Positioning device and positioning method of optical fiber probe

Abstract

The invention discloses a positioning device and a positioning method for an optical fiber probe, and relates to the technical field of wafer testing, the positioning device comprises a chuck displacement table, a prism assembly, an optical fiber probe displacement table and a microscope displacement table, the chuck displacement table is used for arranging a wafer chuck, the prism assembly is provided with a prism chuck and a prism, and the optical fiber probe displacement table is provided with an optical fiber probe. The optical fiber probe displacement table is used for arranging an optical fiber probe, and the microscope displacement table is provided with a microscope. Arranging a prism chuck at the center of a microscope field of view, and measuring the height of the bottom of the prism; adjusting the optical fiber probe to the initial height by using a microscope and a prism; positioning the wafer chuck to the center of a field of view of the microscope, and measuring the height of any to-be-measured area on the surface of the wafer on the wafer chuck; and finally, the initial height of the optical fiber probe is compensated according to the height difference, so that the optical fiber probe is positioned to the optimal coupling height of the corresponding to-be-detected area, the positioning device is simple and effective to operate, a capacitance height detector is not needed for height detection and compensation, and the height detection and compensation efficiency of the optical fiber probe is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer testing, and in particular to a positioning device and a positioning method for an optical fiber probe. Background Art

[0002] In the testing of optoelectronic integrated chips and wafers, grating couplers and external fiber probes are usually used for testing. To ensure the consistency and stability of wafer testing, the incident angle and height of the optical fiber need to be calibrated to couple with the grating coupler.

[0003] In the existing technology, height detection and compensation are usually performed using a capacitive height probe. Different incident angles of the optical fiber are achieved by manufacturing a fixed-angle fixture. The capacitive height probe performs height measurement based on the parallel capacitance value measured at different distances. It has limitations on the angles of the substrate material and the optical fiber, making the positioning process cumbersome and inefficient. Summary of the Invention

[0004] The embodiments of the present invention provide a positioning device and a positioning method for an optical fiber probe, so as to solve the technical problem in the related art that the positioning process is complicated and inefficient when a capacitive height probe is used for height detection.

[0005] In a first aspect, a positioning device for an optical fiber probe is provided, the positioning device comprising:

[0006] A chuck displacement stage, wherein the chuck displacement stage is used to set a wafer chuck;

[0007] A prism assembly, comprising a prism chuck disposed on a chuck displacement stage and a prism disposed on the prism chuck;

[0008] An optical fiber probe displacement stage, wherein the optical fiber probe displacement stage is used to set the optical fiber probe;

[0009] A microscope translation stage is provided with a microscope.

[0010] In some embodiments, the chuck translation stage is a four-axis translation stage.

[0011] In some embodiments, the fiber probe translation stage is a six-axis translation stage.

[0012] In some embodiments, the microscope translation stage is a three-axis translation stage.

[0013] In some embodiments, an industrial camera is provided on the top of the microscope.

[0014] In a second aspect, a method for positioning an optical fiber probe is provided, using the aforementioned positioning device for an optical fiber probe, the positioning method comprising the following steps:

[0015] Place the prism chuck at the center of the microscope field of view and measure the height of the prism base;

[0016] Using a microscope and prism, adjust the fiber optic probe to its initial height;

[0017] Position the wafer chuck at the center of the microscope field of view and measure the height of any area to be measured on the wafer surface on the wafer chuck;

[0018] The initial height of the optical fiber probe is compensated according to the height difference between any area to be measured on the wafer surface and the bottom of the prism.

[0019] In some embodiments, the step of placing the prism chuck at the center of the microscope field of view and measuring the height of the prism bottom includes the following steps:

[0020] Move the prism chuck to the center of the microscope field of view;

[0021] Rotate the prism chuck until the bottom of the prism is level.

[0022] In some embodiments, the step of adjusting the optical fiber probe to an initial height using a microscope and a prism comprises the following steps:

[0023] Move the fiber optic probe to the bottom edge of the prism and adjust the focus or height of the microscope until the tip of the fiber optic probe is in focus.

[0024] Then adjust the focus or height of the microscope so that the microscope viewing angle is shifted to the top edge of the prism and the side view of the fiber optic probe reflected by the prism is focused;

[0025] Adjust the fiber optic probe to its initial height according to the side view of the fiber optic probe.

[0026] In some embodiments, the step of positioning the wafer chuck at the center of the microscope field of view and measuring the height of any area to be measured on the wafer surface on the wafer chuck comprises the following steps:

[0027] Position the wafer chuck to the center of the microscope field of view so that the wafer pattern on any area to be measured on the wafer surface on the wafer chuck remains level;

[0028] Adjust the microscope to focus on any area to be measured on the wafer surface.

[0029] In some embodiments, before the step of positioning the wafer chuck at the center of the microscope field of view and measuring the height of any area to be measured on the wafer surface on the wafer chuck, the following steps are further included:

[0030] Move the fiber optic probe to a preset safe position.

[0031] The beneficial effects brought about by the technical solution provided by the present invention include:

[0032] An embodiment of the present invention provides a positioning device and positioning method for an optical fiber probe. The positioning device includes a chuck translation stage, a prism assembly, an optical fiber probe translation stage, and a microscope translation stage. The chuck translation stage is used to set a wafer chuck. The prism assembly includes a prism chuck arranged on the chuck translation stage and a prism arranged on the prism chuck. The optical fiber probe translation stage is used to set the optical fiber probe. The microscope translation stage is provided with a microscope. In an embodiment of the present invention, a prism chuck is placed at the center of the microscope's field of view, and the height of the bottom of the prism is measured; then, the microscope and the prism are used to adjust the optical fiber probe to an initial height, that is, the optical fiber probe is adjusted to an optimal coupling height using the microscope and the prism, and the optimal coupling height is the initial height; then, the wafer chuck is positioned at the center of the microscope's field of view, and the height of any area to be measured on the wafer surface on the wafer chuck is measured; finally, the initial height of the optical fiber probe is compensated according to the height difference between any area to be measured on the wafer surface and the bottom of the prism, so as to position the optical fiber probe to the optimal coupling height corresponding to the area to be measured. The positioning device of the present invention is simple and effective to operate, and does not require the use of a capacitive height probe for height detection and compensation, thereby improving the efficiency of height detection and compensation of the optical fiber probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A schematic diagram of a positioning device for an optical fiber probe provided by an embodiment of the present invention;

[0035] Figure 2 The present invention provides a flowchart of a method for positioning an optical fiber probe.

[0036] Reference numerals:

[0037] 1. Chuck translation stage;

[0038] 2. Prism assembly; 21. Prism chuck; 22. Prism;

[0039] 3. Fiber optic probe translation stage;

[0040] 4. Microscope translation stage;

[0041] 5. Wafer chuck;

[0042] 6. Fiber optic probe;

[0043] 7. Microscope;

[0044] 8. Industrial cameras. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0046] The embodiments of the present invention provide a positioning device and a positioning method for an optical fiber probe, which can solve the technical problems in the related art of using a capacitive height probe for height detection, such as a complicated positioning process and low efficiency.

[0047] See also Figure 1 As shown, an embodiment of the present invention provides a positioning device for an optical fiber probe, the positioning device comprising a chuck translation stage 1, a prism assembly 2, an optical fiber probe translation stage 3 and a microscope translation stage 4, the chuck translation stage 1 being used to set a wafer chuck 5, the prism assembly 2 being provided with a prism chuck 21 provided on the chuck translation stage 1 and a prism 22 provided on the prism chuck 21, the optical fiber probe translation stage 3 being used to set an optical fiber probe 6, and the microscope translation stage 4 being provided with a microscope 7. In an embodiment of the present invention, the prism chuck 21 is placed at the center of the field of view of the microscope 7, and the height of the bottom of the prism 22, that is, the coordinate value in the Z direction, is measured; then the microscope 7 and the prism 22 are used to adjust the optical fiber probe 6 to the initial height, that is, the optical fiber probe 6 is adjusted to the optimal coupling height using the microscope 7 and the prism 22, and the optimal coupling height is the initial height; then the wafer chuck 5 is positioned at the center of the field of view of the microscope 7, and the height of any area to be measured on the wafer surface on the wafer chuck 5 is measured; finally, the initial height of the optical fiber probe 6 is compensated according to the height difference between any area to be measured on the wafer surface and the bottom of the prism 22, so as to position the optical fiber probe 6 to the optimal coupling height corresponding to the area to be measured. The positioning device of the present invention is simple and effective to operate, and does not require the use of a capacitive height probe for height detection and compensation, thereby improving the efficiency of optical fiber probe height detection and compensation.

[0048] As an optional implementation, in one embodiment of the invention, see Figure 1 As shown, the chuck translation stage 1 is a four-axis translation stage. In this embodiment of the present invention, the four-axis translation stage provides adjustment functions for X, Y, and Z axis translation and θz axis rotation. Together with the stable clamping of the wafer chuck and prism chuck, it improves the adjustment efficiency of the wafer and prism and ensures reliability during the adjustment process.

[0049] As an optional implementation, in one embodiment of the invention, see Figure 1As shown, the fiber probe translation stage 3 is a six-axis translation stage. In this embodiment of the present invention, the six-axis translation stage integrates X, Y, and Z translation and θx, θy, and θz angle adjustment capabilities around these three axes, providing precise control in six degrees of freedom. This facilitates position and angle compensation between the fiber probe and the optical device, i.e., the wafer. The fiber probe can be single-mode fiber, multimode fiber, or multi-core fiber; the top structure can be flat fiber, polished fiber, lensed fiber, or tapered fiber; and the fiber type can be uncoated or coated, making it suitable for a wide range of scenarios.

[0050] As an optional implementation, in one embodiment of the invention, see Figure 1 As shown, the microscope stage 4 is a three-axis stage. In this embodiment of the present invention, microscope 7 is mounted on the three-axis stage, which provides independent translation control in the X, Y, and Z axes. An objective lens facing the prism and wafer is located at the bottom of microscope 7. The three-axis stage ensures precise positioning and scanning of the objective lens in three dimensions. The high stability of the three-axis stage ensures rapid focusing on the area to be measured while eliminating mechanical vibration interference.

[0051] As an optional implementation, in one embodiment of the invention, see Figure 1 As shown, an industrial camera 8 is provided on the top of the microscope 7. In the embodiment of the present invention, the industrial camera 8 on the top of the microscope 7 is used to measure the angle and height of the optical fiber probe in the image, with high measurement efficiency and accuracy.

[0052] An embodiment of the present invention further provides a method for positioning an optical fiber probe, using the aforementioned positioning device for an optical fiber probe, the positioning method comprising the following steps:

[0053] S10: Place the prism chuck 21 at the center of the field of view of the microscope 7 and measure the height of the bottom of the prism 22;

[0054] That is, the prism chuck 21 is moved to the center of the field of view of the microscope 7, and the prism chuck 21 is rotated until the bottom of the prism 22 is level.

[0055] Specifically, the chuck translation stage 1 is used to move the prism chuck 21 to the center of the field of view of the microscope 7. The prism chuck 21 is simultaneously controlled to rotate, adjusting the bottom of the prism 22 to a completely horizontal position within the image. The Z-axis coordinate value Zv1 of the bottom of the prism 22 is then measured using the microscope 7. This facilitates the use of the prism 22 as a reference in subsequent steps, and the horizontal position of the prism 22 ensures an accurate reference for subsequent height calibration, thereby eliminating systematic errors caused by the tilt of the prism 22.

[0056] S20: Using the microscope 7 and the prism 22, adjust the optical fiber probe 6 to an initial height;

[0057] Specifically, the microscope 7 and the prism 22 are used to adjust the optical fiber probe 6 to the initial height Zf1. That is, the microscope 7 and the prism 22 are used to adjust the optical fiber probe 6 to the optimal coupling height, which is the initial height Zf1. In the present invention, the optical fiber probe 6 is ensured to maintain the optimal coupling height by measuring the collective parameters of the optical fiber probe 6 and adjusting them.

[0058] S30: Positioning the wafer chuck 5 at the center of the field of view of the microscope 7, and measuring the height of any area to be measured on the wafer surface on the wafer chuck 5;

[0059] Specifically, the height of the area to be measured on the wafer surface is measured so that correction can be performed in subsequent steps according to the height of any area to be measured on the wafer surface.

[0060] S40 : Compensating the initial height of the optical fiber probe 6 according to the height difference between any area to be measured on the wafer surface and the bottom of the prism 22 .

[0061] That is, the height variation of any area to be measured on the wafer surface is compensated, so that the optical fiber probe 6 can maintain the optimal coupling height in each area to be measured.

[0062] As an optional implementation, in one embodiment of the invention, see Figure 2 As shown, the step S20 of adjusting the optical fiber probe 6 to the initial height using the microscope 7 and the prism 22 includes the following steps:

[0063] First, move the fiber optic probe 6 to the bottom edge of the prism 22 and adjust the focus or height of the microscope 7 until it focuses on the tip of the fiber optic probe 6;

[0064] Specifically, the fiber probe translation stage 3 is controlled to slowly move the fiber probe 6 so that its tip is in contact with the bottom edge of the prism 22 , and the microscope 7 is adjusted until it focuses on the tip of the fiber probe 6 to position the tip of the fiber probe 6 at the bottom edge of the prism 22 .

[0065] Then adjust the focal length or height of the microscope 7 so that the viewing angle of the microscope 7 is shifted to the top edge of the prism 22 and the side view of the optical fiber probe 6 reflected by the prism 22 is focused;

[0066] Specifically, the focal length or height of microscope 7 is adjusted to shift the viewing angle of microscope 7 to the top edge of prism 22. At this point, microscope 7's field of view includes not only the edge of prism 22 but also the side view outline of fiber optic probe 6. Based on the image feedback, the height of microscope 7 is fine-tuned until the side view of fiber optic probe 6 is clearly visible. This side view provides intuitive information for subsequent measurement of the angle and height of fiber optic probe 6, improving the accuracy of fiber optic probe 6 adjustment.

[0067] According to the side view of the optical fiber probe 6, the optical fiber probe 6 is adjusted to an initial height.

[0068] Specifically, the industrial camera 8 is used to measure the height of the optical fiber probe 6 in the image. The measurement methods can be single-point measurement, multi-point measurement and averaging, and linear fitting of different coordinate points. According to the measurement results, the optical fiber translation stage is used for fine-tuning to reach the initial height Zf1.

[0069] As an optional implementation, in one embodiment of the invention, see Figure 2 As shown, the steps of positioning the wafer chuck 5 at the center of the field of view of the microscope 7 and measuring the height of any area to be measured on the wafer surface on the wafer chuck 5 include the following steps: first, positioning the wafer chuck 5 at the center of the field of view of the microscope 7 so that the wafer pattern on any area to be measured on the wafer surface on the wafer chuck 5 remains horizontal, wherein horizontal correction ensures that the wafer pattern does not tilt or distort, thereby improving the accuracy of height data; then, adjusting the microscope 7 to focus on any area to be measured on the wafer surface, and obtaining the current coordinate value Zv2 of the microscope 7 in the Z direction. The height difference ΔZ=Zv2-Zv1 between the wafer and the bottom of the prism 22 is calculated, and the height of the optical fiber probe 6 is corrected to be Zf1+ΔZ.

[0070] As an optional implementation, in one embodiment of the invention, see Figure 2 As shown, before the step of positioning the wafer chuck 5 to the center of the field of view of the microscope 7 and measuring the height of any area to be measured on the wafer surface on the wafer chuck 5, the following steps are provided, in which the optical fiber probe 6 is moved to a preset safe position. After moving to the preset safe position, subsequent operations such as adjusting the wafer position will not cause interference or accidental collision to the optical fiber probe 6.

[0071] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0072] It should be noted that, in the present invention, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0073] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is to be construed in the widest possible manner consistent with the principles and novel features of the present invention.

Claims

1. A positioning device for an optical fiber probe, characterized in that: include: A chuck displacement platform (1), wherein the chuck displacement platform (1) is used to set a wafer chuck (5); A prism assembly (2), comprising a prism chuck (21) disposed on a chuck displacement platform (1) and a prism (22) disposed on the prism chuck (21); An optical fiber probe displacement platform (3), wherein the optical fiber probe displacement platform (3) is used to set the optical fiber probe (6); A microscope displacement stage (4) is provided with a microscope (7).

2. A positioning device for an optical fiber probe according to claim 1, characterized in that: The chuck displacement platform (1) is a four-axis displacement platform.

3. The positioning device for an optical fiber probe according to claim 1, characterized in that: The optical fiber probe displacement platform (3) is a six-axis displacement platform.

4. The positioning device for an optical fiber probe according to claim 1, characterized in that: The microscope displacement stage (4) is a three-axis displacement stage.

5. The positioning device for an optical fiber probe according to claim 1, characterized in that: An industrial camera (8) is provided on the top of the microscope (7).

6. A method for positioning an optical fiber probe, using the optical fiber probe positioning device according to claim 1, characterized in that: The following steps are involved: The prism chuck (21) is placed at the center of the field of view of the microscope (7) and the height of the bottom of the prism (22) is measured; Using a microscope (7) and a prism (22), adjust the fiber optic probe (6) to an initial height; Positioning the wafer chuck (5) at the center of the field of view of the microscope (7) and measuring the height of any area to be measured on the surface of the wafer on the wafer chuck (5); The initial height of the optical fiber probe (6) is compensated according to the height difference between any area to be measured on the wafer surface and the bottom of the prism (22).

7. A method for positioning an optical fiber probe according to claim 6, characterized in that: The step of placing the prism chuck (21) at the center of the field of view of the microscope (7) and measuring the height of the bottom of the prism (22) comprises the following steps: Move the prism chuck (21) to the center of the field of view of the microscope (7); The prism chuck (21) is rotated until the bottom of the prism (22) is level.

8. A method for positioning an optical fiber probe according to claim 6, characterized in that: The step of using the microscope (7) and the prism (22) to adjust the optical fiber probe (6) to an initial height comprises the following steps: Move the fiber optic probe (6) to the bottom edge of the prism (22), and adjust the focal length or height of the microscope (7) to focus on the tip of the fiber optic probe (6); Then adjusting the focal length or height of the microscope (7) so that the viewing angle of the microscope (7) is shifted to the top edge of the prism (22) and the side view of the optical fiber probe (6) reflected by the prism (22) is focused; According to the side view of the optical fiber probe (6), the optical fiber probe (6) is adjusted to an initial height.

9. A method for positioning an optical fiber probe according to claim 6, characterized in that: The step of positioning the wafer chuck (5) at the center of the field of view of the microscope (7) and measuring the height of any area to be measured on the surface of the wafer on the wafer chuck (5) comprises the following steps: Positioning the wafer chuck (5) at the center of the field of view of the microscope (7) so that the wafer pattern of any area to be measured on the wafer surface on the wafer chuck (5) remains horizontal; The microscope (7) is adjusted to focus on any area to be measured on the wafer surface.

10. The method for positioning an optical fiber probe according to claim 6, wherein: Before the step of positioning the wafer chuck (5) at the center of the field of view of the microscope (7) and measuring the height of any area to be measured on the surface of the wafer on the wafer chuck (5), the method further includes the following steps: Move the fiber optic probe (6) to a preset safe position.

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