Wafer slotting light path device and slotting and hidden cutting method thereof

Abstract

The present application relates to the technical field of wafer cutting, and particularly relates to a wafer slotting light path device and a slotting and hidden cutting method thereof, which comprises a dual-wavelength laser, a first beam expander arranged in front of the dual-wavelength laser, a dichroic mirror arranged in front of the first beam expander, an infrared light filtering light path arranged below the dichroic mirror, a slotting light path arranged below the infrared light filtering light path, an ultraviolet light filtering light path arranged in front of the dichroic mirror, and a hidden cutting light path arranged below the ultraviolet light filtering light path. When the present application is used, the first shutter is closed and the second shutter is opened during slotting, and the first shutter is opened and the second shutter is closed during hidden cutting. The slotting and hidden cutting are combined on one device through the first shutter and the second shutter, so that the processing efficiency is improved and the processing cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer cutting, in particular to a wafer grooving light path device and a grooving and hidden cutting method thereof. BACKGROUND

[0002] Grooving and hidden cutting are two processes in the processing of low-k medium wafers. The existing processing flow is to groove on a low-k grooving device first, and then to perform hidden cutting on a hidden cutting device. Grooving and hidden cutting need to be performed on two different devices. With the improvement of wafer functional structure, wafers are more and more sensitive to light and dust, so it is necessary to minimize the time of exposing wafers to air. The existing wafer processing mode is to groove on a low-k grooving device first, and then to perform hidden cutting on a hidden cutting device. Grooving and hidden cutting need to be performed on two devices, which results in long processing time, low processing efficiency and high processing cost. SUMMARY

[0003] In view of the problems in the prior art, the purpose of the present application is to provide a device and method that combines grooving and hidden cutting together with low processing cost and high efficiency.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0005] A wafer grooving light path device, comprising a dual-wavelength laser, a first beam expander arranged in front of the dual-wavelength laser, a dichroic mirror arranged obliquely in front of the first beam expander, an infrared light filtering light path arranged below the dichroic mirror, a grooving light path arranged below the infrared light filtering light path, and a ultraviolet light filtering light path arranged in front of the dichroic mirror, and a hidden cutting light path arranged below the ultraviolet light filtering light path.

[0006] The infrared light filtering light path comprises an ultraviolet filter, a second light shutter and a first 1 / 2 wave plate arranged in sequence below the dichroic mirror, and the grooving light path comprises a beam splitter prism arranged directly below the first 1 / 2 wave plate, a third 1 / 2 wave plate, a second beam splitter, a 45° polarizing beam splitter and a second focusing lens arranged in sequence below the beam splitter prism, a first reflecting mirror arranged obliquely behind the beam splitter prism, a second 1 / 2 wave plate, a first beam splitter and a first focusing lens arranged in sequence below the first reflecting mirror.

[0007] The ultraviolet light filtering light path comprises an infrared filter and a first light shutter arranged in sequence in front of the dichroic mirror, and the hidden cutting light path comprises a second reflecting mirror arranged obliquely in front of the first light shutter, a fourth 1 / 2 wave plate arranged below the second reflecting mirror, a third reflecting mirror arranged obliquely below the fourth 1 / 2 wave plate, and a second beam expander arranged between the third reflecting mirror and the 45° polarizing beam splitter.

[0008] The angles of the first 1 / 2 wave plate, the second 1 / 2 wave plate, the first beam splitter, the third 1 / 2 wave plate and the second beam splitter are adjustable.

[0009] The angles of the first 1 / 2 wave plate, the second 1 / 2 wave plate, the first beam splitter, the third 1 / 2 wave plate and the second beam splitter are adjusted by motors.

[0010] The light emitted by the dual-wavelength laser is ultraviolet light with a wavelength of 355 nm and infrared light with a wavelength of 1064 nm.

[0011] A hidden cutting method of the wafer slotting optical path device of claim 6, comprising the following steps:

[0012] Step one: the wafer is pasted on the steel ring covered with UV film with the front face upward, and then the wafer is placed on the ceramic plate;

[0013] Step two: the first shutter is closed, the second shutter is opened, the dual-wavelength laser emits light through the first beam expander, the two-way beam splitter to the ultraviolet filter, the ultraviolet filter filters out the infrared light, only the ultraviolet light is left, the ultraviolet light passes through the second shutter and the first 1 / 2 wave plate to reach the beam splitter prism, the beam splitter prism divides the ultraviolet light into horizontal polarized light P and vertical polarized light S; the vertical polarized light S reaches the second 1 / 2 wave plate and the first beam splitter through the first 45° mirror, the vertical polarized light S slotting width is adjusted by adjusting the angle of the beam splitter, the vertical polarized light S energy distribution is adjusted by adjusting the angle of the two 1 / 2 waves, and the vertical polarized light S is focused on the wafer through the first focusing mirror to realize double fine slotting;

[0014] Step three: the horizontal polarized light P reaches the third 1 / 2 wave plate and the second beam splitter, the horizontal polarized light P slotting width is adjusted by adjusting the angle of the beam splitter, and the horizontal polarized light P energy distribution is adjusted by adjusting the angle of the third 1 / 2 wave plate; the horizontal polarized light P realizes wide slotting by acting on the wafer through the 45° polarized beam splitter and the second focusing mirror; the wafer is placed on the ceramic plate after the wafer bottom UV film is removed and the wafer front face is pasted on the steel ring covered with UV film;

[0015] Step four: the first shutter is opened, the second shutter is closed, the dual-wavelength laser emits light through the first beam expander, the two-way beam splitter to the infrared filter, the infrared filter filters out the ultraviolet light, only the infrared light is left, the infrared light passes through the first shutter, the second 45° mirror, the fourth 1 / 2 wave plate, the third 45° mirror and the second beam expander to reach the 45° polarized beam splitter, the 45° polarized beam splitter divides the infrared light into horizontal polarized light P and vertical polarized light S, and the vertical polarized light S realizes hidden cutting by acting on the wafer through the second focusing mirror.

[0016] The application combines grooving and hidden cutting on one device through the first light shutter and the second light shutter, improves the processing efficiency, and reduces the processing cost. By adjusting the angles of the first 1 / 2 wave plate, the second 1 / 2 wave plate, the first beam splitter, the third 1 / 2 wave plate and the second beam splitter, the S light grooving width, the S light energy distribution, the P light grooving width and the P light energy distribution are adjusted to meet different wafer grooving requirements. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the application.

[0018] Figure 2 It is a structural schematic diagram of the wafer.

[0019] Figure 3 It is a schematic diagram of opening double fine grooves of the application.

[0020] Figure 4 It is a schematic diagram of opening wide grooves of the application. DETAILED DESCRIPTION

[0021] In the figure, the serial number: 1 is a dual-wavelength laser, 2 is a first beam expander, 3 is a two-way beam splitter, 4 is an infrared filter, 5 is a first light shutter, 6 is an ultraviolet filter, 7 is a second light shutter, 8 is a first 1 / 2 wave plate, 9 is a beam splitter prism, 10 is a first mirror, 11 is a second 1 / 2 wave plate, 12 is a first beam splitter, 13 is a first focusing mirror, 14 is a third 1 / 2 wave plate, 15 is a second beam splitter, 16 is a polarization beam splitter, 17 is a second focusing mirror, 18 is a second mirror, 19 is a fourth 1 / 2 wave plate, 20 is a third mirror, 21 is a second beam expander, 22 is a wafer, 23 is a ceramic disc, 24 is a crystal grain, 25 is a cutting path, 26 is P light and 27 is S light.

[0022] The application discloses a wafer grooving optical path device, which comprises a dual-wavelength laser 1, a first beam expander 2 arranged in front of the dual-wavelength laser 1, a two-way beam splitter 3 arranged in front of the first beam expander 2, an infrared light filtering light path arranged below the two-way beam splitter 3, a grooving light path arranged below the infrared light filtering light path, an ultraviolet light filtering light path arranged in front of the two-way beam splitter, and a hidden cutting light path arranged below the ultraviolet light filtering light path, wherein the light emitted by the dual-wavelength laser 1 is ultraviolet light with a wavelength of 355 nm and ultraviolet light with a wavelength of 355 nm, the grooving light path is used for grooving the wafer, and the hidden cutting light path is used for hidden cutting the wafer.

[0023] The infrared light filtering light path comprises an ultraviolet filter 6, a second shutter 7 and a first 1 / 2 wave plate 8 arranged in sequence below the two-way beam splitter 3, and the slotted light path comprises a beam splitting prism 9 arranged directly below the first 1 / 2 wave plate 8, a third 1 / 2 wave plate 14, a second beam splitter 15, a 45° polarizing beam splitter 16 and a second focusing lens 17 arranged in sequence below the beam splitting prism 9, a first mirror 10 arranged obliquely behind the beam splitting prism 9, a second 1 / 2 wave plate 11, a first beam splitter 12 and a first focusing lens 13 arranged in sequence below the first mirror 10, and the first focusing lens 13 and the second focusing lens 17 are located directly above the ceramic disc 23, the first focusing lens 13 is located behind the second focusing lens 17, the beam splitting prism 9 splits the 355nm ultraviolet light into horizontal polarization light P and vertical polarization light S, the horizontal polarization light P is irradiated onto the third 1 / 2 wave plate 14, and the vertical polarization light S is irradiated onto the first 45° mirror 10.

[0024] The ultraviolet light filtering light path comprises an infrared filter 4 and a first shutter 5 arranged in sequence in front of the two-way beam splitter 3, the hidden cutting light path comprises a second mirror 18 arranged obliquely in front of the first shutter 5, a fourth 1 / 2 wave plate 19 arranged below the second mirror 18, a third mirror 20 arranged obliquely below the fourth 1 / 2 wave plate 19, and a second expansion lens 21 arranged between the third mirror 20 and the 45° polarizing beam splitter 16, and the third mirror 20 is located in front of the 45° polarizing beam splitter 16, the infrared filter filters out the ultraviolet light with a wavelength of 355nm, only leaving the infrared light with a wavelength of 1064nm, the infrared light reaches the 45° polarizing beam splitter 16 after passing through the first shutter 5, the second 45° mirror 18, the fourth 1 / 2 wave plate 19, the third 45° mirror 20 and the second expansion lens 21, and the 45° polarizing beam splitter 16 splits the infrared light into horizontal polarization light P and vertical polarization light S, and the vertical polarization light S acts on the wafer 22 through the second focusing lens 17 to realize hidden cutting.

[0025] The first shutter and the second shutter are also connected with a rotary motor, the rotary motor is produced by thorlabs, and the model is DDR25, which can rotate by 360°, and the first shutter or the second shutter is driven to rotate by the rotary motor, so as to open or close the first shutter or the second shutter, and the corresponding light beam is opened or closed.

[0026] The angles of the first 1 / 2 wave plate 8, the second 1 / 2 wave plate 11, the first beam splitter 12, the third 1 / 2 wave plate 14 and the second beam splitter 15 can be adjusted by motors, which are rotary motors. By adjusting the angle of the first 1 / 2 wave plate, the energy distribution of the S light and the P light of the ultraviolet light with a wavelength of 355 nm can be adjusted. By adjusting the angle of the second 1 / 2 wave plate 11, the energy distribution of the vertical polarization light S of the ultraviolet light with a wavelength of 355 nm can be adjusted. By adjusting the angle of the first beam splitter 12, the slot width of the vertical polarization light S of the ultraviolet light with a wavelength of 355 nm can be adjusted. By adjusting the angle of the third 1 / 2 wave plate, the energy distribution of the horizontal polarization light P of the ultraviolet light with a wavelength of 355 nm can be adjusted. By adjusting the angle of the second beam splitter 15, the slot width of the horizontal polarization light P of the ultraviolet light with a wavelength of 355 nm can be adjusted.

[0027] A slotting and hidden cutting method of a wafer slotting optical path device

[0028] Step 1: The bottom of the wafer 22 is attached to a steel ring covered with a UV film, and the front is upward, and the wafer 22 is placed on a ceramic plate 23.

[0029] Step 2 (slotting): Close the first shutter 5 and open the second shutter 7. The dual-wavelength laser 1 emits ultraviolet light with a wavelength of 355 nm and ultraviolet light with a wavelength of 355 nm. The ultraviolet light with a wavelength of 355 nm and the ultraviolet light with a wavelength of 355 nm pass through the first beam expander 2, the two-way beam splitter 3 and the ultraviolet filter 6. The ultraviolet filter filters out the infrared light with a wavelength of 1064 nm, leaving only the ultraviolet light with a wavelength of 355 nm. The ultraviolet light passes through the first shutter 7 and the first 1 / 2 wave plate 8 to the beam splitting prism 9. The angle of the first 1 / 2 wave plate is adjusted by the motor to adjust the energy distribution of the S light and the P light of the ultraviolet light with a wavelength of 355 nm.

[0030] Step 2.1 (slotting): The beam splitting prism 9 divides the ultraviolet light into horizontal polarization light P and vertical polarization light S. The vertical polarization light S passes through the first 45° mirror 10 to the second 1 / 2 wave plate 11 and the first beam splitter 12. The angles of the second 1 / 2 wave plate 11 and the first beam splitter 12 are adjusted by the motor. By adjusting the angle of the second 1 / 2 wave plate 11, the energy distribution of the vertical polarization light S of the ultraviolet light with a wavelength of 355 nm can be adjusted. By adjusting the angle of the first beam splitter 12, the slot width of the vertical polarization light S of the ultraviolet light with a wavelength of 355 nm can be adjusted. The vertical polarization light S is focused on the wafer 22 by the first focusing lens 13 to realize double slotting.

[0031] Step 2.2 (open wide slot): horizontal polarized light P is through third 1 / 2 wave plate 14 and second beam splitter 15 to 45° polarized light splitter 16, by adjusting the angle of third 1 / 2 wave plate 14 and second beam splitter 15, by adjusting the angle of third 1 / 2 wave plate, the energy distribution of horizontal polarized light P of ultraviolet light with wavelength of 355nm can be adjusted, by adjusting the angle of second beam splitter 15, the slot width of horizontal polarized light P of ultraviolet light with wavelength of 355nm can be adjusted, horizontal polarized light P is through 45° polarized light splitter 16 and second focusing mirror 17 to wafer 22 to realize open wide slot;

[0032] Step 3: after slotting, take wafer 22 from ceramic disc 23, remove the UV film at the bottom of wafer 22, paste the front of wafer on the steel ring with UV film, and then place it on ceramic disc 23;

[0033] Step 4 (hidden cutting): open first shutter 5, close second shutter 7, the wavelength of 355nm ultraviolet light and the wavelength of 355nm ultraviolet light emitted by dual-wavelength laser are through first beam expander 2, two-way beam splitter 3 to infrared filter 4, infrared filter filters out ultraviolet light with wavelength of 355nm, only infrared light with wavelength of 1064nm is left, infrared light is through first shutter 5, second 45° mirror 18, fourth 1 / 2 wave plate 19, third 45° mirror 20 and second beam expander 21 to 45° polarized light splitter 16, 45° polarized light splitter 16 divides infrared light into horizontal polarized light P and vertical polarized light S, vertical polarized light S is through second focusing mirror 17 to act on wafer 22 to realize hidden cutting.

[0034] In use, the first shutter 5 is closed and the second shutter 7 is opened during slotting, and the first shutter 5 is opened and the second shutter 7 is closed during hidden cutting, so that slotting and hidden cutting are combined on one device through the first shutter 5 and the second shutter 7, the processing efficiency is improved, and the processing cost is reduced. By adjusting the angles of first 1 / 2 wave plate 8, second 1 / 2 wave plate 11, first beam splitter 12, third 1 / 2 wave plate 14 and second beam splitter 15, the slot width of S light, the energy distribution of S light, the slot width of P light and the energy distribution of P light are adjusted to meet different wafer slotting requirements.

[0035] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection required by the present application is defined by the appended claims and their equivalents.

Claims

1. A wafer grooving optical path device, characterized in that: The system includes a dual-wavelength laser, a first beam expander positioned directly in front of the dual-wavelength laser, a two-way beam splitter tilted in front of the first beam expander, an infrared light filtering optical path positioned below the two-way beam splitter, a slotted optical path positioned below the infrared light filtering optical path, an ultraviolet light filtering optical path positioned in front of the two-way beam splitter, and a hidden optical path positioned below the ultraviolet light filtering optical path. The infrared light filtering optical path includes an ultraviolet filter, a second optical shutter, and a first half-wave plate sequentially positioned below the two-way beam splitter. The slotted optical path includes a beam splitter prism positioned directly below the first half-wave plate, and a second optical shutter and a first half-wave plate sequentially positioned below the beam splitter prism. The structure comprises a third half-wave plate, a second beam splitter, a 45° polarizing beam splitter, a second focusing lens, a first reflecting mirror tilted behind the beam splitter, a second half-wave plate, a first beam splitter, and a first focusing lens sequentially positioned directly below the first reflecting mirror; the ultraviolet light filtering optical path includes an infrared filter and a first optical shutter sequentially positioned in front of the two-way beam splitter; the hidden optical path includes a second reflecting mirror tilted in front of the first optical shutter, a fourth half-wave plate positioned below the second reflecting mirror, a third reflecting mirror tilted below the fourth half-wave plate, and a second beam expander positioned between the third reflecting mirror and the 45° polarizing beam splitter.

2. The wafer grooving optical path device according to claim 1, characterized in that: The angles of the first half-wave plate, the second half-wave plate, the first beam splitter, the third half-wave plate, and the second beam splitter are adjustable.

3. The wafer grooving optical path device according to claim 2, characterized in that: The angles of the first half-wave plate, the second half-wave plate, the first beam splitter, the third half-wave plate, and the second beam splitter are adjusted by a motor.

4. The wafer grooving optical path device according to claim 3, characterized in that: The light emitted by the dual-wavelength laser is ultraviolet light with a wavelength of 355nm and infrared light with a wavelength of 1064nm.

5. A method for slotting and hidden cutting based on the wafer slotting optical path device according to claim 4, characterized in that: The process includes the following steps: Step 1: The bottom of the wafer is attached to a UV-coated steel ring, with the front side facing up, and then the wafer is placed on a ceramic disk; Step 2: The first optical shutter is closed and the second optical shutter is opened. The dual-wavelength laser emits light through the first beam expander and the two-way beam splitter to the ultraviolet filter. The ultraviolet filter filters out the infrared light, leaving only the ultraviolet light. The ultraviolet light passes through the second optical shutter and the first half-wave plate to reach the beam splitter prism. The beam splitter prism splits the ultraviolet light into horizontally polarized light P and vertically polarized light S; Vertically polarized light S reaches the second half-wave plate and the first beam splitter after passing through the first reflecting mirror. The slot width of vertically polarized light S is adjusted by adjusting the angle of the first beam splitter, and the energy distribution of vertically polarized light S is adjusted by adjusting the angle of the second half-wave plate. It then acts on the wafer through the first focusing mirror to create a double fine slot. Step three: Horizontally polarized light P reaches the third half-wave plate and the second beam splitter. The slot width of horizontally polarized light P is adjusted by adjusting the angle of the second beam splitter, and the energy distribution of horizontally polarized light P is adjusted by adjusting the angle of the third half-wave plate. Horizontally polarized light P acts on the wafer through a 45° polarizing beam splitter and the second focusing mirror to create a wide slot. It then acts on the wafer through the first reflecting mirror and the first beam splitter to create a double fine slot. After the direct polarized light S acts, wafer grooving is achieved. After grooving, the UV film on the bottom of the wafer is removed, and the front of the wafer is attached to the steel ring covered with UV film. The wafer is then placed on a ceramic disk. Step 4: Open the first optical shutter and close the second optical shutter. The dual-wavelength laser emits light through the first beam expander and the two-way beam splitter to the infrared filter. The infrared filter filters out the ultraviolet light, leaving only the infrared light. The infrared light passes through the first optical shutter, the second reflector, the fourth 1 / 2 waveplate, the third reflector, and the second beam expander before reaching the 45° polarization beam splitter. The 45° polarization beam splitter splits the infrared light into horizontally polarized light P and vertically polarized light S. The vertically polarized light S acts on the wafer through the second focusing lens to achieve hidden cutting.

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