KR20050049585A - Apparatus for the dry etching in the semiconductor manufacturing equipment - Google Patents

Abstract

The present invention discloses a dry etching apparatus of a semiconductor manufacturing equipment that can reduce the production cost. Its devices face each other in the upper and lower portions of a chamber filled with an inert gas or reaction gas, and apply a high voltage to make the inert gas or reaction gas into a plasma state, and a wafer during the plasma reaction on the lower electrode. And an insulator surrounding the chuck wall of the electrostatic chuck or the lower electrode to insulate the chamber from the electrostatic chuck to seat or fix the chuck. And an edge ring formed of a ceramic material surrounding the edge and not damaged from the reaction gas in the plasma state.

Description

Apparatus for the dry etching in the semiconductor manufacturing equipment

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor manufacturing equipment, and more particularly, to a dry etching apparatus having an edge ring having excellent corrosion resistance from a reaction gas in a plasma state during an etching process.

The manufacturing technology of a semiconductor device is largely composed of a deposition process of forming a processed film on a semiconductor substrate and a photolithography process of forming and patterning a processed film on the processed film formed by the deposition process.

 The photolithography process may be performed by forming a processing film on a semiconductor substrate on which the processing film is formed, a photo process of patterning the processing film so that the processing film on the processing film is selectively left, and the exposed film from the processing film. Etching process to selectively remove the process film, the processing film used in the etching process using a cleaning solution, and by-products by the etching process is completely removed so that only the processed film not etched from the etching process remains It is divided into washing process. Here, the etching process may be performed by wet etching and dry etching, and etching for forming a micro pattern that requires a recent submicron design rule is mainly performed by dry etching.

Such dry etching applies a high voltage of RF (Radio Frequency) to an inert gas and an etching reaction gas filled in the chamber, thereby making the reaction gas into a plasma state, and reacting the reaction gas in the plasma state with the film to be processed. And a dry etching apparatus for selectively removing the processed film exposed from the.

In the prior art dry etching apparatus, chucks are used to support or hold the semiconductor substrate in order to prevent the semiconductor substrate from moving or misaligning during the process. Electrostatic chucks that use electrostatic attraction forces to hold a semiconductor substrate have some advantages over other types of chucks (eg, mechanical chucks and vacuum chucks). As one of those advantages, electrostatic chucks can reduce stress-related cracks often caused by mechanical clamps.

Such electrostatic chucks are called U.S. Patent No. 4,665,463, entitled "METHOD OF AND APPARATUS FOR APPLYING VOLTAGE TO ELECTROSTATIC CHUCK". Patent No. 5,117,121 and titled "ELECTROSTATIC CHUCK HAVING A THERMAL TRANSFER REGULATED PAD." Patent No. 5,978,202, respectively.

In this case, the electrostatic chuck is composed of a dielectric sheet and a chuck body below the dielectric layer, and a pair of electrodes are positioned in the chuck body to serve to press-fix the wafer during the etching process. To perform. That is, when a workpiece, such as a silicon wafer, is placed on the electrostatic chuck and a voltage is applied between the electrodes, the electrostatic chuck electrostatically attracts the wafer according to the Johnson-Rahbek effect. .

In addition, a by-product, that is, a polymer component generated by the reaction of the reaction gas and the processed film is generated during the etching process, and the polymer is deposited in the chamber. In addition, when the polymer is attached to the electrostatic chuck, a step may be generated at a lower portion of the wafer that is chucked on the electrostatic chuck to cause an etching failure, or chucking or dechucking of the wafer. It can also cause cracking of the wafer.

Accordingly, the dry etching apparatus according to the related art may reduce the polymer component generated in the electrostatic chuck by placing an edge ring extending from the edge of the wafer at the edge of the electrostatic chuck.

In this case, the edge ring is made of a polyimide material named Vespel (VESPEL), a product of synthetic resin manufactured only by DuPont, and supports the wafer at the edge of the wafer chucked on the electrostatic chuck.

Accordingly, the dry etching apparatus according to the related art protects the electrostatic chuck at the edge of the wafer by using an edge ring, thereby preventing the adhesion of polymers generated during the etching process of the wafer onto the electrostatic chuck.

However, the dry etching apparatus of the semiconductor manufacturing equipment according to the prior art has the following problems.

First, the dry etching apparatus of the semiconductor manufacturing apparatus according to the prior art has a disadvantage in that the edge ring of the polyimide component is damaged by the plasma reaction and the production cost increases because the edge ring needs to be replaced periodically.

Second, the dry etching apparatus of the semiconductor manufacturing apparatus according to the prior art not only damages the edge of the electrostatic chuck adjacent to the edge ring when the edge ring is damaged by the plasma reaction, but also the polymer component on the electrostatic chuck. In this case, the etching process defect of the dry etching apparatus may be caused.

An object of the present invention for solving the above problems is to provide a dry etching apparatus of a semiconductor manufacturing equipment that can reduce the production cost by preventing damage to the edge ring.

In addition, another object of the present invention is to provide a dry etching apparatus of a semiconductor manufacturing equipment that can prevent the failure of the dry etching process by protecting the edge ring and the electrostatic chuck inside the wafer during the dry etching process.

 According to an aspect of the present invention for achieving the above object, a dry etching apparatus of a semiconductor manufacturing facility, facing each other in the upper and lower portions of a chamber filled with an inert gas or a reaction gas, by applying a high voltage to the inert gas or reaction An upper electrode and a lower electrode for making gas into a plasma state, an electrostatic chuck for seating or fixing a wafer during the plasma reaction on the lower electrode, an insulator surrounding the chuck wall of the electrostatic chuck or the lower electrode to insulate the chamber; And an edge ring which is placed on the insulator or the electrostatic chuck and is formed of a ceramic material that surrounds the edge of the electrostatic chuck in correspondence with the upper electrode and is not damaged from the reaction gas in the plasma state.

Hereinafter, a dry etching apparatus of a semiconductor manufacturing apparatus according to the present invention will be described with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a dry etching apparatus of a semiconductor manufacturing apparatus according to the present invention.

As shown in FIG. 1, the dry etching apparatus of the semiconductor manufacturing apparatus of the present invention is opposed to an upper electrode 102 formed on an upper portion of the chamber 100 filled with an inert gas or a reaction gas, and opposed to the upper electrode 102. A lower electrode 104 formed below the chamber 100, an electrostatic chuck 108 for seating or fixing the wafer 106 during plasma reaction on the lower electrode 104, the chamber 100, and the An insulator 110 surrounding the chuck wall of the electrostatic chuck 108 or the lower electrode 104 and the insulator 110 or the electrostatic chuck to insulate the electrostatic chuck 108 or the lower electrode 104 from each other. An edge ring 112 placed on and supported by 108 and covering the edge of the electrostatic chuck 108 corresponding to the upper electrode 102 and not damaged by the plasma reaction is formed. It is configured to include.

Here, the upper electrode 102 and the lower electrode 104 each have a high voltage of different phases (for example, several tens of volts to several million volts having a radio frequency (RF) of about several tens of MHz) from the power supply device. When applied, the inert gas or the reaction gas supplied between the upper electrode 102 and the lower electrode 104 is brought into a plasma state in which ions and electrons are separated. It further comprises a magnetic coil 114 wound around the chamber 100 to concentrate the reaction gas or ions in the plasma state on the wafer 106 on the electrostatic chuck 108. .

At this time, the reaction gas or ions in the plasma state selectively removes the processed film exposed by the processing film formed on the surface of the wafer 106. Although not shown, a nozzle for injecting the inert gas or the reactive gas is formed under the upper electrode 102.

In addition, the edge ring 112 has chemical properties (eg, to prevent damage from reactive gases or ions in the plasma state that are accelerated by electromagnetic induction of the magnetic coil 114 during the etching process of the wafer 106. For example, it is made of a ceramic (eg fine ceramic) material that is excellent in corrosion resistance, component diversity) or mechanical properties (eg strength, hardness, toughness). In this case, the edge ring 112 is placed on the insulator 110 that protects the sidewall of the electrostatic chuck 108, and the electrostatic chuck (eg, from the reaction gas or ions in the plasma state at the edge of the wafer 106). The wafer is formed to have the same height as the wafer 106 surrounding the edge of the electrostatic chuck 108 and seated on the electrostatic chuck 108 to protect 108, and seated on the electrostatic chuck 108. (106) A groove having a step size equal to the thickness of the wafer 106 is provided to support the edge.

When the wafer 106 is positioned on the electrostatic chuck 108, the etching of the edge portion of the wafer 106 is excellent during the plasma reaction, and the polymer component is not generated at the edge backside of the wafer 106. The vertical cross section of the edge ring 112 corresponding to the sidewall of the wafer 106 and adjacent to the sidewall of the chamber 100 may be inclined.

Therefore, the dry etching apparatus of the semiconductor manufacturing apparatus according to the present invention comprises the edge ring 112 made of a ceramic material having excellent chemical or mechanical properties in order to prevent damage from the reaction gas or ions in the plasma state. The production cost according to the replacement of the 112 can be reduced.

On the other hand, the reaction gas or ions in the plasma state is the wafer 106 or the wafer 106 exposed by the etching mask using a processing film such as a photoresist or an etch stop layer formed on the wafer 106 as an etching mask. The processed film formed on the substrate is selectively etched.

In this case, the wafer 106 is tightly fixed to the electrostatic chuck 108 by applying an AC or DC constant voltage or a reverse voltage to the chuck in the power supply device during the etching process.

In addition, the electrostatic chuck 108 is composed of a dielectric film 108a directly contacting the wafer 106 and a chuck body 108b below the dielectric film 108a to compress the wafer 106 during the etching process. It plays a role. Although not shown, since the wafer 106 and the electrostatic chuck 108 are heated at a high temperature by the reaction gas or ions in the plasma state, the wafer 106 and the wafer 106 may be disposed on the electrostatic chuck 108 to prevent the high temperature. A coolant supply groove (118 in FIG. 3) is provided between the electrostatic chucks 108 to supply a coolant (for example, helium).

However, the conventional edge ring 112 mounted on the electrostatic chuck 108 is vulnerable from the reaction gas in the plasma state because it uses the polyimide material of Vespel. Thus, the conventional edge ring 112 is corroded by the reaction of the reaction gas during the dry etching process, by-products of the reaction gas, that is, the polymer component is produced, the polymer is the interior of the chamber 100 Is deposited on. In addition, as shown in FIG. 2, it is easily damaged around the edge of the wafer 106 due to the corrosion of the conventional edge ring 112 to form the micro voids 115. In addition, the reaction gas or ions in the plasma state penetrates through the microcavity 115 to damage the dielectric film 108a of the electrostatic chuck 108 inside the edge ring 112, as shown in FIG. 3, and Polymer 116 may occur on dielectric film 108a or chuck body 108b.

At this time, as a component of the polymer 116 generated on the dielectric film 108a or the chuck body 108b, carbon, which is a main component of the polyimide constituting the conventional edge ring 112, and As shown in FIG. 4, a large amount of fluorine component of the reaction gas is detected. At this time, the horizontal axis of Figure 4 is the energy band gap, the vertical axis represents the component content in percent.

When the polymer 116 is generated on the dielectric film 108a or the chuck body 108b, the wafer 106 is adhered to the electrostatic chuck 108 by the polymer 116 before and after the etching process. adhesion), and the wafer 106 on the electrostatic chuck 108 may be uneven, resulting in uneven etching, which may cause chucking or dechucking defects and dry etching process defects. In addition, a constant gap is generated between the wafer 106 and the electrostatic chuck 108 by the polymer 116 formed on the electrostatic chuck 108 such that the refrigerant is between the electrostatic chuck 108 and the wafer 106. The wafer 106 is heated by the reaction gas in the plasma state during the dry etching process because the refrigerant is not supplied along the refrigerant supply groove 118 formed in the chamber 100 and is discharged into the chamber 100. The refrigerant introduced into the whole may cause a poor dry etching process.

Therefore, the dry etching apparatus of the present invention for solving this problem damages the edge ring 112 because it uses an edge ring 112 made of a ceramic material having excellent chemical or mechanical properties from the reaction gas or ions in the plasma state. It is possible to prevent the polymer 116 component due to the plasma reaction on the electrostatic chuck 108 inside the edge ring 112 can be prevented.

As a result, in the dry etching apparatus according to the present invention, when the wafer 106 is positioned on the edge ring 112 and the electrostatic chuck 108, the edge ring 112 is formed around the wafer 106. By preventing the formation of the polymer 116 component on the electrostatic chuck 108 by protecting the electrostatic chuck 108 from the reaction gas or ions in the plasma state, it is possible to prevent the failure of the dry etching process.

As described above, according to the present invention, it is possible to prevent damage of the edge ring from the plasma reaction by using an edge ring of ceramic material having excellent chemical or mechanical properties, thereby reducing the production cost due to the replacement of the edge ring. Or there is an effect that can be minimized.

In addition, since the edge ring made of ceramic material is used to protect the electrostatic chuck from plasma reaction, polymer components are not generated on the electrostatic chuck, thereby preventing the dry etching process defect.

1 is a schematic cross-sectional view showing a dry etching apparatus of a semiconductor manufacturing apparatus according to the present invention.

2 to 3 is a view for showing the problem of the edge ring according to the prior art.

Figure 4 is a graph analyzing the components of the polymer generated on the electrostatic chuck according to the prior art.

  * Description of the symbols for the main parts of the drawings *

100 chamber 102 upper electrode

104: lower electrode 106: wafer

108a: dielectric film 108b: chuck body

108: electrostatic chuck 110: insulator

112: edge ring 114: magnetic coil

115: fine pores 116: polymer

118: refrigerant supply hole

Claims (2)

An upper electrode and a lower electrode facing each other at upper and lower portions of a chamber filled with an inert gas or a reaction gas and applying a high voltage to make the inert gas or the reaction gas into a plasma state; An electrostatic chuck for mounting or fixing a wafer during the plasma reaction on the lower electrode; An insulator surrounding the chuck wall of the electrostatic chuck or the lower electrode to insulate the chamber; And an edge ring which is placed on the insulator or the electrostatic chuck and is formed of a ceramic material which surrounds the edge of the electrostatic chuck in correspondence with the upper electrode and is not damaged by the reaction gas in the plasma state. Dry Etching Equipment. The method of claim 1, And wherein the ceramic material is a fine ceramic having excellent chemical or mechanical properties with respect to the reaction gas in the plasma state.