Device for monitoring laser marking energy
By using bidirectional glass and a reflective light detector to monitor laser energy in the laser marking device, the problem of abnormal laser marking energy was solved, thus improving product quality and yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GTA SEMICON CO LTD
- Filing Date
- 2025-05-29
- Publication Date
- 2026-05-19
AI Technical Summary
In existing technologies, abnormal laser energy in laser marking processes can lead to abnormal hole depths, affecting product quality and yield.
The laser marking energy is monitored by using bidirectional glass and a reflective light detector. The energy value of the reflected light is detected by reflecting it through the bidirectional glass, and the controller is used for real-time monitoring and alarm.
This enables real-time monitoring of laser marking energy, avoiding laser energy anomalies and improving process quality and product yield.
Smart Images
Figure CN224254501U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor manufacturing, and in particular to a device for monitoring laser marking energy. Background Technology
[0002] Laser marking is an important process in semiconductor manufacturing. It involves using a focused laser beam to melt and create holes on the surface of a wafer, and then arranging a large number of holes to form specific characters.
[0003] Figure 1 This is a schematic diagram of the device structure for existing laser marking technology, such as... Figure 1 As shown, the light emitted from the marking light source 11 of the marking machine passes through the double lens group 12 and reaches the refractive plane mirror 13 to form refracted light. The first motor 141 and the second motor 142 respectively control the refraction direction of the refractive plane mirror 13 along the X and Y directions to adjust the optical path of the refracted light. The laser energy of the refracted light is increased by the focusing lens 15, so that the refracted light melts on the surface of the target wafer 10 to form holes. Multiple holes arranged in a set order form characters.
[0004] In practical engineering applications, laser marking follows the principle of drilling from top to bottom and from left to right. During the process, abnormal laser energy can cause abnormalities in hole depth and surface appearance. For example, if the process requires a drilling depth of 5μm, but an abnormal process occurs, the hole depth may reach 87μm, leading to defects in a large batch of products.
[0005] Therefore, providing a monitoring device for laser marking that can monitor the laser energy in the laser marking process in real time is of great importance for improving process quality and product yield. Summary of the Invention
[0006] The technical problem to be solved by this utility model is to provide a device for monitoring laser marking energy, which can monitor the laser energy in the laser marking process in real time.
[0007] To address the aforementioned problems, this invention provides a device for monitoring laser marking energy, comprising: a bidirectional glass, wherein the bidirectional glass is disposed in the optical path of the marking beam marking a target wafer, the bidirectional glass comprising a glass body and a reflective surface covering the glass body, the reflective surface comprising a reflective layer formed by multiple dielectric films, the reflective surface facing the target wafer, and the reflective surface forming an angle with the surface of the target wafer, the bottom end of the bidirectional glass having a gap with the surface of the target wafer, and the reflective surface capable of reflecting the reflected light formed after the marking beam strikes the surface of the target wafer; and a reflected light detector, wherein the reflected light detector is disposed in the optical path of the beam after the reflected light is reflected by the reflective surface, for detecting the reflected energy value of the beam reflected by the reflective surface.
[0008] In some embodiments, the total thickness of the bidirectional glass is less than or equal to 1.5 mm.
[0009] In some embodiments, the included angle is 45 degrees.
[0010] In some embodiments, the spacing is less than or equal to 1 cm.
[0011] In some embodiments, the size of the bidirectional glass is capable of covering the marking area on the surface of the target wafer.
[0012] In some embodiments, the bidirectional glass can withstand temperatures greater than the melting point of the target wafer.
[0013] In some embodiments, the reflective surface includes a first metal layer and a second metal layer, wherein the first metal layer covers the surface of the glass body and the second metal layer covers the surface of the first metal layer.
[0014] In some embodiments, the marking beam is a green laser; the glass body is made of synthetic quartz; the first metal layer is made of copper with a thickness of 0.97 μm; and the second metal layer is made of silver with a thickness of 1 μm.
[0015] In some embodiments, a controller is also included, which is connected to the reflective light detector to obtain the reflected energy value of the light beam after the reflected light is reflected by the reflective surface.
[0016] In some embodiments, the controller is configured to compare the reflected energy value with a reflected energy threshold range, and trigger an alarm when the reflected energy value exceeds the reflected energy threshold range.
[0017] The above technical solution provides a device for monitoring laser marking energy. By placing a bidirectional glass, including a glass body and a reflective surface, in the optical path of the marking beam marking a target wafer, the bidirectional glass includes a glass body and a reflective surface covering the glass body. The reflective surface comprises a reflective layer formed by multiple dielectric films, and faces the target wafer. While ensuring the transmittance of the marking beam, it reflects the reflected light from the surface of the target wafer. A reflective light detector detects the reflected energy value of the beam after the marking beam strikes the target wafer surface and is reflected by the reflective surface. By monitoring the reflected energy value, the energy change of the laser marking output light is monitored. This allows for the timely detection of abnormal energy output light during laser marking, preventing large-scale product defects and playing a crucial role in improving process quality and product yield.
[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the device structure for laser marking in existing technology;
[0021] Figure 2 This is an enlarged schematic diagram of a device for monitoring laser marking energy provided in an embodiment of this utility model;
[0022] Figure 3 This is a schematic diagram of a device for monitoring laser marking energy provided in an embodiment of the present invention;
[0023] Figure 4A This is an energy diagram of the marking light source beam under normal conditions and the beam beam after reflection by the reflective surface, provided by an embodiment of this utility model;
[0024] Figure 4B This is an energy diagram of the beam of the marking light source under abnormal conditions and the beam after reflection by the reflective surface, provided by an embodiment of this utility model.
[0025] Explanation of reference numerals in the attached figures:
[0026] 10 target wafers;
[0027] 11 Marking light source;
[0028] 12-lens group;
[0029] 13 refracting plane mirrors;
[0030] 141 First Motor;
[0031] 142 Second motor;
[0032] 15 focusing lenses;
[0033] 21-way dual-view glass;
[0034] 211 glass body;
[0035] 212 reflective surface;
[0036] 2121 First metal layer;
[0037] 2122 Second metal layer;
[0038] 22. Reflected light detector;
[0039] 23 Controllers. Detailed Implementation
[0040] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0041] Figure 2 This is an enlarged schematic diagram of a device for monitoring laser marking energy according to an embodiment of this utility model. Figure 2 As shown, the device for monitoring laser marking energy includes: a bidirectional glass 21 and a reflective light detector 22.
[0042] The bidirectional glass 21 is disposed in the optical path of the marking beam marking the target wafer 10. The bidirectional glass 21 includes a glass body 211 and a reflective surface 212 covering the glass body 211. The reflective surface 212 includes a reflective layer formed by multiple dielectric films. The reflective surface 212 faces the target wafer 10, and the reflective surface 212 forms an angle α with the surface of the target wafer 10. The bottom end of the bidirectional glass 21 has a distance D from the surface of the target wafer 10. The reflective surface 212 can reflect the reflected light formed after the marking beam strikes the surface of the target wafer 10. The bidirectional glass 21 is a bidirectional mirror, also known as a one-way mirror, which can reflect most of the projected light.
[0043] The marking beam is a beam emitted by a laser marking device onto the target wafer 10. Figure 3 This is a schematic diagram illustrating the monitoring of laser marking energy using a device for monitoring laser marking energy, provided in one embodiment of this utility model. (See diagram for example.) Figure 3 As shown, the marking beam is the emitted light from the marking light source 11 of the marking machine, which passes through the double lens group 12 and reaches the refractive plane mirror 13 to form refracted light, and then passes through the focusing lens 15 to increase the laser energy. The first motor 141 and the second motor 142 respectively control the refraction direction of the refractive plane mirror 13 along the X and Y directions, so that the marking beam is emitted perpendicularly to the surface of the target wafer 10. Accordingly, the optical path of the marking beam is perpendicular to the surface of the target wafer 10 and points downwards.
[0044] The marking beam is a green laser. Green lasers possess characteristics such as short wavelength, high energy density, and precise focusing, enabling high-precision marking on various material surfaces. When the target wafer 10 is irradiated by the green laser, changes occur, including thermal diffusion and thermal expansion, simultaneously generating the reflected light.
[0045] The total thickness of the bidirectional glass 21 is less than or equal to 1.5 mm to reduce the loss of the marking beam and prevent the device monitoring the laser marking energy from obstructing the marking optical path. The total thickness of the bidirectional glass 21 includes the sum of the thickness of the glass body 211 and the reflective surface 212. In this embodiment, the total thickness of the bidirectional glass 21 is 1.5 mm; in some embodiments, the total thickness of the bidirectional glass 21 is 1 mm.
[0046] The distance D between the bottom end of the bidirectional glass 21 and the surface of the target wafer 10 is less than or equal to 1 cm, thereby ensuring that the reflective surface 212 can receive sufficient reflected light.
[0047] The bidirectional glass 21 is sized to cover the marking area on the surface of the target wafer 10. The marking area refers to the region on the surface of the target wafer 10 where specific characters are formed by marking. In this embodiment, the bidirectional glass 21 is a square thin plate with dimensions of 100mm × 100mm.
[0048] The bidirectional glass 21 can withstand temperatures greater than the melting point of the target wafer 10, or equal to 1500°C. The temperature that the bidirectional glass 21 can withstand refers to the highest temperature that the bidirectional glass 21 can withstand while maintaining its original performance and structural integrity, without significant deformation, cracking, softening, or other harmful changes. In this embodiment, the melting point of the wafer 20 is 1410°C, and the bidirectional glass 21 used has a temperature resistance greater than or equal to 1500°C to ensure that the marking beam will not damage the bidirectional glass 21.
[0049] The material of the glass body 211 is selected such that the transmittance of the glass body 211 to the marking beam exceeds 90%. In this embodiment, the marking beam is a green laser, and the material of the glass body 211 is synthetic quartz, which has a transmittance of 94% to the green laser.
[0050] The reflective surface 212 is used to reflect the reflected light formed after the marking beam is directed at the surface of the target wafer 10. The reflective surface 212 includes a first metal layer 2121 and a second metal layer 2122, the first metal layer 2121 covering the surface of the glass body 211, and the second metal layer 2122 covering the surface of the first metal layer 2121.
[0051] The reflective surface 212 is a reflective layer formed by multiple dielectric films. Specifically, the reflective surface 212 includes a first metal layer 2121 and a second metal layer 2122. The first metal layer 2121 is made of copper and has a thickness of 0.97 μm; the second metal layer 2122 is made of silver and has a thickness of 1 μm. The first metal layer 2121 has a reflectivity of 60% for green laser light, and the second metal layer 2122 has a reflectivity of 95% for green laser light.
[0052] The specific process for forming the reflective surface 212 includes: using a vacuum coating method, applying a first layer of 0.97 μm thick copper and a second layer of 1 μm thick silver. Since copper is easily oxidized, covering the copper surface with silver reduces oxidation. The two metal layers combine to form a reflective layer, enabling the reflective surface 212 to achieve a reflectivity of up to 98%. For example, in this embodiment, the reflectivity of the reflective surface 212 is 98.84%.
[0053] The reflected light detector 22 is disposed in the optical path of the light beam after the reflected light is reflected by the reflecting surface 212, and is used to detect the reflected energy value of the light beam reflected by the reflecting surface 212. The unit of the reflected energy value detected by the reflected light detector 22 can be joules (J), or other units that can be converted to joules.
[0054] like Figure 2 As shown, the optical path of the marking beam is perpendicular to the target wafer 10 and points downwards, with an included angle α of 45 degrees. Correspondingly, the reflected light generated by the marking beam hitting the surface of the target wafer 10, after being reflected by the reflecting surface 212, is basically parallel to the surface of the target wafer 10. Therefore, the probe of the reflected light detector can be set perpendicular to the surface of the target wafer 10, which facilitates the light collection by the reflected light detector 22.
[0055] The device for monitoring laser marking energy further includes a controller 23, which is connected to the reflective light detector 22 to obtain the reflected energy value of the beam after the reflected light is reflected by the reflective surface 212. In this embodiment, the controller 23 and the reflective light detector 22 are connected via a network, which can be one or more of wired, wireless, Wi-Fi, Bluetooth, and other communication networks.
[0056] The controller 23 is configured to compare the reflected energy value with a reflected energy threshold range, and trigger an alarm when the reflected energy value exceeds the reflected energy threshold range. The reflected energy threshold range is the normal fluctuation range of the energy of the light beam after reflection by the reflective surface 212 when the marking process is normal.
[0057] In this embodiment, the controller 23 is integrated into the laser marking machine, which includes a display device. When the reflected energy value exceeds the reflected energy threshold, the laser marking machine stops operating and displays an alarm message on the display device to remind technicians to adjust the marking laser energy. In some embodiments, the laser marking machine is also connected to an alarm, which sounds an alarm when the reflected energy value exceeds the reflected energy threshold.
[0058] Figure 4A This is an energy diagram of the marking light source beam under normal conditions and the beam beam after reflection by the reflective surface, provided by an embodiment of this utility model; Figure 4B This is an energy diagram of the beam of the marking light source under abnormal conditions and the beam after reflection by the reflective surface, provided by an embodiment of this utility model.
[0059] refer to Figure 4A and Figure 4BThe red curve represents the energy curve of the light beam after reflection by the reflective surface, while the blue curve represents the energy curve of the marking light source beam. Clearly, the energy trends of the marking light source beam and the beam after reflection by the reflective surface are consistent. Specifically, when the energy of the beam after reflection by the reflective surface remains within the reflection energy threshold range, the energy of the marking light source beam also remains within a normal threshold range; when the energy of the beam after reflection by the reflective surface fluctuates beyond the reflection energy threshold range, the energy of the marking light source beam also fluctuates abnormally beyond the normal threshold range. Therefore, by monitoring the energy of the beam after reflection by the reflective surface, this invention can monitor the energy changes of the marking light source beam, thereby preventing the marking beam from drilling holes on the surface of the target wafer 10 beyond the normal depth range.
[0060] The above technical solution provides a device for monitoring laser marking energy. By placing a bidirectional glass, including a glass body and a reflective surface, in the optical path of the marking beam marking the target wafer, the device reflects the reflected light from the target wafer surface while ensuring the transmittance of the marking beam. A reflective light detector detects the reflected energy value of the beam after the reflected light from the marking beam on the target wafer surface is reflected by the reflective surface. By monitoring the reflected energy value, the energy change of the laser marking output light is monitored. This allows for the timely detection of abnormal energy output light during laser marking, preventing large-scale product defects and playing a crucial role in improving process quality and product yield.
[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion. The various embodiments in this specification are described in a related manner, and similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.
[0062] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.
Claims
1. An apparatus for monitoring laser marking energy, characterized in that, include: A bidirectional glass is disposed in the optical path of a marking beam marking a target wafer. The bidirectional glass includes a glass body and a reflective surface covering the glass body. The reflective surface includes a reflective layer formed by multiple dielectric films. The reflective surface faces the target wafer and forms an angle with the surface of the target wafer. There is a gap between the bottom end of the bidirectional glass and the surface of the target wafer. The reflective surface can reflect the reflected light formed after the marking beam hits the surface of the target wafer. A reflected light detector is disposed in the optical path of the light beam after the reflected light is reflected by the reflecting surface, and is used to detect the reflected energy value of the light beam reflected by the reflecting surface.
2. The apparatus for monitoring laser marking energy according to claim 1, wherein, The total thickness of the bidirectional glass is less than or equal to 1.5 mm.
3. The apparatus for monitoring laser marking energy according to claim 1, wherein, The included angle is 45 degrees.
4. The apparatus for monitoring laser marking energy according to claim 1, wherein, The spacing is less than or equal to 1 cm.
5. The apparatus for monitoring laser marking energy according to claim 1, wherein, The size of the bidirectional glass is sufficient to cover the marking area on the surface of the target wafer.
6. The apparatus for monitoring laser marking energy of claim 1, wherein, The bidirectional glass can withstand temperatures higher than the melting point of the target wafer.
7. The apparatus for monitoring laser marking energy according to claim 1, wherein, The reflective surface includes a first metal layer and a second metal layer, wherein the first metal layer covers the surface of the glass body and the second metal layer covers the surface of the first metal layer.
8. The apparatus for monitoring laser marking energy according to claim 7, wherein, The marking beam is a green laser; the glass body is made of synthetic quartz; the first metal layer is made of copper with a thickness of 0.97 μm; and the second metal layer is made of silver with a thickness of 1 μm.
9. The apparatus for monitoring laser marking energy of claim 1, wherein, It also includes a controller connected to the reflected light detector to obtain the reflected energy value.
10. The apparatus for monitoring laser marking energy according to claim 9, wherein, The controller is configured to compare the reflected energy value with a reflected energy threshold range, and trigger an alarm when the reflected energy value exceeds the reflected energy threshold range.