CN1501762A - Plasma treatment device - Google Patents

Abstract

The invention provides a plasma processing device, which mainly improves the structure of an upper electrode plate in the plasma processing device. The upper electrode plate of the present invention includes a gas distribution plate; an insulating cover plate covering an upper portion of the gas distribution plate; and a plurality of fixing parts for fixing the gas distribution plate and the insulating cover plate. Each of the fixing portions includes a screw and a nut, the screw includes a head portion and a shank portion, and the head portion of the screw has an external thread thereon. The screw caps are formed of an insulating material and each has an internal thread on an inner surface thereof corresponding to the external thread of the screw head to be engaged with each screw head. The head of the screw is protected by the insulating screw cap, so that the screw can bear the long-time bombardment of plasma, avoid the phenomenon of arc discharge, eliminate the defects of products and improve the rate of excellence.

Description

Plasma treatment device

technical field

The invention relates to a plasma processing device, in particular to a plasma processing device capable of avoiding arc discharge.

Background technique

In the TFF-LCD front-end array (array) manufacturing process, it is often necessary to use a plasma processing device for etching and deposition. For example, etching of an amorphous silicon layer or a polysilicon layer in a TFT is performed using a plasma processing apparatus.

FIG. 1 shows a schematic diagram of a conventional plasma processing device, which includes a processing chamber 1 with an upper electrode plate 10 and a lower electrode plate 20 inside. A gas supply system 30 and a power source 40 are connected to the upper electrode plate 10, and the power source 40 may be radio frequency (radio frequency RF). The gas supply system 30 can supply gas into the cavity 1 , and the radio frequency is used to provide a voltage difference between the upper and lower electrode plates 10 , 20 .

The processing chamber 1 is generally made of aluminum, and the inner surface of the chamber is usually anodized to form an anodized aluminum film to resist plasma erosion. The lower electrode plate 20 is usually made of aluminum, and the surface is treated with anodic oxidation. A substrate (such as a glass substrate or a silicon substrate) S is placed on the lower electrode plate 20 and etched or deposited using the plasma generated in the chamber 1 .

FIG. 2 shows a bottom view of the upper electrode plate 10, which includes a cross-shaped gas distribution plate (shower plate) 12, and an insulating cover plate 14 covering the gas distribution plate 12, such as a ceramic cover plate. The ceramic cover plate 14 is generally composed of four ceramic cover plates 14a. The gas distribution plate 12 is arranged at the bottom of the joints of the ceramic cover plates 14 , and a plurality of screws 50 are provided to fix the gas distribution plate 12 and the ceramic cover plate 14 . A plurality of air holes 16 are also provided on the gas distribution plate 12 . FIG. 3 shows the configuration of a screw 50 typically used to secure the gas distribution plate 12 and the ceramic cover plate 14 , including a head 52 and a shank 54 . The shank 54 is threaded, while the head 52 is not threaded. When the fixing is completed, the head 52 of the screw 50 will be exposed. As shown in FIG. 2 , the head 52 is exposed outside the gas distribution plate 12 . The material of the screw 50 is generally anodized aluminum film to resist plasma erosion.

Referring to Fig. 1 and Fig. 2 simultaneously, when carrying out plasma etching or depositing, under the state of suitable low pressure in whole chamber 1, by gas supply system 30 supply gas, gas is supplied to via the gas hole 16 of upper electrode plate 10 Inside the cavity 1 , a radio frequency 40 is activated to apply a voltage difference between the two electrode plates 10 and 20 . In this way, these originally neutral gas molecules will be excited or dissociated into various charged ions, atomic groups, molecules, and electrons. The composition of these particles is called plasma. Part of the particles will be accelerated due to electrical reasons, and then bombard the surface of the electrode plate or other parts in contact with it. This phenomenon is the plasma ion bombardment phenomenon. The generated plasma etches or deposits the substrate S placed on the lower electrode plate 20 .

Any material that comes into contact with the plasma must be a non-conductive material. However, some parts in the cavity 1 are often bombarded by long-term and intense plasma ions after being used for a period of time. For example, the head 52 of the above-mentioned screw 50 used to fix the gas distribution plate 12 and the ceramic cover plate 14 will be exposed to the plasma. Parts or on the surface of the thinner anodized film are damaged, and the damaged surface will form a conductor. This phenomenon is called arc discharge. Under the continuous bombardment of the plasma, the aluminum inside the part falls onto the product (glass), thus producing defects and causing a serious loss of good rate.

An inductively coupled plasma (ICP) processing device is a commonly used plasma processing device that can generate high-density plasma. In the ICP processing device, in addition to applying a potential difference between the upper and lower electrode plates 10 and 20, a coil (not shown) is added above the upper electrode plate 10, which makes the plasma in the chamber 1 Charged ions gain greater energy. In addition, the operating pressure of the cavity is usually controlled in a very low range, between about a few to tens of mTorr, so that the average free path of the particles increases to reduce the frequency of collisions between particles; The RF power applied to the lower electrode plate 20 of the substrate S is also relatively high. Under the cooperation of the above conditions, the ion bombardment ability in the plasma becomes stronger, and the parts in the cavity, such as the above-mentioned screws 50 for fixing the gas distribution plate 12 and the ceramic cover plate 14, will have more serious arc discharge phenomenon.

Contents of the invention

In view of this, the purpose of the present invention is to provide a plasma processing device to solve the above problems, which can avoid the arc discharge phenomenon caused by the plasma ion bombardment of the screws used to fix the gas distribution plate and the insulating cover plate. For the TFT-LCD manufacturing process, it can also avoid the occurrence of bright spots, eliminate product defects and improve the good rate.

To achieve the purpose of the present invention, the plasma treatment device of the present invention comprises:

a processing chamber;

The lower electrode plate is located in the processing chamber, on which a substrate to be treated by plasma can be placed;

a gas supply system for supplying gas into the processing chamber;

an upper electrode plate, located in the processing chamber, above the lower electrode plate; and

A power source is used to apply a voltage difference between the upper and lower electrode plates to convert the gas in the processing chamber into plasma.

The above-mentioned upper electrode plate includes:

a gas distribution plate, which has an upper portion and a bottom portion, and the bottom portion has a plurality of gas holes, and the gas holes communicate with the gas supply system, so that gas can be supplied into the processing chamber through the gas holes;

an insulating cover plate covering the upper portion of the gas distribution plate; and

A plurality of fixing parts are used to fix the gas distribution plate and the insulating cover plate, each fixing part includes a screw and a nut, the screw includes a head and a rod, and the head of the screw has The nuts are made of insulating material, and the inner surface of each nut has an inner thread corresponding to the outer thread of the screw head, so as to engage with each screw head.

Description of drawings

Figure 1 shows a schematic diagram of a conventional plasma processing device;

Figure 2 shows a bottom view of a conventional electrode plate;

Fig. 3 shows the structure of conventional screws for fixing the gas distribution plate and the ceramic cover plate;

Figure 4 shows a schematic diagram of a plasma processing apparatus according to a preferred embodiment of the present invention;

Fig. 5 shows the schematic diagram of the bottom surface of the upper electrode plate of the present invention;

Fig. 6 shows the structure of the fixed part of the present invention, and the combination of the fixed part with the gas distribution plate and the insulating cover.

Detailed ways

FIG. 4 shows a schematic diagram of a plasma processing apparatus according to a preferred embodiment of the present invention. The plasma processing device includes a processing chamber 1 , a gas supply system 30 and a power source 40 . Inside the processing chamber 1 , there is an upper electrode plate 60 and a lower electrode plate 20 . A substrate S to be subjected to plasma treatment can be placed on the lower electrode plate 20, such as a semiconductor substrate used in the semiconductor manufacturing process, or a glass substrate or transparent plastic substrate used in the TFT-LCD manufacturing process. The gas supply system 30 can supply gas into the processing chamber 1 . The power source 40 may be radio frequency (RF) for applying a voltage difference between the upper and lower electrode plates 60 and 20 to convert the gas in the processing chamber 1 into plasma.

The present invention is characterized by the improvement of the upper electrode plate in the plasma processing apparatus. Therefore, the difference between the conventional plasma processing apparatus shown in FIG. 1 and the plasma processing apparatus of the present invention shown in FIG. 4 is that a different upper electrode plate is used. FIG. 5 shows a schematic bottom view of the upper electrode plate 60 of the present invention. The upper electrode plate 60 includes a gas distribution plate 12 , an insulating cover plate 14 and a plurality of fixing parts 70 . The fixing part 70 is used for fixing the gas distribution plate 12 and the insulating cover plate 14 . The gas distribution plate 12 has an upper part and a bottom part, and the bottom part has a plurality of gas holes 16 which communicate with a gas supply system 30 so that gas can be supplied into the processing chamber 1 through the gas holes 16 . The insulating cover plate 14 covers the upper part of the gas distribution plate 16 . The insulating cover plate 14 shown in FIG. 5 is composed of four insulating cover plates 14a, and the gas distribution plate 12 is cross-shaped and located at the joint of the insulating cover plates 14a. The gas distribution plate 12 can be made of metal, such as aluminum, preferably anodized aluminum film with anodized surface. The insulating cover plate 14 may consist of ceramics.

The present invention uses a special fixing part 70 to fix the gas distribution plate 12 and the insulating cover plate 14 . FIG. 6 shows the structure of the fixing part 70 of the present invention, and the combination of the fixing part 70 with the gas distribution plate 12 and the insulating cover plate 14 . As shown in FIG. 6 , each fixing portion 70 includes a screw 72 and a nut 74 . Each screw 72 includes a head 721 and a shaft 722 , and the screw head 721 has an external thread 725 . The nut 74 is made of an insulating material, for example, ceramics. The inner surface of each nut has an internal thread (not shown) corresponding to the thread 725 of the screw head 721 to interengage with each screw head 721 through threads.

The screw 72 is usually made of metal (such as aluminum), preferably an anodized aluminum film whose surface has been anodized. As shown in Figures 5 and 6, after engagement, the head 721 of the screw 72 is protected by the nut 74, the head 721 is not exposed to the plasma, but the nut 74 is exposed to the plasma. The material of the nut 74 exposed to the plasma is an insulating material (such as ceramics), so it can increase the ability of resisting the plasma and can withstand the bombardment of the plasma for a long time. This can prevent the head 721 of the screw 72 from being bombarded by the plasma to cause arc discharge, thereby preventing the metal or aluminum material from falling onto the substrate S, and also reducing the occurrence of S-S short circuit. For the TFT-LCD manufacturing process, it can also avoid the occurrence of bright spots, eliminate product defects and improve the good rate.

The plasma processing apparatus of the present invention covers various forms of plasma processing apparatus, such as inductively coupled plasma (ICP) processing apparatus. The plasma processing device of the present invention can utilize plasma to carry out deposition or etching, such as plasma-assisted chemical vapor deposition (PECVD), high-density plasma chemical vapor deposition (HDPCVD), sputtering, dry etching, etc., and can be used It is used in the general semiconductor manufacturing process or the front-end array manufacturing process of TFT-LCD.

Although the present invention has been disclosed with a preferred implementation, it is not intended to limit the present invention. Any person skilled in the art can make changes and modifications without departing from the essence and scope of the present invention, so the protection scope of the present invention as defined in the appended claims.

Claims (12)

1. plasma processing apparatus, it comprises:

One process chambers;

One lower electrode plate is positioned at described process chambers, can place a substrate that will carry out plasma treatment on it;

One gas supply system arrives in the described process chambers in order to supply gas;

One electric pole plate is positioned at the top of described process chambers, lower electrode plate; And

One power supply is in order to apply voltage difference, so that the gas in the described process chambers changes plasma between described upper and lower battery lead plate;

Wherein said electric pole plate comprises:

One gas distribution plate, it has top and bottom, and its bottom has a plurality of pores, and described pore is communicated with described gas supply system, makes gas to be fed in the described process chambers via described pore;

One insulation cover plate, it covers the top at described gas distribution plate; And

A plurality of fixed parts, in order to fixing described gas distribution plate and insulation cover plate, each fixed part comprises a screw and a nut, described screw comprises a head and a bar portion, and has external screw thread on the described screw head, described nut is made of insulating material, and the inner surface of each nut has and the corresponding internal thread of the external screw thread of described screw head, so that intermesh with each screw head.

2. plasma processing apparatus as claimed in claim 1, wherein said nut is made by pottery.

3. plasma processing apparatus as claimed in claim 1, wherein said insulation cover plate is combined into by four insulation cover plates, and described gas distribution plate is cross, and is positioned at the seam crossing of described insulation cover plate.

4. plasma processing apparatus as claimed in claim 1, wherein said gas distribution plate is made of metal.

5. plasma processing apparatus as claimed in claim 4, wherein said gas distribution plate is made of aluminum.

6. plasma processing apparatus as claimed in claim 5, anodized is carried out on the surface of wherein said gas distribution plate.

7. plasma processing apparatus as claimed in claim 1, wherein said insulation cover plate is made by pottery.

8. plasma processing apparatus as claimed in claim 1, wherein said screw is made of metal.

9. plasma processing apparatus as claimed in claim 8, wherein said screw is made of aluminum.

10. plasma processing apparatus as claimed in claim 9, anodized is carried out on the surface of wherein said screw.

11. plasma processing apparatus as claimed in claim 1, wherein said power supply are radio frequency (RF).

12. plasma processing apparatus as claimed in claim 1, wherein said plasma processing apparatus are inductively coupled plasma (ICP) processing unit.

Images