JPH06168932A - Device for patterning semiconductor device - Google Patents

Abstract

PURPOSE:To provide a patterning device, which is capable of performing a patterning by a simpler process, for a semiconductor device. CONSTITUTION:A patterning object substrate 30 is put on a support base 20 in a chamber 10. A mask plate 40 formed with an opening window of a shape corresponding to a pattern to be formed is put on this substrate and is attracted and fixed by a magnet 21. While the air and pressure in the chamber are exhausted and decompressed by an exhaust tube 12, reactive gas is introduced through a gas introducing tube 11. An alternating current is fed to generate discharge between the support electrode 20 and an opposed electrode 50 by an RP generator 60 and the introduced gas is brought into a plasma state. The surface, which is exposed through the opening window in the mask plate 40, of the substrate generates a chemical reaction by the plasma gas and a film consisting of another compound is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a patterning device for semiconductor devices, and more particularly to a patterning device suitable for manufacturing thin film transistors, solar cells, various sensors and the like.

[0002]

2. Description of the Related Art A general semiconductor device has a structure in which a plurality of layers are laminated in various patterns on a substrate.
Therefore, in the manufacturing process of the semiconductor device, the formation of the layer on the substrate and the patterning of the formed layer are repeatedly performed. The most commonly used patterning method conventionally used is photolithography. In this method, a resist layer is formed on a layer to be patterned, and exposure is performed with a mask on which a predetermined pattern is drawn placed on the resist layer, and the resist layer is developed to expose or unexpose. The part is removed, and the remaining resist layer is used as a protective film to etch the patterning target layer.

[0003]

In the photolithography method described above, in order to pattern one target layer, formation of a resist layer, exposure using a mask,
Four steps of developing and etching the resist layer are required, and a processing device is required in each step. Generally, in order to manufacture one semiconductor device, patterning for many layers is required.
By the end of the whole manufacturing process, a complex process with a very large number of steps has to be carried out. Therefore, there is a problem in that manufacturing takes time and costs increase.

Therefore, an object of the present invention is to provide a patterning device for a semiconductor device which can perform patterning by a simpler process.

[0005]

[Means for Solving the Problems]

(1) The first invention of the present application relates to a material to be patterned in a device used in a patterning step of forming a predetermined pattern by removing a part of a material layer constituting a semiconductor device in a manufacturing process. A chamber for accommodating the substrate on which the layer is formed, an evacuation means for reducing the pressure in the chamber, and a reaction for introducing a reactive gas that causes a chemical reaction with the material layer to be patterned into the chamber. Gas introducing means, a supporting electrode for supporting the substrate in the chamber, a counter electrode provided to face the supporting electrode, and an electric field generating means for generating an electric field between the supporting electrode and the counter electrode, When a substrate is placed on the supporting electrode and a metal mask plate having an opening window having a shape corresponding to a predetermined pattern to be formed is placed on the substrate. Is provided with a magnetic field generating means for generating a magnetic field having a function of attracting and fixing the metal mask plate toward the support electrode so as to be distributed substantially uniformly on the substrate, and the generated electric field The reactive gas is turned into plasma in the chamber, and the surface of the material layer exposed through the opening window of the mask plate and the reactive gas turned into plasma are chemically reacted to form another compound.

(2) The second invention of the present application is, in the patterning apparatus for a semiconductor device according to the first invention, further provided with a position adjusting mechanism for moving the mask plate in the chamber in the horizontal direction, and as a magnetic field generating means. The electromagnet is used so that the mask plate can be sucked and fixed by energizing the electromagnet after the alignment by the position adjusting mechanism is completed.

[0007]

Operation The present invention provides a patterning device suitable for carrying out the novel patterning method. In this novel patterning method, a mask plate having a physical opening window physically covers a part of the material layer on the substrate to be patterned. In this state, when the substrate is placed in the chamber of a predetermined reactive gas that has been turned into plasma, a chemical reaction occurs with the material layer exposed through the opening window of the mask plate, and another compound is formed only in this exposed portion. Let After all,
The portion covered with the mask plate remains the original material layer, but a pattern made of another compound is formed in the portion exposed by the opening window. During this chemical reaction, the mask plate made of metal is in a state of being attracted and fixed to the surface of the material layer by the attraction force of the magnetic field generated by the magnetic field generator. Moreover, since this magnetic field is distributed almost uniformly on the substrate, a chemical reaction with the gas turned into plasma also occurs uniformly on the substrate, and a uniform pattern can be formed.

As described above, when the processing by the patterning apparatus for a semiconductor device according to the present invention is performed, a pattern is formed by another compound on the material layer to be patterned on the substrate. Therefore, after that, if etching is performed by a method in which the original material layer and the different compound have different etching rates, desired patterning becomes possible. According to this method, the patterning for one layer is completed by the two-step process of compound formation and etching in a reactive gas atmosphere by the apparatus according to the present invention.

[0009]

The present invention will be described below based on illustrated embodiments. First, the principle of a novel patterning method using the device according to the present invention will be described. Here, a process of patterning a metal wiring layer made of Cr on a glass substrate will be described as an example with reference to the cross-sectional view of FIG. First, as shown in FIG. 1A, Cr is deposited on the glass substrate 1 to form a Cr material layer 2. As a method of depositing Cr, a general film forming method which has been conventionally used may be used. For example, a vacuum vapor deposition method, a sputtering method, a CVD method, a plating method or the like can be used.
The thickness of the Cr material layer 2 is 0.0, as will be described later.
The range of 1 to 1 μm is preferable, and particularly 0.05 to 0.5.
It is preferable to set it in the range of μm.

Then, the glass substrate 1 having the Cr material layer 2 formed thereon is housed in the chamber of the patterning apparatus according to the present invention, and as shown in FIG. Then, a metal mask plate 3 is placed on and covered. As will be described later, since the mask plate 3 made of metal is attracted downward in the figure by the attraction force of the magnet, the mask plate 3
And the Cr material layer 2 are in close contact with each other. The mask plate 3 is provided with an opening window 4 having a shape corresponding to a predetermined pattern to be formed as a metal wiring layer. The opening window 4 forms a through hole, and a portion of the surface of the Cr material layer 2 corresponding to the opening window 4 is exposed. continue,
The inside of this chamber is decompressed and a reactive gas is introduced. The reactive gas used here may be any gas as long as it chemically reacts with the surface of the Cr material layer 2 to generate a compound different from Cr, but here, a gas containing fluorine is reacted. Used as a natural gas. This reactive gas is
It is turned into plasma in the chamber. Thus, when the one shown in FIG. 1 (b) is placed in a plasma gas atmosphere containing fluorine, the exposed surface of the Cr material layer 2 exposed by the opening window 4 causes a chemical reaction, and The fluorine compound film 5 is formed. Depending on the conditions, a coating film of fluorine may be formed, but in this specification, such a fluorine coating film is also referred to as a fluorine compound film 5. When the above chemical reaction is completed,
This is taken out from the chamber and the mask plate 3 is removed. FIG. 1C is a diagram showing a state in which the mask plate 3 has been removed, and a state in which the fluorine compound film 5 is formed on the surface of the Cr material layer 2 is clearly shown.

What is important in carrying out the above-mentioned chemical reaction in the plasma gas atmosphere is that the reaction occurs only on the exposed surface of the Cr material layer 2 and not on the non-exposed surface. For that purpose, the plasma gas must be supplied only to the exposed surface and not to contact the unexposed surface. This is possible by improving the physical adhesion between the upper surface of the Cr material layer 2 and the lower surface of the mask plate 3. Generally, the upper surface of the glass substrate 1 has a considerable degree of smoothness, and C deposited thereon by a vacuum vapor deposition method, a sputtering method, a CVD method, a plating method or the like.
The upper surface of the r material layer 2 is also a surface having a fairly smooth surface. Therefore, the mask plate 3 having the lower surface having the same degree of smoothness
If the reaction is carried out while keeping the mask plate 3 in close contact with the Cr material layer 2 by using, it is possible to prevent the plasma gas from flowing between the two.
The fluorine compound film 5 is formed only on the exposed surface of the material layer 2. A magnet is used to bring the mask plate 3 into close contact with the Cr material layer 2 as described later.

Now, as shown in FIG. 1C, when the fluorine compound film 5 is formed in a predetermined pattern, selective etching is performed on it. That is, an etching method with different etching rates is performed between the Cr material layer 2 and the fluorine compound film 5. For example, when etching is performed using a ceric ammonium nitrate solution, the etching rate for the Cr material layer 2 is about 10 times the etching rate for the fluorine compound film 5, and the fluorine compound film 5 having a slow etching rate is used as a mask. , Cr material layer 2
It is possible to remove only the part of the film where the fluorine compound film 5 is not formed. Thus, FIG.
As shown in (d), only the Cr patterning layer 6 of the Cr material layer 2 remains without being removed by etching, and this Cr patterning layer 6 becomes a target metal wiring layer. Even if dry etching using CCL ₄ is performed as another etching method, the same etching selection ratio can be obtained.

As described above, the thickness of the Cr material layer 2 is preferably in the range of 0.01 to 1 μm. This is for the following reason. That is, when the thickness of the Cr material layer 2 is 0.01 μm or less, the resistance becomes too high as a metal wiring layer, which is not practical, and the layer may disappear due to the sputtering effect during the chemical treatment in the plasma atmosphere. Is inappropriate. If the thickness of the Cr material layer 2 is 1 μm or more, the ratio of the thickness of the Cr material layer 2 to the thickness of the fluorine compound film 5 becomes too large, so that the fluorine compound film 5 functioning as a mask is etched during the etching process. It is also unsuitable because it is removed or the shape of the Cr patterning layer 6 is deteriorated due to the influence of side etching.

The principle of the novel patterning method devised by the inventor of the present application has been described above. In short, this patterning method is constituted by a plasma gas reaction process (FIG. 1 (b)) which is the first step and an etching process (FIG. 1 (d)) which is the second step. The patterning device according to the present invention is a device for performing this former step. An embodiment of this device will be described below with reference to FIG. In the chamber 10, a reactive gas (for example, a gas containing fluorine) is introduced from the gas introduction pipe 11.
Is introduced and is evacuated to a vacuum through an exhaust pipe 12 by an exhaust system (such as a vacuum pump not shown). A support electrode 20 is provided below the chamber 10. A magnet 21 is built in the support electrode 20, and a patterning target substrate 30 is placed on the upper surface thereof. The patterning target substrate 30 is, for example,
As shown in FIG. 1 (a), this is a substrate in which a Cr material layer 2 is formed on the upper surface of a glass substrate 1. On this, mask plate 40
(Corresponding to the mask plate 3 in FIG. 1) is placed. In this embodiment, a support frame 41 is provided around the mask plate 40. Further, on the upper part of the chamber 10, the supporting electrode 2
A counter electrode 50 is provided at a position opposed to 0. RF AC power is supplied between the counter electrode 50 and the support electrode 20 by an RF generator 60, and R electrode is provided between both electrodes.
An F AC electric field is generated.

The pre-step process of patterning using this apparatus is performed as follows. First, the patterning target substrate 30 is placed on the upper surface of the support electrode 20, and the mask plate 40 is placed thereon. Since the mask plate 40 is made of metal and the support electrode 20 has the magnet 21 built therein,
The mask plate 40 is attracted downward by the magnet 21 and is fixed on the upper surface of the patterning target substrate 30 while being pressed. That is, in the example shown in FIG. 1B, the mask plate 3 is fixed in a state of being in close contact with the upper surface of the Cr material layer 2. Such close fixing is important in order to prevent the reactive gas from flowing into the area other than the opening window 4. Subsequently, the chamber 10 is evacuated to a vacuum through the exhaust pipe 12 to maintain a reduced pressure state (for example, 5 Pa), and the reactive gas (for example, CF ₄ and O ₂ is mixed at a mixing ratio of 95: 5) through the gas introduction pipe 11. The mixed gas) is introduced into the chamber 10 at a predetermined flow rate (for example, 100 cc per minute).
Then, the RF generator 60 gives AC power (for example, 500 W) to the support electrode 20 and the counter electrode 50,
An alternating electric field is generated between both electrodes to cause discharge, and the introduced reactive gas is turned into plasma. By holding this state for a predetermined time (for example, 3 minutes), the mask plate 4
A fluorine compound film 5 is formed on the exposed surface from the 0 opening.
In the subsequent subsequent step, the patterning target substrate 30 taken out from the chamber 10 may be dipped in, for example, a solution of cerium ammonium nitrate to etch it.

By the way, an apparatus for applying a AC electric field in a depressurized chamber and converting the introduced reactive gas into plasma to carry out a predetermined chemical reaction has been conventionally used when performing a sputtering process. Further, an apparatus for providing a magnet in a chamber to generate a magnetic field is also known. However, the device according to the present invention is distinguished from this type of conventional device in that the magnetic field generated by the magnet 21 is substantially evenly distributed with respect to the patterning target substrate 30. That is, in the device of the present invention, the magnet 21 that produces the magnetic force lines shown by the broken line in FIG. 3 is prepared on the support electrode 20. It can be seen that the lines of magnetic force are distributed almost uniformly on the patterning target substrate 30. Such uniform distribution of the magnetic field is necessary to make the reaction by the plasma gas uniform. A device for generating a magnetic field in a chamber is also used in a conventional sputtering device or the like, but this is used for the purpose of concentrating a reaction by a plasma gas on a specific portion of a substrate to be subjected to a sputtering process. It is a thing. That is, the reaction by the plasma gas can be localized by generating a localized magnetic field. Therefore, the magnetic field generator used in the conventional sputtering apparatus or the like is provided for the purpose of generating a localized magnetic field on the substrate.

On the other hand, the magnetic field generator used in the present invention is intended to attract and fix the mask plate 40, and not to localize the reaction by the plasma gas. On the contrary, if the reaction by the plasma gas is localized, there arises a problem. This is because unevenness occurs in the pattern of the fluorine compound film 5 caused by the reaction of the plasma gas. Therefore, in the apparatus of the present invention, although it is necessary to generate a magnetic field to attract and fix the mask plate 40, the magnetic field needs to be substantially uniform with respect to the patterning target substrate 30. Therefore, in the apparatus of the present invention, as shown in FIG. 3, a disk-shaped permanent magnet having a larger cross section than the patterning target substrate 30 or a patterning target substrate 3 as shown in FIG.
An electromagnet constituted by an iron core 22 having a cross section larger than 0 and a coil 23 wound around the iron core 22 is
It is preferably used as 1. By using such a magnet 21, the mask plate 40 made of metal is sufficiently attracted and fixed, and the patterning target substrate 30 is not affected by the reaction by the plasma gas.
It becomes possible to apply a substantially uniform magnetic field.

A position at which the mask plate 40 is moved horizontally (in the direction of arrow A in FIG. 2) in the chamber 10 so that the mask plate 40 and the patterning target substrate 30 can be easily aligned with each other. It is advisable to further provide an adjusting mechanism. As such a position adjusting mechanism, a general mechanism conventionally used for aligning the photomask in the photolithography method may be used. For the patterning target substrate 30 and the mask plate 40,
Positioning marks may be provided respectively and the positions may be adjusted while observing these marks optically. In this case, it is preferable to use an electromagnet as the magnet 21. If an electromagnet is used, when the alignment in the direction of arrow A in FIG. 2 is performed, the energization of this electromagnet is stopped, and when the alignment is completed, the electromagnet is energized to move the mask plate 40 to the position shown in FIG. It can be fixed by suction in the direction of arrow B.

The present invention has been described above based on the illustrated embodiment, but the present invention is not limited to this embodiment and can be implemented in various modes other than this. For example, in the above-described embodiment, the discharge for converting the reactive gas into plasma is performed by supplying the RF AC power, but this discharge may be performed by supplying the DC power. Further, this discharge may be performed by a cathode couple type or an anode couple type. Further, the discharge may be performed using a narrow gap, a magnetron, a triode, or the like.

The patterning method according to the present invention is
Since it is necessary to physically contact the mask plate, it is somewhat difficult to improve the dimensional accuracy as compared with the photolithography method. Therefore, it is preferably used for patterning a semiconductor device such as a thin film transistor, a solar cell, and various sensors that does not require relatively dimensional accuracy, rather than being used for patterning a semiconductor device such as a MOS transistor that requires dimensional accuracy.

[0021]

As described above, according to the patterning apparatus for a semiconductor device of the present invention, the substrate to be patterned is housed in the chamber, the metal mask plate is placed on the substrate, and the magnet plate is attracted and fixed by the magnet. Since the chemical reaction is caused by the converted reactive gas, patterning can be performed by a simpler process.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a patterning process using a patterning device according to the present invention.

FIG. 2 is a vertical cross-sectional view showing the basic configuration of a patterning device according to an embodiment of the present invention.

3 is a cross-sectional view showing a magnetic field of a magnet 21 of the device shown in FIG.

FIG. 4 is a diagram showing an example in which a magnet 21 of the device shown in FIG. 2 is composed of an electromagnet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Cr material layer 3 ... Mask plate 4 ... Opening window 5 ... Fluorine compound film 6 ... Cr patterning layer 10 ... Chamber 11 ... Gas introduction pipe 12 ... Exhaust pipe 20 ... Support electrode 21 ... Magnet 22 ... Iron core 23 ... Coil 30 ... Patterning target substrate 40 ... Mask plate 41 ... Support frame 50 ... Counter electrode 60 ... RF generator

Claims (2)

[Claims] 1. A device used in a patterning process for forming a predetermined pattern by removing a part of a material layer constituting a semiconductor device during a manufacturing process, wherein a material layer to be patterned is formed. A chamber for accommodating the formed substrate, an evacuation means for reducing the pressure in the chamber, and a reactive gas introducing means for introducing a reactive gas that causes a chemical reaction with the material layer into the chamber, A supporting electrode for supporting the substrate in the chamber; a counter electrode provided to face the supporting electrode; an electric field generating unit for generating an electric field between the supporting electrode and the counter electrode; When the substrate is placed on a metal mask plate on which an opening window having a shape corresponding to a predetermined pattern to be formed is formed. And a magnetic field generating means for generating a magnetic field having a function of attracting and fixing the metal mask plate toward the support electrode so as to be distributed substantially evenly with respect to the substrate. The reactive gas is turned into plasma in the chamber, and the surface of the material layer exposed through the opening window of the mask plate is chemically reacted with the reactive gas turned into plasma to form another compound. A patterning device for a semiconductor device that features. 2. The patterning device according to claim 1, further comprising a position adjusting mechanism for moving the mask plate in the chamber in the horizontal direction, and using an electromagnet as the magnetic field generating means, the position adjusting mechanism completes the alignment. After that, the electromagnet is energized so that the mask plate can be suction-fixed and fixed.