JP2008300605A - Collecting method of impurities, and collecting device of impurities - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collecting method of impurities capable of precisely collecting the impurities on the surface of a semiconductor substrate. <P>SOLUTION: The collecting method of impurities measures the impurities present on the surface of a semiconductor substrate 1. A collecting member 2 for collecting impurities is made to contact to a region to be measured of the surface of the semiconductor substrate 1. While the collecting member 2 is kept to contact the region to be measured, it is shifted relative to the semiconductor substrate 1, to allow the collecting member 2 to collect the impurities present on the semiconductor substrate 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an impurity recovery method and an impurity recovery apparatus for analyzing the surface of a semiconductor substrate.

  In a conventional method for analyzing impurities on the surface of a semiconductor substrate, for example, a silicon oxide film or a nitride film on the surface is vapor-phase decomposed together with impurities by hydrofluoric acid vapor, and the impurities are acid solution on the surface. There is one that collects the acid solution droplets and analyzes the acid solution droplets (see, for example, Patent Document 1).

  However, in the above prior art, a film in a region that is not an analysis target of the semiconductor substrate is also decomposed by the vapor phase decomposition. Thereby, the component of the film is also included in the acid solution droplet, that is, a component that becomes noise other than the impurity to be measured is also collected.

That is, when analyzing the acid solution droplet, there is a problem that the background with respect to the amount of impurities changes and the analysis accuracy of the impurities can be lowered.
Japanese Patent No. 2944099

  An object of the present invention is to provide an impurity recovery method and an impurity recovery apparatus capable of recovering impurities on the surface of a semiconductor substrate with higher accuracy.

An impurity recovery method according to one embodiment of the present invention includes:
An impurity recovery method for measuring impurities present on the surface of a semiconductor substrate,
A recovery member for recovering the impurities is brought into contact with a region to be measured on the surface of the semiconductor substrate;
The recovery member is moved relative to the semiconductor substrate while maintaining a state in which the recovery member is in contact with the region to be measured, and the impurities present on the semiconductor substrate are recovered by the recovery member. .

An impurity recovery apparatus according to one embodiment of the present invention includes:
An impurity recovery device for measuring impurities present on the surface of a semiconductor substrate,
A holding part for holding a collecting member for collecting the impurities;
A control unit for controlling a relative operation of the recovery member with respect to the semiconductor substrate,
The controller is
The recovery member is brought into contact with a region to be measured on the surface of the semiconductor substrate, and the recovery member is moved relative to the semiconductor substrate while maintaining the state in which the recovery member is in contact with the region to be measured. By controlling the relative operation of the member with respect to the semiconductor substrate, the recovery member recovers impurities present on the semiconductor substrate.

  According to the impurity recovery method and the impurity recovery apparatus of one embodiment of the present invention, impurities on the surface of the semiconductor substrate can be recovered with higher accuracy.

  In the impurity recovery method and the impurity recovery apparatus according to the present embodiment, the impurities adhering to the surface of the measurement region of the semiconductor substrate are physically or physically and chemically removed from the recovery member or the chemical solution. Recovered by the impregnated recovery member. Therefore, it is not necessary to dissolve the film on the semiconductor substrate.

  In addition, when the impurities are chemically collected, for example, the liquid is impregnated into a porous sponge to collect the impurities.

  By analyzing the impurities collected as described above, the impurities present on the surface of the semiconductor substrate can be measured.

  Embodiments to which the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of an impurity recovery apparatus according to a first embodiment which is an aspect of the present invention. FIG. 2 is a cross-sectional view showing a state in which a recovery member is brought into contact with the bevel portion of the semiconductor substrate to recover impurities present on the surface of the bevel portion. FIG. 3 is a cross-sectional view showing a state in which a recovery member is brought into contact with the upper surface end portion of the semiconductor substrate to recover impurities existing on the end surface.

  2 and 3, the configuration other than the recovery member of the impurity recovery device is omitted for simplicity.

  As shown in FIG. 1, the impurity recovery apparatus 100 includes a recovery member 2 that recovers impurities present on the surface of a semiconductor substrate (wafer) 1, and a holding unit 3 that holds the recovery member 2. .

  Further, the impurity recovery device 100 is connected to the drive unit 4 to which the holding unit 3 is connected and the recovery member 2 can be moved relative to the semiconductor substrate 1 together with the holding unit 3, and the rotation shaft 5a. The substrate support part 5 which supports the semiconductor substrate 1 rotatably, and the main-body part 6 which drives the drive part 4 and the substrate support part 5 are provided.

  For example, the drive unit 4 can rotate the collection member 2 together with the holding unit 3 around the rotation shaft 4a. Furthermore, the drive part 4 can raise / lower the height of the collection | recovery member 2 by driving up and down. By the operation of the drive unit 4, the recovery member 2 can scan the bevel portion 1a and the upper surface 1b of the semiconductor substrate 1 (FIGS. 2 and 3).

  The main body 6 controls the relative positional relationship of the recovery member 2 with respect to the semiconductor substrate 1 by driving the driving unit 4, and controls the rotation of the semiconductor substrate 1 by driving the substrate support unit 5. A control unit 7 is included.

  The control unit 7 drives the drive unit 4 and the substrate support unit 5 in conjunction with each other, thereby bringing the collection member 2 into contact with the measurement region on the surface of the semiconductor substrate 1 and bringing the collection member 2 into contact with the measurement region. The relative operation of the recovery member 2 with respect to the semiconductor substrate 1 is controlled so as to move relative to the semiconductor substrate 1 while maintaining the above state. As a result, the control unit 7 causes the recovery member 2 to scan the region to be measured on the surface of the semiconductor substrate 1, and causes the recovery member 2 to recover impurities present on the semiconductor substrate 1.

  The recovery member 2 is, for example, a porous member or a fiber member.

  Here, for example, a PVA (polyvinyl alcohol) sponge, a film made of PVA mesh, a flexible PTFE (polytetrafluoroethylene) sheet, and a water-soluble pore-forming agent are added to the PVA. PVF (polyvinyl formal) and PU (polyurethane) sponges such as formed sponge are included.

  The fiber member includes, for example, microfiber, nanofiber, cotton, rubber fiber, quartz wool and the like.

The recovery member 2 may be a member formed by solidifying a SiO ₂ or SiN powder into a spherical shape, a rod shape, or a sheet shape, or rubber.

  Here, examples of impurities that may exist on the surface of the semiconductor substrate 1 include inorganic contaminants such as metals and ion impurities, and organic contaminants such as resist.

  By directly attaching these impurities to the recovery member 2, the impurities are recovered by the recovery member 2.

  Further, the recovery member 2 may be impregnated with a liquid that can take in impurities (for example, a chemical solution such as an acid or an organic solvent). In this case, the chemical solution to be impregnated in the recovery member 2 is selected according to the impurity to be measured.

  Further, the recovery member 2 may be formed in accordance with the measurement region of the semiconductor substrate 1 such as a rod shape, a nib shape, or a needle shape.

  Here, the operation of the impurity recovery apparatus 100 having the above configuration will be described.

  First, the control unit 7 of the impurity recovery apparatus 100 drives the drive unit 4 to bring the recovery member 2 that recovers impurities into contact with the measurement region on the surface of the semiconductor substrate 1.

  Next, the control unit 7 drives the drive unit 4 and the substrate support unit 5 in conjunction with each other, and moves relative to the semiconductor substrate 1 while maintaining the state in which the recovery member 2 is in contact with the region to be measured. Let Thereby, the impurities present on the semiconductor substrate 1 are recovered by the recovery member.

  When scanning the recovery member 2 on the surface of the bevel portion 1a of the semiconductor substrate 1, for example, the control unit 7 drives the drive unit 4 to move the recovery member 2 to the end of the semiconductor substrate 1. And move in the direction of the rotating shaft 4a. Then, the control unit 7 drives the substrate support unit 5 to rotate the semiconductor substrate 1. Thereby, the recovery member 2 scans the surface of the bevel portion 1 a of the semiconductor substrate 1.

  Further, as described above, the recovery member 2 may be impregnated with a chemical solution such as an acid or an organic solvent to recover impurities. Thereby, it is thought that the recovery efficiency of impurities by the recovery member 2 is improved.

  Note that after the impurities are collected, for example, the impurities to be analyzed collected by the collecting member may be extracted with an acid or an organic solvent. By analyzing the impurities extracted in this way, the impurities present on the surface of the semiconductor substrate can be measured.

  If the recovery member is combustible, such as PVA sponge, the recovery member from which impurities have been recovered may be burned to dissolve the metal residue with acid, and this solution may be analyzed.

  When the recovery member is, for example, quartz wool, the quartz wool from which impurities are recovered may be dissolved with hydrofluoric acid, and the solution may be analyzed.

  Here, the difference between the solution holding impregnated in the recovery member according to the above-described embodiment and the conventional droplet holding will be examined.

  In the prior art, for example, a normal lump (one drop) of droplets is held by the surface tension of a Teflon droplet holding unit or the like. However, in that case, the liquid adsorbing property (wetting property) becomes larger on the hydrophilic wafer surface than the Teflon surface (hydrophobic property). For this reason, the liquid droplet remains on the hydrophilic wafer surface side and cannot be retained by the liquid droplet holding section.

  On the other hand, in this embodiment, the porous member, for example, PVA sponge, has a solution retention property (hygroscopic property) larger than that of the hydrophilic wafer surface. For this reason, the solution which the impurity melt | dissolved by the PVA sponge side is hold | maintained, without a solution remaining on the hydrophilic surface.

  As described above, according to the impurity recovery method according to the present embodiment, the impurities on the surface of the semiconductor substrate can be recovered with higher accuracy.

  Even if the analysis target surface of the semiconductor substrate is hydrophobic or hydrophilic, it is possible to analyze impurities adhering to the surface of the film in an arbitrary region.

  Therefore, it is possible to measure impurities on the surface of the wafer (laminated structure) on which the device is formed.

  In the above embodiment, the case where the recovery member is scanned on the upper surface and the bevel portion of the wafer has been described. However, in order to recover impurities on the lower surface of the wafer, the lower surface may be scanned.

It is a figure which shows the structure of the collection | recovery apparatus of the impurity which concerns on Example 1 which is 1 aspect of this invention. It is sectional drawing which shows the state which makes a collection | recovery member contact the bevel part of a semiconductor substrate, and collect | recovers the impurities which exist on this bevel part surface. It is sectional drawing which shows the state which makes a collection | recovery member contact the upper surface edge part of a semiconductor substrate, and collect | recovers the impurities which exist on this edge part surface.

Explanation of symbols

1 Semiconductor substrate (wafer)
DESCRIPTION OF SYMBOLS 1a Bevel part 1b Upper surface 2 Collection | recovery member 3 Holding part 4 Drive part 4a Rotating shaft 5 Substrate support part 5a Rotating shaft 6 Main body part 7 Control part 100 Impurity collection | recovery apparatus

Claims (5)

An impurity recovery method for measuring impurities present on the surface of a semiconductor substrate,
A recovery member for recovering the impurities is brought into contact with a region to be measured on the surface of the semiconductor substrate;
The recovery member is moved relative to the semiconductor substrate while maintaining a state in which the recovery member is in contact with the region to be measured, and the impurities present on the semiconductor substrate are recovered by the recovery member. How to recover impurities.   The method for recovering impurities according to claim 1, wherein the recovery member is a porous member or a fiber member.   The method for recovering impurities according to claim 1 or 2, wherein the recovery member is impregnated with a liquid capable of taking in the impurities. The method for collecting impurities according to claim 1, wherein the impurities are collected on the collecting member by directly attaching the impurities to the collecting member. An impurity recovery device for measuring impurities present on the surface of a semiconductor substrate,
A holding part for holding a collecting member for collecting the impurities;
A control unit for controlling a relative operation of the recovery member with respect to the semiconductor substrate,
The controller is
The recovery member is brought into contact with a region to be measured on the surface of the semiconductor substrate, and the recovery member is moved relative to the semiconductor substrate while maintaining the state in which the recovery member is in contact with the region to be measured. An impurity recovery device, wherein the recovery member recovers impurities present on the semiconductor substrate by controlling relative movement of the member with respect to the semiconductor substrate.

Images