KR100780285B1 - an apparatus for dry etching - Google Patents

Abstract

The present invention relates to a dry etching apparatus of a thin film.

In the conventional dry etching apparatus, a plurality of holes are formed in the upper electrode, so that the reaction gas injected from the upper surface of the chamber moves to the reaction region between the upper electrode and the lower electrode through the hole of the upper electrode to form a plasma. The upper electrode is generally formed of an aluminum-based material and covered with a protective film to prevent the upper electrode from corroding to the reaction gas. However, since the protective film has a weak bonding force in the hole portion, cracks are generated during plasma formation, and impurities fall on the substrate.

In the present invention, a plurality of nozzles are formed outside the upper electrode without forming a hole in the upper electrode to inject the reaction gas. Accordingly, cracks do not occur in the protective film of the upper electrode during plasma generation, and generation of impurities by the protective film can be prevented.

Dry etching,

Description

Apparatus for dry etching             

1 is a cross-sectional view of a conventional dry visual device.

2 is a plan view of the upper electrode of the conventional dry etching device.

3 is a cross-sectional view of a dry etching apparatus according to a first embodiment of the present invention.

4 is a plan view of the upper electrode of the dry etching apparatus according to the first embodiment of the present invention.

5 is a cross-sectional view of a dry etching apparatus according to a second embodiment of the present invention.

6 is a plan view of the upper electrode of the dry etching apparatus according to the second embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

110: chamber 111: exhaust port

112 gas inlet 121 lower electrode

122: substrate 123: lower shield

131: upper electrode 132: nozzle

133: upper shield

The present invention relates to a device for manufacturing a semiconductor device, and more particularly to a dry etching device of a thin film.

Recently, with the rapid development of the information society, the necessity of a flat panel display having excellent characteristics such as high density integrated circuit fabrication, thinning, light weight, and low power consumption has emerged.

Integrated circuits are classified into large scale integration (LSI), very large scale integration (VLSI), and the like according to their integration degree.

On the other hand, a liquid crystal display (liquid crystal display) having advantages such as resolution, color display, image quality, etc. of the flat panel display device is widely used, the liquid crystal display includes an array substrate in which a plurality of thin film transistors are arranged.

An array substrate and a high density integrated circuit of such a liquid crystal display device are formed by repeating a process of depositing and photographic etching a thin film.

Photolithography consists of application and baking of photoresist, exposure, development, and etching of thin films. The etching methods of thin films are dry etching using gas plasma and wet etching using chemical solution. It is largely divided by law.                         

Wet etching is mainly applied to the formation of indium-tin-oxide (ITO) patterns used for metal films or pixel electrodes used for wiring, and has good selectivity and large area etching. It is excellent in uniformity, productivity and the like, and it is possible to reduce the price and to obtain a cleaning effect at the same time.

These wet etching methods include a dipping method and a spray method. The dipping method is a method of dipping a substrate in a chemical solution, and the spray method is a method in which a chemical solution is sprayed onto a substrate. .

When the thin film is etched by a dipping method, a batch method in which a plurality of substrates are placed in a bath and processed at a time may be used. This may allow mass production to reduce manufacturing costs.

On the other hand, the dry etching method is mainly used when forming the pattern of the insulating film or the semiconductor layer, the pattern accuracy is superior to the wet etching method.

In such a dry etching method, the reaction gas introduced into the chamber is plasma discharged under a constant pressure, and the thin film is etched by physical collision or chemical reaction by the generated ions or radicals.

Dry etching may be classified into a plasma etching method and a reactive ion etching method according to a reaction method.

In the plasma etching method, mainly radicals of the generated reactants are used for etching by chemical reaction. The radicals are not affected by the direction of the electric field because the molecules are in a neutral state where they are excited. Therefore, the etching ratio is the same regardless of the electric field direction (isotropy) etching, the physical impact is small, there is little effect on the lower layer is advantageous for selective etching.

In contrast, reactive ion etching is mainly performed by etching ions accelerated by an electric field and colliding with a thin film. However, since an etch ratio varies depending on the direction since ions accelerate in an electric field direction, anisotropy etching is performed. Is done.

Hereinafter, a conventional dry etching apparatus using plasma will be described with reference to the accompanying drawings.

The dry etching apparatus includes a chamber, which is a sealed reaction container having an object to be treated, a gas inlet for storing gas material introduced into the chamber and introducing the gas material into the chamber, and a gas material flowing from the gas inlet into plasma in the chamber. It consists of a power supply that is electrically connected to the inside of the chamber to make.

1 is a cross-sectional view illustrating a chamber of a conventional dry etching apparatus, and FIG. 2 is a plan view of an upper electrode portion of a conventional dry etching apparatus.

As shown, a gas inlet 12 for introducing a reaction gas into the chamber 10 from a gas inlet (not shown) is formed on the upper surface of the chamber 10 that is a reaction container, An exhaust port 11 for discharging air in the chamber 10 is formed on the lower surface. In the chamber 10, the lower electrode 21 and the upper electrode 31 are arranged at regular intervals, and the space between the two electrodes 21 and 31 becomes a reaction region. The upper electrode 31 is grounded, has a plurality of holes 32, and first to third gas jet plates 41, 42, and 43 are disposed on the upper electrode 31, respectively. The third gas jet plates 41, 42, 43 are for evenly distributing the gas introduced into the chamber 10 through the gas inlet 12. Therefore, the gas introduced into the chamber 10 is delivered to the upper electrode 31 in an even distribution through the gas injection plates 41, 42, and 43, and the upper electrode 31 and the hole through the hole of the upper electrode 31. The diffusion is sent to the reaction region between the lower electrodes 21.

Next, the substrate 22 including the object to be processed, that is, the thin film to be patterned, is placed on the lower electrode 21. The lower electrode 21 is connected to an external power supply so that a voltage having a radio frequency is applied.

Shields 23 and 33, which are shields, are formed around the lower electrode 21 and the upper electrode 31. Particularly, the upper shield 33 extends partially within the reaction region, so that the plasma density is increased. It serves to increase in the portion corresponding to the substrate 22.

In the dry etching apparatus, since the plurality of holes 32 are formed in the upper electrode 31, the plasma density may be uniform by uniformly injecting the gas, but the first to third gas ejection plates 41 and 42 may be used. , 43, and the like, and the gas injection plate 41, 42, 43 has a disadvantage in that the structure is complicated and expensive to manufacture.

In general, aluminum is used as an electrode material of a dry etching apparatus, and in order to prevent corrosion of the electrode by the reaction gas, anodization is performed to form a thin protective film on the surface of the electrode. However, since the passivation layer has a weak bonding force in the hole 32 portion, cracks are generated in the hole 32 portion during plasma generation, and some portions are separated and fall on the substrate (22 in FIG. 1). Defect will appear.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to provide a dry etching apparatus that can prevent the etching failure by the protective film of the electrode by allowing the reaction gas is injected from the outer electrode. .

It is another object of the present invention to provide a dry etching apparatus which is simple in structure and which can reduce manufacturing costs.

Dry etching apparatus according to the present invention for achieving the above object is the chamber and the upper electrode located inside the chamber, and the lower electrode spaced apart from the upper electrode and the object to be placed, the reaction gas is introduced into the chamber Gas inlet, located outside the upper electrode, a nozzle for transferring gas from the gas inlet between the upper electrode and the lower electrode, an exhaust for discharging air in the chamber, and the power connected to the upper electrode and the lower electrode It includes a supply.

Here, the dry etching apparatus may further include a shield made of ceramic around the upper electrode.                     

The nozzle may be located between the top electrode and the shield, or may be located outside the shield.

As described above, in the dry etching apparatus according to the present invention, a plurality of nozzles are formed outside the upper electrode to inject the reaction gas, thereby preventing cracks in the protective film of the upper electrode during plasma generation, and preventing the generation of impurities by the protective film. In addition, the structure of the device for gas injection can be simple and reduce the manufacturing cost.

Hereinafter, a dry etching apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of a dry etching apparatus according to the present invention, Figure 4 is a plan view of the upper electrode portion of the dry etching apparatus according to the present invention.

As shown, as shown, a gas inlet 112 for introducing the reaction gas into the chamber 110 from the gas inlet (not shown) is formed on the upper surface of the chamber 110 that is a reaction vessel, An exhaust port 111 for discharging air in the chamber 110 is formed at a lower surface of the chamber 110. In the chamber 110, the lower electrode 121 and the upper electrode 131 are disposed at a predetermined interval, and the space between the two electrodes 121 and 131 becomes a reaction region in which plasma is generated. The upper electrode 131 is grounded, and a shield 133 made of a material such as ceramic is formed around the upper electrode 131, and a plurality of nozzles are formed between the upper electrode 131 and the shield 133. 132 is formed. Here, the shield 133 has a structure in which a part is located in the reaction region to prevent the plasma from spreading, and the nozzle 132 forms a 'b' shape along the shape of the shield 133.

Next, a substrate 122 including an object to be processed, that is, a thin film to be patterned, is placed on the lower electrode 121. The lower electrode 121 is connected to an external power supply and a voltage having a radio frequency is applied, and a shield 123, which is a shield made of ceramic, is formed around the lower electrode 121.

In the present invention, the upper electrode 131 and the lower electrode 121 may be formed of aluminum, and may be anodized to form a protective film in order to prevent corrosion by plasma.

Meanwhile, in the present invention, the end of the nozzle 132 is adjusted to increase the uniformity of gas injection, so that the end of the nozzle 132 is evenly directed at the upper surface of the substrate 122.

Therefore, in the present invention, since the hole for gas injection is not formed in the upper electrode, the protective film on the surface of the upper electrode can be prevented from falling off, and by injecting gas through a nozzle that ejects the fluid from the small hole at the end. The fall of the uniformity of plasma density can be prevented.

In the above embodiment, although the nozzle is disposed between the upper electrode and the shield, the nozzle may be disposed outside the shield. The cross-sectional view of the dry etching apparatus according to the second embodiment of the present invention and a plan view of the upper electrode portion are shown in FIGS. 6, respectively. Since the second embodiment has the same structure as the first embodiment except for the position of the nozzle, it will be briefly described.

As shown in the drawing, the upper electrode 231 and the lower electrode 221 are disposed at a predetermined interval in the chamber 210 having the lower exhaust port 211 and the upper gas injection port 212, and the lower electrode 221. On the upper portion of the substrate 222, which is a sample, is placed. Shields 223 and 233 made of ceramic surround the lower electrode 221 and the upper electrode 231 and surround the lower electrode 221 and the upper electrode 231, and a plurality of nozzles outside the upper shield 233. 232 is formed surrounding the shield 233.

Here, in order to increase the uniformity of the gas injection, the end of the nozzle 232 may be directed toward the top surface of the substrate 222 evenly.

The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

In the dry etching apparatus according to the present invention, by forming a plurality of nozzles around the upper electrode and injecting the reaction gas, cracks may be prevented from occurring in the protective film of the upper electrode during plasma generation, and generation of impurities by the protective film may be prevented. In addition, the structure of the device for gas injection is simple and the manufacturing cost can be reduced.

Claims (5)

A chamber; An upper electrode positioned inside the chamber; A lower electrode positioned to be spaced apart from the upper electrode and having an object to be treated placed therein; A gas inlet for introducing a reaction gas into the chamber; A nozzle positioned on a side of the upper electrode and transferring the reaction gas introduced into the gas inlet between the upper electrode and the lower electrode; An exhaust unit for discharging air in the chamber; A power supply unit connected to the upper and lower electrodes Dry etching apparatus comprising a. The method of claim 1, Dry etching apparatus further comprises a shield made of a ceramic around the upper electrode. The method of claim 2, And the nozzle is positioned between the upper electrode and the shield. The method of claim 2, And the nozzle is located outside the shield. The method of claim 1, The nozzle is a dry etching apparatus, characterized in that the straight or 'b' shape of the lower end extending horizontally below the upper electrode.

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