CUTTING METHOD

Abstract

A cutting process comprises: forming a reshaped area in a workpiece (1); and after forming the reshaped area in the workpiece (1), forming a groove (9) in the workpiece (1) along an intended cutting line. During the formation of the groove (9), a first dry etching process is performed from a front surface (3) to a back surface (4) of the workpiece (1). After the first dry etching process, a first pressure reduction process is performed, in which the workpiece (1) is placed under an atmosphere with reduced pressure compared to the pressure during the first dry etching process. After the first pressure reduction process, a second dry etching process is performed from the front surface (3) to the back surface (4) of the workpiece (1).

Description

Scope of the invention

[0001] The present invention relates to cutting methods, in particular to a cutting method for cutting a workpiece in the form of a plate along an intended cutting line. State of the art

[0002] There is a well-known machining process for using a laser beam to position a condensation point in a workpiece in the form of a plate, thereby creating a remodeled area, and then performing an etching process on this remodeled area. This machining process is described, for example, in Japanese patent number 2004-359475 (PTL 1). In the machining process described in this publication, a wet etching process is used as the etching process for the remodeled area. Citation list for patent literature

[0003] PTL 1: Japanese patent, publication number: 2004-35947575 Summary of the invention: Technical problem

[0004] A cutting process is conceivable in which a workpiece, such as a semiconductor substrate, is cut using the processing method described in the preceding publication. If the chips to be formed from the semiconductor substrate are small, it is advantageous to use a dry etching process, which can be manufactured using microfabrication compared to a wet etching process. If a conventional dry etching process is used for the remodeled area, a groove formed along an intended cutting line has a small width, making it difficult for etching gas to penetrate the groove. This adversely results in a low groove formation rate.

[0005] The present invention was made with regard to the above problem, and one objective of the present invention is to provide a cutting method which can increase the formation rate of a groove along an intended cutting line. Solution to the problem

[0006] A cutting method of the present invention is for cutting a workpiece in the form of a plate along an intended cutting line. The cutting method comprises: forming a reshaped area in the workpiece along the intended cutting line by applying a laser beam while positioning a condensation point in the workpiece; and, after forming the reshaped area in the workpiece, forming a groove in the workpiece along the intended cutting line. During groove formation, a first dry etching process is performed from a front surface to a back surface of the workpiece. After the first dry etching process, a first pressure reduction process is performed in which the workpiece is placed under an atmosphere with reduced pressure compared to the pressure during the first dry etching process.After the first pressure reduction process, a second dry etching process is carried out from the front surface to the back surface of the workpiece. Advantageous effects of the invention

[0007] According to the cutting method of the present invention, the formation rate of a groove along an intended cutting line can be increased. List of characters Fig. Figure 1 is a schematic top view of a workpiece in a cutting process according to an embodiment of the present invention. Fig. 2 is a section view along the line II-II in Fig. 1. Fig. Figure 3 is a schematic configuration diagram of a laser processing device for use in the formation of transformed areas in the cutting process according to the embodiment of the present invention. Fig. Figure 4 is a schematic top view of the workpiece in which the transformed areas are to be formed in the cutting process according to the embodiment of the present invention. Fig. 5 is a section view along the line V-V in Fig. 4. Fig. Figure 6 is a schematic top view of the workpiece after laser processing in the cutting process according to the embodiment of the present invention. Fig. 7 is a section view along the line VII-VII in Fig. 6. Fig. 8 is a section view along the line VIII-VIII in Fig. 6. Fig. Figure 9 is a schematic top view of the workpiece after the transformed areas have been formed in the cutting process according to the embodiment of the present invention. Fig. 10 is a sectional view along the line X-X in Fig. 9. Fig. Figure 11 is a schematic configuration diagram of an etching device for use in the formation of grooves in the cutting process according to the embodiment of the present invention. Fig. Figure 12 is a schematic top view of the workpiece after the grooves have been formed in the cutting process according to the embodiment of the present invention. Fig. 13 is a sectional view along the line XIII-XIII in Fig. 12. Fig. Figure 14 is an enlarged cross-sectional view of an area. A in Fig. 10. Fig. Figure 15 is an enlarged sectional view illustrating an initial dry etching process, which is shown in Fig. 10 in the area A was carried out. Fig. Figure 16 is an enlarged sectional view illustrating an initial pressure reduction process that occurs in Fig. 10 in the area A was carried out. Fig. Figure 17 is an enlarged sectional view illustrating a second dry etching process, which is carried out in Fig. 10 in the area A was carried out. Fig. Figure 18 is an enlarged sectional view illustrating a second pressure reduction process that occurs in Fig. 10 in the area A was carried out. Fig. Figure 19 is an enlarged sectional view illustrating a third dry etching process, which is described in Fig. 10 in the area A was carried out. Fig. Figure 20 is a schematic top view of the workpiece after division. Fig. 21 is a sectional view along the line XXI-XXI in Fig. 20. Fig. Figure 22 is a flowchart illustrating the cutting process according to the embodiment of the present invention. Fig. Figure 23 is a schematic sectional view of a TEG formation area in the workpiece after laser processing in the cutting process according to the embodiment of the present invention. Fig. 24 is an enlarged sectional view showing an initial dry etching process at the TEG formation area in Fig. 23 is illustrated. Detailed description of embodiments of the invention

[0008] A cutting method according to an embodiment of the present invention is described below with reference to the drawings. Unless otherwise specified, the same elements are designated by the same symbols and their description is not repeated.

[0009] With reference to the Fig. 1 and Fig. 2. A workpiece will be 1 prepared for the cutting process according to the embodiment of the present invention. As in the Fig. 1 and Fig. 2 shown is the workpiece 1 For example, a semiconductor substrate. The following describes the case in which the workpiece 1 is a semiconductor substrate.

[0010] The semiconductor substrate as a workpiece 1 is designed so that it essentially has a disk shape. The workpiece (semiconductor substrate) 1 Its outer circumference features an orientation surface. 2 on. The workpiece (semiconductor substrate) 1 For example, a silicon (Si) wafer.

[0011] A variety of functional devices (not shown) are located on a front surface. 3 of the workpiece (semiconductor substrate) 1 intended. In other words, the workpiece (semiconductor substrate) 1It comprises a substrate body and the multitude of functional devices arranged on a front surface of the substrate body. The functional devices are, for example, semiconductor operating layers formed by crystal growth, light-receiving devices such as photodiodes, light-emitting devices such as laser diodes, or circuit elements formed as a circuit. The multiple functional devices are arranged in a matrix in directions parallel and perpendicular to the orientation surface. 2 intended for the semiconductor substrate.

[0012] With reference to the Fig. 3 to Fig. Section 10 describes the formation of a transformed area in the cutting process according to the embodiment of the present invention. First, a laser processing device is used. 100 described for use in the formation of the transformed area.

[0013] As in Fig. The laser processing device shown in section 3 includes 100 : a laser source 101 , to create a pulse oscillation of a laser beam (processing laser beam) L to cause; a dichroic mirror 103 , which is set up to determine the orientation of an optical axis of the laser beam L to change by 90°; and a condenser lens 105 to focus the laser beam L The laser processing device 100 also includes: a support table 107 for carrying the workpiece (semiconductor substrate) 1 , the one with the condenser lens 105 focused laser beam L is irradiated; a stage 111 to move the support table 107 in the X, Y and Z directions; a laser source control 102 to control the laser source 101 , to control the output, pulse width, and other parameters of the laser beam L to adjust; and a stage control system 115to control the movement of the stage 111 .

[0014] In this laser processing device 100 is the laser source 101 emitted laser beam L in the alignment of its optical axis by the dichroic mirror 103 changed by 90° and through the condenser lens 105 onto the support table 107 arranged workpiece (semiconductor substrate) 1 bundled. At the same time, the stage 111 moves, which causes the workpiece (semiconductor substrate) to move 1 relative to the laser beam L moved along an intended cutting line. As a result, a reshaped area is created in the workpiece (semiconductor substrate). 1 along an intended cutting line 5 The resulting area serves as the starting point for cutting. This reshaped area is described in detail below.

[0015] As in Fig. Figure 4 shows the workpiece (semiconductor substrate). 1 in the form of a plate with an intended cutting line 5 provided along which the workpiece (semiconductor substrate) 1 to be cut. The intended cutting line 5 is an imaginary line extending linearly. When forming the transformed area within the workpiece. 1 will the laser beam L relatively along the intended cutting line 5 (namely in the direction of an arrow) A in Fig. 4) moves while a condensation point P is positioned within the workpiece (semiconductor substrate), as shown in Fig. 5 shown. Consequently, as shown in the Fig. 6 to Fig. 8 shown, a transformed area 7 within the workpiece (semiconductor substrate) 1 along the intended cutting line 5formed, and along the intended cutting line 5 educated transformed area 7 serves as a cutting starting point area 8 .

[0016] It should be noted that the condensation point P is a point at which the laser beam L is bundled. The intended cutting line 5 It may be curved instead of linear, or a line that actually lies on the front surface. 3 of the workpiece 1 The area is drawn, instead of being the imagined line. 7 can be continuous or formed with breaks. The transformed area 7 should only be within the workpiece at least 1 Cracks can form in the transformed area. 7 exit, and the cracks and the transformed area 7 can be applied to an outer surface (front surface, back surface or outer circumferential surface) of the workpiece 1be exposed.

[0017] The remodeled area 7 This refers to an area whose density, refractive index, mechanical strength, or other physical properties have been altered compared to those of a surrounding area. Examples include a melt processing area, a cracked area, a dielectric breakdown area, an area with a changed refractive index, and also an area exhibiting a mixture of these properties.

[0018] With renewed reference to Fig. 3 is the workpiece (semiconductor substrate) 1 on the carrier table 107 the laser processing device 100 attached. Then, with the front surface 3 of the workpiece (semiconductor substrate) 1 as the laser beam entry surface, the laser beam L applied while the condensation point P is within the workpiece (semiconductor substrate) 1is positioned, and the condensation point P is determined by the movement of the support table. 107 along the intended cutting lines 5 The system scans the condensation point P on the intended cutting line. The condensation point P is located on the intended cutting line. 5 along a thickness direction of the workpiece (semiconductor substrate) 1 scanned.

[0019] As a result, as in Fig. 9 shown, remodeled areas 7 in a grid pattern in the workpiece (semiconductor substrate) 1 formed. Each restructured area 7 is within the workpiece (semiconductor substrate) 1 from the front surface 3 to a back surface 4 of the workpiece (semiconductor substrate) 1 trained, as in Fig. 10 shown. In other words, the transformed area 7is applied in the thickness direction of the workpiece (semiconductor substrate) 1 educated.

[0020] The remodeled area 7 can be formed in such a way that a state of formation of the transformed area is achieved. 7 on the front surface and a state of formation of the transformed area 7 on the back surface of the workpiece (semiconductor substrate) 1 are essentially identical. In this case, they are in the thickness direction of the workpiece (semiconductor substrate). 1 a state of education of the transformed area 7 from the center of the workpiece (semiconductor substrate) 1 to the front surface 3 and a state of formation of the transformed area 7 from the center to the back surface 4 Essentially identical. In other words, the transformed area 7 is symmetrical about the center in the thickness direction of the workpiece (semiconductor substrate) 1 educated.

[0021] With reference to the Fig. 11 to Fig. 19 will be the formation of a groove 9 The cutting process is described according to the embodiment of the present invention. First, an etching device is used. 200 for use in the formation of the groove 9 described.

[0022] As in Fig. As shown in 11, the etching device includes 200 a chamber 201 , a stage 202 , a pressure gauge 203 , a thermometer 204 , a valve 205 , a vacuum pump 206 , a valve 207 , a valve 208 , a flow regulator 209 , a first gas supply device 210 , a valve 211 , a flow regulator 212 and a second gas supply device 213 .

[0023] In the etching device 200 is the chamber 201 set up to handle the workpiece (semiconductor substrate) 1to include the remodeled areas 7 were formed. The workpiece (semiconductor substrate) 1 will be on stage 202 in the chamber 201 placed on the stage. 202 It is set up so that it has an adjustable temperature. Stage 202 is heated, whereby the workpiece (semiconductor substrate) 1 is placed on it, whereby the workpiece (semiconductor substrate) 1 is heated to a temperature equal to that of the stage 202 is.

[0024] The chamber 201 is with the manometer 203 to measure the pressure in the chamber 201 connected. The stage 202 is with the thermometer 204 to measure the temperature of the workpiece 1 based on the temperature of the stage 202 connected. The thermometer 204 is with the stage 202 connected and measures the temperature of the stage 202, in order to thereby control the temperature of the workpiece (semiconductor substrate) 1 to measure that is at the same temperature as the stage 202 was heated. The chamber 201 is through a pipeline via a valve 205 with the vacuum pump 206 connected. The vacuum pump 206 is a turbomolecular pump or a mechanical booster pump.

[0025] The chamber 201 is through a pipeline via a valve 207 , valve 208 and flow regulator 209 with the first gas supply device 210 connected. The first gas supply device 210 is designed to supply an initial etching gas. The chamber 201 is through a pipeline via a valve 207 , valve 211 and flow regulator 212 also with the second gas supply device 213 connected. The second gas supply device 213It is designed to supply a second etching gas. The second etching gas can be identical to or different from the first etching gas. Valve 205 , valve 207 , valve 208 and valve 211 Examples include electronic control valves and flow regulators. 209 , 212 Examples include mass flow meters.

[0026] While in the Fig. 11, the etching device 200 in addition to the first gas supply device 210 the second gas supply device 213 The etching device includes 200 only the first gas supply device 210 include. In other words, the etching device 200 can only include a gas supply device. Alternatively, the etching device can 200 include three or more gas supply devices.

[0027] As in the Fig. 12 and Fig. As shown in 13, the etching device200 a dry etching process from the front surface 3 to the back surface 4 of the workpiece (semiconductor substrate) 1 carried out. The dry etching process is an anisotropic dry etching process using a mixed gas of sulfur hexafluoride (SF6), octafluorocyclobutane (C4F8) and oxygen ( O2 ). The front surface 3 of the workpiece (semiconductor substrate) 1 This process involves etching. Here, the workpiece (semiconductor substrate) shows... 1 the remodeled area 7 , which for example consists of polycrystalline silicon, has a higher etch rate than an unmodified area which for example consists of monocrystalline silicon, and therefore in the front surface 3 of the workpiece (semiconductor substrate) 1 along the intended cutting line 5 the groove 9The dry etching process can be carried out, for example, with a photoresist that forms on the functional devices. This photoresist is removed after the dry etching process is complete.

[0028] A pressure reduction process is also carried out, in which the workpiece (semiconductor substrate) 1 It is placed under an atmosphere with reduced pressure compared to the pressure during the dry etching process. The vacuum pump operates during the pressure reduction process. 206 to vacuum the chamber 201 In other words, in the chamber 201 A vacuum is created during the pressure reduction process. A possible reaction byproduct resulting from the dry etching process is removed via a pipeline using a vacuum pump. 206 removed.

[0029] The following refers to the Fig. 14 to Fig. 19 the formation of the groove 9described in detail. Fig. 14 to Fig. 19 correspond to an area A , who in the Fig. 10 and Fig. 13 is enclosed by a dash-dot-dash line.

[0030] As in Fig. As shown in 14, after the formation of the transformed area 7 in the workpiece (semiconductor substrate) 1 the groove 9 in the workpiece (semiconductor substrate) 1 along the in Fig. 4 shown intended cutting line 5 educated. As in Fig. As shown in 15, a first dry etching process is performed on the workpiece (semiconductor substrate). 1 from the front surface 3 to the back surface 4 of the workpiece (semiconductor substrate) 1 carried out. The front surface 3 of the workpiece (semiconductor substrate) 1 The first dry etching process etches the surface. The groove is then further etched. 9 partially in the remodeled area7 into from the front surface 3 to the back surface 4 of the workpiece (semiconductor substrate) 1 educated.

[0031] As in Fig. As shown in Figure 16, a first pressure reduction process is carried out after the first dry etching process. In the first pressure reduction process, the workpiece (semiconductor substrate) 1 The chamber is placed under an atmosphere with reduced pressure compared to the pressure during the first dry etching process. This removes any potential reaction byproduct from the first dry etching process from inside the chamber. 201 removed, as in Fig. 11 shown. Accordingly, the possible reaction byproduct that forms in the groove created by the first dry etching process is 9 remains, from the inside of the groove 9 removed.

[0032] As in Fig. As shown in 17, after the first pressure reduction process, a second dry etching process is carried out on the front surface. 3 to the back surface 4 of the workpiece (semiconductor substrate) 1 carried out. The front surface 3 of the workpiece (semiconductor substrate) 1 The second dry etching process is used to etch the groove. 9 at the end of the remodeled area 7 from the front surface 3 to the back surface 4 of the workpiece (semiconductor substrate) 1 The second dry etching process can be carried out for a longer period than the first. The second dry etching process can be carried out under a higher pressure than the first. This allows a sufficient amount of etching gas to penetrate the groove formed by the first dry etching process.

[0033] As in Fig. As shown in Figure 18, a second pressure reduction process is carried out after the second dry etching process. In the second pressure reduction process, the workpiece 1 Compared to the pressure during the second dry etching process, the sample is placed under a reduced-pressure atmosphere. This removes any potential reaction byproduct from the second dry etching process.

[0034] As in Fig. As shown in 19, after the second pressure reduction process, a third dry etching process is carried out from the front side. 3 to the back surface 4 of the workpiece (semiconductor substrate) 1 carried out. The front surface 3 of the workpiece (semiconductor substrate) 1 The third dry etching process is used. Furthermore, the groove is... 9 from the front surface 3 formed so that they form the back surface 4 of the workpiece 1This is achieved. In this way, the workpiece (semiconductor substrate) 1 along the redesigned area 7 cut. The groove 9 can be from the front surface 3 from being formed so that they form the back surface 4 of the workpiece (semiconductor substrate) 1 achieved during the second dry etching process. In which the Fig. 12 and Fig. The condition shown in 13 is the distance between the cut workpiece (semiconductor substrate). 1 The number of chips produced was essentially zero.

[0035] Next, with reference to the Fig. 21 and Fig. 22, the cut workpiece (semiconductor substrate) 1 divided into chips. In other words, the distance between the chips is increased. In the Fig. 20 and Fig. In the state shown in Figure 21, the distance between the chips is maintained at a minimum prescribed distance. The distance between the chips should only be a distance suitable for the next step.

[0036] While the above description states that the dry etching process is performed three times in the first to third dry etching processes and the pressure reduction process is performed twice in the first to second pressure reduction processes, the cutting process according to the embodiment of the present invention is not limited to these numbers. The dry etching process should only be performed several times (twice or more), and the pressure reduction process should only be performed once or several times (twice or more).

[0037] With reference to Fig. 22 describes the case where the dry etching process is performed four or more times and the pressure reduction process three or more times. The case where the dry etching process is performed n times and the pressure reduction process is performed n-1 times is described. N, as used here, means an integer of 4 or more.

[0038] First, a step is performed to create a transformed area (step S1 After the transformed area has been formed, a step is performed to form a groove (step S2 In the step of forming a groove, a first dry etching process is carried out successively (step S21 ), a first pressure reduction process (step S22 ), a second dry etching process (step S23 ), a second pressure reduction process ( S24 ) and a third dry etching process (step S25 ). Subsequently, the n-2 pressure reduction process (step ) is carried out. S26), the n-1 dry etching process (step S27 ), the n-1 pressure reduction process (step S28 ) and the n. dry etching process (step S29 ) are carried out sequentially. In each pressure reduction process, the workpiece is placed under an atmosphere with reduced pressure compared to the pressure during the dry etching process immediately prior to the pressure reduction process. Once the groove has formed from the front surface so that it reaches the back surface of the workpiece, the workpiece is cut (step 1). S30 ).

[0039] Next, etching gases for use in dry etching processes in the cutting process according to the embodiment of the present invention will be described in detail.

[0040] A halogen-based etching gas can be used for each of the first and second dry etching processes. A halogen-based etching gas can also be used for each of the first through nth dry etching processes. The halogen-based etching gas can include at least one of the following: chlorine trifluoride (CIF3), nitrogen trifluoride (NF3), sulfur hexafluoride (SF6), fluorine (F2), chlorine (Cl2), hydrogen bromide (HBr), carbon tetrafluoride (CF4), octafluorocyclobutane (C4F8), methane trifluoride (CHF3), and boron trichloride (BCI3). In other words, the halogen-based etching gas can be either a single gas or a mixture containing these materials. For example, the halogen-based etching gas can be a mixture of octafluorocyclobutane (C4F8) and oxygen (O2).

[0041] Next, the function and effect of the cutting method according to the embodiment of the present invention will be described. According to the cutting method in the embodiment of the present invention, after the formation of the transformed area... 7 in the workpiece (semiconductor substrate) 1 the groove 9 in the workpiece (semiconductor substrate) 1 along the intended cutting line 5 formed. In the step of forming the groove 9 will, taking advantage of the fact that the transformed area 7 exhibiting a higher etch rate than an unmodified area, the first dry etching process was carried out to create the groove 9 in the workpiece (semiconductor substrate) 1 along the intended cutting line 5to form. After the first dry etching process, the first pressure reduction process is carried out to remove the remaining reaction byproduct. After the first pressure reduction process, the second dry etching process is carried out to allow the etching gas to quickly enter the groove formed in the first dry etching process. 9 to penetrate. This can improve the etching rate in the second dry etching process.

[0042] Namely, when a conventional dry etching process is used after the formation of the transformed area. 7 In the first dry etching process, the pressure in the chamber is kept constant, which leads to a decrease in the etching rate due to the remaining reaction byproduct. In contrast, in the cutting process according to the embodiment of the present invention, the second dry etching process is carried out after the remaining reaction byproduct generated during the first dry etching process has been removed from the groove. 9and the interior of the chamber 201 by carrying out the first pressure reduction process, in order to allow the etching gas to quickly enter the groove formed in the first dry etching process 9 to penetrate. This allows the etching rate to be improved compared to a conventional dry etching process.

[0043] According to the cutting method in the embodiment of the present invention, in the step of forming the groove 9 the groove 9 from the front surface to the back surface of the workpiece 1 are formed to cut the workpiece 1 along the intended cutting line 5 to achieve this. The etching rate can be improved to enable faster cutting of the workpiece. 1 to enable.

[0044] According to the cutting method in the embodiment of the present invention, in the step of forming the groove 9The second pressure reduction process is carried out after the second dry etching process to remove the remaining reaction byproduct. The third dry etching process is carried out after the second pressure reduction process so that the etching gas quickly enters the groove formed in the second dry etching process. 9 can penetrate. Furthermore, the groove 9 This can be achieved by repeatedly performing a cycle of dry etching, pressure reduction, and dry etching. This allows for further improvement of the etching rate.

[0045] According to the cutting method in the embodiment of the present invention, a halogen-based etching gas can be used for each of the first dry etching process and the second dry etching process.

[0046] According to the cutting process in the embodiment of the present invention, at least one of the following halogen-based etching gases can be used: chlorine trifluoride (ClF3), nitrogen trifluoride (NF3), sulfur hexafluoride (SF6), fluorine (F2), chlorine (CI2), hydrogen bromide (HBr), carbon tetrafluoride (CF4), octafluorocyclobutane (C4F8), methane trifluoride (CHF3) and boron trichloride (BCI3).

[0047] According to the cutting method in the embodiment of the present invention, in the step of forming the transformed area 7 in the workpiece 1 the remodeled area 7 are formed in such a way that a state of formation of the transformed area is achieved. 7 on the front surface side and a state of formation of the transformed area 7 on the back surface they are essentially identical. This allows the transformed area to 7 from the front surface and the back surface of the workpiece 1to be etched evenly.

[0048] Next, various variants of the cutting method according to the embodiment of the present invention will be described. A first variant of the cutting method according to the embodiment of the present invention will be described first. This first variant relates to the Fig. 23 and Fig. 24 refers to a TEG (Test Element Group) 10 on the intended cutting line of the workpiece (semiconductor substrate) 1 can be formed. In this case, at least one of tungsten (W), titanium (Ti), titanium nitride (TiN) and molybdenum (Mo) can be used as a material for the TEG. 10 to be used. In other words, in this case, the workpiece (semiconductor substrate) includes 1 the substrate body, the functional devices (not shown) and the TEG 10 .

[0049] Therefore, the material for the workpiece can 1at least one of silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo) may be used. In this case, during the groove formation step, 9 The first dry etching process and the second dry etching process shall be carried out using a plasma-free chlorine trifluoride (CIF3) gas as a halogen-based etching gas at a pressure of not less than 10 Pa and not more than 90 kPa (abs) and at a temperature of not less than the boiling point of any fluoride in the material and less than 200°C. With further reference to Fig. 11 is this pressure the pressure in the chamber 201 This temperature is the temperature of the workpiece. 1 .

[0050] The pressure is set to no less than 10 Pa because the etching rate decreases due to a reduction in the etching reaction rate when the pressure is below 10 Pa. The pressure is also set to no less than 10 Pa because it takes time to maintain the pressure with the vacuum pump. 206 to be set to less than 10 Pa. The pressure is not set to less than 10 Pa, also because of the amount of possible reaction byproduct that might escape from the groove. 9The amount of fluid discharged when the pressure is set to less than 10 Pa remains essentially unchanged compared to when the pressure is set to 10 Pa. The pressure is set to no less than 10 Pa, partly because a mechanical booster pump, not a turbomolecular pump, can be used to achieve this pressure. The pressure is set to no more than 90 kPa because it is difficult to set the pressure above 90 kPa in a vacuum device. Etching can be performed with plasmaless chlorine trifluoride (CIF3) gas over a pressure range of no less than 10 Pa and no more than 90 kPa (abs). For this reason, the pressure range is set to no less than 10 Pa and no more than 90 kPa (abs). Chlorine trifluoride (CIF3) gas can etch silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo).For this reason, silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN) and molybdenum (Mo) are used as materials for workpieces. 1 used. The temperature is set to no less than the boiling point of each fluoride in the workpiece material. 1 This setting ensures a consistent etch rate for every material. The temperature is set to less than 200°C because a maximum temperature is not possible during the dicing process on the workpiece. 1 The temperature of the devices formed is 200°C.

[0051] In the first variant of the cutting method according to the embodiment of the present invention, the material for the workpiece can be 1 The material must include at least one of silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo). In this case, the groove formation step can include [the following]. 9The first dry etching process and the second dry etching process are carried out using a plasma-free chlorine trifluoride (CIF3) gas as a halogen-based etching gas at a pressure of not less than 10 Pa and not more than 90 kPa (abs) and at a temperature of not less than the boiling point of any fluoride in the material and less than 200°C. As a result, the workpiece can be 1 , which includes at least one of silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN) and molybdenum (Mo), to be etched.

[0052] Next, a second variant of the cutting method according to the embodiment of the present invention is described. In this second variant, an insulating film can be formed on the intended cutting line of the workpiece. In this case, at least one of silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx) can be used as the material for the insulating film. It should be noted that the composition (x) of SiNx can vary around Si3N4, where x represents the ratio of the number of atoms (composition) that form a SiN compound according to the chemical formula. The value of x, for example, must not be less than 1.0 and not greater than 1.5. In this case, the workpiece (semiconductor substrate) comprises the substrate body, the functional devices, and the insulating film.

[0053] Therefore, the workpiece material can include at least one of silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx). In this case, the first dry etching process and the second dry etching process can be performed using anhydrous hydrogen fluoride (HF) added to the halogen-based etching gas during the groove formation step. The etching gas containing anhydrous hydrogen fluoride (HF), added to the halogen-based etching gas, can etch silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx). For this reason, the etching gas includes anhydrous hydrogen fluoride (HF), which is added to the halogen-based etching gas.

[0054] In the second variant of the cutting process according to the embodiment of the present invention, the workpiece material can comprise at least one of silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx). In this case, the first dry etching process and the second dry etching process can be carried out in the groove-forming step using anhydrous hydrogen fluoride (HF) added to the halogen-based etching gas. As a result, the workpiece can be 1 , comprising at least one of silicon dioxide (SiO2), silicon oxynitride (SiON) and silicon nitride (SiNx), can be etched.

[0055] In the multitude of plasma-free dry etching processes in the first variant and the second variant of the cutting process according to the embodiment of the present invention described above, the volume density of gas molecules can be varied within a range of not less than 10 times and not more than 10000 times compared to the volume density during the pressure reduction process that immediately precedes each dry etching process.

[0056] Next, a third variant of the cutting method according to the embodiment of the present invention is described. In this third variant, a TEG and an insulating film can be formed on the intended cutting line of the workpiece. In this case, at least one of tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo) can be used as the material for the TEG, and at least one of silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx) can be used as the material for the insulating film.

[0057] Therefore, the workpiece material can include at least one of silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx). In this case, the first dry etching process and the second dry etching process can be performed in the groove formation step using at least one of carbon tetrafluoride (CF4), sulfur hexafluoride (SF6), methane trifluoride (CHF3), hydrogen fluoride (HF), and oxygen (O2) in a plasma state as the etching gas at a pressure of not less than 10 Pa and not more than 0.8 kPa (abs) and at a temperature of less than 200°C. This pressure is the pressure in the chamber. This temperature is the temperature of the workpiece.

[0058] Carbon tetrafluoride (CF4), sulfur hexafluoride (SF6), methane trifluoride (CHF3), hydrogen fluoride (HF), and oxygen (O2) in the plasma state can etch silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx). Therefore, silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx) are used as workpiece materials. The pressure is set to no more than 0.8 kPa (abs) because the maximum power in the remote plasma is achieved at a pressure of 0.8 kPa.

[0059] In the third variant of the cutting process according to the embodiment of the present invention, the workpiece material can comprise at least one of silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), silicon dioxide (SiO2), silicon oxynitride (SiON), and silicon nitride (SiNx). In this case, the first dry etching process and the second dry etching process can be carried out in the groove-forming step using at least one of carbon tetrafluoride (CF4), sulfur hexafluoride (SF6), methane trifluoride (CHF3), hydrogen fluoride (HF), and oxygen (O2) in a plasma state as the etching gas at a pressure of not less than 10 Pa and not more than 0.8 kPa (abs) and at a temperature of less than 200°C. This allows the workpiece, which comprises at least one of silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), silicon dioxide (SiO2), silicon oxynitride (SiON) and silicon nitride (SiNx), to be etched.

[0060] Next, a fourth variant of the cutting method according to the embodiment of the present invention is described. In this fourth variant, an aluminum foil and a TEG can be formed on the intended cutting line of the workpiece. In this case, aluminum (Al) can be used as the material for the aluminum layer, and at least one of tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo) can be used as the material for the TEG.

[0061] Therefore, the workpiece material can include at least one of aluminum (Al), silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo). In this case, the first dry etching process and the second dry etching process can be carried out in the groove formation step using at least one of chlorine (Cl₂), hydrogen bromide (HBr), hydrogen chloride (HCl), and boron trichloride (BCl₃) in a plasma state as the etching gas at a pressure of not less than 10 Pa and not more than 0.8 kPa (abs) and a temperature of less than 200°C. This pressure is the pressure in the chamber. This temperature is the temperature of the workpiece.

[0062] Chlorine (Cl₂), hydrogen bromide (HBr), hydrogen chloride (HCl), and boron trichloride (BCI₃) in the plasma state can etch aluminum (Al), silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo). For this reason, aluminum (Al), silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo) are used as materials for the workpiece.

[0063] In the fourth variant of the cutting process according to the embodiment of the present invention, the workpiece material comprises at least one of aluminum (Al), silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo). In the groove formation step, the first dry etching process and the second dry etching process can be carried out with at least one of chlorine (Cl₂), hydrogen bromide (HBr), hydrogen chloride (HCl), and boron trichloride (BCl₃) in the plasma state as the etching gas at a pressure of not less than 10 Pa and not more than 0.8 kPa (abs) and at a temperature of less than 200°C. This allows the workpiece, which comprises at least one of aluminum (Al), silicon (Si), tungsten (W), titanium (Ti), titanium nitride (TiN), and molybdenum (Mo), to be etched.

[0064] In the multitude of dry etching processes in the plasma discharge in the third variation and the fourth variation of the cutting process according to the embodiment of the present invention described above, the pressure can be varied in a range of not less than 10% and not more than 100% compared to the pressure reduction process that immediately precedes each dry etching process.

[0065] In the case of a downstream plasma treatment, where a gas discharge chamber and a substrate-installed chamber are separated by a discharge pressure control valve, the pressure in the substrate-installed chamber can be varied in a range of at least 1 / 10 and at most 1 / 10000 of the pressure in the gas discharge chamber, while the discharge pressure is kept constant.

[0066] It is to be understood that the embodiments disclosed herein are in every respect illustrative and not limiting. The scope of the present invention is defined by the terms of the claims, not by the foregoing description, and is intended to include all modifications in meaning and scope that are equivalent to the terms of the claims. Reference symbol list

[0067] 1 Workpiece; 3 Front surface; 4 Back surface; 5 Intended cutting line; 7 Reshaped area; 9 Groove; 100 Laser processing device; 200 Etching device; 201 Chamber; 202 Stage; 203 Manometer; 204 Thermometer; 205, 207, 208, 211 Valve; 206 Vacuum pump; 209, 212 Flow regulator; 210 First gas supply device; 213 Second gas supply device. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2004359475

[0002] JP 200435947575

[0003]

Claims

[1] Cutting method for cutting a workpiece in the form of a plate along an intended cutting line, the cutting method comprising: Forming a reshaped area in the workpiece along the intended cutting line by applying a laser beam while positioning a condensation point in the workpiece; and After forming the transformed area in the workpiece, a groove is formed in the workpiece along the intended cutting line. where, in the formation of a groove, A first dry etching process is carried out from a front surface to a back surface of the workpiece, After the first dry etching process, a first pressure reduction process is carried out, in which the workpiece is placed under an atmosphere with reduced pressure compared to the pressure during the first dry etching process, and After the first pressure reduction process, a second dry etching process is carried out from the front surface to the back surface of the workpiece. [2] Cutting method according to claim 1, wherein when forming a groove the groove is formed from the front surface so that it reaches the rear surface of the workpiece to effect cutting the workpiece along the intended cutting line. [3] Cutting method according to claim 1 or 2, wherein during the formation of a groove, After the second dry etching process, a second pressure reduction process is carried out, in which the workpiece is placed under an atmosphere with reduced pressure compared to the pressure during the second dry etching process, and After the second pressure reduction process, a third dry etching process is carried out from the front surface to the back surface of the workpiece. [4] Cutting method according to any one of claims 1 to 3, wherein When forming a groove, a halogen-based etching gas is used for both the first dry etching process and the second dry etching process. [5] Cutting method according to claim 4, wherein the halogen-based etching gas comprises at least one of chlorine trifluoride, nitrogen trifluoride, sulfur hexafluoride, fluorine, chlorine, hydrogen bromide, carbon tetrafluoride, octafluorocyclobutane, methane trifluoride and boron trichloride. [6] Cutting method according to claim 5, wherein a material for the workpiece comprising at least one of silicon, tungsten, titanium, titanium nitride and molybdenum and When forming a groove, the first dry etching process and the second dry etching process shall be carried out using a plasma-free chlorine trifluoride gas as a halogen-based etching gas, at a pressure of not less than 10 Pa and not more than 90 kPa (abs) and at a temperature of not less than one boiling point of each fluoride in the material and less than 200°C. [7] Cutting method according to claim 6, wherein the material for the workpiece contains at least one of silicon dioxide, silicon oxynitride and silicon nitride and When forming a groove, the first dry etching process and the second dry etching process are carried out with anhydrous hydrogen fluoride added to the halogen-based etching gas. [8] Cutting method according to claim 1, wherein a material for the workpiece comprising at least one of silicon, tungsten, titanium, titanium nitride, molybdenum, silicon dioxide, silicon oxynitride and silicon nitride, and When forming a groove, the first dry etching process and the second dry etching process are carried out using carbon tetrafluoride, sulfur hexafluoride, methane trifluoride, hydrogen fluoride and oxygen in the plasma state as etching gas, at a pressure of not less than 10 Pa and not more than 0.8 kPa (abs) and at a temperature of less than 200°C. [9] Cutting method according to claim 1, wherein a material for the workpiece includes at least one made of aluminium, silicon, tungsten, titanium, titanium nitride and molybdenum and When forming a groove, the first dry etching process and the second dry etching process shall be carried out using at least one of chlorine, hydrogen bromide, hydrogen chloride and boron trichloride in the plasma state as the etching gas, at a pressure of not less than 10 Pa and not more than 0.8 kPa (abs) and at a temperature of less than 200°C. [10] Cutting method according to any one of claims 1 to 9, wherein When forming a transformed area in the workpiece, the transformed area is formed in such a way that a formation state of the transformed area on the front surface side and a formation state of the transformed area on the back surface side are essentially identical.