KR20160054415A - Method for manufacturing semiconductor piece - Google Patents

Abstract

A method for manufacturing a semiconductor piece comprises the following processes of: forming a groove, which has a first groove portion and a second groove portion and which is on a surface of a shape not having an edge portion between the first groove portion and the second groove portion, by dry etching wherein a width of the first groove portion gradually decreases toward a rear surface from a surface of a substrate and the second groove portion is a groove portion connected to a lower portion of the first groove portion and is extended downwardly at a steeper angle than an angle of the first groove portion; sticking a holding member having an adhesive layer to the surface where the groove is formed; making the substrate thin from the rear surface of the substrate while the holding member is stuck; and peeling the surface and the holding member after the process of making the substrate thin.

Description

[0001] METHOD FOR MANUFACTURING SEMICONDUCTOR PIECE [0002]

The present invention relates to a method of manufacturing a semiconductor piece.

A first groove is formed from the front side of the sapphire substrate by the first blade and then a second groove is formed by the second blade which is wider and deeper than the first groove from the back side, There has been proposed a dicing method capable of improving the yield without reducing the number (Patent Document 1). A method of forming grooves by laser from the wafer surface to the middle of the wafer and thereafter cutting the wafer from the back surface of the wafer to a position where the laser reaches the grooves is used to increase the number of semiconductor elements that can be formed on the wafer (Patent Document 2).

Japanese Patent Application Laid-Open No. 2003-124151 Japanese Patent Application Laid-Open No. 2009-88252

It is an object of the present invention to provide a method of manufacturing a semiconductor piece which is easy to both suppress the residual adhesive layer on the surface of the semiconductor substrate and suppress breakage of the semiconductor piece.

(1) a first groove portion that gradually narrows in width from the front surface of the substrate toward the rear surface, and a groove portion that is formed in the lower portion of the first groove portion and extends in a downward direction at a steeper angle than the angle of the first groove portion A step of forming a groove on the surface side of the first groove portion and the second groove portion having a shape that does not have an edge portion by dry etching;

A step of sticking a holding member having an adhesive layer on the surface on which the grooves on the surface side are formed,

A step of thinning the substrate from the back surface of the substrate in a state where the holding member is attached,

Peeling the surface and the holding member after the thinning step

And a step of forming the semiconductor piece.

(2) a first groove portion that gradually narrows in width from the front surface of the substrate toward the back surface, and a groove portion that is formed in a lower portion of the first groove portion and that extends in a downward direction at a steeper angle than the angle of the first groove portion A step of forming a groove on the surface side of the first groove portion and the second groove portion having a shape that does not have an edge portion by dry etching;

A step of attaching a holding member having an adhesive layer on the surface on which the grooves on the surface side are formed,

A step of forming a groove on a back surface side with a cutting member rotating from a back surface of the substrate toward a groove on the front surface side in a state where the holding member is attached,

A step of peeling the surface and the holding member after forming the grooves on the back surface side

And a step of forming the semiconductor piece.

(3) the surface-side grooves are formed by the dry etching with the etching strength such that the width of the grooves on the surface side gradually narrows toward the back surface, and during the formation of the grooves on the surface side, The gas flow rate of the gas for forming the protective film contained in the etching gas is switched from the first flow rate to a second flow rate smaller than the first flow rate within a range not stopping the flow rate of the gas for forming the protective film, (1) or (2).

(4) The method as claimed in any one of the above items (1) to (4), wherein the formation of the grooves on the front surface side is started by the dry etching with the etching strength such that the width of the grooves on the surface side gradually narrows toward the back surface, (1) or (2) described in (1) or (2) above, in which the flow rate of the etching gas contained in the etching gas is changed from the first flow rate to the second flow rate larger than the first flow rate, A method of manufacturing a semiconductor piece.

(5) The method of manufacturing a semiconductor piece according to (1) or (2), wherein the second groove portion has a shape extending downward without increasing the width of the lowermost portion of the first groove portion.

(6) The depth of the first groove portion is deeper than the depth at which the adhesive layer penetrates,

The method of manufacturing a semiconductor piece according to (1) or (2), wherein the second groove portion has a shape that widens downward than a width of a lowermost portion of the first groove portion.

According to the above (1) and (2), it is easy to both suppress the remaining adhesive layer on the surface of the semiconductor substrate and suppress breakage of the semiconductor chip, as compared with the case of forming the grooves on the surface side under a single etching condition.

According to the above (3) and (4), it is easy to both suppress the residual adhesive layer on the surface of the semiconductor substrate and suppress breakage of the semiconductor piece, compared with the case where the flow rate of the gas is not changed during formation of grooves on the surface side.

According to the above (5), in comparison with the structure having the second groove portion having a width larger than the width of the lowermost portion of the first groove portion when the adhesive layer intrudes into the second groove portion, Can be suppressed.

According to the above (6), the area of the back surface of the semiconductor piece can be made smaller when the groove is separated into individual pieces, as compared with the case where the groove has a shape gradually narrowed to the bottom of the groove have.

1 is a flowchart showing an example of a process of manufacturing a semiconductor piece according to an embodiment of the present invention.
2 is a schematic sectional view of a semiconductor substrate in a process of manufacturing a semiconductor piece according to an embodiment of the present invention.
3 is a schematic sectional view of a semiconductor substrate in a process of manufacturing a semiconductor piece according to an embodiment of the present invention.
4 is a schematic plan view of a semiconductor substrate (wafer) upon completion of circuit formation;
5 is a sectional view for explaining details of half dicing by a dicing blade;
6 is a cross-sectional view illustrating the remaining adhesive layer when the dicing tape is peeled from the substrate surface;
7 (A) and 7 (B) are cross-sectional views showing the shapes of the first fine grooves, and FIGS. 7 (C) and (D) Fig.
8 (A) and 8 (B) are cross-sectional views showing a reverse tapered fine groove, and FIGS. 8 (C) and (D) show a vertical fine groove Fig.
9 (B) and 9 (C) are sectional views showing fine grooves of only the forward tapered shape. Fig. 9 (B) and Fig. 9 Sectional view showing the groove.
10 is a schematic process sectional view illustrating a method of manufacturing a fine groove according to an embodiment of the present invention;
11 (A) is a cross-sectional view showing a step formed on a semiconductor chip, FIG. 11 (B) is a view for explaining a load applied to a step portion at the time of cutting by a dicing blade, Fig.

The method of manufacturing a semiconductor piece of the present invention is applied to a method of manufacturing individual semiconductor pieces (semiconductor chips) by dividing (separating) a substrate-shaped member such as a semiconductor wafer on which a plurality of semiconductor elements are formed. The semiconductor device formed on the substrate is not particularly limited, and may include a light emitting device, an active device, a passive device, and the like. In a preferred aspect, the manufacturing method of the present invention is applied to a method of taking out a semiconductor piece including a light emitting element from a substrate, and the light emitting element may be, for example, a surface emitting type semiconductor laser, a light emitting diode, or a light emitting thyristor. One semiconductor piece may include a single light emitting element, or a plurality of light emitting elements may be arranged in an array, and one semiconductor piece may include a driving circuit for driving such one or a plurality of light emitting elements . The substrate may be a substrate made of, for example, silicon, SiC, a compound semiconductor, sapphire or the like, but is not limited thereto. The substrate (hereinafter, collectively referred to as a semiconductor substrate) Substrate. In a preferred embodiment, the light emitting device is a III-V compound semiconductor substrate such as GaAs in which a light emitting device such as a surface emitting type semiconductor laser or a light emitting diode is formed.

In the following description, a plurality of light emitting elements are formed on a semiconductor substrate, and a method of taking out individual semiconductor chips (semiconductor chips) from the semiconductor substrate will be described with reference to the drawings. It should be noted that the scale and the shape of the drawings are emphasized in order to facilitate understanding of the features of the invention and are not necessarily the same as the scale and shape of the actual device.

[Example]

1 is a flow chart showing an example of a process of manufacturing a semiconductor piece according to an embodiment of the present invention. As shown in the figure, the semiconductor piece manufacturing method of this embodiment includes a step (S100) of forming a light emitting element, a step (S102) of forming a resist pattern, a step (S104) of forming a fine groove on the surface of the semiconductor substrate, (S108) of applying a dicing tape to the surface of the semiconductor substrate (S108); a step (S110) of performing half-dicing from the back surface of the semiconductor substrate; (S112) of peeling the dicing tape and irradiating ultraviolet rays to the expanding tape (S114); a step of peeling the semiconductor piece (semiconductor chip) on the back surface of the semiconductor substrate And a step (S116) of performing die mounting on a circuit board or the like. Sectional views of the semiconductor substrate shown in Figs. 2 (A) to 2 (D) and Figs. 3 (A) to 3 (E) correspond to the respective steps of steps S100 to S116.

In the step of forming a light emitting element (S100), as shown in Fig. 2A, a plurality of light emitting elements 100 are formed on the surface of a semiconductor substrate W such as GaAs. The light emitting device 100 is, for example, a surface emitting semiconductor laser, a light emitting diode, or a light emitting thyristor. Although one area is shown as the light emitting device 100 in the drawing, one light emitting device 100 exemplifies a device included in one piece of semiconductor pieces that are separated, and the area of one light emitting device 100 It is to be noted that not only one light emitting element but also a plurality of light emitting elements or other circuit elements may be included.

4 is a plan view showing an example of the semiconductor substrate W when the forming step of the light emitting element is completed. For the sake of convenience, only the light emitting element 100 in the central portion is illustrated in the drawings. On the surface of the semiconductor substrate W, a plurality of light emitting devices 100 are formed in an array in the matrix direction. The planar region of one light emitting device 100 has a substantially rectangular shape and each light emitting device 100 is divided into a lattice shape by a cut region 120 defined by a scribing line having a constant spacing S, .

After the formation of the light emitting element is completed, a resist pattern is formed on the surface of the semiconductor substrate W (S102). As shown in FIG. 2B, the resist pattern 130 is processed such that a cut region 120 defined by a scribe line or the like on the surface of the semiconductor substrate W is exposed. The processing of the resist pattern 130 is performed by a photolithography process.

Next, fine grooves are formed on the surface of the semiconductor substrate W (S104). A minute groove (hereinafter referred to as a fine groove or a groove on the front surface side) 140 having a predetermined depth is formed on the surface of the semiconductor substrate W using the resist pattern 130 as a mask, as shown in FIG. 2 (C) . These grooves can be formed by, for example, dry etching, and are preferably formed by anisotropic plasma etching (reactive ion etching), which is an anisotropic dry etching. The width Sa of the fine grooves 140 is substantially equal to the width of the openings formed in the resist pattern 130 and the width Sa of the fine grooves 140 is in the range of several micrometers to several tens of micrometers. Preferably the width Sa is from about 3 [mu] m to about 15 [mu] m. The depth is, for example, about 10 탆 to 100 탆, and is at least deeper than the depth at which functional devices such as a light emitting device are formed. Preferably, the depth of the fine grooves 140 is about 30 占 퐉 to about 80 占 퐉. When the fine grooves 140 are formed by a general dicing blade, the interval S between the cut regions 120 is about 40 to 80 占 퐉 as the sum of the margin width considering the groove width of the dicing blade itself and the amount of chipping It grows. On the other hand, when the fine grooves 140 are formed by a semiconductor process, not only the groove width itself is narrow, but also the margin width for cutting can be narrower than the margin width when the dicing blade is used. In other words, 120 can be made small. Therefore, the number of semiconductor pieces can be increased by disposing the light emitting elements on the wafer at a high density. In the present embodiment, the term "surface side" refers to a surface side on which a functional element such as a light emitting element is formed, and "back side" refers to a surface side opposite to the "surface side".

Next, the resist pattern is peeled off (S106). As shown in FIG. 2D, when the resist pattern 130 is peeled from the surface of the semiconductor substrate, the fine grooves 140 formed along the cut regions 120 are exposed on the surface. Details of the shape of the fine grooves 140 will be described later.

Next, an ultraviolet curable dicing tape is stuck (S108). As shown in Fig. 3 (A), a dicing tape 160 having an adhesive layer is attached to the light emitting device side. Next, half dicing is performed along the fine grooves 140 by the dicing blade from the back side of the substrate (S110). The positioning of the dicing blade is performed by arranging an infrared camera on the back surface of the substrate to indirectly detect the fine grooves 140 by passing through the substrate or by arranging a camera on the substrate surface side to directly detect the position of the fine grooves 140 Or other known methods can be used. By such positioning, half dicing is performed by a dicing blade as shown in Fig. 3 (B), and grooves 170 are formed on the back side of the semiconductor substrate. The groove 170 has a depth reaching the fine groove 140 formed on the surface of the semiconductor substrate. Here, the fine grooves 140 are formed on the back side of the dicing blade with a narrower width than the grooves 170. This is because if the fine grooves 140 are formed to have a narrower width than the grooves 170 on the back side This is because the number of semiconductor chips that can be obtained from one wafer can be increased as compared with the case where the semiconductor substrate is cut only by the dicing blade. 2C can be formed from the surface to the back surface of the semiconductor substrate, it is necessary to form the grooves on the back side by using the dicing blade in the beginning However, it is not easy to form fine grooves at such depths. Therefore, as shown in Fig. 3 (B), the half dicing from the back surface by the dicing blade is combined.

Next, the dicing tape is irradiated with ultraviolet rays (UV), and the expanding tape is attached (S112). The ultraviolet ray 180 is irradiated on the dicing tape 160 to cure the adhesive layer as shown in Fig. 3 (C). Thereafter, the expansive tape 190 is attached to the back surface of the semiconductor substrate.

Next, the dicing tape is peeled off and the expansive tape is irradiated with ultraviolet rays (S114). As shown in Fig. 3 (D), the dicing tape 160 is peeled from the surface of the semiconductor substrate. In addition, the ultraviolet rays 200 are irradiated to the expanding tape 190 on the back surface of the substrate to cure the adhesive layer. The expanding tape 190 has a stretchability in the base material and expands the tape so as to facilitate picking up of the piece of semiconductor material after dicing.

Next, picking and die mounting of the individualized semiconductor pieces are performed (S116). The semiconductor piece 210 picked up from the expanding tape 190 is fixed on the circuit board 230 through the fixing member 220 such as an adhesive or a conductive paste such as solder, It is mounted.

Next, details of the half dicing by the dicing blade will be described. Fig. 5 shows a state in which the enlarged cross-sectional view when half dicing is performed by the dicing blade shown in Fig. 3 (B) is vertically inverted. Although FIG. 3 emphasizes the light emitting device 100 formed on the surface of the substrate, FIG. 5 does not show the light emitting device on the surface of the substrate, but the light emitting device is formed on the surface of the substrate do.

5, the dicing blade 300 cuts the semiconductor substrate W from the back surface while rotating along the fine grooves 140 to form the grooves 170 in the semiconductor substrate W. As shown in Fig. The dicing blade 300 is, for example, a disk-shaped cutting member. In this example, the tip end portion has a constant thickness, but the tip end portion may be a dicing blade having a tapered end. The groove 170 formed by the dicing blade 300 has a width substantially equal to the thickness of the dicing blade 300 and the groove 170 is processed to a depth reaching the fine grooves 140 . The dicing blade 300 is aligned in a direction parallel to the back surface of the semiconductor substrate W from the outside of the semiconductor substrate W. The stepped portion 800 formed by the step formed at the connecting portion between the groove 170 and the fine groove 140 by moving a predetermined amount in the direction Y perpendicular to the back surface of the semiconductor substrate W, Alignment in the thickness direction of the semiconductor substrate W is performed so as to have a desired thickness T in the Y direction. At least one of the dicing blade 300 or the semiconductor substrate W is pressed against the semiconductor substrate W in a state in which the dicing blade 300 is rotated after positioning on the outside of the semiconductor substrate W, The grooves 170 are formed in the semiconductor substrate W. As shown in FIG. The stepped portion 800 is a portion between the step formed at the connection portion between the groove 170 and the fine groove 140 and the surface of the semiconductor substrate W. In other words, 140 in the width direction.

When the half dicing by the dicing blade 300 is performed, the dicing tape 160 is attached to the surface of the substrate. The dicing tape 160 includes a tape substrate 162 and an adhesive layer 164 stacked thereon. The adhesive layer 164 is made of an ultraviolet curable resin and has a property of having a constant viscosity or viscosity until irradiated with ultraviolet rays, and having a property of being cured when ultraviolet rays are irradiated to lose its adhesiveness. Therefore, when the dicing tape 160 is attached, the adhesive layer 164 adheres to the surface of the substrate including the fine grooves 140 and holds them so that the semiconductor pieces do not come off after dicing.

5, during the cutting of the semiconductor substrate W, the groove 170 (see FIG. 5) is formed by the rotation of the dicing blade 300 and the relative movement of the dicing blade 300 and the semiconductor substrate W, The vibration B and the cutting pressure P are applied to the semiconductor substrate W through the inner wall of the semiconductor substrate W. When the semiconductor substrate W is pressed in the Y direction by the cutting pressure P, the viscous adhesive layer 164 flows and enters the fine grooves 140. In addition, vibration (B) is transmitted to the vicinity of the fine grooves (140), thereby promoting the flow of the adhesive layer (164). In the cutting with the dicing blade 300, a cutting water stream (jet flow) mixed with cutting chips is supplied to the grooves 170, and the cutting grooves 170 are formed in the direction in which the fine grooves 140 are expanded Since the pressure P1 is received, the entry of the adhesive layer 164 can be further promoted. As a result, in the case of a fine groove having no net taper shape in this embodiment described later, for example, the adhesive layer 164 may enter the fine groove 140 having a width of about 5 占 퐉 at an entry depth of about 10 占 퐉 . Therefore, in this embodiment, even if the groove width on the front surface side is narrower than the groove width on the back surface side for improving the number of semiconductor pieces obtained or the like, the groove is formed by the cutting member , A micro trench having a net taper shape to be described later is formed although the number of semiconductor chips obtained is slightly sacrificed.

In the cutting line A1 on which the dicing is completed, since the fine grooves 140 are subjected to a pressure that narrows in the width direction during cutting of the side cutting line A2, It is considered that the layer 164 is more likely to enter the inside. It is considered that the amount of the adhesive layer 164 entering the fine grooves 140 is relatively small because the adhesive layer 164 is only attached to the cutting line A3 on the opposite side before cutting.

When the half dicing by the dicing blade 300 is completed, the expanding tape 190 is attached to the back surface of the substrate, and then the ultraviolet ray 180 is irradiated to the dicing tape 160. Next, The adhesive layer 164 irradiated with ultraviolet rays is cured and its adhesive force is lost (Fig. 3 (C)). Next, the dicing tape is peeled from the substrate surface. 6 is a cross-sectional view for explaining the remaining adhesive layer when peeling the dicing tape. An expanding tape 190 adhered to the back surface of the substrate, a tape base material 192 and an adhesive layer 194 laminated thereon. The cut semiconductor piece is held by an adhesive layer 194.

When the dicing tape 160 and the substrate surface are peeled off, the adhesive layer 164a that has entered the fine grooves 140 has advanced to a deep position, so that a part of the adhesive layer 164a is not sufficiently irradiated with ultraviolet rays, . The uncured adhesive layer 164 is cut off when the adhesive layer 164 is peeled from the surface of the substrate and the adhesive layer 164a is separated from the fine grooves 140. As a result, Or may remain on the surface of the substrate again. In addition, even in the cured state, the adhesive layer 164a is deeply penetrated into the narrow fine grooves, so that the adhesive layer 164a can remain torn due to the stress at the time of peeling. If the remaining adhesive layer 164b is reattached to the surface of the light emitting element, the light amount of the light emitting element is lowered and the light emitting element becomes defective and the yield is lowered. Further, even in the case of a semiconductor chip other than the light emitting element, other adverse influences are assumed, such as the appearance of the adhesive layer 164b being judged to be defective due to the presence of the adhesive layer 164b. For this reason, it is not preferable that the adhesive layers 164a and 164b remain on the surface of the substrate at the time of peeling the dicing tape. In this embodiment, by changing the shape of fine grooves formed on the surface of the substrate to a net taper shape as described later, it is possible to prevent the adhesive layer from remaining in the fine grooves or the surface of the substrate at the time of peeling the dicing tape.

When the plurality of light emitting devices 100 are formed in a mesa shape, the light emitting device 100 forms a convex portion, the space between the light emitting device 100 and the other light emitting device 100 becomes a concave portion, In many cases, fine grooves 140 are formed in the concave portions. In such a configuration, not only the convex portion but also the entrance portion of the fine groove 140 formed in the concave portion is pasted so as to follow the adhesive layer 164 so as to prevent the cutting water mixed with the cut powder from entering the substrate surface side . However, in order to follow the adhesive layer 164 at the entrance of the fine grooves 140, a dicing tape having a pressure-sensitive adhesive layer 164 of a sufficient thickness is required, so that the pressure- It becomes easier to enter the deeper part of the groove 140. Therefore, by applying the net tapered fine grooves of the present embodiment described below under the condition that the adhesive layer 164 easily penetrates deeply into the fine grooves 140, a higher effect on the remaining of the adhesive layer 164 Is obtained.

Further, when the fine grooves perpendicular to the surface of the semiconductor substrate are formed, when the pressure-sensitive adhesive layer 164 penetrates deeper than the groove width of the fine grooves, that is, in the pressure- 164a are longer in length than in the case where the adhesive layer 164 is not elongated in length, it is easy to be torn by the stress applied to the root portion of the adhesive layer 164a in the fine groove when peeling off the adhesive layer 164 It can be thought that it will be easy to remain. Therefore, in the manufacturing conditions such as the width of the fine grooves and the thickness of the adhesive layer 164 in which the shape of the adhesive layer 164a in the fine grooves becomes longer when the net taper shape of this embodiment is not applied , And by applying the net tapered fine grooves of this embodiment described later, a higher effect is obtained for the remaining of the adhesive layer 164.

Next, the shape of the fine groove according to the embodiment of the present invention will be described. FIG. 7A is a cross-sectional view showing the shape of the first fine groove in this embodiment, and FIG. 7B is a view for explaining ultraviolet irradiation on an adhesive layer which has entered the fine groove in FIG. 7A .

As shown in Fig. 7A, the fine grooves 400 of the present embodiment are formed so that the width Sa2 of the bottom portion of the depth D from the opening width Sa1 of the substrate surface (Sa1 > Sa2) (Hereinafter referred to as a net taper shape) that is inclined so as to narrow the slope Sa1. In other words, the fine grooves 400 have a shape in which the width gradually narrows from the opening width Sa1 of the surface of the semiconductor substrate W to the depth D. [ Further, the side surfaces 402 and 404 are not straight, but have a shape in which the lower side extends downward at a steep angle than the upper side of the groove. This groove shape is formed by changing the etching conditions during the formation of the groove (details will be described later). The opening width Sa1 is, for example, about several mu m to several ten mu m. The depth D is greater than the depth at which a circuit such as a light emitting element is formed and is formed by a difference in width between the groove 170 and the fine groove 400 when the groove 170 is formed from the back side. (800) is not broken. If the fine groove 400 is too shallow, the stepped portion 800 may be damaged by the stress caused by the dicing blade 300 when the groove 170 is formed from the back side. Therefore, . On the other hand, when the fine grooves 400 are excessively deep, the strength of the semiconductor substrate is weakened by the deep grooves. Therefore, compared with the case where the handling of the semiconductor substrate W in the process after the formation of the fine grooves 140 is shallow It gets harder. Therefore, it is preferable not to form it deeper than necessary. The fine grooves 400 are preferably formed by anisotropic dry etching, and the inclination angles of the side surfaces 402 and 404 can be appropriately selected by changing the shape and etching conditions of the photoresist. 7A is a shape in which there is no portion (corner portion) in which the angle of the side surface of the groove changes discontinuously at the boundary portion between the first groove portion and the second groove portion, The boundary between the first groove portion on the side of the lower side and the second groove portion on the lower side is not a definite shape. However, since the angle between the upper side and the lower side of the fine grooves 400 is different from each other, the first groove portion gradually narrows in width from the substrate surface toward the back surface, and the groove formed below the first groove portion Side grooves (fine grooves) including a second groove portion extending downward at a steeper angle than the angle of the first groove portion without being wider than the width of the lowermost portion of the first groove portion .

The groove 170 of the cuff width Sb is formed by the cutting of the dicing blade 300 and the groove 170 extends to the fine groove 400 as shown in Fig. The width of the groove 170 (cuff width Sb) is, for example, about 20 to 60 mu m. A part of the adhesive layer 164 enters the net tapered fine grooves 400 by the stress such as pressure or vibration from the dicing blade 300 and the adhesive layer 164 is pressed against the surface of the substrate after the application of the expanding tape. The dicing tape 160 is irradiated by the ultraviolet ray 180. [ At this time, the ultraviolet rays 180 are not shielded by the semiconductor substrate W and the adhesive layer 164a in the fine grooves 400 is sufficiently irradiated to form the fine grooves 400 The adhesive layer 164a in the adhesive layer 400 tends to be hardened. As a result, when the dicing tape 160 and the surface of the substrate are peeled off, the adhesive layer 164a in the fine groove 400 has the same opening width as that of the fine groove 400, And is easily detached from the substrate surface and the fine grooves 400, so that the adhesive layer is restrained from reattaching to the substrate surface. In addition, even if the pressure-sensitive adhesive layer 164a press-fitted into the fine grooves 400 is not cured, the net taper shape of the fine grooves 400 is inclined in the groove shape, 164a.

7C is a cross-sectional view showing the shape of the second fine groove of the present embodiment. The second fine grooves 410 are formed by the groove portions of the opposing side surfaces 412 and 414 inclined forward from the opening width Sa1 of the substrate surface to the width Sa2 in the middle of the depth D, ) To the bottom portion of the opposite side surfaces 412a, 414a. That is, the first groove portion gradually narrows in width from the substrate surface toward the back surface, and the groove portion formed in the lower side of the first groove portion, does not become wider than the width of the lowermost portion of the first groove portion, And a second groove portion extending downward at a steeper angle than the angle of the first groove portion. This shape is formed, for example, by changing the etching conditions during the formation of the grooves. 7C, the shape of the portion at which the angle of the side surface of the groove changes discontinuously at the boundary portion between the first groove portion and the second groove portion Part) does not exist. The depth D of the inclined groove portion by the side surfaces 412 and 414 is preferably deeper than the depth at which the adhesive layer 164 enters when the dicing tape 160 is pasted. Since the width of the groove portion deeper than the depth D is narrower than the groove width of the net tapered shape, the ratio of the fluctuation of groove width due to vibration or stress of the dicing blade becomes larger than that of the net tapered groove portion. Therefore, when the adhesive layer 164 has already penetrated into the groove portion deeper than the depth D at the time when the dicing tape 160 is attached, the adhesive layer 164 is adhered to a deeper portion of the groove by vibration or stress of the dicing blade Layer 164 can penetrate. Therefore, the depth D is preferably deeper than the depth at which the adhesive layer 164 enters in the state where the dicing tape 160 is pasted.

It is preferable that the depth D is a depth capable of maintaining a state in which the adhesive layer 164 does not enter the groove portion deeper than the depth D after the back side groove is formed by the dicing blade . Preferably, the depth D is 10 mu m or more. This is because, if the adhesive layer 164 penetrates into the groove portion deeper than the depth D, it is easier to remain at the time of peeling. The other conditions such as the depth of the entire fine grooves are shown in Fig. 7 (A).

Here, as another embodiment of Fig. 7C, the depth of the penetration of the adhesive layer is within 10 占 퐉. Therefore, under the condition that the depth D is 10 占 퐉 or more, The groove portion may have a shape in which the width of the second groove portion gradually widens from the depth D toward the bottom of the second fine groove 410.

Here, if the fine grooves are to be formed deeply only by the net taper shape as shown in Fig. 7A, the opening Sa1 needs to be widened. Further, when the fine grooves 400 are formed deeply only by the net taper shape with the aperture Sa1 narrow, the taper angle becomes a steep angle, so that the adhesive layer 164 tends to remain in the fine grooves 400. [ On the other hand, in the shape of FIG. 7 (C), the width of the opening Sa1 is easily maintained in the fine groove and the fine groove with a desired depth is easily formed while keeping the adhesive layer hardly remaining. It is possible to form the grooves 170 having a width larger than the width of the second fine grooves 410 from the back side as compared with the case where the depths of the fine grooves are shallow, .

Further, when the fine grooves perpendicular to the surface of the semiconductor substrate are formed, when the pressure-sensitive adhesive layer 164 penetrates deeper than the groove width of the fine grooves, that is, in the pressure- 164a of the adhesive layer 164 is longer than the case where the adhesive layer 164 is not longitudinally elongated, the adhesive layer 164 easily remains due to the stress applied to the root portion of the adhesive layer 164a in the fine groove Loses. Therefore, in the case of assuming that a vertical fine groove shape is formed, the width of the fine groove, the thickness of the adhesive layer 164, and the like, in which the shape of the adhesive layer 164a entering into the fine groove becomes longer, It is preferable that the inlet portions of the fine grooves have a net taper shape as shown in Fig. 7 (C). That is, in the case where it is assumed that the groove width of the groove portion located below the pure tapered groove portion is formed with the groove width as a whole of the second fine groove 410, In this case, when the inlet portion of the groove is formed in a net taper shape, a higher effect is obtained for the remaining of the adhesive layer 164.

7C, when the groove 170 of the cuff width Sb is formed by cutting of the dicing blade 300, as shown in Fig. 7D, the grooves 170 Is formed in a shape continuing to the second fine groove (410). The portion 164a of the adhesive layer 164 enters the second fine groove 410 and the groove portion of the net tapered shape of the second fine groove 410 The adhesive layer 164a in the second fine grooves 410 is sufficiently irradiated with ultraviolet rays to be easily cured. This makes it possible to prevent the adhesive layer from remaining on the second fine grooves 410 or the substrate surface when the dicing tape is peeled off. In addition, since the side surface of the second fine groove 410 is inclined, even if the pressure sensitive adhesive layer 164a press-fitted into the second fine groove 410 is not cured, It encourages.

According to the present embodiment, the fine grooves 400 and 410 include a groove portion of a net taper shape at least such that the opening width of the substrate surface becomes narrow toward the bottom portion. Therefore, the adhesive layer of the dicing tape The adhesive layer in the fine grooves can be irradiated with ultraviolet rays to harden the adhesive layer and to easily lose its adhesiveness even when it enters the fine grooves. In addition, since the tapered shape has a net taper shape, when the tape is peeled off from the dicing tape, the adhesive layer is inhibited from being broken on the way as compared with the case where the tape is not in a net taper shape. 9A to be described later, the side surface of the fine grooves is not a straight line, but the side surface of the lower side has a steep angle more steeper than the side of the upper side so that the width of the entrance portion of the fine grooves is the same 9A, it is possible to form a groove that is deeper than the shape shown in Fig. 9A. If the grooves 170 are formed from the back side, the stress caused by the dicing blades makes it difficult for the stepped portions 800 to be broken. Therefore, when the shape of Fig. 9A is compared with the shapes of Figs. 7A and 7C, the shape of Fig. 7A and Fig. It is easy to combat breakage.

7A to 7D show a configuration in which the opening width Sa1 of the substrate surface is narrower than the width of the groove 170. This is because the opening width Sa1 of the substrate surface, Is smaller than the width of the groove 170, the number of semiconductor chips obtained can be increased as compared with the method of full dicing as the width of the groove 170. Here, in general, in order to increase the number of semiconductor pieces obtained, the grooves on the surface side are formed to have grooves having a narrower width and a vertical shape than those having grooves on the surface side with isotropic etching or dicing blade However, if anisotropic dry etching is used to form a groove having a narrow width and a vertical shape, it is not preferable from the viewpoint of the remaining of the adhesive layer. On the other hand, paying attention to the residual of the adhesive layer, it is more preferable to form the grooves on the surface side by isotropic etching or the like in which the openings of the fine grooves are not vertically formed by anisotropic dry etching, However, it is difficult to form a groove with a narrow width and a deep groove by isotropic etching. Thus, in this embodiment, even in the case of anisotropic dry etching, by forming the fine grooves having the shapes shown in Figs. 7A to 7D, it is possible to improve both the number of semiconductor pieces obtained and the residual pressure of the adhesive layer.

Figs. 8A and 8B are comparative examples when the fine grooves are machined into an inverted taper shape. Fig. 8A, the fine grooves 500 are formed in a so-called reverse tapered shape having an inclined side face 502, 504 opposed so that the width Sa2 of the bottom portion is larger than the opening width Sa1 As shown in Fig. The shape of the width of the bottom side can be adjusted by controlling the flow rate of the etching gas (Cl 2 or the like) contained in the etching gas and the gas for forming the protective film for protecting the side wall, even if the isotropic etching or the anisotropic dry etching is used C4F8, etc.) to be processed in an inverse taper shape. The width of the opening width Sa1 is narrowed when the portion 164a of the adhesive layer 164 enters the reverse tapered fine groove 500 as shown in Fig. 180 are easily shielded by the semiconductor substrate W and ultraviolet rays are not sufficiently irradiated to the periphery 165 (fill portion in the figure) of the pressure-sensitive adhesive layer 164a so that any uncured adhesive layer 165 ) Is easy to leave a lot. Therefore, when peeling off the dicing tape, the adhesive layer 165 having adhesiveness is liable to be broken in the middle as compared with the case of the pure tapered shape, so that it remains in the fine grooves or is reattached to the surface of the substrate. In addition, since it is an inverted tapered shape, the hardened adhesive layer 164 press-fitted into the fine grooves 500 is difficult to smoothly escape.

8C and 8D are comparative examples when the fine grooves are processed into a vertical shape. As shown in Fig. 8C, the fine grooves 510 are processed into so-called vertical grooves including opposed side surfaces 512, 514 whose opening width Sa1 on the surface of the substrate is vertical. This shape is formed when general anisotropic dry etching is employed. As shown in FIG. 8D, the adhesive layer 164a that has entered the vertical fine groove 510 deepens into the inside of the fine groove width Sa1. Therefore, in the case of a pure taper shape The entirety of the adhesive layer 164a is not sufficiently irradiated by the ultraviolet ray 180 and a part of the adhesive layer 166 of the periphery thereof is liable to be uncured. 8 (A), the adhesive layer 166 is formed on the surface of the fine grooves 510 at the time of peeling the dicing tape, Or on the surface of the substrate, or can be reattached.

9A is a comparative example in which the fine grooves 520 are processed into a net taper shape having only straight side surfaces 522 and 524. For example, in this anisotropic dry etching, the balance between the flow rate of the etching gas (Cl2 or the like) contained in the etching gas and the flow rate of the protective film forming gas (C4F8 or the like) To be processed into a shape. 9A, the adhesive layer 164a that has entered the net tapered fine grooves 520 has a larger total thickness of the adhesive layer 164a than the shapes of FIGS. 8A and 8C, The ultraviolet rays 180 are easily irradiated. Therefore, an uncured adhesive layer is hardly generated after the ultraviolet ray 180 is irradiated, and the adhesive layer remains on the fine grooves 520 or the substrate surface at the time of peeling of the dicing tape, or becomes difficult to reattach. However, the shape of FIG. 9A differs from the shape of FIG. 7A and FIG. 7C, and the side surfaces 522 and 524 of the fine grooves 520 are formed of straight side surfaces with constant angles Therefore, it is impossible to form a groove that is deeper than (A) or (C) in Fig. 7 by comparing the width Sa1 of the inlet of the fine groove under the same conditions. When the grooves 170 are formed from the back side as described above, the stepped portions 800 are likely to be damaged by the stress caused by the dicing blade. Therefore, when the shape of Fig. 9A is compared with the shapes of Figs. 7A and 7C, the shape of Fig. 7A and Fig. It is easy to combat breakage.

9B shows a state in which the fine grooves 530 include first groove portions 532 and 534 that gradually narrow in width from the substrate surface toward the back surface and second groove portions 532 and 534 which are formed in the groove portion And includes second groove portions 532a and 534a which are not wider than the lowermost width of the first groove portion and extend downward at a steeper angle than the angle of the first groove portion. This shape can be realized, for example, by forming the groove portion on the upper side corresponding to the first groove portion by isotropic etching and forming the groove portion on the lower side corresponding to the second groove portion by anisotropic dry etching. 9B, since the entrance portion of the fine groove 530 has a net taper shape as in Fig. 9A, as compared with the shape of Figs. 8A and 8C, It is difficult to remain on the fine grooves 530 or the surface of the substrate. 9A, the deeper grooves can be formed even if the width Sa1 of the entrance portion of the fine grooves 530 is the same, so that breakage of the stepped portion 800 is suppressed. However, in the shape of Fig. 9B, the fine grooves 530 have edges on their side surfaces. 7A and 7C, the angle of the side surfaces 532, 532a and 534 and 534a of the groove is discontinuously changed between the first groove portion and the second groove portion When the adhesive layer enters the second groove portion due to the presence of the portion (corner portion), the ultraviolet ray 180 is hardly irradiated to the entirety of the adhesive layer, and an uncured adhesive layer is likely to be generated. In addition, when the dicing tape 160 and the surface of the substrate are separated from each other, since the portions (corner portions) where the angles of the side surfaces 532, 532a and 534 and 534a of the grooves discontinuously exist exist, The adhesive layer 164a which has penetrated to the portion of the adhesive layer 164a is caught by the corner portion or is easily torn off, thereby promoting the remnant of the adhesive layer 164a. Therefore, when the shape of FIG. 9 (B) is compared with the shape of FIG. 7 (A) or (C), the shape of FIG. 7 (A) It is easy to combat breakage.

9C shows a state in which the fine grooves 540 have a first groove portion composed of straight side surfaces 542 and 544 in which the width gradually narrows from the substrate surface toward the back surface, And a second groove portion composed of side surfaces 542a and 544a extending substantially vertically downward. For example, such a shape can be obtained by forming only a portion corresponding to the first groove portion using only the tip portion of the dicing blade having a sharp tip end portion and forming a portion corresponding to the second groove portion with a thin dicing blade Can be realized. 9 (C), the fine grooves 540 have edges on their side surfaces. In other words, as in the case of the shape shown in Fig. 9B described above, there are portions (corner portions) where the angles of the side surfaces 542, 542a and 544, 544a of the fine grooves discontinuously change, 7 (A) and 7 (C) are compared with each other, the shapes of FIGS. 7 (A) and 7 (C) are easier to both suppress the remaining adhesive layer and suppress breakage of the stepped portion.

Next, a method of manufacturing the fine grooves of this embodiment will be described. Fig. 10 is a cross-sectional view showing the steps of the method of manufacturing the fine grooves shown in Figs. 7 (A) and 7 (C). 10A, a photoresist 600 is applied to the surface of a semiconductor substrate W (GaAs substrate) on which a plurality of light emitting elements are formed. The photoresist 600 is, for example, an i-line resist with a viscosity of 100 cpi and is formed to a thickness of about several micrometers. An opening 610 is formed in the photoresist 600 by using a known photolithography process, for example, an i-line stepper, and a developer of TMAH 2.38%. The opening 610 is formed to expose the cut region 120 as described in Fig. 2A.

Next, as shown in FIG. 10B, the semiconductor substrate W is anisotropically dry-etched using the photoresist 600 having the opening 610 formed therein as an etching mask. As an example, an inductively coupled plasma (ICP) is used as a reactive ion etching (RIE) device. As the etching gas, a protective film 630 is formed on the sidewall of the trench 620 simultaneously with the etching by adding a CF gas. Radicals and ions are generated by the plasma of the reaction gas, but the sidewalls of the trenches 620 are attacked only by the radicals, and the bottoms are attacked by both the radicals and the ions, and thus the anisotropic etching is achieved. Here, the etching is performed under the condition that the tapered grooves are formed by adjusting the etching conditions such as the output of the etching apparatus, the flow rate of the gas, and the time. For example, by increasing the flow rate of the etching gas (Cl 2 or the like) contained in the etching gas or reducing the flow rate of the CF-based gas (C 4 F 8 or the like), which is a gas for forming the side wall protective film, Since the protective film 630 is thinned, the angle of the side wall of the groove becomes a steep angle with respect to the depth direction (i.e., becomes an angle close to vertical). On the contrary, by reducing the flow rate of the etching gas (Cl2 or the like) contained in the etching gas or increasing the flow rate of the CF-based gas (C4F8 or the like) which is the gas for forming the side wall protective film, 630 are thick, the angle of the side wall of the groove becomes a gentle angle with respect to the depth direction. As an example, etching conditions are as follows: power of ICP of 500 W, bias power of 50 W, pressure of 3 Pa, Cl 2 = 150 sccm, BCl 3 = 50 sccm, C 4 F 8 = 50 sccm as etching gas, substrate temperature of 20 캜 and etching time of 20 minutes.

Next, as shown in Fig. 10 (C), the etching conditions are switched so that the angle becomes a steep angle than the angle of the net taper formed in Fig. 10 (B). For example, by increasing the flow rate of the etching gas (Cl2 or the like) contained in the etching gas or reducing the flow rate of the CF-based gas (C4F8 or the like), which is a gas for forming the side wall protective film, So that the groove portion 640 is formed at a steeper angle than the angle of the side wall of the groove 620 formed in the groove 620. [ As an example, etching conditions are as follows: a power of 500 W for inductively coupled plasma (ICP), a bias power of 50 W, a pressure of 3 Pa, Cl 2 = 200 sccm, BCl 3 = 50 sccm, C 4 F 8 = 35 sccm as an etching gas, The thickness of the sidewall protective film 630 tends to be thinner at the bottom side of the groove than at the top side of the groove so that the etching strength is strengthened in the middle, 630 are scraped off and the side wall is easily exposed. As a result, the groove width on the bottom side of the already formed groove becomes slightly wider and the groove extends downward. On the other hand, since the thick side wall protecting film 630 is attached to the upper side of the already formed groove, if the etching conditions are not extremely strong, the side wall protecting film 630 is not cut until the side wall is exposed, (Inlet portion) remains unchanged.

In the case of reducing the flow rate of the CF-based gas (C4F8 or the like) which is the gas for forming the side wall protective film, it is desirable to reduce the flow rate within a range where the gas is not completely stopped. This is because if the gas for forming the sidewall protective film is stopped, the etching strength in the sidewall direction becomes excessively large, and a groove portion that widens toward the bottom of the fine groove is formed. When the groove portion having a larger width toward the lower side of the fine groove is formed in this manner, if the adhesive layer 164a penetrates the groove portion, the ultraviolet ray 180 is hardly irradiated to the entirety of the adhesive layer 164a, The adhesive layer 164a tends to remain as in the case of (A) of Fig. 5, when grooves are formed from the back surface of the substrate with the rotating cutting member such as the dicing blade with respect to the fine grooves, for example, the grooves are formed in the fine grooves with a width of about 10 mu m The pressure-sensitive adhesive layer may enter at a depth, and the pressure-sensitive adhesive layer may enter the pressure sensitive adhesive layer to a depth equal to or greater than a predetermined value. Therefore, in the case where there is no particular reason for forming the groove portion whose width widens toward the lower side of the fine groove, such a groove portion is not formed from the viewpoint of the remaining suppression of the pressure-sensitive adhesive layer. In addition, when the etching strength in the direction of the side wall is excessively increased by stopping the gas for forming the side wall protective film, the side wall protective film 630 may be scraped off until the side wall of the upper side (inlet portion) of the groove is exposed. This is thought to be caused by the fact that the inlet portion of the fine grooves has a higher concentration of fresh etching gas than the bottom portion. In this case, the upper side of the groove is etched so as to be wider in the width direction, which may affect the formation region of the element in some cases. Therefore, it is preferable to switch to an etching intensity within such a range that the side wall on the upper side of the groove is not exposed.

10 (C), after the formation of the fine grooves is completed, the photoresist 600 is removed by oxygen ashing as shown in FIG. 10 (D). Thus, fine grooves 400 and 410 shown in Figs. 7A and 7C are obtained.

As described above, in the method of manufacturing a fine groove according to the present embodiment, formation of fine grooves is started at a first etching intensity at which the width of the fine grooves gradually narrows toward the depth direction, and during the formation of the fine grooves, The dry etching condition is changed with the second etching intensity extending downward without widening the width of the entrance portion of the groove on the surface side as the strong etching strength so as to have a portion where the width of the groove is widened from the surface of the substrate toward the back surface So as to form a fine groove. Since the etching is performed at the first etching intensity at which the width of the fine grooves gradually narrows toward the depth direction, Grooves are formed. Further, during the formation of the fine grooves, the strength of the dry etching is strengthened by the second etching intensity extending downward without increasing the width of the entrance portion of the fine grooves, and the fine etching is performed without fine portions Grooves are formed so that fine grooves are formed without edge portions as shown in Fig. 9 (C). Further, deeper fine grooves are formed even when the widths of the entrance portions of the fine grooves are the same, as compared with a pure tapered shape having only linear side surfaces as shown in Fig. 9 (A).

The manufacturing method in this embodiment is merely an example and is not necessarily limited to the manufacturing process shown in Fig. For example, although the opening 610 of the photoresist 600 formed in FIG. 10A has an opening side perpendicular to the surface of the substrate, the opening 610 shown in FIGS. In order to facilitate formation of the shape, the opening may be gradually widened from the substrate surface upward. When the photoresist having such a shape is used, the etching range is gradually widened from the thin portion to the thick portion of the photoresist, so that a pure taper shape can be easily formed. In addition, it is not necessary to switch the etching conditions once, and the etching may be performed a plurality of times as needed, for example, the etching strength is gradually increased.

Next, breakage of the stepped portion formed by the difference between the widths of the fine grooves and the grooves on the back side will be described. 11A is an enlarged view of a step portion shown in Fig. 11A, Fig. 11B is an enlarged view of a stepped portion shown in Fig. 11A, Fig. 11 (C) shows breakage of the stepped portion.

A plurality of light emitting devices 100 are formed on the surface of the semiconductor substrate W as described above and each light emitting device 100 is formed by a cut region 120 defined by a scribing line or the like of an interval S Respectively. The cut region 120 is formed with fine grooves 140 (vertical grooves shown in FIG. 8 (C)) of width Sa by anisotropic dry etching. The groove 170 having a width substantially equal to the cuff width Sb is formed in the semiconductor substrate W by cutting the dicing blade 300 of the cuff width Sb from the back surface of the semiconductor substrate W while rotating the dicing blade 300. [ Since the cuff width Sb is larger than the width Sa of the fine grooves 140, a difference between the cuff width Sb and the width Sa is formed in the cut region 120 when the groove 170 is formed, The cantilever beam-shaped stepped portion 800 of the thickness T is formed by the difference in the positions of the fine grooves 140 and the side surfaces of the grooves 170. [ If the center of the dicing blade 300 and the center of the fine grooves 140 are completely aligned, the length of the step portion 800 extending in the transverse direction is (Sb-Sa) / 2.

A force F is applied to the stepped portion 800 by pressing the semiconductor substrate W in the Y direction by the flat surface of the tip end portion of the dicing blade 300 when the cutting with the dicing blade 300 is performed , So that the stress is concentrated on the corner portion C of the step portion 800. [ When the stress on the corner C exceeds the break stress of the wafer, breakage (cracking, cracking, picking, etc.) of the stepped portion 800 occurs as shown in Fig. 11 (C). Particularly, since the compound semiconductor substrate such as GaAs has a weaker strength than the silicon substrate, breakage is likely to occur in the stepped portion 800. If the breakage of the stepped portion 800 occurs, a margin M for cutting the stepped portion 800 must be ensured. This means that the interval S of the cutout region 120 is equal to or larger than the margin M, Which means that the number of semiconductor chips obtained is reduced. Therefore, it is preferable to suppress breakage of the stepped portion 800.

The following three factors are considered to be factors that are highly influential on the stress causing the step portion 800 to break. First, the shape of the tip of the dicing blade, second, the thickness T of the step 800, and third, the size of the step in the step, that is, the case of using the dicing blade 300 of any given thickness Is the positional displacement of the fine groove (140) and the groove (170). As in the present embodiment, formation of the fine grooves is started with the first etching intensity gradually narrowing toward the depth direction of the fine grooves, and during the formation of the fine grooves, as the etching strength stronger than the first etching intensity, Since deeper fine grooves are formed as compared with the case where fine grooves are formed only by the first etching intensity by changing the conditions of the dry etching with the second etching intensity extending downward without increasing the width of the entrance portion of the step portion, The thickness T of the base plate 800 becomes thick. Therefore, breakage of the stepped portion is suppressed even if the shape and positional shift amount of the tip portion of the dicing blade are the same.

Next, an application example of the embodiment of the present invention will be described. In this application example, the semiconductor substrate is divided (divided) by grinding (back-grinding) from the back surface of the semiconductor substrate to the fine grooves on the surface side of the semiconductor substrate without forming the grooves 170 on the back surface side in the above- do. More specifically, a tape for back grinding is affixed to the surface of the substrate in place of the dicing tape attached in step S108 in Fig. The dicing tape may be directly used as a tape for back grinding. Then, back grinding is performed to reach the surface-side fine grooves instead of half dicing in step S110 in Fig. The back grinding is arranged so that the back surface of the substrate is viewed like the half dicing, and the thickness of the substrate is made thin as a whole until the surface-side fine grooves are exposed, for example, by moving the rotating grindstone in the horizontal or vertical direction. The subsequent steps may be the same as in Fig. In the case where the strength of the substrate after back grinding is a problem, it is also possible to make a so-called rib structure by not grinding only the portion around the substrate.

Here, in the back grinding process, vibration or a cutting pressure is applied to the adhesive layer of the back grinding tape through the inner wall of the fine groove by rotation of the grindstone, relative movement of the grindstone and the semiconductor substrate, and the like. When the semiconductor substrate is pressed by the cutting pressure, the viscous adhesive layer flows into the fine grooves. Further, vibration is transmitted to the vicinity of the fine grooves, thereby promoting the flow of the adhesive layer. Particularly, in the case of a fine groove having a width of several mu m to several tens of mu m, the adhesive layer tends to penetrate deeper, and when it is 10 mu m or less, this becomes more remarkable.

When the grinding by the grindstone is finished, the expanding tape is attached to the back surface of the substrate, and ultraviolet rays are applied to the back grinding tape. The adhesive layer irradiated with ultraviolet rays is cured to lose its adhesive force and the back grinding tape is peeled from the substrate surface. Here, the adhesive layer, which has entered the fine grooves on the front surface side, may remain in the grooves or on the surface of the substrate at the time of peeling off the backgrinding tape, as described with reference to Fig. Therefore, in order to suppress the adhesive layer from remaining at the time of peeling off the tape for back grinding, the fine grooves of the embodiment described in Figs. 7 and 10 may be applied. By applying the fine grooves shown in Figs. 7 and 10, not only the residual adhesive layer is suppressed but also a deeper groove is formed, so that the thickness of the semiconductor piece after grinding can be ensured.

Further, in this application example, the semiconductor substrate is ground to the middle of reaching the fine grooves on the front surface side of the semiconductor substrate from the back surface of the semiconductor substrate, and then the semiconductor substrate is subjected to stress such as tensile stress or bending stress, .

Further, in the manufacturing method according to the above-described application, it is preferable that, during the formation of the grooves on the front surface side, the etching strength which is stronger than the first etching strength and does not increase the width of the entrance portion of the groove on the front surface side, The dry etching may be switched by the second etching strength so as to form the groove on the surface side that does not have a portion that widens toward the bottom of the groove. In such a configuration, since a reverse taper shape or the like in which the adhesive layer is likely to remain is not formed, the residual adhesive layer can be suppressed even when the depth of the adhesive layer of the tape is deepened.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the specific embodiments, but various modifications and changes may be made within the scope of the present invention described in the claims.

For example, the grooves 170 on the back surface side may reach the vicinity of the fine grooves on the surface side, but may be formed so as not to communicate with the fine grooves on the surface side. That is, the grooves 170 on the back surface side may be formed while leaving a part of the thickness of the semiconductor substrate in the step of forming the grooves 170 on the back surface side of FIG. 3B. In this case, a stress such as a tensile stress or a bending stress is applied to the semiconductor substrate in a subsequent step, and the remaining portion is removed to divide the semiconductor substrate. When the first groove portion (the upper side of the fine grooves on the front surface side) is in a forward tapered shape, the second groove portion (the lower side of the fine grooves on the front surface side) . For example, in the case where the depth of the penetration of the adhesive layer is grasped in advance, the shape of the fine groove at a portion deeper than the penetration depth of the adhesive layer may have a shape that widens in the depth direction. In other words, the second groove portion may have a shape that widens downward beyond the width of the lowermost portion of the first groove portion. This is because if the depth of the first groove portion is deeper than the depth at which the adhesive layer penetrates, even if the second groove portion widens in the depth direction, the problem such as difficulty in irradiation with ultraviolet rays is not promoted. Of course, since the semiconductor component has a shape that widens in the depth direction, the area of the back surface of the semiconductor component in the case of discretization becomes small, so that the bonding member can be prevented from becoming vacant or burnt when the semiconductor component is mounted on a circuit board or the like . This shape is formed by switching the flow rate of the gas for forming the protective film contained in the etching gas or the flow rate of the etching gas so that the intensity of etching becomes stronger. In this case, it is preferable to switch the flow rate of the gas within a range in which no edge portion is formed on the sidewall of the groove. The fine groove on the front surface side need not be formed only by the first and second groove portions and may include a third groove portion below the second groove portion. In this case, It may be wider than the groove portion.

Further, the manufacturing method of the present invention may be applied to a case where individual elements are separated from a substrate not including a semiconductor such as glass or polymer.

The inhibition of breakage in the present specification is not limited to suppressing breakage or cracking to such an extent that the breakage or the like can be confirmed visually, and it is possible to suppress the degree of breakage to some degree or to reduce the possibility of occurrence of breakage to some degree The extent of the containment is irrelevant. In addition, the present invention does not mean that the remaining of the adhesive layer is completely suppressed, but it does not mean that the residual degree is somewhat suppressed, and the possibility of the occurrence of the residual is somewhat reduced. . The shape of the fine grooves in this embodiment shown in Figs. 7 and 10 is merely an example, and the shape and angle of the inclination may be irregardless as long as it is formed by changing the intensity of etching.

100: Light emitting device 120: Cutting area (scribing line)
130: resist pattern 140: fine groove on the surface side
160: Dicing tape 162: tape substrate
164: adhesive layer 165, 166: uncured adhesive layer
170: groove 190 on the back side: an expanding tape
210: semiconductor chip 300: dicing blade
400, 410: fine groove
402, 404, 412, 414, 412a, 414a:
500, 510, 520, 530, 540: fine grooves
502, 504, 512, 514, 522, 524, 532, 534:
600: photoresist 610: opening
620: groove 630: shield
800: stepped portion

Claims (6)

A first groove portion that gradually narrows in width from the front surface of the substrate toward the back surface and a groove portion that is formed in a continuous manner below the first groove portion and that extends downward at a steep angle than the angle of the first groove portion, Forming a groove on the surface side of the first groove portion and the second groove portion having a second groove portion and having no corner portion by dry etching;
A step of sticking a holding member having an adhesive layer on the surface on which the grooves on the surface side are formed,
A step of thinning the substrate from the back surface of the substrate in a state where the holding member is attached,
Peeling the surface and the holding member after the thinning step
And a step of forming the semiconductor piece. A first groove portion that gradually narrows in width from the front surface of the substrate toward the back surface and a groove portion that is formed in a continuous manner below the first groove portion and that extends downward at a steep angle than the angle of the first groove portion, Forming a groove on the surface side of the first groove portion and the second groove portion having a second groove portion and having no corner portion by dry etching;
A step of attaching a holding member having an adhesive layer on the surface on which the grooves on the surface side are formed,
A step of forming a groove on a back surface side with a cutting member rotating from a back surface of the substrate toward a groove on the front surface side in a state where the holding member is attached,
A step of peeling the surface and the holding member after forming the grooves on the back surface side
And a step of forming the semiconductor piece. 3. The method according to claim 1 or 2,
The etching of the front surface side of the groove is gradually narrowed toward the back surface to form a groove on the front surface side, and etching of the etching gas used for the dry etching Is changed from a first flow rate to a second flow rate smaller than the first flow rate within a range that does not stop the flow rate of the gas for forming the protective film, Wherein the step of forming the semiconductor piece comprises the steps of: 3. The method according to claim 1 or 2,
The etching of the front surface side of the groove is gradually narrowed toward the back surface to form a groove on the front surface side, and etching of the etching gas used for the dry etching Wherein a groove on the surface side is formed by switching the flow rate of the etching gas contained in the first flow rate from the first flow rate to the second flow rate larger than the first flow rate. 3. The method according to claim 1 or 2,
And the second groove portion has a shape extending downward without being wider than the width of the lowermost portion of the first groove portion. 3. The method according to claim 1 or 2,
The depth of the first groove portion is deeper than the depth at which the adhesive layer penetrates,
And the second groove portion has a shape that widens downward beyond the width of the lowermost portion of the first groove portion.

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