CN111618439A - Method and apparatus for dicing semiconductor substrate, and method and apparatus for removing coating film - Google Patents
Method and apparatus for dicing semiconductor substrate, and method and apparatus for removing coating film Download PDFInfo
- Publication number
- CN111618439A CN111618439A CN202010107819.3A CN202010107819A CN111618439A CN 111618439 A CN111618439 A CN 111618439A CN 202010107819 A CN202010107819 A CN 202010107819A CN 111618439 A CN111618439 A CN 111618439A
- Authority
- CN
- China
- Prior art keywords
- semiconductor substrate
- coating film
- dicing
- cutting
- laser
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 134
- 238000000576 coating method Methods 0.000 title claims abstract description 117
- 239000011248 coating agent Substances 0.000 title claims abstract description 116
- 239000004065 semiconductor Substances 0.000 title claims abstract description 114
- 238000000034 method Methods 0.000 title claims abstract description 47
- 238000005520 cutting process Methods 0.000 claims abstract description 46
- 239000002184 metal Substances 0.000 claims abstract description 28
- 239000011159 matrix material Substances 0.000 claims abstract description 11
- 238000005096 rolling process Methods 0.000 claims abstract description 6
- 230000001678 irradiating effect Effects 0.000 claims description 4
- 238000003825 pressing Methods 0.000 claims description 4
- 239000010408 film Substances 0.000 description 94
- 238000012545 processing Methods 0.000 description 26
- 238000005336 cracking Methods 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000012795 verification Methods 0.000 description 3
- 230000005856 abnormality Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 239000013039 cover film Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/36—Removing material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/0445—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising crystalline silicon carbide
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/67005—Apparatus not specifically provided for elsewhere
- H01L21/67011—Apparatus for manufacture or treatment
- H01L21/67126—Apparatus for sealing, encapsulating, glassing, decapsulating or the like
Abstract
The purpose of the present invention is to uniformly remove a coating film including a metal film such as TEG formed in a laminated state on a dicing street of a semiconductor substrate, form a scribe line, and dice the semiconductor substrate along the scribe line. The present invention provides a method for cutting a semiconductor substrate (1) into elements (2) by cutting the semiconductor substrate (1), wherein a plurality of elements (2) are formed in a matrix on the substrate, and a cutting trace is provided between adjacent elements (2), the method for cutting the semiconductor substrate comprises the steps of: a coating film removing step of removing a coating film including a metal film formed on the dicing streets by scanning the coating film in parallel with a laser beam (5) a plurality of times; a scribing step of forming a scribing line by rolling a blade of a scribing wheel in a pressure-contact state on a dicing street (3) of the semiconductor substrate (1) from which the coating film has been removed; and a breaking step of cutting the semiconductor substrate (1) along the scribe line to divide the semiconductor substrate into the individual elements (2).
Description
Technical Field
The present invention relates to a technique of dicing a semiconductor substrate. The present invention also relates to a technique for removing a coating film including a metal film such as TEG formed over a semiconductor substrate by laser light.
Background
The manufacturing process of the semiconductor comprises the following steps: a process for manufacturing a substrate (wafer) serving as a support of a semiconductor, a process for manufacturing elements (semiconductor chips) by forming electronic circuits on the substrate, a process for cutting the manufactured semiconductor substrate and individually dicing (chipping) the elements, and a process for assembling a semiconductor using the elements.
As a method of cutting out elements from a semiconductor substrate, for example, there is a method of forming a scribe line on a semiconductor substrate using a scribing wheel, and cutting the substrate along the scribe line to cut out elements one by one.
However, the surface of the semiconductor substrate is divided into a plurality of regions in a lattice shape. The lattice-like lines are lines to be divided, which are called dicing streets. Elements are formed in each of the divided regions.
Various film-like laminates are formed on the upper surface of the dicing street (street). If the film-like laminate remains, an abnormality occurs when dicing a semiconductor substrate to form scribe lines. Therefore, the film-like laminate is removed before forming the scribe line. Techniques for removing the film-like laminate are disclosed in, for example, patent documents 1 to 3.
Documents of the prior art
Patent document
Patent document 1: japanese patent No. 5645593;
patent document 2: japanese patent laid-open publication No. 2013-197108;
patent document 3: japanese patent No. 4741822.
Problems to be solved by the invention
Examples of various film-like laminates formed on the upper surface of a semiconductor substrate (e.g., dicing streets) include metal films including circuits for testing called TEG (Test Element Group), alignment marks (alignment marks), and PI films (polarizing films). A laminated film (laminated film) is formed on the upper surface of the dicing street. Since the laminated film has different lamination states, the laminated film has unevenness and unevenness on a dicing street of the semiconductor substrate. That is, the laminated films differ in structure (thickness).
On the dicing streets, for example, substantially only a PI film (thickness: about 2 μm) is formed. In the portion where the dicing streets are formed with the alignment marks, for example, (PI film + SiO)2) (thickness: about 3 μm). In the portion where the dicing streets are formed with TEGs (dicing streets TEG), for example, (PI film + metal Al + SiO) is formed2) (thickness: about 5 μm).
In a portion where the pattern TEG is formed on the semiconductor substrate, for example, (PI film + metal Al + SiO) is formed2+ poly Si + SiO2) (thickness: about 10 μm).
In this manner, when the TEG or the like is formed over the semiconductor substrate, the thickness thereof becomes thicker than other portions. That is, in the semiconductor substrate, the thickness of the laminated film varies depending on the location, and a difference occurs in the structure.
Even if the TEG or the like formed on the semiconductor substrate (for example, dicing streets) is removed by the conventional techniques such as patent documents 1 to 3, the TEG or the like cannot be removed uniformly. For example, if the output of the laser beam is increased to remove the TEG or the like, even if the TEG or the like can be removed, the intersection portion of the dicing streets (only the thin film portion such as the PI film) is cut deeper, and the intersection portion is cut deeper by more than a necessary amount in the case of the cross dicing, which is not preferable (see fig. 3). Therefore, when forming a scribe line in a semiconductor substrate, there is a possibility that the scribe line is not a straight line but a broken line. In addition, the cracking causes abnormal cracking when the semiconductor substrate is broken.
If the output of the laser beam is reduced to remove the TEG, the TEG cannot be reliably removed. In order to cut the semiconductor substrate, it is necessary to form a scribe line in the semiconductor substrate itself, but when the TEG remains at the position where the scribe line is formed, the semiconductor substrate itself is not exposed, and therefore it is difficult to form the scribe line in the semiconductor substrate itself. If the scribe line is not formed in the semiconductor substrate itself at the dicing streets, an abnormality may occur in which cracks develop toward the device side when the semiconductor substrate is diced along the scribe line.
Disclosure of Invention
In view of the above-described problems, it is an object of the present invention to provide a method and an apparatus for removing a coating on a substrate by laser, which can uniformly remove a coating including a metal film such as TEG formed in a laminated state on an upper surface of a semiconductor substrate, for example, a dicing street, and a method and an apparatus for dicing a semiconductor substrate, which can form a scribe line on the dicing street of the substrate from which the coating on the substrate has been removed, and can cut the semiconductor substrate along the scribe line.
Means for solving the problems
To achieve the above object, the present invention adopts the following technical means. A method of removing a coating film on a semiconductor substrate according to the present invention is a method of removing a coating film from a semiconductor substrate on which a plurality of elements are formed in a matrix, dicing streets are formed between adjacent elements, and a coating film including a metal film is formed on the dicing streets, the method including: and irradiating laser to the cutting track, and scanning the laser for multiple times along multiple mutually parallel scanning lines in the cutting track. Preferably, the irradiation width of the laser is narrower than the width of the dicing street. Preferably, the laser beam is scanned a plurality of times to form a plurality of grooves along the plurality of scanning lines, and a stripe-shaped convex portion is formed between adjacent grooves. Preferably, at an intersection where the dicing streets intersect each other, a plurality of grooves formed in one of the intersecting dicing streets intersect a plurality of grooves formed in the other of the intersecting dicing streets, and a protrusion is formed at a center of the intersection where a group of adjacent grooves among the plurality of grooves formed in the one of the intersecting streets intersects a group of adjacent grooves among the plurality of grooves formed in the other of the intersecting streets. Preferably, the interval between adjacent scanning lines among the plurality of scanning lines is set to 20 μm or more. Preferably, the semiconductor substrate is a SiC substrate.
The device for removing a coating on a semiconductor substrate according to the present invention is a device for removing a coating from a semiconductor substrate, wherein a plurality of elements are formed in a matrix on the substrate, dicing streets are formed between adjacent elements, and coatings including metal films are formed on the dicing streets, and the device for removing a coating on a semiconductor substrate includes a laser irradiation section that irradiates a laser beam onto the dicing streets so as to scan the laser beam a plurality of times along a plurality of mutually parallel scan lines within the dicing streets along the dicing streets.
A method for cutting a semiconductor substrate according to the present invention is a method for cutting a semiconductor substrate along a dicing street into individual elements, the substrate having a plurality of elements formed in a matrix, the dicing street being formed between adjacent ones of the elements, and a coating film including a metal film being formed on the dicing street, the method comprising: a coating removal step of irradiating the dicing street with laser light and scanning the laser light a plurality of times along a plurality of mutually parallel scanning lines within the dicing street along the dicing street to remove the coating; a scribing step of forming a scribing line by pressing a scribing wheel against the cutting track from which the coating film is removed and rolling the scribing wheel along the cutting track; and a breaking step of cutting the semiconductor substrate along the scribe line to separate the semiconductor substrate into the respective elements.
A semiconductor substrate cutting device according to the present invention is a semiconductor substrate cutting device that cuts a semiconductor substrate along a dicing street to divide the semiconductor substrate into individual elements, the substrate having a plurality of elements formed in a matrix, the dicing street being provided between adjacent ones of the elements, the dicing street having a coating film including a metal film formed thereon, the semiconductor substrate cutting device including: a laser irradiation unit that irradiates the dicing street with laser light and removes the coating by scanning the laser light a plurality of times along a plurality of mutually parallel scanning lines in the dicing street; a scribing part for forming a scribing line by pressing a scribing wheel onto the cutting track from which the coating film is removed and rolling the scribing wheel along the cutting track; and a breaking portion that cuts the semiconductor substrate along the scribe line to be divided into individual elements.
Effects of the invention
According to the present invention, a coating film including a metal film such as TEG formed in a laminated state on an upper surface of a semiconductor substrate, for example, a dicing street, can be uniformly removed. Further, a scribe line can be formed along the dicing street after the removal of the cover film, and the semiconductor substrate can be diced along the scribe line.
Drawings
Fig. 1 is a diagram schematically showing an outline of a coating removal step (a coating removal method on a semiconductor substrate by laser light) constituting a method for dicing a semiconductor substrate according to the present invention.
Fig. 2 is an image of a dicing street showing a state after laser irradiation is scanned once to remove a coating film including a metal film.
Fig. 3 is an image showing the state of the intersection of the dicing streets after the laser irradiation is scanned once to remove the coating film including the metal film, and a cross-sectional view (section a-a) of the intersection.
Fig. 4 is an image of a dicing street showing a state where a coating film including a metal film is removed by scanning laser irradiation twice and a cross-sectional view (section B-B) of the dicing street.
Fig. 5 is an image showing the state of the intersection of the dicing streets after the laser irradiation is scanned twice to remove the coating film including the metal film, and a cross-sectional view (cross-section C-C) of the intersection.
Detailed Description
Embodiments of a method and an apparatus for dicing a semiconductor substrate 1 (including a method and an apparatus for removing a coating on a semiconductor substrate 1 by a laser beam 5) according to the present invention will be described below with reference to the drawings. The embodiment described below is an example of embodying the present invention, and the configuration of the present invention is not limited to the specific example.
The substrate 1 (wafer) is a support substrate for the element 2 and is formed in a disk shape. In the present embodiment, substrate 1 is formed of SiC and is a SiC layer serving as a support substrate for element 2.
As shown in fig. 1, a semiconductor substrate 1 is formed by arranging a plurality of elements 2 (semiconductor chips) having electronic circuits formed thereon in a checkered pattern on a surface of a substrate made of, for example, SiC.
That is, in the semiconductor substrate 1, a plurality of elements 2 are formed in a matrix on an SiC substrate, and dicing streets 3 (lines to divide) are provided between the adjacent elements 2. The dicing streets 3 are formed in a lattice shape on the semiconductor substrate 1.
In such a semiconductor substrate 1, various processes are performed on the surface of a substrate made of SiC in order to manufacture an element 2 (semiconductor chip) in which an electronic circuit is formed. Therefore, a laminated film (laminated film) having various structures including, for example, a metal film such as a circuit for test called a TEG (test element Group), an alignment mark, a PI film (polarizing film), and the like is formed on the dicing streets 3.
In the scribing process, a scribing line is formed in the dicing street 3. If the laminated film is present on the dicing streets 3, it becomes difficult to cut the semiconductor substrate 1 along the scribe lines when it is broken, and there is a possibility that cracks or the like occur on the element 2 side. Therefore, the laminated film formed on the dicing streets 3 needs to be removed uniformly. In this laminated film, the TEG is thicker than the alignment mark, the PI film. That is, since the laminated films having different thicknesses are formed on the dicing streets 3, the laminated films have irregularities. That is, the surface of the dicing street 3 becomes uneven.
Therefore, in the present invention, the laminated films having different thicknesses, such as TEG, formed on the dicing streets 3 are reliably removed, scribe lines are formed on the dicing streets 3, and the semiconductor substrate 1 is cut along the scribe lines to be divided into the respective elements 2. The method for cutting a semiconductor substrate 1 of the present invention comprises: a coating removal step of removing a coating including a metal film formed on the dicing streets 3 by scanning the laser beam 5 in parallel a plurality of times; a scribing step of forming a scribing line by rolling a blade of a scribing wheel in a pressure-contact state on the dicing street 3 of the semiconductor substrate 1 from which the coating film has been removed; and a breaking step of cutting the semiconductor substrate 1 along the scribe lines to separate the semiconductor substrate into the respective elements 2.
As shown in fig. 1, the coating removal step (coating removal method) is a step (method) as follows: before the scribing step is performed, the dicing street 3 on which the coating including the metal film such as TEG is formed is scanned in parallel a plurality of times with the laser light 5 focused by the laser irradiation unit 4 using a coating removal section (coating removal device) provided in the laser irradiation unit 4, and the TEG and the like are removed. By performing this coating film removal step, TEG can be reliably removed, and a single scribing line is formed on the dicing street 3 in the scribing step.
In the coating film removing step, the laser beam 5 having a width smaller than the width of the dicing streets 3 may be scanned in parallel a plurality of times. Preferably, the laser beam 5 is scanned at least twice in the coating film removing step.
In the coating film removing step, when the laser beam 5 is scanned in parallel a plurality of times, the laser beam 5 is irradiated to remove the coating film at the adjacent intervals of the coating film removing portions 6 formed by the laser beam, thereby forming the stripe-shaped ridges 7.
In the coating removal step, a projection 8 is formed at the center where the coating removal portions 6 formed by the laser light intersect at the intersection 3a where the two dicing streets 3 intersect.
In the coating film removal step, it was verified that the coating film including the metal film formed on the dicing streets 3 was removed by scanning the laser beam 5.
In the present embodiment, verification was performed using the semiconductor substrate 1 having the dicing streets 3 of 90 μm in width.
The purpose is to verify the condition that TEG can be removed by replacing the condensing lens with one having a short focal length. In the present embodiment, the condenser lens is replaced from F300mm to F150 mm. The purpose is to make the processing depth by the laser 5 shallow at the intersection 3a of the dicing streets 3. The object is to make the removal width of the coating on the dicing streets 3 40 μm or more and to make the processing width by the laser light 5 smaller than 80 μm.
As an example of the verification, the pattern TEG (In-TEG) is processed by scanning the laser beam 5 once to remove the coating film. At this time, the laser beam 5 is defocused (blurred in focus) and the spot diameter is changed. In the present embodiment, the spot diameter of the laser light 5 is changed to Φ 35 μm and Φ 40 μm. The scanning speed of the laser 5 was set to 300 mm/s.
In the pattern TEG, (PI film + metal Al + SiO) is formed on the SiC layer2+ poly Si + SiO2) Such a coating film (thickness: about 10 μm). As a result, when the spot diameter is Φ 35 μm, TEG (coating) can be uniformly removed at an output of 5W. When the spot diameter is Φ 40 μm, TEG (coating) can be removed uniformly with an output of 6W.
When the output of the laser beam 5 is reduced, problems such as the SiC layer is not exposed and burrs are generated on the processing line occur.
Next, processing is performed to remove the coating on the dicing streets 3 by scanning the laser beam 5 once for the dicing streets 3. The scanning speed of the laser 5 was set to 300 mm/s. The laser beam 5 had a spot diameter of Φ 35 μm and an output of 5W. In the dicing streets 3, a coating film (thickness: about 2 μm) of only a PI film was formed on the SiC layer.
As a result, as shown in FIG. 2, the removal width of the PI film alone was 46 μm and the processing width by the laser beam 5 was 61 μm, under the conditions of a spot diameter of Φ 35 μm and an output of 5W. The removal width of the target coating is 40 μm or more and the processing width by the laser beam 5 is 80 μm or less. An intersection 3a where the two dicing streets 3 intersect is observed.
As shown in fig. 3, the size of the intersection 3a of the dicing street 3 was 39 μm × 35 μm when the spot diameter was 35 μm and the output was 5W. The processing depth by the laser light 5 at the intersection 3a of the dicing streets 3 was 7.7 μm (section a-a). It is found that the SiC layer is processed deeply although the region at the intersection 3a of the dicing streets 3 is small.
The repetition frequency, scanning speed, and the like of the laser beam 5 are changed to increase the interval between pulses of the laser beam 5, and the laser beam 5 is scanned once to remove the TEG.
In the present embodiment, the interval between pulses of the laser light 5 is changed from 3 μm to 6 μm. The processing conditions for removing the coating by the laser 5 are: the repetition frequency is 80kHz, the scanning speed is 480mm/s, and the spot diameter phi is 40 mu m. The object of the scan is a pattern TEG.
As a result, it is difficult to uniformly remove the TEG in a portion where the laser beam 5 is difficult to process. Even if the output of the laser light 5 is increased, the machining state is unstable. Therefore, the dicing streets 3 are processed as follows: the TEG on the dicing street 3 is removed by focusing precisely (focusing the focal point on the surface of the dicing street 3) and shifting the laser 5 to scan twice.
The processing conditions for removing the coating by the laser 5 are: the output of the laser 5 was 2W, the scanning speed was 300mm/s, and the spot diameter was Φ 24 μm. Further, the shift width of the laser light 5 is 20 μm. As a result, as shown in FIG. 4, the removal width of the coating was 50 μm and the processing width by the laser beam 5 was 59 μm under the conditions of the spot diameter of Φ 24 μm and the output of 2W. That is, the removal width of the intended coating is 40 μm or more, and the processing width by the laser beam 5 is 80 μm or less. The processing depth of the laser light 5 in the dicing streets 3 was 4.3 μm (section B-B).
When this laser light 5 is scanned twice in parallel and with a shift width of 20 μm, two rows of the coating film removed portions 6 formed by the laser light are formed. It was confirmed that stripe-shaped ridges 7 were formed at adjacent intervals in the two rows of the coating film removed portions 6 formed by the laser. When the laser beam 5 was scanned twice with the displacement width of 30 μm, it was also confirmed that the convex stripe 7 was formed. The raised strip portion 7 serves as a line for guiding the blade of the scribing wheel when forming the scribing line. In other words, the ridge portions 7 form the basis of the dicing lines of the semiconductor substrate 1.
It is found that when scanning is performed twice with the displacement width of the laser light 5 being 20 μm or more, the ridge portions 7, which are portions where only the coating is removed without exposing the SiC layer, are formed at the adjacent intervals of the coating removal portions 6 formed by the laser light. The scanning interval of the laser beam 5 may be set to at least 20 μm. The raised strip 7 may have a displacement width of the laser beam 5 of 30 μm or more so that the blade of the scribing wheel passes straight.
In the present embodiment, when scanning is performed twice with the shift width of the laser light 5 being 10 μm, no ridge 7 is formed at the adjacent intervals of the coating film removed portion 6 formed by the laser light.
An intersection 3a where the two dicing streets 3 intersect is observed. As shown in fig. 5, the size of the intersection 3a of the dicing street 3 was 51 μm × 53 μm when the spot diameter was Φ 24 μm and the output was 3W. The processing depth of the laser light 5 at the intersection 3a of the dicing streets 3 was 2.9 μm at the center thereof (section C-C). That is, it is found that the processing depth of the laser beam 5 is shallow at the intersection 3a of the dicing street 3.
However, it was confirmed that a raised portion 8 was formed in the center (center of the cross shape) where the two rows of the coating film removed portions 6 formed by the laser beam intersect (orthogonally) at the intersection 3a where the two dicing streets 3 intersect.
The convex portion 8 serves as a point where the blade of the scribing wheel contacts, and a scribing line is also formed at the intersection 3a of the dicing streets 3. That is, when forming the scribe line, the convex portion 8 shortens the break of the line in the intersection portion 3 a. Even when the cutting edge of the scribing wheel deviates from the convex part 8 and passes by the convex part 8, both side surfaces of the convex part 8 are opposite to each other to form the convex part, and the break of the line can be shortened when the scribing line is formed.
By forming the convex portion 8, the cutting edge of the scribing wheel can be made to enter the center of the intersection point portion 3a of the dicing street 3, and the formation of the scribing line intermittently, that is, the formation of the scribing line in a dotted line shape can be suppressed. That is, a scribe line equivalent to one continuous scribe line is formed. This can reduce the occurrence of abnormal cracking due to the break of the scribe line when the semiconductor substrate 1 is broken.
A summary of the above verification is shown below. The condition that TEG could be removed was verified by replacing the laser beam 5 with a condenser lens having a short focal length (F300mm is changed to F150 mm). When the spot diameters were Φ 35 μm and Φ 40 μm, the output of the laser 5 was changed to verify that the TEG could be removed uniformly. Examples of processing conditions and processing results for removing the coating by the laser beam 5 are shown in (1) to (3) below.
(1) The spot diameter was 50 μm, the output was 10W, the scanning speed was 300mm/s, the removal width of the coating was 63 μm, the processing width by the laser beam 5 was 80 μm, the size of the intersection 3a of the dicing street 3 was 51 μm × 44 μm, and the processing depth by the laser beam 5 at the intersection 3a was 4.8 μm.
(2) The spot diameter Φ 40 μm, the output 6W, the scanning speed 300mm/s, the removal width of the coating film 53 μm, the processing width by the laser beam 5 67 μm, the size of the intersection 3a of the dicing streets 3 41 μm × 33 μm, and the processing depth by the laser beam 5 at the intersection 3a 7.3 μm.
(3) A spot diameter of 35 μm, an output of 5W, a scanning speed of 300mm/s, a removal width of the coating film of 46 μm, a processing width of 61 μm by the laser beam 5, a size of the intersection portion 3a of the dicing street 3 of 39 μm × 35 μm, and a processing depth of 7.7 μm by the laser beam 5 at the intersection portion 3 a.
According to the results (1) to (3), the removal width of the coating film is 40 μm or more and the processing width by the laser beam 5 is less than 80 μm by reducing the spot diameter of the laser beam 5.
However, although the size of the intersection 3a of the dicing streets 3 becomes small, the SiC layer is processed deep. Therefore, it is attempted to remove the TEG by enlarging the interval between pulses of the laser beam 5 (3 μm is changed to 6 μm), but it is difficult to remove the TEG uniformly in a portion which is difficult to be processed by the laser beam 5, and even if the output of the laser beam 5 is increased, the processing state becomes unstable.
As a result of this, the laser light 5 is displaced and the laser light 5 focused precisely is scanned twice to remove TEG (coating) on the dicing streets 3, and as a result, when the displacement width of the laser light 5 is 20 to 30 μm, the ridge portions 7 are formed between two rows of coating removal portions 6 formed by the laser light, and the ridge portions 7 are portions where only the coating is removed without exposing the SiC layer.
In the intersection 3a of the dicing streets 3, a projection 8 is formed at a portion where two rows of the coating film removed portions 6 (ridge portions 7) formed by the laser intersect with each other.
By forming the convex portion 8, the cutting edge of the scribing wheel enters the center of the intersection point portion 3a of the dicing street 3, and the occurrence of abnormal cracking due to the discontinuity of the scribing line can be reduced. Even when the cutting edge of the scribing wheel is deviated from the center of the intersection point part 3a of the dicing street 3 and passes through the side surface of the center of the intersection point part 3a, the two side surfaces of the center of the intersection point part 3a are relatively convex parts, and the occurrence of abnormal cracking due to the break of the scribing line can be reduced.
In the present invention, when a laser beam 5 is scanned in a dicing street 3 to remove a coating such as TEG, the focused laser beam 5 is scanned twice at a predetermined interval, whereby TEG can be removed uniformly.
As described above, according to the findings of the present inventors, the spot diameter of the laser beam 5 is preferably Φ 20 to 100 μm. The shift width of the laser 5 is preferably 20 to 30 μm. The spot diameter and the displacement width of the laser 5 preferably do not exceed the width of the dicing street 3.
The output of the laser 5 is preferably 2-10W. As the laser, UV laser, green laser, or the like can be used, and a pulsed laser is preferable.
In the present embodiment, since the dicing streets 3 have a width of 90 μm, the removal width of the coating is set to 40 μm or more and the processing width by the laser beam 5 is set to 80 μm or less. This is an example, and the removal width of the coating film and the processing width formed by the laser 5 depend on the width of the dicing streets 3.
As a dicing apparatus for the semiconductor substrate 1 of the present invention, there may be provided: a coating removal unit (a coating removal device on a semiconductor substrate by laser light) for removing a coating formed on a substrate by scanning a plurality of coating films including a metal film formed on a dicing street 3 in parallel by forming a plurality of elements 2 in a matrix on the substrate, and forming the dicing street 3 between the adjacent elements 2; a scribing part which vertically contacts the cutting trace 3 of the semiconductor substrate 1 after the film is removed by the cutting edge of the scribing wheel, applies load to the scribing wheel and rolls the scribing wheel to form a scribing line; and a breaking portion that cuts the semiconductor substrate 1 along the scribe line, thereby dividing into the respective elements 2.
The following structure may be adopted: in the coating film removing portion, a plurality of scans are performed in parallel with the laser beam 5 having a width smaller than the width of the dicing streets 3, and when the plurality of scans are performed in parallel with the laser beam 5, stripe-shaped convex portions 7 are formed at adjacent intervals of the coating film removing portions 6 formed by the laser beam from which the coating film is removed by irradiation of the laser beam 5, and a convex portion 8 is formed at the center where the plurality of coating film removing portions 6 formed by the laser beam intersect with each other at the intersection portion 3a where two dicing streets 3 intersect.
When the coating removal process is completed using the coating removal section, the semiconductor substrate 1 proceeds to a scribing process.
The scribing step is a step of forming a scribing line serving as a guide line for cutting on the dicing streets 3 of the semiconductor substrate 1 by using the scribing portion. First, the semiconductor substrate 1 is provided in a scribe portion. The scoring portion has a scoring tool.
A scribing wheel is rotatably mounted on the scribing tool. The periphery of the score wheel becomes the edge of the score line. The scribing wheel has a blade coated with diamond (for example, single crystal diamond) on the outer periphery thereof.
The cutting edge of the scribing wheel is brought into vertical contact with the dicing streets 3 of the semiconductor substrate 1. Specifically, the blade of the scoring wheel is brought into contact with the ridge 7 formed between the two coating film removing portions 6 formed by the laser.
When the scribing wheel is advanced while being pressed with a predetermined load, the scribing wheel rolls on the ridge portion 7 of the dicing street 3, thereby forming a scribe line on the surface of the semiconductor substrate 1.
That is, it is desirable that the scribe line is formed on the ridge portion 7 formed between the two rows of the coating film removed portions 6 formed by the laser. Even when the coating film removing portions 6 formed by the laser are formed along both side surfaces of the ridge portion 7 while being deviated from the ridge portion 7, the side surfaces of the ridge portion 7 are formed as ridge portions in opposition to each other, and therefore, the same effect can be obtained.
When the scribing process is completed using the scribing portion, the semiconductor substrate 1 proceeds to a breaking process.
The breaking step is a step of cutting the semiconductor substrate 1 along a scribe line serving as a cutting guide line using a breaking portion. First, the semiconductor substrate 1 on which the scribe line is formed is provided at the breaking portion. In the breaking portion, the semiconductor substrate 1 is disposed with the scribe line down so that the scribe line is centered. The breaking portion has a breaking member provided with a breaking edge at a tip end thereof. The breaking member is brought close to a position corresponding to the scribe line from the side of the surface on which the scribe line is not formed.
The blade of the breaking member (breaking edge) is pressed to press a position corresponding to the scribe line. Thus, the semiconductor substrate 1 is cut along the scribing line.
According to the present invention, the coating film including the metal film such as TEG formed in a laminated state on the upper surface of the semiconductor substrate 1, for example, on the dicing streets 3 can be uniformly removed. Further, a scribe line can be formed on the dicing streets 3 from which the coating film is removed, and the semiconductor substrate 1 can be diced along the scribe line.
By uniformly removing the coating film including the metal film such as TEG, a scribe line can be formed linearly, and the semiconductor substrate 1 can be cut without causing cracks or the like on the element 2 side.
The embodiments disclosed herein are considered to be illustrative in all respects and not restrictive.
In particular, matters not explicitly described in the embodiment disclosed herein, such as working conditions, operating conditions, sizes and weights of members, and the like, do not exceed the range usually implemented by those skilled in the art, and matters that can be easily conceived by those skilled in the art are adopted.
Description of the reference numerals
1: semiconductor substrate (SiC substrate)
2: component
3: cutting track
3 a: intersection part
4: laser irradiation unit
5: laser
6: coating film removing part formed by laser
7: convex strip part
8: convex part
Claims (10)
1. A method of removing a coating film on a semiconductor substrate, characterized in that the coating film is removed from the semiconductor substrate on which a plurality of elements are formed in a matrix form, dicing streets are formed between adjacent ones of the elements, the coating film including a metal film is formed on the dicing streets,
the method for removing the coating film on the semiconductor substrate comprises the following steps:
and irradiating laser to the cutting track, and scanning the laser for multiple times along multiple mutually parallel scanning lines in the cutting track.
2. The method according to claim 1, wherein the step of removing the coating film on the semiconductor substrate,
the irradiation width of the laser is narrower than the width of the dicing street.
3. The method for removing a coating film on a semiconductor substrate according to claim 1 or 2,
by scanning the laser light a plurality of times, a plurality of grooves are formed along the plurality of scanning lines, and a stripe-shaped convex portion is formed between adjacent grooves.
4. The method for removing a coating film on a semiconductor substrate according to any one of claims 1 to 3,
in the intersection portion where the dicing streets intersect with each other, a plurality of grooves formed in one of the intersecting dicing streets intersect with a plurality of grooves formed in the other dicing street, and a protrusion is formed at the center of the intersection portion where a pair of adjacent grooves among the plurality of grooves formed in the one dicing street intersect with a pair of adjacent grooves among the plurality of grooves formed in the other dicing street.
5. The method for removing a coating film on a semiconductor substrate according to any one of claims 1 to 4,
the interval between adjacent scanning lines among the plurality of scanning lines is set to be 20 [ mu ] m or more.
6. The method for removing a coating film on a semiconductor substrate according to any one of claims 1 to 5,
the semiconductor substrate is a SiC substrate.
7. A device for removing a coating film from a semiconductor substrate, wherein a plurality of elements are formed in a matrix on the substrate, a dicing street is formed between adjacent elements, the coating film including a metal film is formed on the dicing street,
the coating film removing device is provided with a laser irradiation part, and the laser irradiation part irradiates laser to the cutting trace, so that the laser scans for a plurality of times along a plurality of mutually parallel scanning lines in the cutting trace.
8. A method of dicing a semiconductor substrate, characterized in that the semiconductor substrate is diced along dicing streets to be divided into individual elements, a plurality of elements are formed in a matrix on the substrate, the dicing streets are formed between adjacent ones of the elements, a coating film including a metal film is formed on the dicing streets,
the method for cutting a semiconductor substrate comprises:
a coating removal step of irradiating the dicing street with laser light and scanning the laser light a plurality of times along a plurality of mutually parallel scanning lines in the dicing street, thereby removing the coating;
a scribing step of forming a scribing line by pressing a scribing wheel against the cutting track from which the coating film is removed and rolling the scribing wheel along the cutting track; and
and a breaking step of cutting the semiconductor substrate along the scribe line to separate the semiconductor substrate into the individual elements.
9. The method for cutting a semiconductor substrate according to claim 8,
the semiconductor substrate is a SiC substrate.
10. A semiconductor substrate cutting device characterized in that a semiconductor substrate is cut along a dicing street to be divided into individual elements, a plurality of elements are formed in a matrix on the substrate, the dicing street is provided between adjacent ones of the elements, a coating film including a metal film is formed on the dicing street,
the semiconductor substrate cutting device comprises:
a laser irradiation unit that irradiates the dicing street with laser light and removes the coating by scanning the laser light a plurality of times along a plurality of mutually parallel scanning lines in the dicing street;
a scribing part for forming a scribing line by pressing a scribing wheel onto the cutting track from which the coating film is removed and rolling the scribing wheel along the cutting track; and
and a breaking section that cuts the semiconductor substrate along the scribe line to be divided into individual elements.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019-036384 | 2019-02-28 | ||
| JP2019036384A JP7361357B2 (en) | 2019-02-28 | 2019-02-28 | Semiconductor substrate cutting method and cutting device |
| JP2019-036385 | 2019-02-28 | ||
| JP2019036385A JP2020141070A (en) | 2019-02-28 | 2019-02-28 | Method and device for removing film on semiconductor substrate by laser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111618439A true CN111618439A (en) | 2020-09-04 |
Family
ID=72267942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010107819.3A Pending CN111618439A (en) | 2019-02-28 | 2020-02-21 | Method and apparatus for dicing semiconductor substrate, and method and apparatus for removing coating film |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111618439A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005064231A (en) * | 2003-08-12 | 2005-03-10 | Disco Abrasive Syst Ltd | Dividing method of plate-shaped article |
| JP2005116844A (en) * | 2003-10-09 | 2005-04-28 | Matsushita Electric Ind Co Ltd | Method for manufacturing semiconductor device |
| JP2014093445A (en) * | 2012-11-05 | 2014-05-19 | Disco Abrasive Syst Ltd | Method for processing optical device wafer |
| CN105261560A (en) * | 2014-07-08 | 2016-01-20 | 株式会社迪思科 | Method for machining wafer |
-
2020
- 2020-02-21 CN CN202010107819.3A patent/CN111618439A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005064231A (en) * | 2003-08-12 | 2005-03-10 | Disco Abrasive Syst Ltd | Dividing method of plate-shaped article |
| JP2005116844A (en) * | 2003-10-09 | 2005-04-28 | Matsushita Electric Ind Co Ltd | Method for manufacturing semiconductor device |
| JP2014093445A (en) * | 2012-11-05 | 2014-05-19 | Disco Abrasive Syst Ltd | Method for processing optical device wafer |
| CN105261560A (en) * | 2014-07-08 | 2016-01-20 | 株式会社迪思科 | Method for machining wafer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7554211B2 (en) | Semiconductor wafer and manufacturing process for semiconductor device | |
| US11551974B2 (en) | Manufacturing process of element chip using laser grooving and plasma-etching | |
| JP4422463B2 (en) | Semiconductor wafer dividing method | |
| JP4750427B2 (en) | Wafer laser processing method | |
| JP2005268752A (en) | Method of laser cutting, workpiece and semiconductor-element chip | |
| US20060009008A1 (en) | Method for the laser processing of a wafer | |
| US20050035100A1 (en) | Method of dividing a plate-like workpiece | |
| JP2007317935A (en) | Semiconductor substrate, substrate-dividing method, and element chip manufacturing method | |
| TWI622092B (en) | Method of manufacturing chips | |
| JP2006150385A (en) | Laser cutting method | |
| KR20110138225A (en) | Method for laser singulation of chip scale packages on glass substrates | |
| JP2009010105A (en) | Laser processing method for wafer | |
| CN108067746B (en) | Method for processing substrate | |
| US20230040267A1 (en) | Laser dicing for singulation | |
| JP2006073779A (en) | Method of manufacturing semiconductor device | |
| US7211500B2 (en) | Pre-process before cutting a wafer and method of cutting a wafer | |
| JP3395620B2 (en) | Semiconductor light emitting device and method of manufacturing the same | |
| JP6455166B2 (en) | Manufacturing method of semiconductor wafer and semiconductor chip | |
| JP2004276386A (en) | Splitting ceramic substrate and its manufacturing method | |
| CN111618439A (en) | Method and apparatus for dicing semiconductor substrate, and method and apparatus for removing coating film | |
| JP7361357B2 (en) | Semiconductor substrate cutting method and cutting device | |
| JP2006179790A (en) | Laser cutting method and member that can be cut by it | |
| CN110480158B (en) | Dicing of silicon carbide semiconductor wafers | |
| JP2020141070A (en) | Method and device for removing film on semiconductor substrate by laser | |
| JP5285741B2 (en) | Semiconductor wafer and processing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |