The various aspects and embodiments described herein pertain generally to a laser processing apparatus, a substrate processing system, a laser processing method, and a substrate processing method.
A manufacturing method for a semiconductor device described in Patent Document 1 includes forming a silicon oxide film on a top surface of a substrate in a required pattern; forming a carbon-containing film on a top surface of the silicon oxide film by a spin-on method; and polishing the carbon-containing film by CMP (Chemical Mechanical Polishing) until the silicon oxide film is exposed. According to this polishing method, a flat surface of the silicon oxide film and a flat surface of the carbon-containing film are formed on a level with each other.
A manufacturing method for a semiconductor device described in Patent Document 2 includes forming an insulating film on a first substrate; forming an insulating film on a second substrate; and bonding the first substrate and the second substrate with the two insulating films therebetween. The insulating films are made of silicon oxide, silicon carbide, silicon carbonitride, or the like.
A manufacturing method for a semiconductor device described in Patent Document 3 (a manufacturing method according to a tenth modification example) includes forming an insulating film on a top surface of a silicon substrate; forming an opening in a part of a top surface of the insulating film; and forming a buried material film in the opening. The buried material film may be, for example, a silicon oxide film. The buried material film is formed on the top surface of the insulating film as well as in the opening, and is then flattened by CMP. Afterwards, the buried material film and a temporarily bonding substrate are bonded.
Exemplary embodiments provide a technique enabling to flatten an irregularity layer in a short time.
In an exemplary embodiment, a laser processing apparatus includes a holder configured to hold a substrate including a base substrate, an irregularity pattern formed on a main surface of the base substrate, and an irregularity layer formed along the irregularity pattern; a radiation unit configured to radiate a laser beam to a protrusion of the irregularity layer to flatten the irregularity layer in a state that the substrate is held by the holder; and a controller configured to control a position of an irradiation point of the laser beam.
According to the exemplary embodiments, it is possible to flatten the irregularity layer in a short time.
Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In the various drawings, same or corresponding parts will be assigned same reference numerals, and redundant description will be omitted. In the present specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other. Further, the X-axis direction and the Y-axis direction are horizontal directions, whereas the Z-axis direction is a vertical direction.
The substrate 100 includes, as illustrated in
The substrate 100 includes the irregularity layer 130 formed along the irregularity pattern 120. The irregularity layer 130 may be formed by, for example, a CVD (Chemical Vapor deposition) method, an ALD (Atomic Layer Deposition) method, or a spin-on method.
In the present exemplary embodiment, the irregularity layer 130 is formed by the CVD method or the ALD method. Unlike in the spin-on method, since a solid is precipitated from a gas in the CVD or ALD method, the irregularity pattern 120 can be transferred to the irregularity layer 130. Meanwhile, in the spin-on method, a liquid is coated by spin-coating, and the coated liquid film is solidified by heat treatment. As will be described later in detail, the irregularity layer 130 is formed along the irregularity pattern 120 in the spin-on method as well, having a shape defined by the irregularity pattern 120.
The irregularity layer 130 includes a bottom surface 131 closest to and parallel to the base substrate 110; and a protrusion 132 protruding from the bottom surface 131 in an opposite direction from the base substrate 110. The protrusion 132 has, for example, a rectangle shape, when viewed from the top, as illustrated in
The protrusion 132 is plural in number, and the plurality of protrusions 132 are arranged in, for example, a matrix shape. The protrusions 132 may have the same height H. The bottom surface 131 is provided between the neighboring protrusions 132, and the bottom surface 131 is formed in a quadrangle lattice shape. Alternatively, the bottom surface 131 may be not provided between the neighboring protrusions 132, and two kinds of protrusions 132 having different heights H may be arranged one after another.
Since the irregularity layer 130 is flattened by polishing after it is flattened by a laser beam LB as will be described later, the time taken for the polishing can be shortened. If the irregularity layer 130 includes silicon oxide, silicon carbide, silicon nitride, silicon carbonitride, or carbon, these materials are hard and have a slow polishing speed. Thus, the flattening by the laser beam LB is of great significance.
Further, as long as the irregularity layer 130 is flattened by the laser beam LB, it does not need to be flattened by the polishing. The polishing may be performed depending on the purpose of the irregularity layer 130. This is because the level of flatness required varies depending on what the irregularity layer 130 is used for.
As an example, the irregularity layer 130 may be used as a bonding layer. In this case, the irregularity layer 130 is made of silicon oxide, silicon carbide, silicon nitride, or silicon carbonitride. The irregularity layer 130 is a flattened surface and is bonded to a substrate that is different from the substrate 100. Since the surface of the irregularity layer 130 to be bonded to another substrate is previously flattened, the irregularity layer 130 and the substrate can come into firm contact with each other to be firmly bonded to each other.
Furthermore, the irregularity layer 130 may be used as a protective layer. By way of example, the irregularity layer 130 may be inverted upside down after being flattened, and then attracted to a chuck. In this state, the base substrate 110 is ground by a whetstone or the like. Since the surface of the irregularity layer 130 to be attracted to the chuck is previously flattened, the base substrate 110 can be ground flat.
As depicted in
The carry-in/out station 2 includes a plurality of placing tables 21. These placing tables 21 are arranged in a row in the Y-axis direction. A cassette C is placed in each of the plurality of (for example, three) placing tables 21. One of these cassettes C accommodates therein a multiple number of substrates 100 before being processed. Another cassette C accommodates therein a multiple number of substrates 100 after being processed. The other cassette C accommodates therein a multiple number of substrates 100 sorted as being abnormal during a processing thereof. The number of the placing tables 21 and the number of the cassettes C are not particularly limited.
Further, the carry-in/out station 2 includes a transfer section 23. The transfer section 23 is disposed next to the plurality of placing tables 21, for example, at a positive X-axis side of the placing tables 21. Further, this transfer section 23 is disposed next to a delivery section 26, for example, at a negative X-axis side of the delivery section 26. The transfer section 23 has a transfer device 24 therein.
The transfer device 24 is equipped with a holding mechanism configured to hold the substrates 100. The holding mechanism is movable in horizontal directions (both X-axis and Y-axis directions) and a vertical direction and pivotable around a vertical axis. The transfer device 24 transfers the substrates 100 between the cassettes C placed in the placing tables 21 and the delivery section 26.
Further, the carry-in/out station 2 is equipped with the delivery section 26. The delivery section 26 is disposed next to the transfer section 23, for example, at a positive X-axis side of the transfer section 23. Further, this delivery section 26 is disposed next to the processing station 3, for example, at a negative X-axis side of the processing station 3. The delivery section 26 has a transition device 27. The transition device 27 accommodates therein the substrates 100 temporarily. The transition device 27 may be plural in number, and the plurality of transition devices 27 may be stacked in the vertical direction. The layout and the number of the transition device 27 are not particularly limited.
The processing station 3 is equipped with a first processing block 4, a second processing block 5, and a transfer block 6. The first processing block 4 is disposed next to the transfer block 6, for example, at a positive Y-axis direction of the transfer block 6. The second processing block 5 is disposed next to the transfer block 6, for example, at a negative Y-axis side of the transfer block 6.
The first processing block 4 includes, for example, a laser processing apparatus 41. The laser processing apparatus 41 forms an irradiation point P of the laser beam LB on the protrusion 132 of the irregularity layer 130, as illustrated in
The second processing block 5 has, for example, a debris removing apparatus 51 and a polishing apparatus 52. The debris removing apparatus 51 is configured to remove debris produced when the laser beam LB is radiated. The debris is a material scattered from the irradiation point P. The polishing apparatus 52 is configured to polish the irregularity layer 130 after the irregularity layer 130 is flattened by the laser beam LB. The polishing method may be, for example, CMP (Chemical Mechanical Polishing). The polishing apparatus 52 may polish the irregularity layer 130 until the irregularity pattern 120 is exposed, or such that the irregularity pattern 120 is not exposed. The polishing amount of the polishing apparatus 52 depends on what the irregularity layer 130 is to be used for. Before the polishing apparatus 52 polishes the irregularity layer 130, the debris removing apparatus 51 removes the debris. However, the removal of the debris may be performed even if the irregularity layer 130 is not polished. Further, there may be occasions where the removal of the debris is not necessary.
The transfer block 6 is disposed next to the transition device 27, for example, at a positive X-axis side of the transition device 27. The transfer block 6 has a transfer device 61 therein. The transfer device 61 is equipped with a holding mechanism configured to hold the substrate 100. The holding mechanism is movable in the horizontal directions (both X-axis and Y-axis directions) and the vertical direction and pivotable around a vertical axis. The transfer device 61 transfers the substrates 100 to/from the transition device 27, the laser processing apparatus 41, the debris removing apparatus 51 and the polishing apparatus 52 in a preset order.
Further, the layout and the number of the laser processing apparatus 41, the debris removing apparatus 51 and the polishing apparatus 52 are not limited to the example shown in
The control device 9 may be, for example, a computer, and includes a CPU (Central Processing Unit) 91 and a recording medium 82 such as a memory, as illustrated in
The program may be recorded in, for example, a computer-readable recording medium and installed from this recording medium to the recording medium 92 of the control device 9. The computer-readable recording medium may be, by way of non-limiting example, a hard disc (HD), a flexible disc (FD), a compact disc (CD), a magneto optical disc (MO), or a memory card. Further, the program may be installed to the recording medium 92 of the control device 9 by being downloaded from a server through Internet.
Then, the laser processing apparatus 41 performs a laser processing on the irregularity layer 130 of the substrate 100 (process S1). To be specific, the laser processing apparatus 41 radiates the laser beam LB to the protrusions 132 of the irregularity layer 130, thus flattening the irregularity layer 130. Thereafter, the transfer device 61 receives the substrate 100 from the laser processing apparatus 41, and transfers it to the debris removing apparatus 51.
Subsequently, the debris removing apparatus 51 removes the debris produced when the laser beam LB is radiated (process S2). The debris removing apparatus 51 is, for example, an etching apparatus configured to remove the debris by etching. The etching is, for example, wet-etching. An etching liquid etches a contact point between the debris and a surface of the irregularity layer 130 after being flattened, thus allowing the debris to be removed and flown away. Since the removal (process S2) of the debris is performed after it is flattened by the laser processing (process S1) and before polishing (process S3) is performed to flatten the irregularity layer 130 more, the debris can be suppressed from being caught between a polishing tool and the substrate 100, so that the level of flatness after the polishing can be improved. If the wet-etching is performed by using a dilute hydrofluoric acid solution, a discolored layer formed in the irregularity layer 130 by the laser processing (process S1) can be removed. Thereafter, the transfer device 61 receives the substrate 100 from the debris removing apparatus 51, and transfers it to the polishing apparatus 52.
Then, the polishing apparatus 52 polishes the irregularity layer 130 flattened by the laser processing (process S1) (process S3). The polishing method may be, for example, CMP (Chemical Mechanical Polishing). Since the polishing (process S3) is performed after the laser processing (process S1), the time taken for the polishing can be reduced.
Thereafter, the transfer device 61 receives the substrate 100 from the polishing apparatus 52, and transfers it to the transition device 27. Then, the transfer device 24 receives the substrate 100 from the transition device 27, and transfers it into the cassette C placed in the placing table 21. Then, the current processing is ended.
Now, a configuration and an operation of the laser processing apparatus 41 will be explained.
The holder 210 is configured to hold the substrate 100. For example, the holder 210 holds the substrate 100 horizontally from below it such that the irregularity layer 130 of the substrate 100 faces upwards. The holder 210 may be, by way of non-limiting example, a vacuum chuck or an electrostatic chuck.
The radiation unit 220 is configured to radiate the laser beam LB to the protrusion 132 of the irregularity layer 130 in the state that the substrate 100 is held by the holder 210. The irradiation point P of the laser beam LB is formed in the irregularity layer 130. The radiation unit 220 may concentrate the laser beam LB toward the irregularity layer 130, and the irradiation point P is a light condensing point with the highest power density in the present exemplary embodiment. Here, the irradiation point P may not be the condensing point. The protrusion 132 absorbs the laser beam LB to be scattered by being turned into a gas state from a solid state, or scattered while being kept in the solid state. Since the protrusion 132 is removed, the irregularity layer 130 is flattened.
The radiation unit 220 may include, for example, a galvano scanner 221. The galvano scanner 221 is disposed, for example, above the substrate 100 held by the holder 210. With the galvano scanner 221, the irradiation point P in the irregularity layer 130 can be displaced even if the relative position of the galvano scanner 221 and the holder 210 is fixed.
The galvano scanner 221 may include two sets each including a galvano mirror 222 and a galvano motor 223 (only one set is shown in
The radiation unit 220 may include a fθ lens 224. The fθ lens 224 forms a focal plane 225 which is orthogonal to the Z-axis direction. While the galvano scanner 221 is displacing the irradiation point P in the X-axis direction or the Y-axis direction, the fθ lens 224 maintains the Z-axis position of the irradiation point P on the focal plane 225, and maintains the shape and the size of the irradiation point P on the focal plane 225. As a result, the irradiation point P of the rectangle shape can be two-dimensionally arranged in the rectangle-shaped protrusion 132 regularly without any gaps.
The pattern measuring device 230 is configured to measure the pattern of the irregularity layer 130 before being flattened. For example, a displacement meter 231 configured to measure the height H of the irregularity layer 130 is used as the pattern measuring device 230. The height H of the irregularity layer 130 is measured with respect to, for example, the bottom surface 131. The displacement meter 231 may be, for example, a laser displacement meter, and measures the height H of the irregularity layer 130 by measuring a distance to the irregularity layer 130. Although the displacement meter 231 is of a non-contact type in the present exemplary embodiment, it may be of a contact type. The displacement meter 231 sends data of the measurement result thereof to the control device 9. The control device 9 measures the height H of the irregularity layer 130 with the displacement meter 231 while moving the displacement meter 231 and the holder 210 relatively in the X-axis and Y-axis directions, thus measuring the pattern of the irregularity layer 130 on a cross section thereof.
Further, a camera 232 configured to image the outline of the protrusion 132 of the irregularity layer 130 may be used as the pattern measuring device 230. The camera 232 images the outline of the protrusion 132 from a direction perpendicular to the bottom surface 131, and sends data of the obtained image to the control device 9. The control device 9 measures the pattern of the irregularity layer 130 in a plan view thereof by performing an image processing on the image received from the camera 232. The pattern of the irregularity layer 130 in the plan view includes the outline of the protrusion 132.
The rotation driving unit 240 is configured to rotate the holder 210. A rotation center line 241 of the holder 210 is parallel to the Z-axis direction. The rotation driving unit 240 includes, for example, a rotation motor. The rotation driving unit 240 rotates the substrate 100 along with the holder 210, allowing the two sides of the protrusion 132 having the rectangle shape in the plan view to be parallel to the X-axis direction and the other two sides of the protrusion 132 to be parallel to the Y-axis direction in the plan view thereof.
The movement driving unit 250 is configured to move the holder 210 and the radiation unit 220 relatively in the X-axis, Y-axis and Z-axis directions. The movement driving unit 250 includes, for example, a first driving unit 251 and a second driving unit 252. The first driving unit 251 moves the holder 210 in the X-axis and Y-axis directions, and the second driving unit 252 moves the radiation unit 220 in the Z-axis direction.
The first driving unit 251 is, by way of non-limiting example, a XY-stage. The second driving unit 252 includes a Z-axis guide 253 and a driving source 254 such as a motor configured to move the radiation unit 220 along the Z-axis guide 253. Since the radiation unit 220 does not move in the X-axis and Y-axis directions, the laser beam LB from the Z-axis direction can always be received at the same point. The radiation unit 220 is moved in the Z-axis direction so that the focal plane 225 of the fθ lens 224 coincides with the top surface of the protrusion 132. Further, the holder 210 instead of the radiation unit 220 may be moved in the Z-axis direction.
First, the control device 9 measures the pattern of the irregularity layer 130 with the pattern measuring device 230 (process S11). To elaborate, the control device 9 measures the height of the irregularity layer 130 with the displacement meter 231 while moving the displacement meter 231 and the holder 210 relatively in the X-axis and Y-axis directions, thus measuring the pattern of the irregularity layer 130 on the cross section thereof. Further, the control device 9 images the irregularity layer 130 with the camera 232, and measures the pattern of the irregularity layer 130 in the plan view by performing the image processing on the obtained image.
Then, the control device 9 controls the rotation driving unit 240 and the movement driving unit 250 to perform position adjustment between the holder 210 and the radiation unit 220 (process S12). To elaborate, the control device 9 controls the rotation of the holder 210 based on the outline of the protrusion 132 measured by the camera 232, thus allowing the two sides of the protrusion 132 having the rectangle shape in the plan view to be parallel to the X-axis direction and the other two sides of the protrusion 132 to be parallel to the Y-axis direction. Further, the control device 9 moves the radiation unit 220 in the Z-axis direction to align the height of the irradiation point P with the height of the protrusion 132. The height of the irradiation point P is the height of the focal plane 225. Further, the control device 9 moves the holder 210 in the X-axis and Y-axis directions to overlap a target area of the substrate 100 and an area A where the irradiation point P of the galvano scanner 221 can be formed. The area A is a region in which the irradiation point P can be moved by the rotation of the galvano mirror 222.
Then, the control device 9 removes the protrusion 132 by radiating the laser beam LB to the protrusion 132 (process S13). The control device 9 controls an output W of a light source 270 of the laser beam LB based on the height H of the protrusion 132 measured by the displacement meter 231. The output is set such that the flat surface 133 is formed at the position of the protrusion 132 to be removed to be on a level with the bottom surface 131. The higher the height H of the protrusion 132 is, the higher the output of the light source 270 is set to be. The control device 9 controls the galvano scanner 221 to remove multiple protrusions 132 within the area B1.
Subsequently, the control device 9 checks whether the protrusions 132 have been removed in all of the four areas B1 to B4 (process S14).
If there is any protrusion 132 remaining in one or more of the four areas B1 to B4 (S14, NO), the control device 9 returns to the process S12 to remove the remaining protrusion 132, and performs the process S12 and the subsequent processes again. To elaborate, the control device 9 rotates the holder 210 to allow, among the four areas B1 to B4, the area (for example, the area B2) in which the protrusion 132 remains to overlap with the area A. The control device 9 rotates the holder 210 by 90°×n (n is an integer equal to or larger than 1) to switch the area of the substrate 100 overlapping with the area A. Since the holder 210 is rotated 90°×n (n is an integer equal to or larger than 1), the two sides of the protrusion 132 having the rectangle shape in the plan view become parallel to the X-axis and the other two sides thereof become parallel to the Y-axis. In the present exemplary embodiment, since the substrate 100 is divided into the four areas B1 to B4, the processes S12 and S13 are performed four times.
Meanwhile, if there is left any protrusion 132 in none of the four areas B1 to B4 (S14, YES), the control device 9 ends the current processing. Then, the control device 9 releases the holding of the substrate 100 by the holder 210. Thereafter, the transfer device 61 receives the substrate 100 from the laser processing apparatus 41, and transfers it to the debris removing apparatus 51.
The substrate 100 of the present exemplary embodiment is divided into the four areas B1 to B4 in the circumferential direction thereof, as shown in
The control device 9 controls the position of the irradiation point P by controlling the galvano scanner 221, the rotation driving unit 240 and the movement driving unit 250, as stated above. Further, the control device 9 may control the position of the irradiation point P by controlling only the movement driving unit 250. In such a case, the galvano scanner 221 may be omitted.
As depicted in
Further, as shown in
By the homogenizer 260 and the aperture 265, it is possible to form the rectangle-shaped irradiation point P with the uniform intensity distribution. By two-dimensionally arranging this irradiation point P regularly without gaps as will be described later, a total radiation amount J of the laser beam LB per unit area can be uniformed, so that local heating can be suppressed. Thus, it is possible to remove a required portion of the irregularity layer 130 selectively while suppressing damage to the irregularity pattern 120 under the irregularity layer 130. Further, since the intensity distribution varies discontinuously at the outer edge of the irradiation point P, a boundary between the portion of the irregularity layer 130 to be removed and a portion of the irregularity layer 130 to be left can be sharply formed.
As depicted in
So far, the laser processing apparatus, the substrate processing system, the laser processing method and the substrate processing method according to the exemplary embodiment have been described. However, it should be noted that the present disclosure is not limited to the above-described exemplary embodiment. Various changes, modifications, replacements, addition, deletion and combinations may be made within the scope of the claims, and all of these are included in the scope of the inventive concept of the present disclosure.
The way how to form the irregularity pattern 120 is not particularly limited as long as it is formed on the main surface of the base substrate 110. By way of example, multiple semiconductor chips formed on a substrate different from the base substrate 110 may be arranged on the main surface of the base substrate 110 at a distance therebetween, and bonded to the base substrate 110 to thereby form the irregularity pattern 120. The multiple semiconductor chips may be arranged in a matrix shape with a gap therebetween.
The present application claims priority to Japanese Patent Application No. 2019-073042, field on Apr. 5, 2019, which application is hereby incorporated by reference in their entirety.
Number | Date | Country | Kind |
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2019-073042 | Apr 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/008696 | 3/2/2020 | WO | 00 |