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DE-102024003414-A1 - Method and apparatus for adjusting the position of a recess on the outer circumference of a disk made of a semiconductor material

DE102024003414A1DE 102024003414 A1DE102024003414 A1DE 102024003414A1DE-102024003414-A1

Abstract

Method for adjusting the position (cp) of a recess (114) on the outer circumference (112) of a disk (110) made of a semiconductor material, characterized in that, if the recess (114) is not arranged at a position (φ*) specified with respect to a crystal orientation of the disk, the recess (114) is enlarged such that the enlarged recess (116) is arranged at the position (φ*) specified with respect to the crystal orientation of the disk, or at least closer than before.

Inventors

  • Erich Daub
  • Benedikt Röska
  • Robert Zierer

Assignees

  • SILTRONIC AG

Dates

Publication Date
20260513
Application Date
20241111

Claims (10)

  1. Method for adjusting the position (φ) of a recess (114) on the outer circumference (112) of a disk (110) made of a semiconductor material, characterized in that, if the recess (114) is not arranged at a position (φ*) specified with respect to a crystal orientation of the disk, the recess (114) is enlarged such that the enlarged recess (116) is arranged at the position (φ*) specified with respect to the crystal orientation of the disk, or at least closer than before.
  2. Procedure according to Claim 1 , wherein the position (φ) of the recess (114) and the enlarged recess (116) with respect to the crystal orientation of the disk (110) is defined by a position line (P) lying in the plane of the disk, which runs midway between two lateral boundaries (114.1, 114.2) of the recess or the enlarged recess.
  3. Procedure according to Claim 2 , wherein the position line (P) passes through a rotational symmetry axis (A) of the disk (110).
  4. Method according to one of the preceding claims, wherein, before enlarging the recess, a deviation (Δφ) of the current position of the disk with respect to the crystal orientation from the predetermined position is determined, based on which the recess (114) is enlarged such that the enlarged recess (116) is arranged at the predetermined position (φ*) with respect to the crystal orientation of the disk.
  5. Procedure according to Claim 4 , wherein the deviation is determined by means of an X-ray image of the disk (110).
  6. Method according to one of the preceding claims, wherein the enlargement of the recess is carried out as part of an edge and recess rounding process.
  7. A method according to one of the preceding claims, wherein, in order to obtain the disk (110), a groove (104) is introduced on an outer surface (102) of a crystal rod (100) made of the semiconductor material, the groove extending along a longitudinal axis (A) of the crystal rod, wherein the disk (110) is obtained by dividing the crystal rod (100), after introducing the groove (104), in particular perpendicular to the longitudinal direction (A) of the crystal rod, in particular into a plurality of disks.
  8. Device (400) for adjusting the position (φ) of a recess (114) on the outer circumference (112) of a disk (110) made of a semiconductor material, wherein the device (400) is configured to enlarge the recess (114) such that the enlarged recess (116) is arranged at a position (φ*) predetermined with respect to the crystal orientation of the disk, or at least closer than before.
  9. Device (400) according to Claim 8 , comprising a determining means (320), in particular an X-ray device, by means of which a deviation (Δφ) of the current position (φ) of the disk (110) with respect to the crystal orientation from the predetermined position, or the current position (φ) of the disk, can be determined.
  10. Device (400) according to Claim 8 or 9 , comprising a grinding device (410) for an edge and recess rounding process of the disc, wherein the device is configured to enlarge the recess (114) by means of the grinding device (410).

Description

The present invention relates to a method for adjusting the position of a recess, in particular a so-called notch, on the outer circumference of a disk made of a semiconductor material, e.g. a so-called wafer, and to a corresponding device for this purpose. State of the art Semiconductor wafers, such as silicon wafers, are typically produced from a crystal rod, usually a single crystal of the semiconductor material in question. Such a crystal rod or single crystal can be produced, for example, using the so-called Czochralski process. In this process, the single crystal is grown from a crucible containing molten semiconductor material using a seed. This method is therefore also known as the crucible drawing process or the crucible drawing process. Such a crystal rod, or single crystal, can also be obtained, for example, using the FZ method, also known as the floating-zone method or zone-pulling method. In this process, a polycrystal, i.e., a crystal made of polycrystalline semiconductor material, is melted and then recrystallized. The single crystal is formed during this recrystallization process. The crystal rod can then be ground to achieve a more cylindrical shape. However, before the crystal rod is cut into numerous thin slices, known as wafers, a groove is typically cut into one of the outer surfaces of the crystal rod, running along its longitudinal axis. This groove is also known as a notch groove. This groove results in the individual slices or wafers being produced having a notch (or, more generally, a cutout) on their outer circumference. This recess serves to align the disk during subsequent semiconductor processes, e.g., when depositing circuits onto the disk. For this purpose, the recess should be positioned at a location specified with respect to a crystal orientation (or, more specifically, a crystallographic orientation) of the disk. Similarly, the groove should also be positioned with respect to the crystal orientation of the crystal rod. Technically important positions for this recess include, for example, the crystallographic directions [100] and [110]. To ensure the groove in the crystal rod, and thus the subsequent recess in the disc, is in the desired position, the crystal rod is measured appropriately. The crystal rod can then be aligned accordingly to create the groove, for example, by grinding. One way to measure the crystal rod, and more generally to create the groove, is described, for example, in the... DE 100 23 001 A1 explained in more detail. However, it has now become apparent that conventional devices for creating the groove at the desired position relative to the crystal orientation of the crystal rod are often not sufficiently precise. This can be due to various factors, such as the devices themselves or the setting accuracy. Consequently, the recess on the resulting wafer is not positioned with sufficient accuracy relative to the crystal orientation. Such wafers are then sometimes unusable, or at least not suitable for all types of semiconductor processes, as achieving the desired wafer orientation is either impossible or extremely difficult. Against this background, the task arises to specify a way in which the position of such recesses in disks made of semiconductor material corresponds more precisely to a desired position with respect to the crystal orientation. Disclosure of the invention According to the invention, a method and a device for adjusting the position of a recess on the outer circumference of a disk made of a semiconductor material, comprising the features of the independent claims, are proposed. Advantageous embodiments are the subject of the dependent claims and the following description. The invention relates to disks made of a semiconductor material, in particular so-called wafers, and to the notch or recess in such disks, which serves to align the disks in subsequent uses. To obtain such a disk, a groove can be cut into the outer surface of a crystal rod made of the semiconductor material, running along a longitudinal axis of the crystal rod. The disk can then be obtained by cutting the crystal rod after the groove has been cut, e.g., by sawing. Typically, a multitude of such disks are obtained, each of which then has a notch corresponding to the groove. The cutting of the crystal rod is carried out, in particular, perpendicular to the longitudinal direction of the crystal rod. However, if the groove in the crystal rod is not arranged at a position specified with respect to a crystal orientation of the crystal rod, this also applies to the position of the recess of the individual disks that are produced from the crystal rod. The position of the notch relative to the crystal orientation of the disk is defined, in particular, by a position line lying in the plane of the disk, which runs midway between two lateral boundaries of the notch. Typically, such a notch has a (lying in the plane of the disk) at least substantially triangular shape, with its apex