region (i.e., light-transmitting portion 310) can be rotated around axis C as needed to obtain better image quality. In the example shown in Figure 11, the sector-shaped region (i.e., the light-transmitting portion 310) is configured as a sector-shaped aperture having an aperture angle of less than 90 degrees. In other embodiments where the axis C is central and the light point is circular, the sector-shaped region (i.e., the light-transmitting portion 310) can be configured as a sector-shaped aperture having an aperture angle equal to 90 degrees or at least less than 180 degrees.

[0035] Therefore, regarding the detection method for making ripple marks on a quartz wafer visible, the illumination light is mainly focused onto the quartz wafer, which is the object under test, after passing through the objective lens set, to obtain a detection image. The method for making the ripple marks on the quartz wafer visible is to partially shield this illumination light. This shielding is done to include an oblique component that is incident on the quartz wafer at an angle and a perpendicular component that is incident on the quartz wafer perpendicularly in the illumination light passing through the objective lens set. The illumination light is defined as having an axis, and the oblique component needs to be asymmetric with respect to this axis. In this way, by adjusting or modifying a part of the coaxial imaging device on a conventional detection system, the detection system can be given the capability to detect ripple marks on a quartz wafer.

[0036] In short, the detection system and detection method disclosed in the embodiments, through the configuration of the coaxial imaging device, can make ripple marks on a quartz wafer visible in the detection image under specific detection conditions, thereby solving the problem of ripple marks being difficult to detect and improving yield.

[0037] Although the present invention has disclosed the best embodiment above, as those skilled in the art will understand, this embodiment is used solely to illustrate the invention and should not be understood as limiting the scope of the invention. It should be noted that all modifications and substitutions having equivalent effects to this embodiment are included within the scope of the invention. Therefore, the scope of protection of the present invention is as defined in the claims. [Explanation of symbols]

[0038] 100 Light source device 200 Coaxial Imaging Device 201 Reflective material 202 Spectroscopic component 210 Objective Lens Set 220 Imaging Unit 300 dimmers 301 Adjustment area 302 Shielding member 310 Translucent part 311 Translucent part 312 Translucent part 320 Interruption section 321 Shut-off section 400 quartz wafers A cross-sectional area A1 Action part A2 Action part B Optical path area L1 illumination light L11 Illumination Light L11' Diagonal component L12 illumination light L12' vertical component L13 illumination light L13' Diagonal component L2 illumination light L3 Illumination Light LR reflected light

Claims

1. A light source device for emitting illumination light, A coaxial imaging device that receives the illumination light, passes the illumination light through an objective lens set in the form of coaxial illumination, and then irradiates a quartz wafer with it, A dimming device is positioned between the light source device and the coaxial imaging device. A detection system capable of detecting ripple marks on a quartz wafer containing the above, A detection system in which the illumination light that has passed through the objective lens set has an oblique component that is incident obliquely on the quartz wafer and a vertical component that is incident perpendicularly on the quartz wafer, the illumination light is defined to have an axis, and the arrangement of the dimming device is such that the illumination light provided to the quartz wafer includes both the vertical component and the oblique component simultaneously, and the oblique component is asymmetric with respect to the axis.

2. The detection system according to claim 1, wherein the dimming device comprises a movable shielding member for selectively and partially shielding the illumination light incident on the dimming device.

3. The detection system according to claim 2, wherein the shielding member has two working parts, one of which is used to allow all of the illumination light incident on the dimming device to pass through, and the other working part is used to partially shield the illumination light incident on the dimming device.

4. The detection system according to claim 3, wherein the other working part is defined to have a blocking part that blocks the illumination light and a light-transmitting part that allows the illumination light to pass through, and the area of ​​the blocking part is larger than that of the light-transmitting part.

5. The detection system according to claim 4, wherein the light-transmitting portion has a fan-shaped opening with an opening angle of 90 degrees or less.

6. The detection system according to claim 1, wherein the dimming device includes a blocking section that blocks the illumination light and a light-transmitting section that allows the illumination light to pass through, and the area of ​​the blocking section is larger than that of the light-transmitting section.

7. A method for detecting ripple marks on a quartz wafer used in a coaxial imaging apparatus for acquiring a detection image by focusing illumination light onto a quartz wafer after it has passed through an objective lens set, wherein the illumination light that has passed through the objective lens set is partially shielded such that it has an oblique component incident on the quartz wafer at an angle and a vertical component incident perpendicular to the quartz wafer, the illumination light is defined as having an axis, and the illumination light provided to the quartz wafer simultaneously includes both the vertical component and the oblique component, and the oblique component is asymmetric with respect to the axis.

8. The detection method according to claim 7, wherein the illumination light is defined as having a cross-sectional region through which light passes along the axis, a sector-shaped region with the axis as its vertex is defined within the cross-sectional region, and the illumination light is partially shielded by shielding the portion other than the sector-shaped region.

9. The detection method according to claim 8, wherein the sector-shaped region is a sector-shaped opening having an opening angle of 90 degrees or less.

10. The detection method according to claim 7, wherein the illumination light is defined as having a cross-sectional region through which light passes along the axis, and the cross-sectional region is defined as having four quadrant regions, and the illumination light is partially shielded only in light-passing regions smaller than one quadrant region.

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