JP2004363154A - Method of manufacturing semiconductor device and semiconductor substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing semiconductor device and a semiconductor substrate by which the occurrence of chipping and cracks can be suppressed. <P>SOLUTION: The method of manufacturing semiconductor device includes a step (a) of working the outer peripheral end of a semiconductor substrate 10 having a first surface 14 on which a plurality of integrated circuits 12 are formed, and a second surface 16 on the opposite side of the first surface 14 so that the first surface 12 may obtain an inclined section 18 which is spread more than the second surface 16; and a step (b) of making the semiconductor substrate 10 thin by grinding the substrate 10 from the second surface 16 side on a holding member 30 which holds the substrate 10 by the first surface 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor device and a semiconductor substrate.
[0002]
[Prior art]
[0003]
[Patent Document 1]
JP-A-53-38594
BACKGROUND OF THE INVENTION
It is known that a semiconductor wafer is thinly ground in order to reduce the size of a semiconductor device. A semiconductor wafer is ground on a tape. In the conventional grinding method, the outer peripheral edge of the semiconductor wafer has a knife edge shape (for example, a shape having an acute angle on the side opposite to the tape), and chipping or cracking may occur from the outer peripheral edge. This sometimes destroyed the semiconductor wafer. In addition, a gap is formed between the semiconductor wafer and the tape, and grinding chips, water, and the like are likely to enter, and the reliability may be impaired.
[0005]
An object of the present invention is to suppress occurrence of chipping and cracks in a method of manufacturing a semiconductor device and a semiconductor substrate.
[0006]
[Means for Solving the Problems]
(1) A method of manufacturing a semiconductor device according to the present invention includes (a) a first surface on which a plurality of integrated circuits are formed, and a second surface opposite to the first surface. Forming an inclined portion at the outer peripheral end of the semiconductor substrate, wherein the first surface is wider than the second surface;
(B) grinding the semiconductor substrate from the second surface on a holding member held from the first surface to reduce the thickness;
including. According to the present invention, the inclined portion is formed in the semiconductor substrate, and the inclined portion is inclined in a direction in which the first surface is wider than the second surface. According to this, the surface held by the holding member is widened, so that the semiconductor substrate can be held extremely stably. Specifically, in the thinning step, the transporting step, the storing step, and the like, the semiconductor substrate is less likely to rattle on the holding member, and chipping and cracking due to physical contact or impact can be suppressed.
(2) In this method of manufacturing a semiconductor device,
In the step (a), an inclination angle between the inclined portion and the first surface may be equal to or greater than 45 ° and less than 90 °. According to this, the portion that becomes thinner due to the inclination can be relatively reduced, and the occurrence of chipping and cracking of the semiconductor substrate can be more effectively suppressed.
(3) In this method of manufacturing a semiconductor device,
In the step (a), the inclined portion may be formed all around an outer peripheral end of the semiconductor substrate.
(4) In this method of manufacturing a semiconductor device,
In the step (a), grinding may be performed so that the inclined portion is obtained.
(5) In the method of manufacturing a semiconductor device,
In the step (a), the outer peripheral edge of the semiconductor substrate may be ground by obliquely contacting a ground surface. According to this, since the contact is made obliquely, the semiconductor substrate can be ground with a small load, and the semiconductor substrate can be processed smoothly.
(6) In this method of manufacturing a semiconductor device,
The outer peripheral end of the semiconductor substrate has a convex portion whose cross-sectional shape protrudes outward,
In the step (a), grinding may be performed so as to remove the convex portion. By doing so, the first surface can be made flat, and the adhesion of the holding member is improved.
(7) In this method of manufacturing a semiconductor device,
In the step (a), a corner provided between the inclined portion and the second surface may be a smooth curved surface. This disperses the stress and improves the strength of the semiconductor substrate.
(8) In this method of manufacturing a semiconductor device,
After the step (b), the method may further include making a corner provided between the surface opposite to the first surface and the inclined portion a smooth curved surface. This disperses the stress and improves the strength of the semiconductor substrate.
(9) In this method of manufacturing a semiconductor device,
After the step (b), the method may further include cutting the semiconductor substrate so as to obtain a plurality of semiconductor chips including the integrated circuit.
(10) In this method of manufacturing a semiconductor device,
The semiconductor substrate may be a semiconductor wafer.
(11) A semiconductor substrate according to the present invention has a first surface on which a plurality of integrated circuits are formed, and a second surface opposite to the first surface, and the first surface is provided on an outer peripheral end portion. Is formed with an inclined portion wider than the second surface. According to the present invention, the inclined portion is formed in the semiconductor substrate, and the inclined portion is inclined in a direction in which the first surface is wider than the second surface. According to this, for example, when the semiconductor substrate is thinly ground, the surface to be held by the holding member is widened, so that the semiconductor substrate can be held extremely stably. Specifically, in the thinning step, the transporting step, the storing step, and the like, the semiconductor substrate is less likely to rattle on the holding member, and chipping and cracking due to physical contact or impact can be suppressed.
(12) In this semiconductor substrate,
The inclination angle between the inclined portion and the first surface may be equal to or greater than 45 ° and less than 90 °. According to this, the portion that becomes thinner due to the inclination can be relatively reduced, and the occurrence of chipping and cracking of the semiconductor substrate can be more effectively suppressed.
(13) In this semiconductor substrate,
The inclined portion may be formed all around the outer peripheral end of the semiconductor substrate.
(14) In this semiconductor substrate,
A smooth curved surface may be formed between the inclined portion and the second surface. This disperses the stress and improves the strength of the semiconductor substrate.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to an embodiment to which the present invention is applied. 2A and 2B are views showing the semiconductor substrate after the step shown in FIG. In the present embodiment, a semiconductor substrate 10 is used.
[0008]
The semiconductor substrate 10 may be a semiconductor wafer (for example, a silicon wafer). A plurality of integrated circuits (eg, transistors and memories) 12 are formed on a semiconductor substrate 10. The integrated circuit 12 is formed on the first surface 14 side of the semiconductor substrate 10. First surface 14 may be an active surface. On a second surface 16 opposite to the first surface 14, a semiconductor portion (for example, a silicon portion) is exposed. A plurality of electrodes (see FIG. 7) are formed on the semiconductor substrate 10. The electrode has a pad (for example, an aluminum pad) and may further have a bump (for example, a gold bump) on the pad. The plurality of electrodes may be formed around each integrated circuit 12. For example, at least one electrode of a semiconductor chip 11 (a portion surrounded by a two-dot chain line in FIG. 2A) obtained in a process described later. They may be arranged along a side (for example, two or four sides facing each other). On the first surface 12 of the semiconductor substrate 10, a passivation film (not shown) that covers the integrated circuit 12 is formed. The passivation film is formed of SiO ₂ , SiN, polyimide resin, or the like, and exposes at least a part of each electrode.
[0009]
In the present embodiment, the outer peripheral end of the semiconductor substrate 10 is processed so that the inclined portion 18 is obtained. As shown in FIG. 2B, the inclined portion 18 is inclined in a direction in which the first surface 14 is wider than the second surface 16. At least a part of the side surface of the semiconductor substrate 10 becomes the inclined portion 18. In the example shown in FIG. 2B, the entire side surface of the semiconductor substrate 10 is an inclined portion 18, that is, only the inclined portion 18 is interposed between the first and second surfaces 14, 16. ing.
[0010]
As shown in FIG. 2 (B), the inclined portion 18 may be linearly inclined or may be curved in a sectional view. When inclined in a curved shape, the semiconductor substrate 10 may be curved so as to be depressed inward, or conversely, may be curved so as to rise outward.
[0011]
As shown in FIG. 2A, the inclined portion 18 may be formed on the entire outer peripheral end of the semiconductor substrate 10. The inclined portion 18 may also be formed on a portion (for example, the orientation flat 20) for specifying the planar direction of the semiconductor substrate 10. As shown in FIG. 2B, the inclined portion 18 may be formed such that the outer shape of the semiconductor substrate 10 in a sectional view becomes trapezoidal.
[0012]
As a processing means of the semiconductor substrate 10, any of grinding (polishing) by grinding or the like, cutting by cutter or laser irradiation (for example, CO ₂ laser irradiation, YAG laser irradiation), and chemical etching (for example, wet etching) is applied. You may. For example, as shown in FIG. 1, the grinding surface 24 of the grinding tool 22 may be obliquely brought into contact with the outer peripheral end of the semiconductor substrate 10 for grinding. According to this, since the contact is made obliquely, the semiconductor substrate 10 can be ground with a small load, and the semiconductor substrate 10 can be processed smoothly. The ground surface 24 may be a flat surface or a curved surface, and may be in surface contact or line contact with the semiconductor substrate 10. During grinding, the grinding surface 24 may be rotated. When grinding the entire circumference of the semiconductor substrate 10, the ground surface 24 is relatively moved along the outer circumference of the semiconductor substrate 10. In that case, the stage 26 supporting the semiconductor substrate 10 may rotate around an axis.
[0013]
As shown in FIG. 1, the outer peripheral end of the semiconductor substrate 10 before processing often has a convex portion whose cross-sectional shape protrudes outward. In the example shown in FIG. 1, the convex portion 28 has a rounded corner. The convex portion 28 often has a semicircular (or semielliptical) shape. Then, in the present embodiment, as shown in FIG. 2B, the inclined portion 18 is formed so as to remove the convex portion 28. It is preferable to grind to the extent that the entire convex portion 28 (semicircular portion (or semielliptical portion in FIG. 2B)) is removed. By doing so, the first surface 14 can be made flat, and the adhesion of the holding member 30 described later is improved.
[0014]
After the above processing is completed, the semiconductor substrate 10 is ground and thinned. Specifically, the semiconductor substrate 10 is ground from the second surface 16 on the holding member 30 that holds the semiconductor substrate 10 from the first surface 14. The holding member 30 may be an adhesive tape (for example, a UV tape), or may be a sheet in which a liquid adhesive (for example, a UV adhesive) is applied to the sheet. Affixed to surface 14. The first surface 14 (particularly, the integrated circuit 12) can be protected by the holding member 30. When the holding member 30 is an adhesive tape, a grip portion (for example, a ring) 32 is provided on the outer peripheral portion. Then, as shown in FIG. 3, the semiconductor substrate 10 is ground by the grinding tool 34 (thinning step). More specifically, a part of the semiconductor substrate 10 where the integrated circuit 12 is not formed is removed by grinding.
[0015]
According to the present embodiment, the inclined portion 18 is formed in the semiconductor substrate 10, and the inclined portion 18 is inclined in a direction in which the first surface 14 is wider than the second surface 16. According to this, the surface on the side to be held by the holding member 30 is widened, so that the semiconductor substrate 10 can be held extremely stably. More specifically, the semiconductor substrate 10 is less likely to rattle on the holding member 30 in the thinning step, the transporting step, the storing step, and the like, and chipping and cracking due to physical contact or impact can be suppressed. Further, since it is difficult to form a gap between the semiconductor substrate 10 and the holding member 30, for example, foreign matter such as grinding waste and water generated in the thinning process is prevented from entering between the semiconductor substrate 10 and the holding member 30. Can be prevented. Further, the inclined portion 18 makes it easier for cutting waste and the like to flow outside the semiconductor substrate 10. Therefore, the reliability of the semiconductor device manufacturing process can be improved. In addition, separately from the above, a processing step of the inclined portion 18 may be performed on the semiconductor substrate 10 simultaneously with or after the thinning step.
[0016]
FIG. 4 is a partially enlarged view of the semiconductor substrate according to the present embodiment. The semiconductor substrate 10 has a first surface 14 on the side on which the plurality of integrated circuits 12 are formed, and a second surface (exposed surface after grinding) 17 on the opposite side. Further, an inclined portion 18 in which the first surface 14 is wider than the second surface 17 is formed at the outer peripheral end of the semiconductor substrate 10. The inclination angle θ between the inclined portion 18 and the first surface 14 is an acute angle (0 ° <θ <90 °), for example,
45 ° ≦ θ <90 °
It is preferable that That is, in the above-described processing step, it is preferable to form the inclined portion 18 within the range of the angle. According to this, the portion that becomes thin due to the inclination can be relatively reduced, and the occurrence of chipping and cracking of the semiconductor substrate 10 can be more effectively suppressed. When a corner is formed between the inclined portion 18 and the second surface 17, the inclination angle is obtuse. Other details are as described above.
[0017]
In the modified example shown in FIG. 5, a smooth curved surface 13 is formed between the inclined portion 18 of the semiconductor substrate 10 and the second surface 17. That is, during the above-described processing step or after the thinning step, the corner 15 provided between the inclined portion 18 and the second surface 16 (or the second surface 17 exposed after the grinding) is ground to form a smooth curved surface 13. May be formed. Further, the curved surface 13 may be formed by etching. This eliminates the corners 15, thereby dispersing the stress and improving the strength of the semiconductor substrate 10. The curved surface 13 may be formed all around the semiconductor substrate 10.
[0018]
After that, the semiconductor substrate 10 is cut (for example, dicing). The semiconductor substrate 10 is held by a holding member 36 and cut by a cutting tool (for example, a blade) 38. As shown in FIG. 6, the semiconductor substrate 10 may be cut from the side on which the integrated circuit 12 is formed. Thus, a plurality of semiconductor chips 11 having the integrated circuit 12 can be obtained.
[0019]
As shown in FIG. 7, the semiconductor chip 11 is packaged to complete a semiconductor device. Specifically, the semiconductor chip 11 is mounted on the substrate 40. The mounting form may be, for example, face-down bonding. For the electrical connection between the electrode 19 of the semiconductor chip 11 and the wiring pattern 42 of the substrate 40, a known form such as metal bonding can be applied. An underfill material (resin) 44 is provided between the semiconductor chip 11 and the substrate 40, and external terminals (for example, solder balls) 46 that are electrically connected to the wiring pattern 42 are provided on the substrate 40. Can be
[0020]
The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the invention includes configurations substantially the same as the configurations described in the embodiments (for example, a configuration having the same function, method, and result, or a configuration having the same object and result). Further, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. Further, the invention includes a configuration having the same operation and effect as the configuration described in the embodiment, or a configuration capable of achieving the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.
FIGS. 2A and 2B are diagrams illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a method of manufacturing a semiconductor device according to an embodiment of the present invention.
FIG. 4 is a diagram showing a semiconductor substrate according to an embodiment of the present invention.
FIG. 5 is a view showing a modification of the semiconductor substrate according to the embodiment of the present invention;
FIG. 6 is a diagram illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating an example of a semiconductor device according to an embodiment of the present invention;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Semiconductor substrate 11 ... Semiconductor chip 12 ... Integrated circuit 13 ... Curved surface 14 ... 1st surface 16, 17 ... 2nd surface 15 ... Corner 18 ... Inclined part 24 ... Grinding surface 28 ... Convex part 30 ... Holding member

Claims (14)

(A) the first surface is formed at an outer peripheral end of a semiconductor substrate having a first surface on which a plurality of integrated circuits are formed and a second surface opposite to the first surface; Forming an inclined portion wider than the second surface;
(B) grinding the semiconductor substrate from the second surface on a holding member held from the first surface to reduce the thickness;
A method for manufacturing a semiconductor device including: The method for manufacturing a semiconductor device according to claim 1,
The method of manufacturing a semiconductor device, wherein in the step (a), an inclination angle between the inclined portion and the first surface is 45 ° or more and less than 90 °. The method for manufacturing a semiconductor device according to claim 1 or 2,
The method of manufacturing a semiconductor device, wherein in the step (a), the inclined portion is formed all around an outer peripheral end of the semiconductor substrate. The method for manufacturing a semiconductor device according to claim 1, wherein
In the method (a), a method for manufacturing a semiconductor device, wherein grinding is performed to obtain the inclined portion. The method for manufacturing a semiconductor device according to claim 4,
In the step (a), a method for manufacturing a semiconductor device in which a grinding surface is obliquely brought into contact with an outer peripheral end of the semiconductor substrate to perform grinding. The method for manufacturing a semiconductor device according to claim 4 or 5,
The outer peripheral end of the semiconductor substrate has a convex portion whose cross-sectional shape protrudes outward,
In the method (a), a method of manufacturing a semiconductor device in which grinding is performed so as to remove the convex portion. The method for manufacturing a semiconductor device according to claim 1, wherein
The method of manufacturing a semiconductor device, wherein in the step (a), a corner provided between the inclined portion and the second surface is formed into a smooth curved surface. The method for manufacturing a semiconductor device according to claim 1, wherein
A method of manufacturing a semiconductor device, further comprising, after the step (b), making a corner provided between the surface opposite to the first surface and the inclined portion a smooth curved surface. 9. The method for manufacturing a semiconductor device according to claim 1, wherein:
A method of manufacturing a semiconductor device, further comprising, after the step (b), cutting the semiconductor substrate so as to obtain a plurality of semiconductor chips including the integrated circuit. The method for manufacturing a semiconductor device according to claim 1, wherein
The method for manufacturing a semiconductor device, wherein the semiconductor substrate is a semiconductor wafer. An inclined portion having a first surface on which a plurality of integrated circuits are formed and a second surface opposite to the first surface, wherein the first surface is larger than the second surface at an outer peripheral end portion. A semiconductor substrate on which is formed. The semiconductor substrate according to claim 11,
A semiconductor substrate, wherein an inclination angle between the inclined portion and the first surface is not less than 45 ° and less than 90 °. The semiconductor substrate according to claim 11 or 12,
The semiconductor substrate, wherein the inclined portion is formed on an entire outer periphery of the semiconductor substrate. The semiconductor substrate according to any one of claims 11 to 13,
A semiconductor substrate having a smooth curved surface formed between the inclined portion and the second surface.

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