JP2009141276A - Semiconductor device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the rigidity of a wafer after dicing processing by a simplified method. <P>SOLUTION: In a semiconductor wafer 1, there is formed a rib 2 at an outer circumferential end of the rear surface of an outer circumferential residual region 5 other than a central region 4 where a device structure 6 is formed. A thin film resin 3 is formed over the entire surface of the rear surface of the wafer 1 where the rib 2 is left so that any gap is not formed. Further, dicing processing is performed from the surface of the wafer 1 , and the device structure 6 separated to individual tips 8 leaving the rib 2. By this, even after the dicing processing, the rib 2 and the individual chips 8 are fixed with the thin film resin 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly to a semiconductor device having a thin device thickness and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, a wafer on which a plurality of devices such as ICs and LSIs are formed on the front side is divided into individual chips using a dicing apparatus or the like and incorporated into various electronic devices. In recent years, in order to reduce the size and weight of electronic equipment, the chip is thinned by polishing the back surface of the wafer so that the thickness becomes, for example, about 50 μm to 100 μm before being divided into individual chips. Development is progressing.

  However, since the rigidity of the wafer cannot be maintained when the wafer is thinned, it becomes difficult to handle the wafer in a process after the dicing process, for example, an appearance check process, a wafer check (electrical evaluation) process, and a pickup process. For example, if the wafer is thin, the wafer is warped due to the stress of the film formed on the front surface and the back surface of the wafer, making it difficult to carry the wafer and process in each process. Furthermore, since the end surface of the wafer becomes a sharp knife edge, there is a problem that the wafer is cracked or chipped.

  In order to solve these problems, a wafer having a rib structure in which the outer peripheral end of the wafer is thicker than the device formation region at the center of the wafer has been proposed (for example, see Patent Document 1 below). Such a wafer is formed by polishing the back surface of the wafer leaving the outer peripheral edge. Or it forms by sticking a ring-shaped protective member to the outer peripheral edge part of the back surface of a wafer with an adhesive.

  When dicing a wafer having a rib structure, a dicing process can be performed without using a dicing frame. Specifically, a dicing tape or the like is affixed to the back surface of the wafer, the back surface of the wafer is fixed on a suction stage having a diameter smaller than the diameter excluding the rib portion, and dicing is performed from the front surface side of the wafer. To do. At this time, the rib portion is cut off and peeled off from the dicing tape. Then, the dicing tape is stretched in order to make it easier to pick up the chip in the subsequent pickup process.

JP 2003-332271 A

  However, in the technique of Patent Document 1 described above, the rib is cut off in the dicing process, so that the rigidity of the wafer cannot be maintained as it is in the pick-up process after dicing. Therefore, after the dicing tape is stretched, a process of attaching a ring for maintaining the rigidity of the wafer to the outer peripheral edge of the wafer is required, which is troublesome.

  An object of the present invention is to provide a semiconductor device capable of maintaining the rigidity of a wafer after a dicing process by a simple method and a method for manufacturing the same in order to solve the above-described problems caused by the prior art.

  In order to solve the above-described problems and achieve the object, a semiconductor device according to a first aspect of the present invention includes a central region in which a plurality of element structures are provided on a front surface, and an outer peripheral end portion surrounding the central region. In a semiconductor device having a semiconductor wafer comprising a rib thicker than the central region provided on the back surface, a thin film resin provided on the entire back surface of the semiconductor wafer, and on the front surface of the semiconductor wafer, A plurality of element structures provided in a central region, and notches provided to divide the chips into respective chips, and the chips and the ribs separated by the notches are fixed by the thin film resin. It is characterized by being.

  A semiconductor device according to a second aspect of the invention is characterized in that, in the first aspect of the invention, the thin film resin protrudes from the outer peripheral end of the back surface of the semiconductor wafer within 2 mm.

  A semiconductor device according to a third aspect of the present invention is the semiconductor device according to the first or second aspect, wherein the cut is provided on the entire surface of the semiconductor wafer, and the depth of the cut is the thickness of the rib. It is within one half.

  A semiconductor device according to a fourth aspect of the present invention is the semiconductor device according to any one of the first to third aspects, wherein the thin film resin is an ultraviolet curable adhesive tape.

  According to a fifth aspect of the present invention, in the semiconductor device according to any one of the first to fourth aspects, the rib has a thickness of 200 μm or more, and the central region has a thickness of 100 μm. It is characterized by the following.

  According to a sixth aspect of the present invention, there is provided a semiconductor device manufacturing method comprising: a central region provided with a plurality of element structures on a front surface; and the central portion provided on a back surface of an outer peripheral end portion surrounding the central region. In a method of manufacturing a semiconductor device having a semiconductor wafer comprising ribs thicker than regions, a resin forming step of forming a thin film resin on the entire back surface of the semiconductor wafer, and a back surface of the semiconductor wafer on which the thin film resin is formed A wafer cutting step in which a plurality of element structures formed in the central region are cut into the respective chips on the front surface of the semiconductor wafer while leaving the ribs down. It is characterized by including.

  According to a seventh aspect of the present invention, in the semiconductor device manufacturing method according to the sixth aspect of the present invention, in the resin forming step, the semiconductor wafer is disposed on a rigid flat plate with the back surface facing up, and the semiconductor wafer An arrangement step of disposing the thin film resin on the back surface of the semiconductor wafer, a pasting step of applying the thin film resin to the entire back surface of the semiconductor wafer by applying pressure from above the thin film resin with a pressing plate, and the semiconductor And a resin cutting step of cutting the thin film resin protruding from the outer peripheral edge of the back surface of the wafer.

  According to a eighth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to the seventh aspect of the present invention, wherein in the attaching step, pressure is applied by the pressing plate having an elastic body on a surface in contact with the thin film resin. And

  According to a ninth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to the seventh aspect of the present invention, wherein, in the attaching step, the pressing plate having a blowing portion that blows out gas from a surface in contact with the thin film resin is used. It is characterized by pressurizing while blowing.

  According to a tenth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to any one of the seventh to ninth aspects, wherein, in the placing step, an ultraviolet curable type is formed on a back surface of the semiconductor wafer. An adhesive tape is arranged.

  The method for manufacturing a semiconductor device according to an invention of claim 11 is the method according to any one of claims 7 to 10, wherein the resin cutting step is performed by the thin film resin protruding from the back surface of the semiconductor wafer. The thin film resin is cut so as to be within 2 mm.

  A semiconductor device manufacturing method according to a twelfth aspect of the present invention is the semiconductor device manufacturing method according to the sixth aspect of the present invention, wherein the resin forming step includes an arrangement step of disposing the semiconductor wafer on a spin chuck with the back surface facing up. A resin coating step of coating a liquid resin on the entire back surface of the semiconductor wafer from above the back surface of the semiconductor wafer while rotating the semiconductor wafer by the spin chuck.

  According to a thirteenth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to any one of the sixth to twelfth aspects, wherein, in the wafer cutting step, from the central region to the central region and the outer peripheral edge. The cut into the outer peripheral surplus area between the portions is within 5 mm.

  According to a fourteenth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to any one of the sixth to thirteenth aspects of the present invention, in the wafer cutting step, over the entire front surface of the semiconductor wafer. Incisions are made at a depth within half the thickness of the rib.

  According to a fifteenth aspect of the present invention, there is provided a semiconductor device manufacturing method according to any one of the sixth to twelfth aspects, wherein the wafer cutting step is performed on the entire front surface of the semiconductor wafer. A resist coating step for applying a resist, a pattern forming step for forming a dicing pattern on the resist, and dry etching using the dicing pattern, leaving the ribs on the front surface of the semiconductor wafer, A trench forming step of forming a trench so that a plurality of element structures formed in the central region are divided into respective chips.

  According to each of the above inventions, the ribs formed on the outer peripheral edge of the back surface of the semiconductor wafer remain after the dicing process, and the ribs and individual chips formed on the semiconductor wafer are made of thin film resin. It is fixed. Therefore, the rigidity of the semiconductor wafer can be maintained without attaching a ring in a process after the dicing process in the semiconductor device manufacturing method, for example, a pick-up process.

  According to the invention of claim 3 and claim 14, the rigidity of the semiconductor wafer after the dicing process can be maintained even if the entire surface of the semiconductor wafer is cut during the dicing process. Therefore, even if the dicing process is performed by a simple method, the rigidity of the semiconductor wafer after the dicing process can be maintained.

  According to the inventions of claims 7 to 12, the thin film resin can be formed on the back surface of the semiconductor wafer without forming a gap between the back surface of the semiconductor wafer and the thin film resin. As a result, chipping or cracking during the dicing process can be prevented.

  According to the inventions of claims 4 and 10, an ultraviolet curable adhesive tape can be attached as a thin film resin to the back surface of the semiconductor wafer. Thus, when the individual chips are picked up, the thin film resin is irradiated with ultraviolet rays in advance, so that the adhesiveness between the semiconductor wafer and the thin film resin is weakened, so that the pick-up process can be easily performed. For this reason, chipping during pickup can be prevented.

  According to the semiconductor device and the method for manufacturing the same according to the present invention, the rigidity of the wafer can be maintained after the dicing process by a simple method.

  Exemplary embodiments of a semiconductor device and a method for manufacturing the same according to the present invention will be explained below in detail with reference to the accompanying drawings. Note that, in the following description of the embodiments and all the attached drawings, the same reference numerals are given to the same components, and duplicate descriptions are omitted.

(Embodiment 1)
First, the semiconductor device according to the first embodiment will be described. FIG. 1 is a plan view showing the structure of the semiconductor device according to the first embodiment. FIG. 2 is a cross-sectional view showing a cross-sectional structure taken along line AA ′ in FIG. As shown in FIG. 1 or FIG. 2, a rib 2 thicker than the central region 4 is provided at the outer peripheral end of the back surface of the wafer 1 such as silicon. In the first embodiment, the thickness of the central region 4 is, for example, 50 to 100 μm, and the thickness of the rib 2 is, for example, 200 to 500 μm.

  FIG. 3 is a characteristic diagram showing the relationship between the amount of warpage of the wafer and the thickness of the rib. As shown in FIG. 3, by increasing the thickness of the rib, the amount of warpage of the wafer is reduced. As an example, the allowable range of the amount of warpage of the wafer when the wafer is transferred is 2 mm or less. Therefore, when the allowable range of the amount of warpage of the wafer is 2 mm or less, the thickness of the rib is preferably 200 μm or more. The characteristic diagram shown in FIG. 3 is the result of measurement for a wafer having a wafer diameter of 150 mm, a wafer central portion (device formation region) thickness of 60 μm, and a rib width of 3 mm.

  As shown in FIG. 1 or FIG. 2, an element structure 6 is formed in the central region 4 of the front surface of the wafer 1 and is divided into individual chips 8 by notches 7 by a dicing process. The excessive cutting length x1 from the edge part of the center area | region 4 of the notch 7 by a dicing process is about 1-5 mm, for example. This is to maintain the rigidity of the wafer 1 after the dicing process. Further, the area other than the central area 4 in the wafer 1 is an outer peripheral surplus area 5 where one chip cannot be taken. Therefore, the surplus cutting length x1 is the length of the cut 7 in the outer peripheral surplus region 5.

  A thin film resin 3 such as a dicing tape is provided on the entire back surface of the wafer 1 without a gap due to bubbles or the like. Further, the protruding width x2 of the thin film resin 3 from the end portion of the wafer 1 is, for example, 2 mm or less. The reason is that it is possible to suppress deterioration of wafer transfer and alignment accuracy. The reason why the thin film resin 3 protrudes from the end of the wafer 1 is that the adhesion area between the rib 2 and the thin film resin 3 can be increased and the adhesion can be improved. If the rib 2 and the thin film resin 3 are sufficiently bonded, the thin film resin 3 may not protrude from the end of the wafer 1.

  Next, a method for manufacturing the semiconductor device according to the first embodiment will be described. First, a method for forming a thin film resin on the back surface of the semiconductor device will be described. 4 to 6 are cross-sectional views sequentially illustrating a method of forming a thin film resin on the back surface of the semiconductor device according to the first embodiment. In these drawings, although not shown, a device element structure is formed on the front surface (lower surface in the drawing) of the wafer 1. First, the back surface of the wafer 1 is ground or etched, and the thickness of the central portion of the wafer 1 is set to 50 to 100 μm, for example. Further, the rib 2 is formed by setting the thickness of the region from the outer peripheral end of the wafer 1 to, for example, 2 to 5 mm inside, for example, 200 to 500 μm. The rib 2 may be formed by attaching a ring-shaped protective member to the outer peripheral end of the back surface of the wafer 1.

  Next, as shown in FIG. 4, the wafer 1 provided with the ribs 2 is disposed on the flat plate 11 with the back surface thereof facing upward, and a thin film resin 3 such as a dicing tape is further disposed thereon. Next, pressure is applied from above the thin film resin 3 by the pressing plate 12, and the thin film resin 3 is brought into close contact with the back surface of the wafer 1. The back surface of the wafer 1 has a concave shape because the rib 2 protrudes. When the thin film resin 3 is affixed to the back surface of the wafer 1, a gap may be formed between the wafer 1 and the thin film resin 3 at the inner corner of the concave shape, and bubbles may enter. Here, in order to prevent bubbles from entering between the wafer 1 and the thin film resin 3, first, the thin film resin 3 is arranged so as not to cause wrinkles, and secondly, the pressing plate 12. The flatness and accuracy of parallelism are important. Further, an elastic body may be attached to the surface of the pressing plate 12 that contacts the thin film resin 3. By sticking the elastic body, the in-plane distribution of the pressure applied by the pressing plate 12 can be made uniform.

  Next, as shown in FIG. 5, the thin film resin 3 is formed along the outer periphery of the back surface of the wafer 1 using the cutter 13 so that the protruding width x2 of the thin film resin 3 from the end of the wafer 1 is, for example, 2 mm or less. Disconnect. If the rib 2 and the thin film resin 3 are sufficiently bonded, the thin film resin 3 may be cut inside the outer peripheral end of the wafer 1. Next, as shown in FIG. 6, the wafer 1 to which the thin film resin 3 is attached is taken out. Thereby, the formation of the thin film resin 3 on the back surface of the wafer 1 is completed. These series of processing may be performed by an automatic or semi-automatic device.

  Next, a method for dicing the front surface of the semiconductor device will be described. FIG. 7 is a cross-sectional view illustrating a method of dicing the front surface of the semiconductor device according to the first embodiment. As shown in FIG. 7, the wafer 1 on which the element structure 6 is formed is placed on a stage 14 having a convex shape substantially the same size as the concave shape on the back surface of the wafer 1 with its front surface facing up. At this time, for example, the wafer 1 can be placed on the stage 14 with a positional accuracy of about ± 100 μm by holding the front surface of the wafer 1 by a suction arm (not shown) and carrying it by a robot.

  Next, the wafer 1 is attracted to the stage 14, and as shown in FIGS. 1 and 2, dicing processing such as blade dicing or laser dicing is performed from the front surface side of the wafer 1. Here, in order to maintain the mechanical strength of the rib 2 after the dicing process, it is preferable to make the dicing area (area where the cut 7 can be made) as small as possible. For this reason, the dicing process is performed so that the excessive cutting length x1 from the end of the central region 4 is, for example, about 1 to 5 mm. At this time, the cut 7 due to the dicing process is prevented from penetrating the thin film resin 3. Thereby, the dicing process of the front surface of the wafer is completed.

  As described above, according to the first embodiment, after the dicing process, the rib remains on the outer peripheral end of the wafer, and the rib and the individual chips separated by the dicing process are fixed by the thin film resin. ing. For this reason, chips are not separated even after the dicing process, and the rigidity of the wafer can be maintained. Therefore, after the dicing process, a process for maintaining the rigidity of the wafer, for example, a process of attaching a ring to the outer peripheral end of the wafer can be omitted. That is, the wafer can be easily handled without performing an extra step after the dicing process.

(Embodiment 2)
Next, a semiconductor device according to the second embodiment will be described. Since the structure of the semiconductor device according to the second embodiment is the same as the structure of the semiconductor device according to the first embodiment, description thereof is omitted.

  Next, a method for manufacturing the semiconductor device according to the second embodiment will be described. The semiconductor device manufacturing method according to the second embodiment is different in a method of forming a thin film resin on the back surface of the wafer. FIG. 8 is a cross-sectional view illustrating a method of forming a thin film resin on the back surface of the semiconductor device according to the second embodiment. As shown in FIG. 8, the push plate 15 is provided with a shower portion 16 on the surface in contact with the thin film resin 3, and a gas inlet 17 is provided in a region other than the shower portion 16 of the push plate 15.

  The wafer 1 provided with the ribs 2 is disposed on the flat plate 11 with the back surface thereof facing up, and the thin film resin 3 is disposed thereon. Next, pressure is applied from above the thin film resin 3 by the pressing plate 15 to bring the thin film resin 3 into close contact with the back surface of the wafer 1. At this time, in the push plate 15, a gas such as air or nitrogen introduced from the gas introduction port 17 blows out from the shower unit 16. In this way, by pressing the thin film resin 3 with the gas blown from the shower unit 16, the in-plane distribution of pressurization becomes uniform. Thus, the thin film resin 3 can be attached to the back surface of the wafer without introducing bubbles between the back surface of the wafer 1 and the thin film resin 3.

  Next, using the cutter 13, the thin film resin 3 is cut along the outer periphery of the back surface of the wafer 1 so that the protruding width x2 of the thin film resin 3 from the end of the wafer 1 is, for example, 2 mm or less (see FIG. 5). ). Next, the wafer 1 to which the thin film resin 3 is attached is taken out (see FIG. 6), and the formation of the thin film resin on the back surface of the wafer is completed.

  According to the second embodiment, in the first embodiment, the same effect as that obtained when the elastic body is attached to the surface of the pressing plate that contacts the thin film resin can be obtained. Further, when a pressing plate with an elastic body attached is used, the elasticity of the elastic body may change due to pressurization, but in the second embodiment, since the elastic body is not used, a member such as an elastic body is used. It is not necessary to exchange. In this way, the push plate can be used stably for a long period of time without performing member replacement.

  In the first and second embodiments, since ribs remain on the wafer even after the dicing process, it is not necessary to perform the dicing tape expanding process, which is a thin film resin, before the chip picking process. If this expanding process is not performed, chipping may occur due to chip rubbing because the chip interval is about 30 to 50 μm during the pick-up process. For this reason, for example, an ultraviolet curable dicing tape is used as the thin film resin, and the chipping is suppressed by irradiating the thin film resin with ultraviolet rays before the pick-up process to reduce the adhesive strength of the thin film resin as much as possible. Can do.

(Embodiment 3)
Next, a semiconductor device according to Embodiment 3 will be described. Since the structure of the semiconductor device according to the third embodiment is the same as the structure of the semiconductor device according to the first and second embodiments, description thereof is omitted.

  Next, a method for manufacturing the semiconductor device according to the third embodiment will be described. The manufacturing method of the semiconductor device according to the third embodiment is different in a method of forming a thin film resin on the back surface of the wafer. In the third embodiment, a thin film resin is formed by applying a liquid resin to the back surface of a wafer using a spin coater. FIG. 9 is a cross-sectional view illustrating a method of forming a thin film resin on the back surface of the semiconductor device according to the third embodiment. As shown in FIG. 9, the front surface (lower surface in the figure) side of the wafer 1 is held by a spin chuck 18. Then, while rotating the wafer 1, the liquid resin is supplied from the liquid resin supply port 19 to the back surface of the wafer 1 and applied to the back surface of the wafer 1. Next, the wafer 1 coated with the thin film resin 3 is taken out (see FIG. 6), and the formation of the thin film resin 3 on the back surface of the wafer 1 is completed.

  According to the third embodiment, the same effects as those of the first or second embodiment can be obtained. Furthermore, since the thin film resin does not protrude from the edge of the wafer, the process of cutting the thin film resin can be omitted.

(Embodiment 4)
Next, a semiconductor device according to Embodiment 4 will be described. FIG. 10 is a plan view showing the structure of the semiconductor device according to the fourth embodiment. FIG. 11 is a cross-sectional view showing a cross-sectional structure taken along the cutting line BB ′ of FIG. As shown in FIG. 10, a notch 7 is formed on the entire surface of the wafer 1 by dicing. Further, as shown in FIG. 11, the depth x3 of the cut 7 by the dicing process is, for example, ½ or less of the thickness x4 of the rib 2. By doing so, the mechanical strength of the wafer can be sufficiently maintained.

  Next, a method for manufacturing the semiconductor device according to the fourth embodiment will be described. In the fourth embodiment, the method of dicing the front surface of the semiconductor device is different. First, a thin film resin is formed on the back surface of the wafer by the method shown in any of Embodiments 1 to 3. Next, the wafer 1 on which the element structure 6 is formed is placed on a stage 14 having the same size as the concave shape on the back surface of the wafer 1 with the front surface facing upward (see FIG. 7).

  Next, the wafer 1 is attracted to the stage 14, and as shown in FIG. 10 or FIG. 11, the depth x3 of the notch 7 by the dicing process is set to, for example, 1/2 or less of the thickness x4 of the rib 2, Dicing is performed on the entire surface of 1. Specifically, for example, a case where a thin film resin 3 having a thickness of 70 μm is attached to a wafer 1 having a thickness of the rib 2 of 500 μm and a thickness of the central region 4 of 70 μm will be described. This wafer is subjected to blade dicing processing on the front surface of the wafer 1 by setting the depth of the notch 7 by dicing processing to 100 μm. At this time, the ratio of the depth x3 of the notch 7 by the dicing process to the thickness x4 of the rib 2 is 20%. Therefore, sufficient mechanical strength is maintained. Thereby, the dicing process of the front surface of the wafer 1 is completed.

  According to the fourth embodiment, even if dicing processing is performed on the entire front surface of the wafer 1, the same effects as those of the first to third embodiments can be obtained.

(Embodiment 5)
Next, a semiconductor device according to Embodiment 5 will be described. Since the structure of the semiconductor device according to the fifth embodiment is the same as the structure of the semiconductor device according to the first to fourth embodiments, description thereof is omitted.

  Next, a method for manufacturing the semiconductor device according to the fifth embodiment will be described. The semiconductor device manufacturing method according to the fifth embodiment differs in the dicing process on the front surface of the wafer. In the fifth embodiment, the front surface of the wafer is diced by dry etching. 12 to 15 are cross-sectional views sequentially illustrating a method of dicing the front surface of the semiconductor device according to the fifth embodiment. First, a thin film resin is formed on the back surface of the wafer by the method shown in any of Embodiments 1 to 3.

  Next, the wafer 1 on which the element structure 6 is formed is placed on a stage 14 having the same size as the concave shape on the back surface of the wafer 1 with the front surface facing upward (see FIG. 7). Next, the wafer 1 is attracted to the stage 14 and, as shown in FIG. 12, a resist 20 is applied to the entire front surface of the wafer 1 on which the thin film resin 3 is formed on the back surface. Next, as shown in FIG. 13, a pattern is formed on the resist 20 by photolithography or the like. Next, as shown in FIG. 14, trench etching is performed on the wafer 1 using the resist 20 on which the pattern is formed as a mask. Here, for the trench etching, for example, carbon tetrafluoride (CF 4), sulfur hexafluoride (SF 6), chlorine (Cl 2), or the like is introduced into the reaction vessel using an inductively coupled plasma etching apparatus, and high-frequency power is supplied. Etching is performed by applying.

  Here, specifically, dry etching by the Bosch process is performed on the wafer 1 having a diameter of 150 mm, in which the thickness of the rib 2 is 500 μm and the thickness of the central region 4 is 50 μm. The Bosch process is an etching method that alternately repeats etching for deeply digging silicon vertically and deposition for forming a protective film on the deepened silicon sidewall. Deposition is performed at a high frequency output of 13.56 MHz and 5000 W at a substrate temperature of 23 ° C., a pressure of 5 Pa, and perfluorocyclobutane (C4F8) of 300 cc / min. Etching is performed at a high frequency output of 13.56 MHz and 5000 W at a substrate temperature of 23 ° C., a pressure of 12 Pa, and SF6 of 1000 cc / min. Then, deposition / etching is performed in a cycle of 2 sec / 7 sec for 4 minutes.

  Next, as shown in FIG. 15, the resist 20 is removed by ashing or the like, and the dicing processing of the front surface of the wafer 1 by dry etching is completed.

  According to the fifth embodiment, even when the dicing process is performed by dry etching, the same effects as those of the first to fourth embodiments can be obtained.

  As described above, the semiconductor device and the manufacturing method thereof according to the present invention are useful for a semiconductor device having a thin device thickness, and in particular, a semiconductor device having a semiconductor wafer having a rib structure in which a rib is formed on the outer peripheral end of the back surface. Suitable for

1 is a plan view showing a structure of a semiconductor device according to a first embodiment; FIG. 2 is a cross-sectional view showing a cross-sectional structure taken along a cutting line A-A ′ in FIG. 1. It is a characteristic view shown about the relationship between the curvature amount of a wafer, and the thickness of a rib. 3 is a cross-sectional view illustrating a method for forming a thin film resin on the back surface of the semiconductor device according to the first embodiment; FIG. 3 is a cross-sectional view illustrating a method for forming a thin film resin on the back surface of the semiconductor device according to the first embodiment; FIG. 3 is a cross-sectional view illustrating a method for forming a thin film resin on the back surface of the semiconductor device according to the first embodiment; FIG. FIG. 3 is a cross-sectional view illustrating a method for dicing the front surface of the semiconductor device according to the first embodiment; FIG. 6 is a cross-sectional view illustrating a method for forming a thin film resin on the back surface of a semiconductor device according to a second embodiment; FIG. 6 is a cross-sectional view illustrating a method for forming a thin film resin on the back surface of a semiconductor device according to a third embodiment; FIG. 6 is a plan view showing a structure of a semiconductor device according to a fourth embodiment. FIG. 11 is a cross-sectional view illustrating a cross-sectional structure taken along a cutting line B-B ′ in FIG. 10. FIG. 10 is a cross-sectional view illustrating a method for dicing a front surface of a semiconductor device according to a fifth embodiment; FIG. 10 is a cross-sectional view illustrating a method for dicing a front surface of a semiconductor device according to a fifth embodiment; FIG. 10 is a cross-sectional view illustrating a method for dicing a front surface of a semiconductor device according to a fifth embodiment; FIG. 10 is a cross-sectional view illustrating a method for dicing a front surface of a semiconductor device according to a fifth embodiment;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 2 Rib 3 Thin film resin 4 Central area | region 5 Peripheral surplus area | region 6 Element structure 7 Notch 8 Chip

Claims (15)

In a semiconductor device having a semiconductor wafer comprising a central region in which a plurality of element structures are provided on the front surface, and a rib thicker than the central region, which is provided on the back surface of the outer peripheral edge surrounding the central region.
A thin film resin provided on the entire back surface of the semiconductor wafer;
On the front surface of the semiconductor wafer, a plurality of element structures provided in the central region, notches provided to divide each chip,
With
Each of the chips delimited by the notches and the ribs are fixed by the thin film resin.   2. The semiconductor device according to claim 1, wherein a protrusion of the thin film resin from an outer peripheral end of the back surface of the semiconductor wafer is within 2 mm.   3. The semiconductor device according to claim 1, wherein the notch is provided on the entire surface of the semiconductor wafer, and the depth of the notch is within a half of the thickness of the rib.   The semiconductor device according to claim 1, wherein the thin film resin is an ultraviolet curable adhesive tape.   The semiconductor device according to claim 1, wherein the rib has a thickness of 200 μm or more, and the central region has a thickness of 100 μm or less. Manufacture of a semiconductor device having a semiconductor wafer comprising a central region provided with a plurality of element structures on the front surface, and a rib thicker than the central region provided on the back surface of the outer peripheral edge surrounding the central region In the method
A resin forming step of forming a thin film resin on the entire back surface of the semiconductor wafer;
A plurality of element structures formed in the central region on the front surface of the semiconductor wafer, with the back surface of the semiconductor wafer on which the thin film resin is formed facing down, leaving the ribs, A wafer cutting process for making a cut so as to divide into chips,
A method for manufacturing a semiconductor device, comprising: The resin forming step includes
Placing the semiconductor wafer on a rigid flat plate with the back side up, and placing the thin film resin on the back side of the semiconductor wafer;
Affixing the thin film resin on the entire back surface of the semiconductor wafer by pressing with a pressing plate from above the thin film resin;
A resin cutting step of cutting the thin film resin protruding from the outer peripheral edge of the back surface of the semiconductor wafer;
The method of manufacturing a semiconductor device according to claim 6, comprising:   8. The method of manufacturing a semiconductor device according to claim 7, wherein in the attaching step, pressure is applied by the pressing plate having an elastic body on a surface in contact with the thin film resin.   The method of manufacturing a semiconductor device according to claim 7, wherein in the attaching step, the gas is blown out by the pressing plate having a blowing portion that blows out the gas from a surface in contact with the thin film resin.   10. The method of manufacturing a semiconductor device according to claim 7, wherein, in the arranging step, an ultraviolet curable adhesive tape is arranged on a back surface of the semiconductor wafer.   11. The semiconductor device according to claim 7, wherein the resin cutting step cuts the thin film resin so that the thin film resin protruding from the back surface of the semiconductor wafer is within 2 mm. Manufacturing method. The resin forming step includes
An arrangement step of arranging the semiconductor wafer on a spin chuck with the back side facing up;
While rotating the semiconductor wafer by the spin chuck, a resin application step of applying a liquid resin to the entire back surface of the semiconductor wafer from the back surface of the semiconductor wafer;
The method of manufacturing a semiconductor device according to claim 6, comprising:   In the said wafer cutting process, the said notch | incision to the outer periphery surplus area | region between the said center area | region and the said outer periphery edge part is less than 5 mm from the said center area | region. The manufacturing method of the semiconductor device of description.   14. In the wafer cutting step, a cut is made in the entire front surface of the semiconductor wafer at a depth within a half of the thickness of the rib. The manufacturing method of the semiconductor device as described in one. The wafer cutting step includes
A resist coating step of coating a resist on the entire front surface of the semiconductor wafer;
A pattern forming step of forming a dicing pattern on the resist;
A trench is formed by dry etching using the dicing pattern so that the plurality of element structures formed in the central region are divided into respective chips on the front surface of the semiconductor wafer while leaving the ribs. A trench forming step,
The method of manufacturing a semiconductor device according to claim 6, comprising:

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