JP2006019623A - Semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that a notch formed in a semiconductor wafer is passed through from its backside to its surface, and by the notch to the surface of the semiconductor wafer, the scattering of its solvent is generated in its resist removing process, and further, the variations of its patterns are generated in the case of its immersion exposure, and moreover, the deterioration of the adhesiveness of its protective tape, etc. are generated in its protective-tape separating process. <P>SOLUTION: There is provided a semiconductor wafer having its notch formed out of a groove which is not passed through from its backside to its front surface. Consequently, since the notch is not exposed to the front surface of the semiconductor wafer, the faults caused by the notch can be prevented from being generated when executing miscellaneous processes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor wafer having an improved notch structure.

  A notch portion formed in a part of the outer periphery of the semiconductor wafer plays an important role in determining the crystal orientation of the semiconductor wafer itself and a wafer reference point when processing is performed by various semiconductor manufacturing apparatuses. As shown in FIG. 5, the structure of the notch portion that is generally used is formed with a notch 52 formed on the outer periphery of the semiconductor wafer 51 by a groove penetrating from the front surface 51a to the back surface 51b. The shape of the notch portion 52 is substantially U-shaped in the example shown in FIG. 5, but a V-shape is also used.

  In the notch portion 52 having a shape penetrating from the front surface 51a to the back surface 51b of the semiconductor wafer 51 as described above, problems occur in some processes of the IC manufacturing process. That is, as shown in FIG. 6, after the photoresist 62 is applied to the surface of the semiconductor wafer 61 in the exposure process, the photoresist film on the outer periphery of the semiconductor wafer 61 is removed with a solvent. In this step, the solvent 63 is sprayed onto the outer periphery of the semiconductor wafer 61 by the spray member 64 while rotating the semiconductor wafer 61 (FIG. 6a). At this time, the solvent 63 hits the notch 60 and scatters around and falls onto the semiconductor wafer 61.

  As a result, the scattered solvent 65 adheres to the photoresist 62 of the semiconductor wafer 61 (FIG. 6b). For this reason, when various resist patterns 66 are formed on the surface of the semiconductor wafer 61 in the subsequent process, there has been a problem that the scattered solvent 65 causes the resist pattern 66 in the element formation region 67 to be destroyed (FIG. 6c).

  In addition, immersion exposure technology is known as an exposure method. FIG. 7 shows a state in which immersion exposure is performed on a conventional semiconductor wafer (FIG. 5). That is, a semiconductor wafer 73 having a notch 72 is mounted on the wafer stage 71 and exposure is performed through the exposure lens 74 and the liquid 75. At this time, as shown in the enlarged view of FIG. 7, in the shot applied to the notch portion 72 of the semiconductor wafer 73, the balance of the surface tension of the liquid 75 is lost and the liquid 75 cannot be uniformly deposited. As a result, the bubbles 76 enter the liquid and the refractive index fluctuates, which not only deteriorates the variation in the pattern in the shot, but also has a great influence on the image formation.

  In addition, in the lapping process, a protective tape 82 is attached to the surface of the semiconductor wafer 81 as shown in FIG. Thereafter, when the excess protective tape 82 is cut along the outer periphery of the semiconductor wafer 81, stress concentrates at the notch portion 83, and the adhesion to the semiconductor wafer 81 deteriorates. For this reason, there is a problem that moisture 84 used during polishing of the back surface of the semiconductor wafer 81 soaks into the protective tape 82 from the notch 83 between the semiconductor wafer 81 and the protective tape 82.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a semiconductor wafer that can solve various problems with a simple configuration and can improve process accuracy. .

  The gist of the semiconductor wafer according to the present invention is that notches are formed by grooves that do not reach the front surface from the back surface.

  In the semiconductor wafer according to the present invention, since the notch portion does not reach the wafer surface, pattern breakage due to solvent scattering at the notch portion can be prevented, and in immersion exposure, the liquid in the shot on the notch is uniformly distributed. It is possible to prevent the generation of bubbles, and it is possible to prevent the deterioration of the adhesion to the semiconductor wafer due to the stress concentration at the notch when the protective tape is separated in the lapping process. .

  A semiconductor wafer according to the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a semiconductor wafer according to the present invention. That is, the single-sided notch portion 14 is formed only on the back surface 13 side without reaching the front surface 12 of the semiconductor wafer 11. Therefore, the notch of the single-side notch portion 14 does not appear on the surface 12 of the semiconductor wafer 11. Note that elements are formed on the surface of the semiconductor wafer 11 by various process steps.

  By using the semiconductor wafer 11 having such a structure, it has become possible to solve various problems that have conventionally occurred. In FIG. 2, after the photoresist 15 is applied to the surface of the semiconductor wafer 11 on which the single-sided notch portion 14 is formed, the outer periphery of the semiconductor wafer 11 that rotates the solvent 17 from the spray member 16 to remove the outer peripheral photoresist film. An example of spraying is shown. As a result, since the notch of the single-sided notch portion 14 does not appear on the outer periphery of the semiconductor wafer 11 to which the solvent 17 is sprayed, the sprayed solvent 17 does not hit the notch portion, and the solvent 17 is applied to the surface of the photoresist 15. It is no longer scattered and pattern breakage can be prevented.

  3 shows a case where immersion exposure is performed on the semiconductor wafer 32 formed with the one-side notch portion 31 via the exposure lens 33 and the liquid 34. As shown in the enlarged view, the semiconductor wafer 32 is also shown. Since the notch portion does not appear on the surface, liquid on the shot can be uniformly deposited, and generation of bubbles can be prevented. That is, it is possible to prevent variations in the pattern in the shot caused by fluctuation of the refractive index due to bubbles.

  Further, as shown in FIG. 4, in the lapping process of the semiconductor wafer 42 on which the single-sided notch portion 41 is formed, stress is not concentrated on the single-side notch portion 41 when the excess tape is cut off, and the protective tape 43 Can be adhered in close contact with the entire surface of the semiconductor wafer 42. As a result, moisture used during polishing of the back surface of the semiconductor wafer 42 does not permeate between the semiconductor wafer 42 and the protective tape 43 from the single-sided notch portion 41, and tape peeling does not occur.

The figure which shows embodiment of this invention. The figure for demonstrating the function of the semiconductor wafer concerning embodiment of this invention. The figure for demonstrating the other function of the semiconductor wafer concerning embodiment of this invention. The figure for demonstrating the further another function of the semiconductor wafer concerning embodiment of this invention. The figure which shows the conventional semiconductor wafer. The figure for demonstrating the process using the conventional semiconductor wafer. The figure for demonstrating the other process using the conventional semiconductor wafer. The figure for demonstrating the further another process using the conventional semiconductor wafer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11, 32, 42 ... Semiconductor wafer, 12 ... Front surface, 13 ... Back surface, 14, 31, 41 ... Single-sided notch part.

Claims (2)

  A semiconductor wafer, wherein a notch is formed by a groove that does not reach the front surface from the back surface.   2. The semiconductor wafer according to claim 1, wherein elements are formed on the surface of the semiconductor wafer by various process steps.

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