JP2004079799A - Method and device for working semiconductor substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce variations in the working depth depending on working positions, and hence efficiently utilize light, and reduce the size of a device. <P>SOLUTION: Uniform parallel light C having a sectional shape needed for working is made incident perpendicularly onto the surface of a silicon substrate 10 using a cylindrical optical path 82 having the sectional shape needed for working, a lamp 84 arranged at the inlet side of the cylindrical optical path 82, and a collimator lens 86 arranged on the outlet side of the cylindrical optical path 82. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for processing a semiconductor substrate, and more particularly, to a through hole used for an interlayer wiring of a three-dimensional stacked element or a three-dimensional waveguide in an optical element, and a thin and deep deep hole which does not penetrate the substrate. The present invention relates to a method and an apparatus for processing a semiconductor substrate, which is suitable for use in forming a semiconductor substrate on a semiconductor substrate, has a small variation in processing depth depending on a processing position, and can efficiently use light.
[0002]
[Prior art]
The present applicant has already applied for a method and apparatus for processing a semiconductor substrate suitable for forming a through-hole having a large height-to-width ratio (aspect ratio) and a deep hole that does not penetrate into a semiconductor substrate such as a silicon substrate. 2001-263618. As shown in FIG. 1, the charge generated in the silicon substrate 10 by immersing the surface of the silicon substrate 10 on which marking (scratching) has been performed in advance in an electrolytic solution 20 and irradiating a laser beam 52 from a light irradiation device 50 is performed. Is used to perforate the silicon substrate 10 by an electrochemical reaction.
[0003]
In the figure, reference numeral 42 denotes an electrolytic cell that supports the silicon substrate 10 at a lower portion, 54 denotes a light source that generates, for example, ultraviolet laser light 52 as excitation light, and 56 denotes the laser light 52 from the light source 54 at an appropriate angle. A rotary mirror 58 for reflecting and scanning at the window 44 of the electrolytic cell 42 to make the rotary mirror 56 rotate and scan around a horizontal axis.
[0004]
[Problems to be solved by the invention]
However, in the processing apparatus proposed in Japanese Patent Application No. 2001-263618, the laser beam 52 output from the light source 54 is made to be incident on the silicon substrate 10 by being swung by the rotating mirror 56. Since light enters the semiconductor substrate 10 at an angle, one of polarized light (hereinafter referred to as S-polarized light) and parallel polarized light (hereinafter referred to as P-polarized light) whose electric field vector is perpendicular to the incident light plane is strong. Be affected. In addition, since light is obliquely incident, reflection is large and efficiency is low. Furthermore, since the light is not arranged, when a plurality of deep pores are simultaneously formed in the silicon substrate, there is a problem that a difference occurs in the opening speed of the pores, and a variation in processing depth occurs. Was.
[0005]
The same applies to the photo-excited electropolishing apparatus described in Japanese Patent Application Laid-Open No. H10-256227, since diffused light is not collimated but directed to a silicon substrate.
[0006]
The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to reduce variations in processing depth depending on processing positions, efficiently use light, and further reduce the size of an apparatus. .
[0007]
[Means for Solving the Problems]
The present invention relates to a method of processing a semiconductor substrate by processing a semiconductor substrate by an electrochemical reaction by using a charge generated in the semiconductor substrate by immersing a surface of the semiconductor substrate, which has been marked in advance, in an electrolytic solution and irradiating light. In the above, the above-mentioned problem has been solved by making uniform parallel light having a cross-sectional shape required for processing perpendicularly enter the surface of the semiconductor substrate.
[0008]
The present invention also provides a method of processing a semiconductor substrate by performing an electrochemical reaction by using a charge generated in the semiconductor substrate by immersing a surface of the semiconductor substrate, which has been marked in advance, in an electrolytic solution and irradiating light. In the processing device, comprising a cylindrical optical path having a cross-sectional shape required for processing, a light source disposed on the entrance side of the cylindrical optical path, and a collimator lens disposed on the exit side of the cylindrical optical path, The above-mentioned problem is also solved by making the light emitted from the collimator lens perpendicularly enter the surface of the semiconductor substrate.
[0009]
The height of the apparatus is reduced by providing a fixed mirror for changing the direction of light in the cylindrical optical path.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
In the first embodiment of the present invention, as shown in FIG. 2, a cylindrical optical path having a cross-sectional shape (here, circular) corresponding to the silicon substrate 10 is used as the light irradiation device 50 of the semiconductor substrate processing apparatus as shown in FIG. 82, a lamp 84 disposed on the entrance side (lower side in the figure) of the cylindrical optical path 82, a collimator lens 86 disposed on the exit side (upper side in the figure) of the cylindrical optical path 82, and the cylindrical optical path 82, a fixed mirror 88 for changing the direction of light from a horizontal direction to a vertical direction.
[0012]
The inner diameter of the cylindrical optical path 82 is adapted to the finally required light diameter. The shape of the cylindrical optical path does not necessarily have to be a circle, but may be a polygon. By applying, for example, a black paint to the inner surface of the cylindrical optical path 82, it is possible to suppress variations in light distribution due to irregular reflection.
[0013]
As the lamp 84, for example, a halogen lamp, a xenon lamp, an incandescent lamp or the like can be used. The lamp 84 is provided with a reflection plate 85 to improve the efficiency.
[0014]
As the collimator lens 86, for example, an array lens or a Fresnel lens is used.
[0015]
The fixed mirror 88 is mounted in the cylindrical optical path 82 at an angle of, for example, 45 ° (not necessarily 45 °).
[0016]
In the present embodiment, the diffused light A extracted by the lamp 84 and the reflector 85 installed in the horizontal direction passes through the round hole 83 formed on the side surface of the cylindrical optical path 82 while increasing the diameter of the light. Incident on. The diffused light B bent 90 ° by the fixed mirror 88 mounted in the cylindrical optical path 82 and directed upward is diffused in the cylindrical optical path 82 to increase the light diameter, and the size of the inner wall of the cylindrical optical path 82 become. The diffused light B is further extracted upward by the collimator lens 86 as parallel light C having a uniform light intensity, and is incident on the silicon substrate 10.
[0017]
In the present embodiment, a fixed mirror 88 is provided in the cylindrical optical path 82 to change the direction of the diffused light by 90 ° in the cylindrical optical path 82, so that the degree of freedom of layout is high and the height of the processing apparatus is increased. It can be kept low.
[0018]
Next, a second embodiment of the present invention will be described.
[0019]
In the present embodiment, as shown in FIG. 3, a lamp 84 and a reflector 85 are disposed below a cylindrical optical path 82 in a light irradiation device 50 similar to the first embodiment, and a fixed mirror 88 is omitted. The difference from the first embodiment is that the diffused light A emitted from the lamp 84 directly enters the collimator lens 86 without passing through the mirror 88.
[0020]
Other points are the same as in the first embodiment, and a description thereof will be omitted.
[0021]
In the present embodiment, since there is no loss due to the fixed mirror 88, the loss of light can be further reduced.
[0022]
In the second embodiment, the height of the device is increased, but the floor area can be reduced.
[0023]
In each of the above embodiments, since the reflector 84 is provided on the lamp 84, the efficiency is high. In addition, it is also possible to omit the reflection plate 85 and to improve heat dissipation.
[0024]
In each of the embodiments, the present invention is applied to the formation of deep pores in a silicon substrate. However, the present invention is not limited to this, and the present invention is not limited to this. The same can be applied to The processing shape is not limited to the hole, and can be applied to the formation of a groove and the like.
[0025]
【The invention's effect】
According to the present invention, since parallel light having a uniform shape required for processing a semiconductor substrate is incident on the semiconductor substrate, variations in the processing depth depending on the processing position can be reduced when performing a plurality of processes on the semiconductor substrate simultaneously. Can be done.
[0026]
In addition, since the uniform parallel light is perpendicularly incident on the surface of the semiconductor substrate, it is possible to avoid the influence that one of the S-polarized light and the P-polarized light becomes strong, and to reduce the reflection. Efficient use of light becomes possible.
[0027]
Furthermore, since the optical system is simple and compact, the size of the apparatus itself can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a portion according to the present invention of a semiconductor substrate processing apparatus proposed by the applicant in Japanese Patent Application No. 2001-263618. FIG. 2 is a cross-sectional view showing a main part configuration of a first embodiment of the present invention. FIG. 3 is a cross-sectional view showing a configuration of a main part of the second embodiment.
Reference Signs List 10 silicon substrate 20 electrolytic solution electrolytic bath 50 light irradiation device 82 cylindrical optical path 83 round hole 84 lamp 85 reflecting plate 86 collimator lens 88 fixed mirrors A and B diffused light C parallel light

Claims (3)

In a semiconductor substrate processing method of processing a semiconductor substrate by electrochemical reaction, using a charge generated in the semiconductor substrate by immersing the surface of the semiconductor substrate that has been marked in advance in an electrolytic solution and irradiating light,
A method for processing a semiconductor substrate, wherein uniform parallel light having a cross-sectional shape required for processing is perpendicularly incident on a surface of the semiconductor substrate. In a semiconductor substrate processing apparatus for processing a semiconductor substrate by an electrochemical reaction by using a charge generated in the semiconductor substrate by immersing a surface of the semiconductor substrate which has been marked in advance in an electrolytic solution and irradiating light,
A cylindrical optical path having a cross-sectional shape required for processing,
A light source disposed on the entrance side of the cylindrical optical path,
A collimator lens disposed on the exit side of the cylindrical optical path,
A semiconductor substrate processing apparatus, wherein the light emitted from the collimator lens is perpendicularly incident on the surface of the semiconductor substrate. 3. The semiconductor substrate processing apparatus according to claim 2, wherein a fixed mirror for changing a direction of light is provided in the cylindrical optical path.

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