JP2007281288A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device which enables to use an ESC (electrostatic chuck) method as a means for fixing an insulating substrate in a dry process and can process to an external periphery without causing a dead space on a semiconductor substrate stuck on this insulating substrate. <P>SOLUTION: This manufacturing method of the semiconductor device 1 is sequentially provided with a step of forming devices on one surface 2a of a first substrate 2 having semiconductors; a step of sticking one surface 3a of an insulating second substrate 3 on the first substrate using a first adhesive 4, so as to cover the formed devices; a step of sticking a conductive thin plate 5, so as to cover the other surface 3b of the second substrate; and a step of applying dry process for the other surface 2b of the first substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which processing is performed up to an outer peripheral region on a substrate in a dry process.

  When manufacturing a wafer level package such as an optical semiconductor device typified by a CCD device, glass or the like is used to protect the semiconductor substrate and a device formed on the semiconductor substrate side made of a semiconductor such as silicon. An insulating substrate made of a member having the above insulating properties may be attached. When a through wiring or the like is to be formed later on the semiconductor substrate side of the substrate on which the semiconductor substrate and the insulating substrate are bonded, a fine hole is formed by a dry process such as plasma processing, and the insulating layer. There are processes such as forming the insulating layer and etching the insulating layer.

  In these dry processes, in the case of plasma processing, the substrate temperature rises due to heating by plasma irradiation, which may affect the formed device. Therefore, it is necessary to cool the substrate and control it to a required temperature. In general, substrate cooling is performed by cooling an apparatus stage on which a substrate is placed by a chiller circulator or the like and sealing a cooling He gas or the like between the cooled stage and the substrate. That is, the He gas is cooled by being sealed between the cooled stage and the substrate, and further, the substrate is cooled by the cooled He gas being in direct contact with the back surface of the substrate. As a method for sealing the He gas for cooling and fixing the substrate, there are a method using an electrostatic chuck (hereinafter referred to as an ESC (Electro Static Chuck) method) and a method called a mechanical clamp. .

This ESC method is a method in which a substrate is electrostatically attracted (electrostatically attracted) by applying a voltage to the substrate and moving operating ions, sealing He gas for cooling the substrate, and cooling the substrate ( For example, see Patent Documents 1 and 2).
Further, the mechanical clamp is a method of sealing the substrate cooling He gas by physically pressing down the substrate outer peripheral region and cooling the substrate (for example, see Patent Document 3). This method can be used with an insulating substrate basically regardless of the amount of working ions in the substrate.

  In addition, in a method of manufacturing an electro-optical device in which a pair of substrates are bonded to each other, a method of providing a conductive member on the back side of one substrate has been proposed (see Patent Document 4).

However, in the case of the ESC method, if the substrate used does not contain working ions, it cannot be adsorbed, so it can be adsorbed by metals or semiconductors, but it is difficult to adsorb by an insulating substrate because there are very few working ions. It is. Therefore, there exists a problem that it cannot use for the board | substrate with which the insulating board | substrate is bonded by the back side.
Further, in the case of the mechanical clamp, it is necessary to press the outer peripheral area of the substrate processing surface by about 3 to 5 mm, so that the clamp area that is pressed by the clamp becomes a dead space and cannot be processed. Therefore, there is a problem that the processing area of the substrate is reduced and the number of chips taken is reduced. Further, since there is a step due to the clamp on the processed surface, the structure is distorted by plasma, and there is a problem of affecting the process.

The technique described in Patent Document 4 relates to a method for manufacturing an electro-optical device, and does not relate to a method for manufacturing a semiconductor device that holds a substrate subjected to a dry process. Moreover, since the technique described in Patent Document 4 is mainly intended to suppress damage to the glass substrate in the bonding process, the conductive member is provided in a portion where the glass substrate mechanically contacts the conveying means or the like. It is not always necessary to cover the entire surface of the glass substrate, and it cannot be easily applied to a method of manufacturing a semiconductor device having a different purpose. Accordingly, no proposal has been found regarding an effective means for fixing the substrate so that the semiconductor device can be manufactured so that the outer peripheral region on the substrate made of semiconductor can be processed in the dry process.
Japanese Patent Laid-Open No. 3-89745 Japanese Patent Laid-Open No. 3-91234 JP-A-4-128308 JP 2004-133110 A

  The present invention has been made in view of the above circumstances, and it is possible to use the ESC method as a means for fixing an insulating substrate in a dry process. It is an object of the present invention to provide a method for manufacturing a semiconductor device that can perform processing up to the outer peripheral region without causing any problems.

  The method for manufacturing a semiconductor device according to claim 1 of the present invention includes a step of forming a device on one surface of a first substrate made of a semiconductor, and an insulating property so as to cover the device with respect to the first substrate. A step of bonding one surface of the second substrate using a first adhesive, a step of bonding a conductive thin body so as to cover the other surface of the second substrate, and A step of performing a dry process on the other surface in order.

  According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to the first aspect, wherein the step of laminating the thin body includes, as the thin body, a member that transmits ultraviolet rays as the thin substrate. In order to bond the bodies, an ultraviolet peeling type second adhesive is used.

In the method for manufacturing a semiconductor device of the present invention, a conductive thin body is formed so as to cover the other surface of the first substrate made of semiconductor and the insulating second substrate to which one surface thereof is bonded. It has the process of bonding. Therefore, the insulating second substrate bonded to the thin body can be adsorbed (electrostatic suction) by the ESC method up to the outer peripheral area in the same manner as the inner peripheral area.
Therefore, in the dry process, the entire surface can be processed (processed) up to the outer peripheral area without generating a dead space on the first substrate bonded to the second substrate, and the processing area is widened to increase the per-wafer size. A method of manufacturing a semiconductor device that increases the number of chips can be provided. In addition, the other surface of the second substrate can be protected by the thin body.

Hereinafter, an embodiment of the present invention will be described.
The present invention proposes a method of manufacturing a semiconductor device that uses the ESC method as a means for fixing a substrate in a dry process and enables processing to the outer peripheral region of the substrate.
Specifically, in this embodiment, the first substrate and the second substrate are bonded together, and further, the conductive thin body is bonded so as to cover the second substrate, whereby the substrate is fixed by the ESC method. The first substrate can be processed by a dry process.
An example of a method for manufacturing a semiconductor device according to the present invention will be described with reference to the drawings.
1A to 1C are schematic cross-sectional schematic views showing an example of a method for manufacturing a semiconductor device according to the present invention in the order of steps.

First, as shown in FIG. 1A, the first substrate 2 is prepared. The first substrate 2 is a variety of substrates including semiconductors such as silicon, glass, and silicon-glass bonded substrate. The thickness of the first substrate 2 is desirably in the range of 100 μm to 800 μm.
A device such as a CCD, a CMOS, a pressure sensor, an acceleration sensor, or a gyro sensor is formed on one surface 2a of the first substrate 2.

  Next, as shown in FIG. 1 (b), the second substrate 2 is interposed via the first adhesive 4 so as to cover the device formed on the one surface 2a of the first substrate 2. The substrate 3 is bonded and fixed. The second substrate 3 protects a device or the like formed on the first substrate 2 side or reinforces the first substrate 2, and is made of an insulating member such as quartz glass, ceramic, or SiC. It is an insulating substrate. The thickness of the second substrate 3 is desirably in the range of 100 μm to 800 μm.

The 1st adhesive material 4 is a member which bonds and fixes the 1st board | substrate 2 and the 2nd board | substrate 3, For example, acrylic resin, an epoxy resin, silicone resin etc. are mentioned.
Further, as shown in the figure, the first adhesive 4 may be arranged so as to provide a space 4a in a predetermined region of the one surface 2a of the first substrate 2 on which the device is formed. This space 4a is a three-dimensional space such as a cavity or a groove, and an extra adhesive material 4 can be stopped in the space 4a to prevent sticking and prevent sticking. Therefore, when the second substrate 3 is fixed to the first substrate 2, the adhesive 4 is crushed and spreads in the space 4a, and the protrusion to the peripheral edge is prevented.
Moreover, the space 4a can also absorb and relieve | moderate the stress at the time of joining in this space 4a.

Furthermore, as shown in FIG.1 (c), the electroconductive thin body 5 is bonded together so that the other surface 3b of the 2nd board | substrate 3 may be covered. The thin body 5 is bonded using the second adhesive 4 so that it can be peeled later.
By bonding the thin body 5 to the second substrate 3, an insulating substrate such as quartz glass that has not been used in the ESC method can be adsorbed and fixed by the ESC method. Therefore, the first substrate 2 bonded using the second substrate 3 and the first adhesive 4 is also fixed.

  Specifically, for example, as shown in FIG. 2, the thin body 5 may be a conductive sheet 5 </ b> A composed of three layers of a transparent base material 11, a second adhesive 12, and a transparent conductive layer 13. it can.

The transparent base material 11 is a transparent base material for forming the second adhesive material 12 and the transparent conductive layer 13, and is required to have a certain degree of strength so that it is as thin as possible and the base material is not cut. Examples of the transparent substrate 11 include thin film-like members such as polyethylene terephthalate (PET) and acrylic. As for the thickness of this transparent base material 11, about 5-100 micrometers is desirable.
The transparent substrate 11 may be made of a material that transmits ultraviolet rays.

The transparent substrate 11 is not limited to a thin film-like substrate, and may be a relatively thick substrate such as glass.
Thereby, by sticking the transparent base material 11 to a substrate having a large warp, the warp of the substrate can be relaxed and adsorption by the ESC method can be performed.

The second adhesive 12 is made of a material that enables the thin body 5 to be peeled from the other surface 3 b of the second substrate 3 after processing the other surface 2 b of the first base 2.
The second adhesive 12 is preferably an ultraviolet peeling type adhesive. By using a UV peelable adhesive that has a proven record in dicing sheets or the like, the second substrate 3 can be processed without being contaminated.
As a result, when the conductive sheet 5A as the thin body 5 becomes unnecessary later, the conductive sheet 5A can be easily peeled off by irradiating with ultraviolet rays.

The transparent conductive layer 13 is a member for adsorption by the ESC method. For example, an ITO (tin-added indium oxide) film, an ITO / FTO (combination of tin-added indium oxide and fluorine-added tin) film, an organic conductive film, etc. It is comprised from the transparent thin film which has the electroconductivity.
At this time, the transparent conductive layer 13 is preferably made of a material that transmits ultraviolet rays.

Further, as shown in FIG. 3, the thin body 5 may be a conductive sheet 5 </ b> B including two layers of a transparent conductive base material 21 and an ultraviolet peelable second adhesive layer 12.
The transparent conductive substrate 21 is a transparent sheet-like substrate having conductivity, and is made of a material that transmits ultraviolet rays.
Thereby, when the conductive sheet 5B as the thin body 5 becomes unnecessary later, the conductive sheet 5B can be easily peeled off by irradiating with ultraviolet rays.

  Then, after bonding the thin body 5, although not shown, for example, the substrate is adsorbed by an ESC method in a vacuum chamber, and a through wiring is formed on the other surface 2b of the first substrate 2 by a dry process such as plasma processing. And so on. Specifically, the dry process includes silicon etching, conductor / insulating layer deposition and etching, ashing, surface treatment, and the like. At this time, the thin body 5 functions as protection on the second substrate 3 side during processing.

Thereby, the first substrate 2 and the second substrate 3 are bonded together, the second substrate 3 is sucked and fixed by the ESC method, and the outer surface of the other surface 2b of the first substrate 2 is reached without causing a dead space. Similar to the inner peripheral region, the semiconductor device 1 that has been processed entirely can be manufactured.
Therefore, in the present invention, since a mechanical clamp that generates a dead space is not required, the processing area is not reduced by the mechanical clamp, and the entire surface can be processed (processed) up to the outer peripheral area of the substrate. A semiconductor device can be manufactured so as to spread and increase the number of chips. In addition, processing variations between the outer peripheral area and the inner peripheral area of the substrate can be reduced.
Further, in the present invention, the thin body 5 can be bonded even to a substrate that has a step or a structure on the other surface 3b of the second substrate 3 and cannot be adsorbed by the ESC method as it is. Yes, it can be adsorbed by the ESC method.

It is a schematic cross-sectional schematic diagram which shows an example of the manufacturing method of the semiconductor device which concerns on this invention in process order. It is a schematic sectional drawing which shows an example of the electroconductive sheet bonded so that the insulating base material of the semiconductor device which concerns on this invention may be covered. It is a schematic sectional drawing which shows another example of the electroconductive sheet bonded together so that the insulating base material of the semiconductor device concerning this invention may be covered.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor device, 2 1st board | substrate (semiconductor board | substrate) 3 2nd board | substrate (insulating board | substrate) 4 1st contact bonding layer material, 5 thin body, 5A, 5B electroconductive sheet, 11 transparent base material, 12 2nd Adhesive material, 13 transparent conductive layer, 21 transparent conductive substrate.

Claims (2)

Forming a device on one surface of the first substrate made of a semiconductor;
Bonding one surface of the insulating second substrate to the first substrate using a first adhesive so as to cover the device;
Bonding the conductive thin body so as to cover the other surface of the second substrate;
Applying a dry process to the other surface of the first substrate;
In order. The manufacturing method of the semiconductor device characterized by the above-mentioned. The step of laminating the thin body includes
As the thin body, a member that transmits ultraviolet rays,
In order to bond the thin body to the second substrate, an ultraviolet peelable second adhesive material is used.
The method of manufacturing a semiconductor device according to claim 1, wherein each method is used.

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