JP2018046209A - Manufacturing method of imprint original plate and division method of wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of imprint original plate capable of creating an imprint original plate inexpensively and simply, and to provide a division method of a wafer using the imprint original plate.SOLUTION: A manufacturing method of imprint original plate forms a mask covering devices on a wafer where a device is formed in each of multiple regions of the substrate surface sectioned by streets. The manufacturing method of imprint original plate includes a preparation step ST1 of preparing a tabular body having a size equivalent to that of the wafer or more, and a convex portion formation step ST2 of forming a convex portion at the parts corresponding to the streets, by irradiating the regions of the tabular body wafer corresponding to the multiple devices with laser light thereby forming recesses.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing an imprint original plate used in a step of forming a mask when a wafer is divided into devices by plasma etching, and a wafer dividing method using the imprint original plate.

  A wafer in which a plurality of devices such as IC (Integrated Circuit), LSI (Large-Scale Integration), etc. are partitioned by a line to be divided and formed on the front surface is ground and then processed to a predetermined thickness, and then a dicing apparatus These are divided into individual devices by a laser processing apparatus, and the divided devices are widely used in various electronic devices such as mobile phones and personal computers.

  In order to divide a wafer into individual devices, etching is performed using a patterned photoresist as a mask (for example, refer to Patent Document 1). According to this, although an exposure process is performed to form a patterned mask, an exposure apparatus used in the exposure process is expensive, leading to an increase in device price.

  On the other hand, in the pre-process of the semiconductor manufacturing process, an imprint technique has been used to form a patterned etching mask.

JP 2006-294807 A

  However, even if an imprint technique is used to form a mask on a wafer, exposure is used to form a pattern when an imprint original plate used in the imprint technique is created, which increases the cost of the device. .

  The present invention has been made in view of the above points, and the object of the present invention is to provide a method for producing an imprint original plate capable of easily and easily producing an imprint original plate and the imprint use. A method of dividing a wafer using an original plate is provided.

  In order to solve the above-described problems and achieve the object, the method for manufacturing an imprinting master according to the present invention covers a device on a wafer in which the devices are respectively formed in a plurality of regions on the substrate surface partitioned by streets. A method of manufacturing an imprint original plate for forming a mask, comprising: a preparation step of preparing a plate-like body having a size equal to or greater than that of the wafer; and the plurality of devices on the wafer of the plate-like body. A projecting portion forming step of forming a projecting portion at a portion corresponding to the street by irradiating a corresponding region with laser light to form a recessed portion.

  A wafer dividing method according to the present invention is a wafer dividing method for dividing a wafer, in which devices are respectively formed in a plurality of regions on a substrate surface partitioned by streets, along the street, and a resist solution is applied to the wafer. A resist solution supplying step for supplying, and a resist mask forming step for forming a resist mask for pressing the imprint original plate manufactured by the manufacturing method toward the wafer to cover the plurality of devices and to expose the street portion; And a plasma etching step of etching the portion corresponding to the street of the substrate through the resist mask by irradiating with plasma.

  According to the present invention, since no exposure is required when preparing an imprint master, the imprint master can be manufactured at low cost. In particular, since the convex portion is formed by irradiating laser light, an imprint original plate for dividing devices having various shapes can be easily formed.

  Further, the wafer dividing method has an effect that the resist mask is patterned using the original plate, so that exposure / development is unnecessary, leading to cost reduction.

FIG. 1 is a perspective view showing a wafer that is divided into devices using the imprint master according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a perspective view of an imprint original plate manufactured by the method for manufacturing an imprint original plate according to the first embodiment. FIG. 4 is a flowchart showing a flow of a method for manufacturing an imprint master according to the first embodiment. FIG. 5 is a perspective view showing a preparation step of the method for manufacturing the imprint master shown in FIG. FIG. 6 is a perspective view showing a protrusion forming step of the method for manufacturing the imprint master shown in FIG. FIG. 7 is a flowchart showing the flow of the wafer dividing method according to the first embodiment. FIG. 8 is a cross-sectional view showing a resist solution supplying step of the wafer dividing method shown in FIG. FIG. 9 is a cross-sectional view showing a state in which the imprint original plate is opposed to the wafer in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 10 is a cross-sectional view showing a state in which the imprint original plate is pressed against the wafer in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 11 is a cross-sectional view showing a state in which the imprint original plate is separated from the wafer in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 12 is a cross-sectional view showing the configuration of an etching apparatus used in the resist mask forming step and the plasma etching step of the wafer dividing method shown in FIG. FIG. 13 is a cross-sectional view showing breakthrough etching for exposing the streets of the wafer that can be included in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 14 is a cross-sectional view showing a plasma etching process of the wafer dividing method shown in FIG. FIG. 15 is a cross-sectional view of the wafer after the plasma etching step of the wafer dividing method shown in FIG. FIG. 16 is a plan view of a part of a wafer of another example to be processed by the wafer dividing method using the imprint master according to the first embodiment. FIG. 17 is a plan view of a part of a wafer of still another example of a processing target of the wafer dividing method using the imprint original plate according to the first embodiment. FIG. 18 is a flowchart illustrating a flow of a wafer dividing method according to the second embodiment. FIG. 19 is a cross-sectional view of the wafer after the plasma etching step of the wafer dividing method shown in FIG. FIG. 20 is a cross-sectional view showing a sticking step of the wafer dividing method shown in FIG. FIG. 21 is a cross-sectional view showing a singulation process of the wafer dividing method shown in FIG. FIG. 22 is a sectional view of the wafer after the singulation process of the wafer dividing method shown in FIG. FIG. 23 is a cross-sectional view of the wafer after the resist mask forming step of the wafer dividing method according to the modification of each embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment 1
A method for manufacturing an imprint original plate and a method for dividing a wafer according to Embodiment 1 will be described with reference to the drawings. FIG. 1 is a perspective view showing a wafer that is divided into devices using the imprint master according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a perspective view of an imprint original plate manufactured by the method for manufacturing an imprint original plate according to the first embodiment.

  The method for manufacturing an imprint original plate according to Embodiment 1 is a method for manufacturing an imprint original plate 1 (shown in FIG. 3) used when the wafer W shown in FIG. The wafer W shown in FIGS. 1 and 2 is a disk-shaped semiconductor wafer or an optical device wafer having a substrate S of silicon, sapphire, gallium arsenide, or the like in the first embodiment. In the wafer W, as shown in FIG. 1, devices D are formed in a plurality of regions of the surface WS partitioned by streets L, respectively. The wafer W according to the first embodiment includes a rectangular device D having a width of the street L of about several tens of μm or less and a size of 0.1 mm or more and 20 mm or less on one side of the surface WS. It is preferable to be divided into two. Further, the thickness of the wafer W according to the first embodiment is not less than 30 μm and not more than 300 μm. Further, in the first embodiment, the device D of the wafer W is formed in a quadrangular planar shape and is equal in size to each other. However, the present invention is not limited to this, and the device D having various sizes on the surface WS of the wafer W. Or a device D having an irregular shape other than a square shape may be used.

  The imprint original plate 1 is used for processing in which a wafer W is subjected to plasma etching, and the wafer W is divided into individual devices D by plasma etching, and a resist mask P (shown in FIG. 14) that is a mask covering the devices D Is formed on the wafer W. The resist mask P is configured by drying and patterning a resist solution R (shown in FIGS. 8 and 9).

  As shown in FIG. 3, the imprint original plate 1 includes a plate-like body 2, a concave portion 3 formed in the plate-like body 2, and a convex portion 4 formed in the plate-like body 2. The plate-like body 2 has a size equal to or larger than the wafer W to be processed. In the first embodiment, the plate-like body 2 is formed in a disk shape having the same size as the wafer W. In the first embodiment, the plate-like body 2 is disc-shaped silicon or glass.

  The recess 3 is formed as a recess from the surface 1S of the plate-like body 2 and is provided in a region corresponding to the plurality of devices D of the wafer W of the plate-like body 2. The concave portion 3 is provided at a position that overlaps the device D, which is a region corresponding to the device D, when the imprint original plate 1 is overlaid on the wafer W coated with the resist solution R. In the first embodiment, the same number of the recesses 3 as the devices D are provided, and are formed in the same planar shape and the same size as the devices D.

  The convex part 4 is provided in the area | region corresponding to the outer peripheral side rather than the recessed part 3 of the outermost periphery between the mutually adjacent recessed parts 3 of the plate-shaped body 2. FIG. The convex portion 4 is formed by a position overlapping with the street L, which is an area corresponding to the street L, and the outermost device D of the wafer W when the imprint master 1 is superimposed on the wafer W coated with the resist solution R. Is also provided at a position overlapping the outer region. In the first embodiment, the convex portion 4 overlapping the street L is formed in the same planar shape as the street L.

  Next, a method for manufacturing an imprint master according to Embodiment 1 will be described with reference to the drawings. FIG. 4 is a flowchart showing a flow of a method for manufacturing an imprint master according to the first embodiment. FIG. 5 is a perspective view showing a preparation step of the method for manufacturing the imprint master shown in FIG. FIG. 6 is a perspective view showing a protrusion forming step of the method for manufacturing the imprint master shown in FIG.

  The method for producing an imprint original plate according to Embodiment 1 (hereinafter simply referred to as a production method) is a method for producing the imprint original plate 1 shown in FIG. As shown in FIG. 4, the manufacturing method includes a preparation step ST1 and a convex portion formation step ST2.

  As shown in FIG. 5, the preparation step ST <b> 1 is a step of preparing a plate-like body 2 in which the concave portion 3 and the convex portion 4 are not formed on the surface 1 </ b> S. When the plate-like body 2 is silicon, the thickness of the plate-like body 2 is about 700 μm. However, the thickness may be any thickness that can maintain the strength depending on the type of the plate-like body 2.

  In the convex portion forming step ST2, the convex portion 4 is formed in the portion corresponding to the street L by irradiating the laser beam LR to the region corresponding to the plurality of devices D of the wafer W of the plate-like body 2 to form the concave portion 3. It is a process to do. The projecting portion forming step ST2 sucks and holds the back surface 1R side of the back surface 1S of the plate-like body 2 on a chuck table (not shown) of the laser processing machine 100, and the imprint master 1 is overlapped on the wafer W. A region RD shown in FIG. 6 that overlaps the device D, which is a region corresponding to D, is irradiated with laser light LR having a wavelength that absorbs the plate-like body 2 from the laser irradiation unit 102, and the plate-like body 2 is ablated. Apply processing.

  In the first embodiment, the convex portion forming step ST2 moves the chuck table of the laser processing machine 100 and the laser irradiation unit 102 relative to each other along the processing feed direction X and the index feed direction Y, so that each device D is moved. As shown in FIG. 6, the overlapping region RD is irradiated with a laser beam LR. In the first embodiment, the projecting portion formation step ST2 is performed when the plate-like body 2 is made of silicon, the laser light LR having a wavelength of, for example, 355 nm is irradiated, and the plate-like body 2 is made of glass such as quartz glass. Irradiates a laser beam LR having a wavelength of 10 μm, for example, and performs ablation processing to form a recess 3 in a region RD that overlaps the device D when the original 1 is stacked. In the convex portion forming step ST <b> 2, the convex portions 4 corresponding to the streets L are formed on the plate-like body 2 by forming the concave portions 3.

  Next, a wafer W dividing method for dividing the wafer W along the street L using the imprint master 1 will be described with reference to the drawings. FIG. 7 is a flowchart showing the flow of the wafer dividing method according to the first embodiment. FIG. 8 is a cross-sectional view showing a resist solution supplying step of the wafer dividing method shown in FIG. FIG. 9 is a cross-sectional view showing a state in which the imprint original plate is opposed to the wafer in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 10 is a cross-sectional view showing a state in which the imprint original plate is pressed against the wafer in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 11 is a cross-sectional view showing a state in which the imprint original plate is separated from the wafer in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 12 is a cross-sectional view showing the configuration of an etching apparatus used in the resist mask forming step and the plasma etching step of the wafer dividing method shown in FIG. FIG. 13 is a cross-sectional view showing breakthrough etching for exposing the streets of the wafer that can be included in the resist mask forming step of the wafer dividing method shown in FIG. FIG. 14 is a cross-sectional view showing a plasma etching process of the wafer dividing method shown in FIG. FIG. 15 is a cross-sectional view of the wafer after the plasma etching step of the wafer dividing method shown in FIG.

  As shown in FIG. 7, a wafer W dividing method (hereinafter simply referred to as a dividing method) for dividing the wafer W along the street L using the imprint original plate 1 (hereinafter simply referred to as an original plate) is a resist It includes a liquid supply step ST11, a resist mask formation step ST12, and a plasma etching step ST13.

  The resist solution supply step ST11 is a step of supplying the resist solution R to the wafer W surface WS. In the resist solution supply step ST11, the back surface WR side of the back surface WS of the wafer W is held, and the resist solution R is supplied onto the device D of the wafer W. The resist solution R is hardened when heated, and is made of a resin having plasma resistance when hardened. As the resist solution R, a water-soluble resin containing polyvinyl alcohol (PVA) or polyvinyl pyrrolidone (PVP) can be used. Further, when the plate-like body 2 of the original plate 1 is quartz glass, the resist solution R may be hardened by irradiation with energy rays such as ultraviolet rays, and may be made of a resin having plasma resistance when cured. . In the first embodiment, the resist solution supply step ST11 supplies the resist solution R onto the device D from the ink jet nozzle 200. In the present invention, the back surface WR of the wafer W is held in the holding unit and held. The resist solution R may be supplied to the entire surface WS of the wafer W while rotating the portion around the axis. In this embodiment, the wafer W may be formed to the finished thickness of the device D by grinding or polishing means. In this embodiment, the resist R includes a surface protective film.

  The resist mask forming step ST12 is a step of pressing the original plate 1 manufactured by the manufacturing method shown in FIG. 4 toward the wafer W to form a resist mask P that covers the plurality of devices D and exposes the street L portions. In the resist mask forming step ST12, as shown in FIG. 9, the original 1 is made to face the surface WS of the wafer W supplied with the resist solution R. At this time, the device D and the concave portion 3 are opposed to each other, and the street L and the convex portion 4 are opposed to each other.

  In the resist mask forming step ST12, the original plate 1 is pressed against the wafer W as shown in FIG. Then, the resist solution R on the device D enters the recess 3 and a part of the resist solution R is pushed out from the space on the device D and applied (exuded) on the street L. In the resist mask formation step ST12, the resist liquid R is cured by heating, and the master 1 is separated from the surface WS of the wafer W as shown in FIG. Then, as shown in FIG. 11, a resist mask P is formed on both the device D and the street L. The resist mask P is thinner on the street L than on the device D.

  In the resist mask forming step ST12, a holding member TP (shown in FIG. 13) is attached to the back surface WR of the wafer W, and the wafer W is accommodated in the housing 21 through the opening 22 of the housing 21 of the etching apparatus 20 shown in FIG. Then, the opening 22 is closed by the gate valve 26. Then, the back surface WR side of the wafer W is adsorbed and held by an electrostatic force on an adsorption holding member 25 (electrostatic chuck, ESC: Electrostatic chuck) on the lower electrode 24 connected to the high frequency power supply 23 via the holding member TP.

Next, in the resist mask forming step ST12, the refrigerant is circulated from a refrigerant supply means (not shown) into a cooling passage (not shown) in the lower electrode 24, and the exhaust device 27 is operated to evacuate the atmosphere in the housing 21 through the exhaust port 28. The exhaust gas is exhausted, and an etching gas is supplied from the gas supply means 29 into the housing 21 through the jet port 31 of the upper electrode 30 connected to the high frequency power supply 32 toward the surface WS of the wafer W. At this time, the inside of the housing 21 is maintained at a predetermined pressure. Then, high-frequency power is applied to the upper electrode 30 from the high-frequency power source 32 with the etching gas supplied. As a result, a plasma PZ is generated between the lower electrode 24 and the upper electrode 30, and a high frequency power higher than that in the plasma etching process is supplied from the high frequency power source 23 to the lower electrode 24 to attract ions in the plasma PZ to the wafer W. Then, breakthrough etching is performed to remove the natural oxide film composed of the resist mask P on the surface WS of the wafer W and the SiO ₂ formed on the surface WS of the wafer W. In the resist mask forming step ST12, as shown in FIG. 13, when the resist mask P and the oxide film on the street L are removed, the breakthrough etching is finished and the surface WS of the substrate S in the street L portion of the wafer W is exposed. . In the present invention, the protective member TP may be attached to the back surface WR of the wafer W before the resist mask forming step ST12.

  The plasma etching step ST13 is a step in which the portion corresponding to the street L of the substrate S is irradiated with plasma PZ through the resist mask P and etched. In the plasma etching step ST13, an etching gas is supplied from the gas supply means 29 into the housing 21 through the jet port 31 of the upper electrode 30 connected to the high frequency power source 32 toward the surface WS of the wafer W, thereby forming a resist mask forming step ST12. In comparison with the breakthrough etching of FIG. 2, a low-frequency power is supplied from the high-frequency power source 23 to the lower electrode 24, ions in the plasma PZ are drawn into the wafer W, and the substrate P is irradiated with the plasma PZ through the resist mask P. The substrate SB is etched from the surface WS of the wafer W.

  Since the substrate S on the street L of the wafer W is exposed, the plasma etching step ST13 etches the substrate S exposed on the street L to form a trench DT in the street L as shown by a dotted line in FIG. To do. In the first embodiment, as shown in FIG. 15, the plasma etching step ST13 ends after etching for the time that the groove DT reaches the holding member TP. In the dividing method, the resist mask P on the device D is removed by ashing or cleaning using pure water.

  In the method of manufacturing the original 1 according to the first embodiment, the plate-like body 2 is irradiated with the laser beam LR to form the convex portions 4 and the concave portions 3. It is not necessary to go through steps such as the exposure step, and the original 1 can be manufactured by a simple process, and the original 1 can be easily manufactured at low cost. Moreover, since the manufacturing method of the original plate 1 which concerns on Embodiment 1 irradiates the laser beam LR to the plate-shaped body 2, and forms the recessed part 3, also in the process of the wafer W in which the device D of various sizes was formed The master 1 that can be used can be easily manufactured.

  Moreover, since the manufacturing method of the original plate 1 according to the first embodiment irradiates the plate-like body 2 with the laser beam LR to form the concave portion 3, the object to which the street L that does not form a continuous straight line from one end to the other end is set. The master 1 that can be used to divide the wafers W ′ and W ″ illustrated in FIGS. 16 and 17 as the workpieces can be easily manufactured. In short, since the manufacturing method of the original 1 according to the first embodiment irradiates the plate-like body 2 with the laser beam LR to form the concave portion 3, the concave portion has a planar shape different from the straight concave portion (straight groove). 3 can be formed.

  In addition, as illustrated in FIG. 16, the wafer W ′ that is a workpiece on which a street L that is a street that is not a straight line continuous from one end to the other end has a square shape and a different size as illustrated in FIG. 16. The device in which the device D ′ is formed is included. The wafer W ′ shown in FIG. 16 is used, for example, for research purposes or as a prototype. Further, the wafer W ′ that is a workpiece in which the street L that is a street that does not form a straight line from one end to the other end is included, includes a device in which devices D having the same size are arranged.

  In addition, as illustrated in FIG. 17, the wafer W ″ that is a workpiece in which a street L that is a street that does not form a straight line from one end to the other end is an irregular shape other than a quadrangle as illustrated in FIG. 17. The device in which the device D ″ is formed is included. In the wafer W ″ shown in FIG. 17, for example, the planar shape of the device D ″ is formed in a honeycomb shape (hexagon). Further, the planar shape of the irregularly shaped device D ″ is not limited to the honeycomb shape, and may be various shapes such as a circle. FIG. 16 is a plan view of a part of a wafer of another example to be processed by the wafer dividing method using the imprint master according to the first embodiment. FIG. 17 is a plan view of a part of a wafer of still another example of a processing target of the wafer dividing method using the imprint original plate according to the first embodiment.

  Further, the dividing method according to the first embodiment divides the wafer W into the devices D using the original 1, so that the wafer W can be divided into the devices D at a low cost.

[Embodiment 2]
A wafer dividing method according to the second embodiment will be described with reference to the drawings. FIG. 18 is a flowchart illustrating a flow of a wafer dividing method according to the second embodiment. FIG. 19 is a cross-sectional view of the wafer after the plasma etching step of the wafer dividing method shown in FIG. FIG. 20 is a cross-sectional view showing a sticking step of the wafer dividing method shown in FIG. FIG. 21 is a cross-sectional view showing a singulation process of the wafer dividing method shown in FIG. FIG. 22 is a sectional view of the wafer after the singulation process of the wafer dividing method shown in FIG. 18 to 22, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The wafer dividing method according to the second embodiment (hereinafter simply referred to as a dividing method) is a method for dividing the original W 1 of the first embodiment along the street L along the wafer W. As shown in FIG. 18, the dividing method includes an adhesion step ST14 and an individualization step ST15 in addition to the resist solution supply step ST11, the resist mask formation step ST12, and the plasma etching step ST13A.

  The resist solution supplying step ST11 and the resist mask forming step ST12 of the dividing method according to the second embodiment are the same as those in the first embodiment. In the plasma etching step ST13A of the dividing method according to the second embodiment, as shown in FIG. 19, a trench DT having a depth DP corresponding to the finished thickness T (shown in FIG. 19) of the device D is formed. The plasma etching step ST13A ends the plasma etching before the depth DP of the groove DT from the surface of the device D exceeds the finished thickness T of the device D and the groove DT reaches the back surface WR.

  The sticking step ST14 is a step of sticking a BG (Back Grind) tape BGT, which is a protective member for protecting the surface WS of the wafer W, on the surface WS side of the wafer W. In the attaching step ST14, the resist mask P is removed by ashing or cleaning with pure water, and as shown in FIG. 20, the BG tape BGT is attached to the surface WS of the wafer W, and the holding member TP is attached to the wafer W. Remove from the back WR. In addition, the BG tape BGT attached to the surface WS side of the wafer W in the attaching step ST14 includes an adhesive layer (not shown) made of an adhesive that decreases in adhesive strength when irradiated with ultraviolet rays. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is composed of, for example, a microcapsule that expands or foams when irradiated with ultraviolet rays or a foaming agent mixed therein. An adhesive may be comprised by what hardens | cures by irradiating an ultraviolet-ray.

  In the singulation step ST15, the front surface WS side of the wafer W is held via the BG tape BGT, the back surface WR side of the wafer W is ground, and the bottom portion of the groove DT is exposed to singulate the wafer W. It is a process. In the singulation step ST15, as shown in FIG. 21, the surface WS side of the wafer W is sucked and held on the chuck table 301 of the grinding apparatus 300 via the BG tape BGT, and the grinding wheel 303 is ground on the back surface WR of the wafer W. The grindstone 302 is pressed, the chuck table 301 and the grinding wheel 303 are rotated around the axis, and the wafer W is ground to the finished thickness T by the grindstone 302. When the wafer W reaches the finished thickness T, as shown in FIG. 22, the bottom of the groove DT is exposed to the back surface WR side, and the wafer W is divided into the devices D. In the singulation step ST15, the back surface WR of the wafer W is polished by using a polishing apparatus or a CMP (Chemical Mechanical Polishing) polishing apparatus after grinding with the grinding wheel 302. In the present invention, the singulation step ST15 may form a gettering layer on the back surface WR of the wafer W, that is, the back surface WR of each device D. The gettering layer is a layer in which crystal defects, strains, etc. (called gettering sites) are formed on the back surface WR of the wafer W, that is, the back surface WR of each device D, and traps impurities that cause metal contamination at the gettering site. It is a fixed layer.

  In the dividing method, the adhesive layer of the BG tape BGT is irradiated with ultraviolet rays, and the devices D are picked up from the BG tape BGT one by one by a pickup unit (not shown).

  As in the first embodiment, the dividing method according to the second embodiment divides the wafer W into the devices D using the original 1, so that the wafer W can be divided into the devices D at a low cost.

[Modification]
A wafer dividing method according to a modification of each embodiment will be described with reference to the drawings. FIG. 23 is a cross-sectional view of the wafer after the resist mask forming step of the wafer dividing method according to the modification of each embodiment. In FIG. 23, the same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  A wafer dividing method according to a modification of each embodiment (hereinafter simply referred to as a dividing method) is to supply a resist solution R to the back surface WR of the wafer W in the resist solution supplying step ST11, and in the resist mask forming step ST12, As shown in FIG. 23, a resist mask P is formed in a region corresponding to the device D on the back surface WR of the wafer W (a region overlapping with the device D), and etching is performed from the back surface WR of the wafer W in the plasma etching step ST13. Also good.

  Since the dividing method according to the modification of each embodiment performs etching from the back surface WR, the device D on the wafer W front surface WS is not damaged during the etching. Further, in the dividing method according to the modification of each embodiment, since the wafer W is divided into the devices D using the original 1 as in the first embodiment, the wafer W can be divided into the devices D at low cost.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention. For example, in the resist mask forming step ST12, a release agent may be applied in advance to the inner surface of the concave portion 3 of the original 1 so that the resist solution R and the resist mask P can be easily released from the original 1.

DESCRIPTION OF SYMBOLS 1 Master for imprint 2 Plate body 3 Concave part 4 Convex part W, W ', W "Wafer L Street D, D', D" Device LR Laser beam P Resist mask (mask)
R resist solution PZ plasma ST1 preparation step ST2 convex portion formation step ST11 resist solution supply step ST12 resist mask formation step ST13 plasma etching step

Claims (2)

A method for producing an imprinting original plate for forming a mask covering a device on a wafer in which the device is formed in each of a plurality of regions on a substrate surface partitioned by a street,
A preparation step of preparing a plate-like body having a size equal to or greater than that of the wafer;
A convex portion forming step of forming a convex portion in a portion corresponding to the street by irradiating a laser beam to a region corresponding to the plurality of devices of the wafer of the plate-like body to form a concave portion;
A method for producing an imprint original plate. A wafer dividing method for dividing a wafer in which devices are respectively formed in a plurality of regions on a substrate surface partitioned by a street, along the street,
A resist solution supplying step for supplying a resist solution to the wafer surface;
A resist mask forming step of forming a resist mask that presses the imprint original plate manufactured by the manufacturing method according to claim 1 toward the wafer to cover the plurality of devices and expose the street portion;
And a plasma etching step of etching the portion of the substrate corresponding to the street corresponding to the street through plasma irradiation, and dividing the wafer.

Images