Method for scribing brittle material substrate

Abstract

To provide a scribe method for a brittle material substrate in which test scribe lines evaluating and comparing the conditions of a scribe line are formed on a brittle material substrate, and, based on the conditions of the test scribe lines, a scanning direction in which separation quality is made satisfactory is decided to scribe the brittle material substrate in the scan direction.SOLUTION: A scribe method comprises: a test scribe step in which test scribes are performed to the surface of the non-product region of a brittle material substrate 1 in scan directions parallel to a planned scribe line and in mutually different directions to form test scribe lines; a condition evaluation step in which the conditions of the test scribe lines are evaluated, respectively; a condition comparison step in which the conditions of the test scribe lines are compared with each other to ascertain the directivity of a scribe; and a scribe step in which a scribe line is formed. In the condition comparison step, when the test scribe lines are mutually compared and are in different conditions from each other, the scribe is performed only in the same direction as that in which the conditions of the test scribe lines are satisfactory in the scribe step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for comparing and evaluating the state of a brittle material substrate and determining the scribing direction when scribing the brittle material substrate. [Background technology]

[0002] Conventionally, a scribing means such as a scribing wheel is used to form scribe lines in the X direction on the surface of a mother substrate (brittle material substrate), as well as scribe lines in the Y direction perpendicular to the X direction, and then the mother substrate is broken into unit substrates along the scribe lines. A technique for forming a scribe line is disclosed in, for example, Patent Document 1.

[0003] Patent Document 1 describes a scribing method in which a grooved cutter wheel 2 having continuous irregularities 2b on a cutting edge ridge 2a is used to form a first scribe line S1 on a brittle material substrate M, and then a second scribe line S2 that intersects with the first scribe line S1. In at least the step of forming the second scribe line S2, oil is supplied to the surface of the brittle material substrate M, and the grooved cutter wheel 2 is rolled while being pressed against the surface along the line to be scribed L to which the oil has been supplied. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-031293 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the state (crystal orientation, etc.) of brittle material substrates (e.g., single crystal substrates such as silicon and sapphire) varies depending on the composition and manufacturing conditions. When forming scribe lines on the surface of such brittle material substrates (especially the above-mentioned single crystal substrates) and breaking them into unit substrates along the scribe lines, it has become clear that the product quality after breaking is not stable.

[0006] For example, when scribing a SiC substrate, it was found that when scribing (including breaking) parallel to the orientation flat (OF) on the SiC substrate, there is a difference in separation quality depending on the scanning direction of the scribe (+X direction (→) and -X direction (←)). Similarly, when scribing perpendicular to the orientation flat, there is a difference in separation quality depending on the scanning direction of the scribe (+Y direction (↓) and -Y direction (↑)).

[0007] Specifically, the inventors of the present application conducted an experiment using an arbitrary brittle material substrate as an example. In the arbitrary brittle material substrate, when the scanning direction of the scribe is the +X direction (→), the possible range of the scribe load that provides good separation quality is narrow, but when it is the -X direction (←), the possible range of the scribe load that provides good separation quality tends to be wider. In other words, it was found that scribing in one direction results in a lot of peeling and chipping and makes it difficult to separate along the scribe lines, but scribing in the opposite direction makes it possible to separate along the scribe lines.

[0008] In view of the above problems, the present invention aims to provide a scribing method for a brittle material substrate, in which, when forming a scribe line on the surface of a brittle material substrate (particularly a single crystal substrate), first a test scribe line for evaluating and comparing the state of the scribe line is formed on the surface of the substrate, a scribe scanning direction that provides good separation quality is determined based on the state of the test scribe line, and scribing is performed in the determined scanning direction to form a scribe line. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides the following technical solutions. The method for scribing a brittle material substrate according to the present invention is a method for scribing a brittle material substrate, which comprises forming a scribe line along a line to be scribed on a surface of a brittle material substrate, the method comprising the steps of: forming a scribe line parallel to the line to be scribed on a surface of a non-product region of the brittle material substrate; ,phase The method includes a test scribing step of forming a test scribe line by performing test scribing in scanning directions oriented different from each other, a condition evaluation step of evaluating the condition of each of the test scribe lines formed by the test scribing performed in the scanning directions oriented different from each other, a condition comparison step of comparing the conditions of the test scribe lines formed by the test scribing performed in the scanning directions oriented different from each other to determine the directionality of scribing, and a scribing step of forming a scribe line along the line to be scribed, wherein, in the condition comparison step, the test scribe lines formed by the test scribing performed in the scanning directions oriented different from each other are compared with each other, and if it is determined that the test scribe lines are in clearly different conditions, in the scribing step, scribing is performed only in the same direction as the scanning direction of the test scribe in which the condition of the test scribe line is good, to form a scribe line.

[0010] Preferably, in the state comparison process, the test scribe lines formed by test scribing performed in the mutually different scanning directions are compared with each other, and if it is determined that the states are the same, it is decided to alternate between scribing in one direction and scribing in the opposite other direction, and in the scribing process, the second and subsequent scribes are scribed in a direction opposite to the direction of the scribe scanned immediately before to form scribe lines.

[0011] Preferably, when scribing a plurality of the brittle material substrates manufactured in a predetermined unit, the test scribing process, the condition evaluation process, the condition comparison process and the scribing process are performed on the first of the brittle material substrates in the predetermined unit, and the scribing process is performed on the second and subsequent brittle material substrates in the predetermined unit based on the results of the condition comparison process determined for the first of the brittle material substrates.

[0012] Preferably, in the test scribing step and the scribing step, the test scribe line and the scribe line are formed by rolling a scribing wheel against the surface of the brittle material substrate while pressing it. Preferably, a surface film is formed on the surface of the brittle material substrate, and when a scribe line is formed from the surface film side, in the condition evaluation process, the condition of the test scribe line is evaluated based on whether or not the surface film is in a state where it is peeled off more than specified, and the directionality of the scribe is determined.

[0013] Preferably, in the condition evaluation step, the brittle material substrate is broken along the test scribe line, and the separated portion is observed to evaluate the condition of the test scribe line. Effect of the Invention

[0014] According to the present invention, when forming a scribe line on the surface of a brittle material substrate (particularly a single crystal substrate), first a test scribe line is formed on the surface of the substrate to evaluate and compare the condition of the scribe line, and a scribe scanning direction that provides good separation quality is determined based on the condition of the test scribe line, and scribed in the determined scanning direction to form the scribe line. [Brief description of the drawings]

[0015] [Figure 1]FIG. 2 is a diagram showing a schematic example of a scribe scanning direction on the surface of a brittle material substrate (single crystal substrate). [Figure 2A] This is a photograph of the state of the edge after a test scribe was formed by scanning parallel to the orientation flat (OF) in a downward direction (-X direction: ←), and then separation was performed along the test scribe. [Figure 2B] This is a photograph showing the state of the edge after a test scribe was formed by scanning parallel to the orientation flat (OF) in an upward direction (+X direction: →), and then separation was performed along the test scribe. [Figure 3A] This is a photograph of the state of the edge after a test scribe was formed by scanning vertically and downward (-Y direction: ↑) with respect to the orientation flat (OF) and then separation was performed along the test scribe. [Figure 3B] This is a photograph showing the state of the edge after a test scribe was formed by scanning perpendicularly to the orientation flat (OF) in an upward direction (+Y direction: ↓), and then separation was performed along the test scribe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the method for scribing a brittle material substrate 1 according to the present invention will be described with reference to the drawings. The embodiment described below is merely an example of the present invention, and the configuration of the present invention is not limited to this specific example. The present invention is a method for scribing a brittle material substrate 1, which forms multiple scribe lines parallel to each other along a line to be scribed on the surface of the brittle material substrate 1, and determines the scribe scanning direction that will result in good quality when cut by determining the scribe directionality.

[0017] Now, the present invention is suitable for a single crystal substrate 1 such as silicon or sapphire. The state of the substrate, such as the crystal orientation, of such a brittle material substrate 1 varies depending on the composition and manufacturing conditions. Furthermore, even if the composition and manufacturing conditions of a brittle material substrate 1 (particularly a single crystal substrate 1) are the same, the state (properties of the substrate 1) may vary for each given unit (for example, one lot).

[0018] In such a case, the inventors of the present application found that the quality of the unit substrates at the time of separation differs depending on the scanning direction of the scribe. In other words, the inventors of the present application found that in the single crystal substrate 1, a difference occurs in the state of peeling or the like at the separated portion of the unit substrate after separation between scribing in the "upward direction (+ direction)" and scribing in the "downward direction (- direction)."

[0019] Therefore, in the scribing method for brittle material substrate 1 of the present invention, before forming the scribe lines, test scribe lines are formed in the "upward" and "downward" directions (the forward and backward directions based on a certain point), and the directionality of the scribe is determined from the separation site along the test scribe lines, and the scribe scanning direction that will result in good separation quality is determined.

[0020] A brittle material substrate 1 shown in FIG. 1 is a mother substrate before scribe lines are formed and the substrate is cut into unit substrates that become products. The direction from left to right in Figure 1 is defined as the "+X direction (upward direction)", the opposite direction (from right to left) is defined as the "-X direction (downward direction)", the direction from top to bottom in Figure 1 is defined as the "+Y direction (upward direction)", and the opposite direction (from bottom to top) is defined as the "-Y direction (downward direction)".

[0021] The brittle material substrate 1 has an "orientation flat" cut out in a straight line. This "orientation flat" is an orientation flat (OF) that indicates the crystal orientation of the substrate 1. The scribing method for a brittle material substrate 1 of the present invention includes a "test scribing process" for forming test scribe lines in the upward and downward directions, a "state evaluation process" for evaluating the states of the test scribe lines in the upward and downward directions, a "state comparison process" for comparing the evaluated states of the test scribe lines in the upward and downward directions and determining a scanning direction, and a "scribing process" for forming scribe lines in the determined scanning direction.

[0022] In the test scribing step, test scribing is performed on the surface of a non-product region (such as an edge of the substrate 1) of the brittle material substrate 1 in scanning directions that are parallel to the lines to be scribed and in "mutually different directions" to form test scribe lines. The "mutually different directions" refer to one direction, the "upward direction," and the "downward direction," which is the direction that returns to the upward direction. In this embodiment, in the X direction, the "upward direction," which is one direction, is the +X direction. The "downward direction," which is the direction that returns to the upward direction (opposite direction), is the -X direction (see FIG. 1). In other words, the +X direction is the outward path, and the -X direction is the return path.

[0023] In addition, in the Y direction, one direction, the "upward direction", is the +Y direction. The "downward direction", which is the direction going back (opposite) to the upward direction, is the -Y direction (see Figure 1). In other words, the +Y direction is the outward route, and the -Y direction is the return route. In the test scribing step, test scribe lines parallel to the multiple lines to be scribed are formed on the surface of the non-product region of the brittle material substrate 1 by test scribing with scanning directions "oriented in mutually different directions".

[0024] That is, in the test scribing process, the surface of the non-product area of ​​the brittle material substrate 1 is scanned in the "+X direction (upward direction)" and the scribing wheel of the scribing device is pressed and rolled to form a test scribe line parallel to the line to be scribed. In addition, the scribing wheel is scanned in the "-X direction (downward direction)" relative to the surface of the non-product region of the brittle material substrate 1, and rolled while pressing, to form a test scribe line parallel to the line to be scribed.

[0025] Furthermore, in the test scribing process, a test scribe line parallel to the line to be scribed is formed by scanning the surface of the non-product area of ​​the brittle material substrate 1 in the "+Y direction (upward direction)" and rolling the scribing wheel while pressing it. In addition, the scribing wheel is scanned in the "-Y direction (downward direction)" relative to the surface of the non-product region of the brittle material substrate 1, and rolled while pressing, to form a test scribe line parallel to the line to be scribed.

[0026] The state evaluation step evaluates the state of each test scribe line formed by test scribing performed in mutually different scanning directions (upward and downward directions). Now, a surface film is formed on the surface of the brittle material substrate 1. When a scribe line is formed from the surface film side, the state of the test scribe line is evaluated in the state evaluation step depending on whether or not the surface film is in a "peeled state" more than specified.

[0027] The "peeling state" refers to the size and number of defects, such as the depth of the depression in the surface film being greater than a predetermined depth, the number of depressions being greater than a predetermined number, etc. Based on these states, the state of the test scribe line is judged. That is, in the state evaluation step, the brittle material substrate 1 is broken along the test scribe line, and the separated portion is observed to evaluate the state (separation quality) of the test scribe line.

[0028] In the state comparison step, the states of the test scribe lines formed by test scribing performed in mutually different scanning directions (upward and downward directions) are compared with each other to determine the directionality of the scribing. In the condition comparison process, the test scribe lines formed by test scribing performed in mutually different scanning directions are compared with each other, and if it is determined that the conditions are clearly different, the direction of the test scribe in which the condition of the test scribe line is relatively better, either the "upward direction" or the "downward direction", is determined to be the scanning direction of the scribe.

[0029] For example, if the scanning direction of the first scribe is set to the "upward direction", the second and subsequent scribes will scribe in the same direction as the scanning direction of the first scribe to form a scribe line. If the "upward direction" is set, scribing will only be performed in the "upward direction", and if the "downward direction" is set, scribing will only be performed in the "downward direction". On the other hand, in the state comparison step, the test scribe lines formed by the test scribes performed in the scanning directions different from each other are compared with each other to determine whether the states are the same as each other. If it is determined that this is the case, it is decided to alternate between scribing in "one direction (upward direction)" and scribing in the opposite "other direction (downward direction)".

[0030] For example, if the scanning direction of the first scribe is the "upward direction," the second and subsequent scribes will be scribed in the opposite direction to the scribe that was scanned immediately before (if the first line is the "upward direction," the second line will be the "downward direction") to form a scribe line. In the scribing step, a scribe line is formed along the line to be scribed. In the scribing process, if the state of the test scribe line is determined to be clearly different in the state comparison process, scribing is performed in a scanning direction (only the same direction as the test scribe) in which the state is relatively better, and a scribe line is formed.

[0031] In the scribing process, if the states of the test scribe lines are determined to be the same in the state comparison process, if the first scribe line is formed by scribing in, for example, an "upward direction," then the second and subsequent scribe lines are formed by scribing in a "downward direction" opposite to the previous scribe line. After that, scribing in the "upward direction" and scribing in the "downward direction" are alternately performed.

[0032] In scribing, a scribing wheel is pressed against and rolled on the surface of the brittle material substrate 1 to form scribe lines. When scribing multiple brittle material substrates 1 manufactured in a predetermined unit (e.g., one lot, the same composition, the same manufacturing conditions, etc.), a "test scribing process," a "condition evaluation process," a "condition comparison process," and a "scribing process" are performed on the first brittle material substrate 1 in the predetermined unit, and a "scribing process" is performed on the second and subsequent brittle material substrates 1 in the predetermined unit based on the results of the "condition comparison process" determined for the first brittle material substrate 1.

[0033] In addition, the specified unit also includes, for example, the same manufacturing conditions, such as manufacturing with the same composition, and cases where the product quality changes slightly even under the same manufacturing conditions (such as between lots), and the present invention is applicable thereto. [Example] An example carried out according to the method for scribing a brittle material substrate 1 of the present invention will be described below.

[0034] In this example, a test scribe experiment was carried out using a SiC substrate 1. As shown in FIG. 2A, a test scribe line is formed on the surface of the non-product area of ​​the brittle material substrate 1 by scanning parallel to the orientation flat (OF) and in the -X direction (downward direction "←"), and the separation site along the test scribe line is observed. It is found that in the case of this SiC substrate 1, scribing in the -X direction results in good separation quality.

[0035] As shown in FIG. 2B, when a test scribe line is formed on the surface of the non-product area of ​​the brittle material substrate 1 by scanning parallel to the orientation flat (OF) in the +X direction (upward direction of “→”) and the separation site along the test scribe line is observed, it can be seen that in the case of this SiC substrate 1, scribing in the +X direction results in unevenness in the separation line. As shown in FIG. 3A, a test scribe line is formed on the surface of the non-product area of ​​the brittle material substrate 1 by scanning perpendicular to the orientation flat (OF) and in the -Y direction (downward direction "↑"), and the separation site along the test scribe line is observed. It can be seen that in the case of this SiC substrate 1, scribing in the -Y direction results in good separation quality.

[0036] As shown in FIG. 3B, when a test scribe line is formed on the surface of the non-product area of ​​the brittle material substrate 1 by scanning perpendicular to the orientation flat (OF) and in the +Y direction (upward direction “↓”), and the separation site along the test scribe line is observed, it is found that in the case of this SiC substrate 1, chipping is likely to occur when scribing in the +Y direction. As described above, when test scribing is performed in mutually different directions (upward and downward), the separation quality differs depending on the scanning direction, so it is preferable to evaluate and compare the state of the test scribe lines to determine the scribe directionality and then determine the scribe scanning direction.

[0037] According to the method for scribing a brittle material substrate 1 of the present invention, a brittle material substrate 1 (particularly a single crystal substrate When forming a scribe line on the surface of the plate (1), first a test scribe line is formed on the surface of the substrate (1) to evaluate and compare the condition of the scribe line, and based on the condition of the test scribe line, a scribe scanning direction that will result in good separation quality is determined, and scribing is performed in the determined scanning direction to form the scribe line.

[0038] It should be noted that the embodiments disclosed herein should be considered as illustrative in all respects and not restrictive. In particular, in the embodiments disclosed herein, matters that are not explicitly stated, such as operating conditions, operating conditions, dimensions and weights of components, etc., do not deviate from the scope of what a person of ordinary skill in the art would normally do, and instead are matters that a person of ordinary skill in the art would easily imagine.

[0039] The method for scribing a brittle material substrate 1 of the present invention may be stored, for example, in a control unit of a scribing device or a control unit of a device in which scribing and breaking are integrated. [Explanation of symbols]

[0040] 1 Brittle material substrate

Claims

1. A method for scribing a brittle material substrate, comprising forming a scribe line along a line to be scribed on a surface of a brittle material substrate, the method comprising: a test scribing step of performing test scribing on a surface of a non-product region of the brittle material substrate in a scanning direction parallel to the line to be scribed and different from each other to form a test scribe line; a state evaluation step of evaluating states of the test scribe lines formed by the test scribes performed in the mutually different scanning directions; a state comparison step of comparing states of the test scribe lines formed by the test scribing performed in the mutually different scanning directions to determine the directionality of the scribing; A scribing step of forming a scribe line along the line to be scribed, In the state comparison step, the test scribe lines formed by the test scribes performed in the mutually different scanning directions are compared with each other, and if it is determined that the states are obviously different, In the scribing step, scribing is performed only in the same direction as the scanning direction of the test scribe where the state of the test scribe line is good, to form a scribe line. A method for scribing a brittle material substrate, comprising:

2. In the state comparison step, the test scribe lines formed by the test scribing performed in the mutually different scanning directions are compared with each other, and when it is determined that the states are the same, it is decided to alternately perform scribing in one direction and scribing in the opposite other direction; In the scribing step, the second and subsequent scribe lines are scribed in a direction opposite to the direction of the scribe line scanned immediately before to form the scribe lines. The method for scribing a brittle material substrate according to claim 1 .

3. When scribing a plurality of the brittle material substrates manufactured in predetermined units, For a first brittle material substrate in the predetermined unit, the test scribing step, the state evaluation step, the state comparison step, and the scribing step are performed; For the second and subsequent brittle material substrates in the predetermined unit, the scribing step is performed based on the result of the state comparison step performed on the first brittle material substrate.

3. The method for scribing a brittle material substrate according to claim 1 or 2.

4. In the test scribing step and the scribing step, The test scribe line and the scribe line are formed by pressing and rolling a scribing wheel against the surface of the brittle material substrate.

4. The method for scribing a brittle material substrate according to claim 1.

5. a surface film is formed on a surface of the brittle material substrate, When the scribe line is formed from the surface film side, the state of the test scribe line is evaluated in the state evaluation step depending on whether the surface film is peeled off more than specified, and the direction of the scribe is determined.

5. The method for scribing a brittle material substrate according to claim 1.

6. In the condition evaluation step, the brittle material substrate is broken along the test scribe line, and the separated portion is observed to evaluate the condition of the test scribe line.

6. The method for scribing a brittle material substrate according to claim 1,

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