TWI759044B - Laser engraving method of silicon carbide wafer - Google Patents

Abstract

The present invention provides a laser engraving method of a silicon carbide wafer, which includes a preparing step, a placing step, and an engraving step. The preparing step is implemented by providing a laser emitter, a carrier, and a transparent silicon carbide wafer that has a first surface and an opposite second surface. The placing step is implemented by placing the second surface of the silicon carbide wafer onto a carrying surface of the carrier that is light non-permeable so as to make the laser emitter to face toward the first surface. The engraving step is implemented by using the laser emitter to emit at least one laser beam toward a predetermined point of the second surface, in which the at least one laser beam is arrived at the predetermined point by passing through the silicon carbide wafer so as to form two laser slots that are respectively recessed in the predetermined point and a sacrificed region of the carrying surface connected to the predetermined point.

Description

Laser engraving method of silicon carbide wafer

The invention relates to a laser engraving method, in particular to a laser engraving method of a silicon carbide wafer.

When the existing laser engraving method directly performs laser engraving on a top surface (such as a processing surface) of the silicon carbide wafer, since the silicon carbide wafer is transparent, the energy of the laser engraving is difficult to completely concentrate on The top surface, thus causing the laser-cut groove formed on the top surface to be prone to defects (for example, the laser-cut groove has a chipped edge, so that the text or image represented by the laser-cut groove is unclear) and cannot be completed. Present the function it is given.

Therefore, the inventor believes that the above-mentioned defects can be improved. Nate has devoted himself to research and application of scientific principles, and finally proposes an invention with reasonable design and effective improvement of the above-mentioned defects.

The embodiments of the present invention provide a laser engraving method for silicon carbide wafers, which can effectively improve the defects that may be generated by the existing laser engraving methods.

The embodiment of the present invention discloses a laser engraving method for a silicon carbide wafer, which includes: a pre-step: providing a laser emitter, a stage corresponding to the laser emitter, and a silicon carbide wafer; Wherein, the stage has a non-translucent bearing processing surface, the silicon carbide wafer has a first surface and a second surface located on opposite sides, and the silicon carbide wafer extends from the first surface One surface to the second surface is transparent; a setting step: placing the second surface of the silicon carbide wafer on the processing surface of the carrier, so that the laser can be emitted the first surface of the silicon carbide wafer facing the silicon carbide wafer; and an engraving step: using the laser emitter to emit at least one laser beam toward a predetermined point on the second surface, and at least one of the lasers The light beam passes through the silicon carbide wafer to form a laser-etched groove in each of the predetermined point and the adjacent sacrificial area of the carrier processing surface.

To sum up, the laser engraving method for a silicon carbide wafer disclosed in the embodiment of the present invention uses a laser beam to pass through the silicon carbide wafer, and the silicon carbide wafer and the carrier are in contact with each other. A laser engraving groove is formed on the second surface and the bearing processing surface, so that the silicon carbide wafer can pass through the non-transparent bearing processing surface, and it is easy to form the laser with a predetermined shape at a predetermined point. grooves, thereby reducing the probability of defects generated by the laser-cut grooves.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings of the present invention, but these descriptions and drawings are only used to illustrate the present invention, rather than make any claims to the protection scope of the present invention. limit.

The following are specific embodiments to illustrate the embodiments of the "laser engraving method for silicon carbide wafers" disclosed in the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are merely schematic illustrations, and are not drawn according to the actual size, and are stated in advance. The following embodiments will further describe the related technical contents of the present invention in detail, but the disclosed contents are not intended to limit the protection scope of the present invention.

It should be understood that although terms such as "first", "second" and "third" may be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are primarily used to distinguish one element from another element, or a signal from another signal. In addition, the term "or", as used herein, should include any one or a combination of more of the associated listed items, as the case may be.

[Example 1]

Please refer to FIG. 1 to FIG. 7 , which are Embodiment 1 of the present invention. The present embodiment discloses a laser engraving method for a silicon carbide wafer, which includes a pre-step S110, a setting step S130, and an engraving step S150. The steps included in the laser engraving method of the silicon carbide wafer will be described below.

As shown in FIG. 1 , the pre-step S110 is to provide a laser transmitter 1 , a stage 2 corresponding to the laser transmitter 1 , and a silicon carbide wafer 3 . Wherein, the stage 2 has a non-transparent bearing processing surface 21, the silicon carbide wafer 3 has a first surface 31 and a second surface 32 on opposite sides, and the silicon carbide wafer 3 has a first surface 31 and a second surface 32 on opposite sides. 3 is transparent from the first surface 31 to the second surface 32.

It should be added that the first surface 31 is the subsequent structure forming processing surface of the silicon carbide wafer 3; that is, after the laser engraving method of the silicon carbide wafer 3 is completed, the The silicon carbide wafer 3 will undergo subsequent processing on the first surface 31 to form a final product, but the invention is not limited to this. For example, in other embodiments not shown in the present invention, the subsequent structure forming processing surface of the silicon carbide wafer 3 may also be the second surface 32 .

In addition, the silicon carbide wafer 3 is further formed with a non-transparent layer 4 on the first surface 31 of the silicon carbide wafer 3 in this embodiment, and the non-transparent layer 4 preferably has a wavelength of 5%～ A light transmittance of 30%, but the present invention is not limited to this. For example, in other embodiments not shown in the present invention, the non-transparent layer 4 may not be formed on the first surface 31 of the silicon carbide wafer 3; or, the non-transparent layer 4 corresponds to The wavelength of visible light may also have a transmittance other than 5% to 30%.

In more detail, the non-transparent layer 4 is connected with the first surface 31 of the silicon carbide wafer 3 without gaps, and the non-transparent layer 4 may be a carbon layer, a resin layer, and one of the titanium dioxide layers. Wherein, the non-transparent layer 4 is coated on the first surface 31 of the silicon carbide wafer 3 in this embodiment, but the manner in which the non-transparent layer 4 is formed on the silicon carbide wafer 3 can be designed according to design It is not limited to this embodiment to be adjusted and changed (eg, vapor deposition method or sputtering method) according to the needs.

As shown in FIG. 2 , in the setting step S130 : placing the second surface 32 of the silicon carbide wafer 3 on the processing surface 21 of the carrier 2 , so that the laser is emitted The device 1 faces the first surface 31 of the silicon carbide wafer 3 . Wherein, in this embodiment, the second surface 32 of the silicon carbide wafer 3 is placed on the carrying surface 21 without gaps, so as to facilitate the implementation of the subsequent engraving step S150, but this The invention is not limited to this.

It should be added that the portion of the stage 2 that supports the silicon carbide wafer 3 is defined as the carrying processing surface 21 ; that is, the stage 2 is only limited to contact with the silicon carbide wafer 3 The part 3 needs to be non-transmissive, and the rest of the carrier 2 (eg: the part of the carrier 2 located outside the bearing processing surface 21 ) is not limited to be non-transparent. In the present embodiment, the stage 2 is illustrated as a silicon wafer, and it preferably has a light transmittance of 0% corresponding to the wavelength of visible light, but the present invention is not limited thereto. For example, the light transmittance of the stage 2 corresponding to the wavelength of visible light may be 0%-20% or 0%-10% according to design requirements.

As shown in FIG. 3 and FIG. 4 , in the engraving step S150, the laser transmitter 1 emits at least one laser beam L toward a predetermined point P on the second surface 32, and at least one laser beam The light beam L passes through the silicon carbide wafer 3 to form a laser engraved groove 22 and 33 at the predetermined point P and its adjacent sacrificial area (not shown) of the processing surface 21 . In more detail, the sacrificial area of the stage 2 absorbs at least a part of the laser beam L to generate a thermal effect, and the predetermined point P and the adjacent sacrificial area are separated from each other by the thermal effect. The laser engraved grooves 22 and 33 are formed in the recess, but the present invention is not limited to this.

Accordingly, in the laser engraving method of the silicon carbide wafer, the laser beam L passes through the silicon carbide wafer 3, and in the second place where the silicon carbide wafer 3 and the stage 2 are in contact with each other Laser-cut grooves 22 and 33 are formed on the surface 32 and the bearing processing surface 21 , so that the silicon carbide wafer 3 can pass through the non-transparent bearing processing surface 21 , and it is easy to form a predetermined point P that conforms to the predetermined shape. The laser-cut groove 33 in the shape of the laser-cut groove 33 further reduces the probability of the laser-cut groove 33 having defects.

Furthermore, in this embodiment, at least one of the laser beams L can pass through the non-transparent layer 4 and be incident on the silicon carbide wafer 3 from the first surface 31 , thereby reducing at least one of the laser beams L. The laser beam L is reflected on the first surface 31 , thereby effectively controlling the energy of the laser engraved grooves 33 formed on the silicon carbide wafer 3 , but the invention is not limited to this. In addition, after the silicon carbide wafer 3 is formed with the laser-etched grooves 33 , the non-transparent layer 4 can be removed (eg, FIG. 6 ).

In more detail, in order to enable the laser-cut grooves 33 formed in the silicon carbide wafer 3 to have a better configuration (that is, the laser-cut grooves 33 conform to a preset shape), the engraving Step S150 may include at least one of the following conditions, but the present invention is not limited to this. For example, in other embodiments not shown in the present invention, the engraving step S150 may not include any of the following conditions.

Condition A: At least one of the laser beams L may be infrared light with wavelengths ranging from 1000 nanometers (nm) to 1100 nanometers (eg, YAG laser light), and at least one of the laser beams L and the first A surface 31 is preferably formed with an incident angle σ ranging from 80 degrees to 100 degrees (eg, the incident angle σ is preferably 90 degrees), but the invention is not limited to this. For example, in other embodiments not shown in the present invention, as long as at least one of the laser beams L can pass through the silicon carbide wafer 3 to reach the predetermined point P, the specific value of the incident angle σ It can also be adjusted and changed according to design requirements.

Condition B: the number of at least one of the laser beams L can be further limited to at least four; that is, one of the laser-etched grooves 33 formed in the silicon carbide wafer 3 is dot-shaped and is formed by at least four beams. formed by the laser beam L. Wherein, the power of the laser transmitter 1 ranges from 5 watts (W) to 20 watts, and the transmission frequency of the laser transmitter 1 ranges from 20 hertz (Hz) to 35 hertz. limit.

In addition, the above is the implementation process of the laser engraving method of the silicon carbide wafer in which the laser engraving groove 33 is formed on the second surface 32 of the silicon carbide wafer 3, but the laser engraving method of the silicon carbide wafer 3 The number of times of the engraving step S150 included in the engraving method may be multiple times (eg, FIG. 5 to FIG. 7 ), so that the silicon carbide wafer 3 is respectively recessed at a plurality of predetermined points P on the second surface 32 . A plurality of scribed grooves 33 are formed (and a plurality of scribed grooves 22 are also formed in a plurality of sacrificial regions adjacent to the plurality of predetermined points P respectively), and a plurality of the scribed grooves 33 constitute at least one Patterned groove distribution D.

Wherein, when the engraving step S150 is performed multiple times, the processing speed of the laser transmitter 1 is preferably 900 millimeters/minute (mm/min) to 1100 mm/min. Furthermore, at least one of the patterned groove distributions D may be at least one of characters, patterns, numbers, and symbols according to design requirements, which is not limited in the present invention.

More specifically, after the silicon carbide wafer 3 has completed the engraving step S150 for many times, the carrier 2 with a plurality of the laser-etched grooves 22 is formed with another carrier without any laser-etched grooves 22 formed thereon. The stage is replaced, according to which the laser engraving method of the silicon carbide wafer is performed again through the other stage. That is to say, in this embodiment, the stage 2 is a consumable that needs to be replaced after the laser engraving is completed along with the silicon carbide wafer 3 .

[Example 2]

Please refer to FIG. 8 , which is the second embodiment of the present invention. Since this embodiment is similar to the above-mentioned first embodiment, the similarities between the two embodiments will not be repeated, and the differences between this embodiment and the above-mentioned first embodiment are roughly described as follows:

In the pre-step S210 of this embodiment, a non-transparent layer 4 is detachably disposed on the first surface 31 of the silicon carbide wafer 3 . For example, the non-transparent layer 4 can be attached to the silicon carbide wafer 3 through a glue material, so that the non-transparent layer 4 and the first surface 31 are spaced apart and not directly connected to each other ( In other words, the glue material can also be regarded as a part of the non-transparent layer 4).

Wherein, the opaque layer 4 preferably has a light transmittance between 5% and 30% corresponding to the wavelength of visible light, and the opaque layer 4 can be a carbon layer, a resin layer, and a titanium dioxide one of the layers. Furthermore, the non-transparent layer 4 may be disposed on the first surface 31 by means of pasting, so that there is no space between the non-transparent layer 4 and the first surface 31 of the silicon carbide wafer 3 . They are connected by gaps, but the present invention is not limited to this.

[Technical effects of the embodiments of the present invention]

To sum up, the laser engraving method for a silicon carbide wafer disclosed in the embodiment of the present invention, the laser beam passes through the silicon carbide wafer, and the silicon carbide wafer and the carrier are in contact with each other. The second surface and the bearing processing surface are formed with laser engraving grooves, so that the silicon carbide wafer can pass through the non-transparent bearing processing surface, and it is easy to form all the predetermined points conforming to the predetermined shape. The laser-etched grooves are further reduced, thereby reducing the probability of defects in the laser-etched grooves.

Furthermore, in the laser engraving method of the silicon carbide wafer disclosed in the embodiment of the present invention, in order to enable the laser engraved groove formed in the silicon carbide wafer to have a better configuration, the engraving step may be: It includes at least one of the following conditions: at least one of the laser beams and the first surface are preferably formed with an incident angle ranging from 80 degrees to 100 degrees; the number of at least one of the laser beams can be further limited There are at least four channels, the power of the laser transmitter is 5 watts (W) to 20 watts, and the emission frequency of the laser transmitter is 30 hertz (Hz).

The content disclosed above is only a preferred feasible embodiment of the present invention, and is not intended to limit the patent scope of the present invention. Therefore, any equivalent technical changes made by using the contents of the description and drawings of the present invention are included in the patent scope of the present invention. Inside.

1: Laser transmitter 2: stage 21: Bearing machined surface 22: Ray Carved Groove 3: Silicon carbide wafer 31: First Surface 32: Second Surface 33: Ray Carved Groove 4: non-transparent layer σ: Incident angle L: laser beam P: scheduled point D: Patterned groove distribution S110: Preliminary Steps S130: Setting steps S150: Engraving step S210: Preliminary Steps

FIG. 1 is a schematic diagram of the pre-steps of the laser engraving method of the silicon carbide wafer according to the first embodiment of the present invention.

FIG. 2 is a schematic diagram of setting steps of the laser engraving method of the silicon carbide wafer according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram of the engraving steps of the laser engraving method of the silicon carbide wafer according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating that a single laser-etched groove is formed on the silicon carbide wafer by the laser engraving method of the silicon carbide wafer according to the first embodiment of the present invention.

5 is a schematic diagram of forming a plurality of laser-etched grooves on the silicon carbide wafer by the laser engraving method of the silicon carbide wafer according to the first embodiment of the present invention.

6 is a schematic diagram of the silicon carbide wafer after the laser engraving method of the silicon carbide wafer according to the first embodiment of the present invention is implemented.

FIG. 7 is a schematic bottom view of FIG. 6 .

FIG. 8 is a schematic diagram of the pre-steps of the laser engraving method of the silicon carbide wafer according to the second embodiment of the present invention.

1: Laser transmitter

2: stage

21: Bearing machined surface

3: Silicon carbide wafer

31: First Surface

32: Second Surface

4: non-transparent layer

σ: Incident angle

L: laser beam

P: scheduled point

S150: Engraving step

Claims (10)

A laser engraving method for a silicon carbide wafer, comprising: A pre-processing step: providing a laser emitter, a stage corresponding to the laser emitter, and a silicon carbide chip; wherein, the stage has a non-translucent bearing processing surface, The silicon carbide wafer has a first surface and a second surface on opposite sides, and the silicon carbide wafer is transparent from the first surface to the second surface; A setting step: placing the second surface of the silicon carbide wafer on the processing surface of the carrier, so that the laser emitter faces the first surface of the silicon carbide wafer surface; and An engraving step: using the laser emitter to emit at least one laser beam toward a predetermined point on the second surface, and at least one of the laser beams passes through the silicon carbide wafer and emits at least one laser beam at the predetermined point and Each of the adjacent sacrificial regions of the bearing processing surface is concavely formed with a laser-cut groove. The method for laser engraving of silicon carbide wafers according to claim 1, wherein, in the engraving step, the number of at least one laser beam is further limited to at least four, and the power of the laser emitter is 5 watts (W) to 20 watts, and the emission frequency of the laser transmitter ranges from 20 hertz (Hz) to 35 hertz. The laser engraving method for silicon carbide wafers as claimed in claim 1, wherein, in the engraving step, at least one of the laser beams and the first surface are formed to have an angle between 80 degrees and 100 degrees. an incident angle of , and the first surface is the processing surface of the subsequent structure forming of the silicon carbide wafer. The laser engraving method for a silicon carbide wafer according to claim 1, wherein the number of the engraving steps included is multiple times, so that the silicon carbide wafer is respectively concave at a plurality of predetermined points on the second surface A plurality of laser-cut grooves are formed, and a plurality of the laser-cut grooves constitute at least one patterned groove distribution. The laser engraving method for a silicon carbide wafer according to claim 1, wherein the number of times of the engraving steps included is multiple times, and the silicon carbide wafer is formed with a plurality of times after the engraving steps are completed multiple times. The stage of the laser-cut groove is replaced with another stage without any laser-cut groove formed thereon. The laser engraving method for a silicon carbide wafer according to claim 1, wherein, in the pre-step, a non-transparent layer is formed on the first surface of the silicon carbide wafer; in the engraving step , at least one of the laser beams can pass through the non-transparent layer and be incident into the silicon carbide wafer from the first surface. The laser engraving method for a silicon carbide wafer according to claim 6, wherein the non-transparent layer is connected to the first surface of the silicon carbide wafer without a gap, and the non-transparent layer is one of a carbon layer, a resin layer, and a titanium dioxide layer. The laser engraving method of silicon carbide wafer according to claim 1, wherein, in the pre-step, a non-transparent layer is detachably provided on the first surface of the silicon carbide wafer; In the engraving step, at least one laser beam can pass through the opaque layer and be incident into the silicon carbide wafer from the first surface. The laser engraving method for silicon carbide wafers according to claim 6 or 8, wherein the non-transparent layer has a light transmittance ranging from 5% to 30% corresponding to the wavelength of visible light. The laser engraving method for silicon carbide wafers according to claim 1, wherein, in the engraving step, the sacrificial region of the stage absorbs at least a part of the laser beam to generate a thermal effect, and the The predetermined point and the adjacent sacrificial area are each concavely formed with the laser engraved groove due to the thermal effect.

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