TWI647761B - Plasma processor, mobile ring cleaning maintenance system and method - Google Patents

Abstract

The invention discloses a mobile ring cleanliness maintenance system, which can prevent the formation of polymers on the bottom of the mobile ring and the surface of the outer side wall during the plasma processing. The mobile ring cleanliness maintenance system includes: Installed in a moving ring; an ultrasonic generator whose output end is connected to an ultrasonic converter. The advantage is that the high-frequency vibration signal transmitted by the ultrasonic generator is converted into high-frequency mechanical oscillations transmitted by the converter and uniformly radiated to the solid medium of the moving ring, so that the pollutants on the surface and gap of the moving ring are quickly stripped, thereby achieving The purpose of surface purification.

Description

Plasma processor, mobile ring cleaning maintenance system and method

The invention relates to a plasma etching system, in particular to a plasma processor, a mobile ring cleaning maintenance system and a method.

In the field of plasma etching, there has always been a problem of polymer deposition on the surface of a moving ring. Specifically, after a period of time, a new moving ring will continuously deposit polymer on the surface, and the thickness of the polymer will continue to change. This polymer deposition causes at least two problems:

1. The deposited polymer will change the chemical, optical, and electrical properties of the moving ring, causing instability errors in the characteristics of the etching process;

2. When the polymer is deposited to a certain extent, it will form a block, which will cause particles to fall during the etching process, which will affect the yield of the etching product in severe cases;

Therefore, there is a need to provide a method for treating polymers deposited on the surface of a moving ring during the etching process.

An object of the present invention is to provide a plasma processor, a mobile ring cleaning maintenance system and method, which transmit high-frequency vibration signals from an ultrasonic generator, convert them into high-frequency mechanical oscillations through a converter, and uniformly radiate to the solid medium of the mobile ring. In this way, the pollutants in the surface and gap of the moving ring are quickly peeled off, so as to achieve the purpose of surface purification.

In order to achieve the above objective, the present invention is achieved through the following technical means:

A mobile ring cleanliness maintenance system is used to prevent the formation of polymers on the bottom of the mobile ring and the surface of the outer side wall of the plasma processor during the plasma processing. The plasma processor includes a reaction chamber, and the reaction chamber includes a The base on which the wafer to be processed is placed. The top of the base includes a reaction gas inlet device for inputting the reaction gas to the top of the base. During the plasma processing process, the reaction gas is ionized above the base to form a plasma. Within the cavity and surrounding the plasma, wherein the mobile ring cleanliness maintenance system comprises:

Ultrasonic converter, installed in moving ring;

The output end of the ultrasonic generator is connected to an ultrasonic converter.

The above-mentioned mobile ring cleanliness maintenance system further includes:

The control system is connected to the input end of the ultrasonic generator, and the output power and power duration of the ultrasonic generator are controlled online.

The above-mentioned moving ring clean maintenance system, wherein:

A plurality of ultrasonic transducers are evenly arranged in the moving ring.

The above-mentioned moving ring clean maintenance system, wherein:

Slotted on the moving ring to accommodate the ultrasonic transducer.

The above-mentioned moving ring clean maintenance system, wherein:

The ultrasonic transducer is buried in the moving ring so that the ultrasonic transducer is not exposed to the plasma.

The above-mentioned moving ring clean maintenance system, wherein:

The ultrasonic transducer is embedded in the bottom surface and / or the outer side wall of the moving ring.

A method for maintaining cleanliness of a moving ring, wherein:

During the plasma processing, an ultrasonic converter is installed in the moving ring, which converts the high-frequency oscillation signal emitted by the ultrasonic generator into a high-frequency mechanical oscillation to prevent the accumulation of polymer on the surface of the moving ring;

The input end of the ultrasonic converter is connected to the output end of the ultrasonic generator, and the ultrasonic generator provides power and high-frequency oscillation signals to the ultrasonic converter.

The above-mentioned method for maintaining cleanliness of a moving ring, wherein:

The input end of the ultrasonic generator is connected to a control system, and the output power and the power duration of the ultrasonic generator are controlled on the control system line, so as to achieve the adjustment and control of the cleaning and maintenance process of the mobile ring line by the ultrasonic converter.

The above-mentioned method for maintaining cleanliness of a moving ring, wherein:

A plurality of ultrasonic transducers are evenly arranged in the moving ring.

The above-mentioned method for maintaining cleanliness of a moving ring, wherein:

Slotted on the moving ring to accommodate the ultrasonic transducer.

The above-mentioned method for maintaining cleanliness of a moving ring, wherein:

The ultrasonic transducer is buried in the moving ring so that the ultrasonic transducer is not exposed to the plasma.

The above-mentioned method for maintaining cleanliness of a moving ring, wherein:

The direction in which the ultrasonic transducer emits ultrasonic waves is the deposition direction of the polymer on the surface of the moving ring.

A plasma processor includes the above-mentioned moving ring cleanliness maintenance system.

Compared with the prior art, the present invention has the following advantages: the high-frequency vibration signal transmitted by the ultrasonic generator is converted into a high-frequency mechanical oscillation through a converter and propagates uniformly to the solid medium of the moving ring, so that the surface and gaps of the moving ring Contaminants are quickly stripped to achieve surface purification.

The present invention will be further described below with reference to the accompanying drawings through detailed description of a preferred specific embodiment.

As shown in FIG. 3, a plasma processor includes a mobile ring cleanliness maintenance system, which is used to prevent the bottom and outer walls of the mobile ring 1 in the plasma processor during the plasma processing process. Polymer 3 is deposited on the surface. The plasma processor includes a reaction chamber 7. The reaction chamber 7 includes a pedestal 6 for placing a wafer to be processed. A reaction gas inlet device is provided above the pedestal 6 for inputting a reaction gas. Going above the base 6, during the plasma processing process, the reaction gas is ionized above the base 6 to form a plasma, and the moving ring 1 is located in the reaction chamber 7 and surrounds the plasma.

As shown in Fig. 1 and Fig. 2, the mobile ring cleanliness maintenance system includes: an ultrasonic converter 2 (Ultrasonic Transducer: UT) installed in the mobile ring 1; an ultrasonic generator 4 whose output end is connected to the ultrasonic converter 2; The control system 5 is connected to the input end of the ultrasonic generator 2 and controls the output power and power duration of the ultrasonic generator 4 online. The high-frequency oscillation signal emitted by the ultrasonic generator is converted into a high-frequency mechanical oscillation by a converter and transmitted. Uniform radiation into the solid medium can realize the rapid stripping of pollutants on the surface of the solid medium and the gap, thereby achieving the purpose of cleaning and purifying the surface of the object, that is, weakening the adhesion of the plasma. It should be noted that the number of settings of the ultrasonic converter 2 may be different according to various factors such as etching requirements, polymer aggregation, and ultrasonic converter power. Generally, the acoustic power density = transmission power / transmission area. When the acoustic power density When it is greater than 0.3W / cm2, it can meet the requirements of industrial cleaning, and the higher the power density, the better the cleaning effect. In addition, the cleaning effect will increase significantly with the increase of the ambient temperature. However, the plurality of ultrasonic transducers 2 must be in The moving rings 1 are arranged at even intervals, for example, in this embodiment, they are evenly distributed along the circumferential direction of the moving rings 1. When a plurality of ultrasonic transducers 2 are provided, the number of ultrasonic generators 4 can be increased accordingly, or a plurality of ultrasonic transducers 2 can be connected to the same ultrasonic generator 4 respectively.

The ultrasonic transducer 2 is embedded in the moving ring 1 so that the ultrasonic converter 2 is not exposed to the plasma. Preferably, the ultrasonic converter 2 is embedded in the bottom surface and / or the outer sidewall of the mobile ring 1 where polymer is easily deposited; In the embodiment, a groove matching the size of the ultrasonic transducer 2 is opened on the side where the polymer will be deposited on the moving ring 1 in advance to accommodate the ultrasonic transducer 2, and then the notch is covered with a layer of moving ring material to realize the moving ring 1 The ultrasonic converter 2 in the inside leads out an ultrasonic generator 4 connected to the outside through a lead. The most effective parts of the ultrasonic wave of the present invention are the bottom surface and the outer side wall of the moving ring 1, because the plasma cannot be reached at these parts and cannot be cleaned with the plasma, and the inner wall of the moving ring 1 facing the plasma will not have a large amount of polymer Accumulated, if any, can be easily removed in subsequent cleaning steps.

The invention also discloses a method for maintaining the cleanness of the mobile ring, which comprises: installing an ultrasonic transducer 2 in the mobile ring 1 to convert a high-frequency oscillation signal emitted by the ultrasonic generator 4 into a high-frequency mechanical oscillation to prevent the surface of the mobile ring 1 The aggregation of the polymer 3; the input end of the ultrasonic converter 2 is connected to the output end of the ultrasonic generator 4, and the ultrasonic generator 4 provides power and high-frequency oscillation signals to the ultrasonic converter 2.

In order to better achieve online adjustment and control of the cleaning process, the input end of the ultrasonic generator 4 is connected to a control system 5 to control the output power and power duration of the ultrasonic generator 4 online. For computer PC.

In this embodiment, the direction in which the ultrasonic transducer 2 emits ultrasonic waves is the deposition direction of the polymer 3 on the surface of the moving ring 1, which makes the cleaning process more purposeful and directional.

As shown in FIG. 3, the moving ring 1 is disposed in the reaction chamber 7, reference numeral 8 is the upper electrode, and the base 6 is connected to the lower electrode. In this embodiment, the area of the moving ring 2 facing the plasma direction is about 600 cm2, so The minimum total power applied to the ultrasonic generator 2 is about 1800W. It is assumed that in actual use, eight ultrasonic generators 2 are uniformly buried in the moving ring 1, and the minimum power (Power Supply) applied to each ultrasonic generator 2 is 250W.

Although the content of the present invention has been described in detail through the above-mentioned preferred embodiments, it should be recognized that the above description should not be considered as limiting the present invention. After reading the above content by those having ordinary knowledge in the art, various modifications and alternatives to the present invention will be apparent. Therefore, the protection scope of the present invention should be defined by the scope of the attached patent application.

1‧‧‧ mobile ring

2‧‧‧ Ultrasonic Converter

3‧‧‧ polymer

4‧‧‧ Ultrasonic generator

5‧‧‧control system

6‧‧‧ base

7‧‧‧ reaction chamber

8‧‧‧up electrode

FIG. 1 is a schematic structural diagram of a moving ring equipped with an ultrasonic transducer in the present invention;

Figure 2 is a system diagram of the present invention;

FIG. 3 is a schematic diagram of an installation structure according to an embodiment of the present invention.

Claims (13)

A mobile ring cleanliness maintenance system is used to prevent a polymer (3) from being deposited on the bottom and the outer side wall surface of a mobile processor in a plasma processor during plasma processing. The plasma processor includes a The reaction chamber (7) includes a pedestal (6) for placing a wafer to be processed, and a reaction gas inlet device is provided above the pedestal (6) for inputting reaction gas to the reaction chamber. Above the base (6), during the plasma processing process, the reaction gas is ionized above the base (6) to form a plasma. The moving ring (1) is located in the reaction chamber (7) and surrounds the electricity. The mobile ring cleanliness maintenance system includes: an ultrasonic converter (2) installed in the mobile ring (1); an ultrasonic generator (4), the output end of which is connected to the ultrasonic converter (2). The mobile ring cleanliness maintenance system described in item 1 of the scope of patent application, further comprising: a control system (5), connected to the input end of the ultrasonic generator (4), and controlling the output of the ultrasonic generator (4) online Power magnitude and power duration. The mobile ring cleanliness maintenance system according to item 1 of the scope of patent application, wherein: a plurality of the ultrasonic transducers (2) are uniformly distributed in the mobile ring (1). The mobile ring cleanliness maintenance system according to item 1 of the scope of patent application, wherein: a groove is formed in the mobile ring (1) for receiving the ultrasonic transducer (2). The mobile ring cleanliness maintenance system according to item 1 of the scope of patent application, wherein: the ultrasonic converter (2) is buried in the mobile ring (1) so that the ultrasonic converter (2) is not exposed to the plasma. The mobile ring cleanliness maintenance system according to item 5 of the scope of patent application, wherein: the ultrasonic transducer (2) is buried in the bottom surface and / or the outer side wall of the mobile ring (1). A method for maintaining cleanliness of a mobile ring, wherein: during the plasma processing, an ultrasonic converter (2) is installed in a mobile ring (1), which converts a high-frequency oscillation signal emitted by an ultrasonic generator (4) into High-frequency mechanical oscillation to prevent the polymer (3) from gathering on the surface of the moving ring (1); the input end of the ultrasonic converter (2) is connected to the output end of the ultrasonic generator (4), and the ultrasonic generator ( 4) Provide power and high-frequency oscillation signals to the ultrasonic converter (2). The method for maintaining cleanness of a moving ring according to item 7 of the scope of patent application, wherein: the input end of the ultrasonic generator (4) is connected to a control system (5), and the control system (5) controls the ultrasonic generator (4) on line ) Output power size and power duration to achieve the adjustment and control of the ultrasonic converter (2) on the cleaning and maintenance process of the mobile ring (1) line. The method for maintaining cleanliness of a moving ring according to item 7 of the scope of patent application, wherein: a plurality of the ultrasonic transducers (2) are uniformly distributed in the moving ring (1). The method for maintaining cleanliness of a moving ring according to item 7 of the scope of patent application, wherein: a groove is formed in the moving ring (1) for receiving the ultrasonic transducer (2). The method for maintaining cleanliness of a moving ring as described in item 7 of the scope of patent application, wherein: the ultrasonic converter (2) is buried in the moving ring (1) so that the ultrasonic converter (2) is not exposed to the plasma. The method for maintaining cleanliness of a moving ring according to item 7 in the scope of the patent application, wherein: the direction in which the ultrasonic transducer (2) emits ultrasonic waves is the deposition direction of the polymer (3) on the surface of the moving ring (1). A plasma processor includes the mobile ring cleanliness maintenance system according to any one of claims 1 to 6 of the scope of patent application.