KR20060077683A - Plasma etching chamber and method for coating focus ring - Google Patents

Abstract

Plasma etch chamber and a focus ring coating method according to the present invention is decomposed such that the polymer is a by coating the focus ring, the lower layer with TiO ₂ layer is generated in the plasma etching process, deposition on the wafer backside provided in the chamber by the photocatalytic action of the TiO ₂ layer This eliminates the need for additional cleaning processes and reduces manufacturing costs. In addition, since there is no problem of polymer deposition during the plasma etching process, a stable etching state of the chamber may be maintained, thereby increasing reliability of the semiconductor device. In addition, the present invention relates to a technique for preventing particle generation by the polymer to improve the yield of the device.

Description

Plasma Etch Chamber and Focus Ring Coating Method {PLASMA ETCHING CHAMBER AND METHOD FOR COATING FOCUS RING}

1A and 1B are schematic diagrams showing a plasma etching chamber and a focus ring according to the prior art.

2 is a schematic diagram illustrating a plasma etching chamber and a focus ring according to the present invention.

3A and 3B are views illustrating a reaction process of a focus ring lower layer in a plasma etching chamber according to the present invention.

<Explanation of Signs of Major Parts of Drawings>

10, 100: ESC 20, 110: Wafer

30: support 40, 140: focus ring

50 electrode 120 silicon layer

130: TiO ₂ layer

The present invention relates to a plasma etching chamber and a focus ring coating method, wherein a polymer generated in a plasma etching process and deposited on a wafer backside by coating a lower layer of the focus ring in the plasma etching chamber with a TiO ₂ layer is formed on the TiO ₂ layer. Decomposition by the photocatalytic action eliminates the need for an additional cleaning process, reducing manufacturing costs. In addition, since there is no problem of polymer deposition during the plasma etching process, a stable etching state of the chamber may be maintained, thereby improving reliability of the semiconductor device. The present invention also relates to a plasma etching chamber and a focus ring coating method for preventing particle generation by the polymer to improve device yield.

1A and 1B are schematic diagrams showing a plasma etching chamber according to the prior art and a problem according to the prior art.

1A and 1B, a schematic diagram of a plasma etching chamber is provided with an ESC (Electro Static Chuck) to fix a wafer during plasma etching, and the same silicon as the wafer material to trap the plasma formed for etching into the wafer region. It is provided with a focus ring formed.

In this case, when the 'A' is enlarged, the gap between the wafer edge and the focus ring is generated, and as the etching process proceeds, the focus ring is etched to increase the size of the gap. Therefore, the polymer generated during etching is introduced into the wafer backside and deposited as 'B'.

In the plasma etching chamber and the focus ring coating method according to the related art described above, as the gap between the wafer edge and the focus ring is generated and the etching process proceeds, the size of the gap increases as the focus ring is etched. As the polymer is introduced into the wafer backside and deposited, the stacked polymer causes contamination of the chamber in a subsequent process, and the polymer is redeposited to the front surface of the wafer, thereby degrading the yield of the device by the particles. In addition, a wafer backside cleaning process is added to remove the polymer, and the polymer cleaning layer is shortened by the polymer stacked around the focus ring, thereby increasing manufacturing costs.

In order to solve the above problem, by coating the lower layer of the focus ring in the plasma etching chamber with the TiO ₂ layer, the polymer generated during the plasma etching process and deposited on the wafer backside is decomposed by the photocatalytic action of the TiO ₂ layer, thus eliminating the need for an additional cleaning process. This reduces manufacturing costs. In addition, since there is no problem of polymer deposition during the plasma etching process, a stable etching state of the chamber may be maintained, thereby improving reliability of the semiconductor device. In addition, an object of the present invention is to provide a plasma etching chamber and a focus ring coating method for preventing particle generation by the polymer to improve device yield.

The plasma etching chamber according to the present invention

In a chamber used for a plasma etching process having an electro static chuck (ESC), an electrode and a focus ring,                     

The focus ring is characterized by having a coated TiO ₂ layer.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described in detail.

2 illustrates a plasma etching chamber according to the present invention.

Referring to FIG. 2, an ESC (Electro Static Chuck), an electrode and a focus ring are provided, the ESC being used to fix the wafer in the chamber and having a size smaller than the wafer size to prevent the ESC from being directly exposed to the plasma. It is provided with.

In addition, a focus ring is provided to trap the plasma formed for etching into the wafer region. At this time, the focus ring is composed of a double layer of a silicon layer and a TiO ₂ layer, the lower layer of the focus ring coated with the TiO ₂ layer is provided below 1 to 2mm from the top of the ESC.

Here, the TiO ₂ layer bandgap has a size of 3.0 eV, and the generation of active oxygen and the coordination of water molecules are simultaneously generated by light generated during plasma etching, and the hydrolysis property is affected by the coordination effect of the water molecules. Indicates. Superoxide anion (O ^2- ) is generated from the oxygen, and hydroxyl radical (OH) is generated from the water, and is generated in a plasma etching process by decomposition of the superoxide anion (O ^2- ) and hydroxyl radical (OH). The deposited polymer on the wafer backside is degraded.

The focus ring coating method in the plasma etching chamber according to the present invention                     

Ti (OC ₃ H ₇ ) ₄ and O ₂ are source gas and Ar is a carrier gas to react Ti (OC ₃ H ₇ ) ₄ and O ₂ to coat the focus ring lower layer in the plasma etching chamber with the TiO ₂ layer. Characterized in that it comprises a step.

Here, the step of coating the Ti0 ₂ layer to a focus ring lower layer in the chamber is formed by using a CVD apparatus, and Ti (OC ₃ H _{7) 4} and O ₂ source gas in the Ti the Ar as a carrier gas (OC ₃ H ₇ ) The Ti0 ₂ layer is coated by reacting ₄ with O ₂ , wherein the Ti (OC ₃ H ₇ ) ₄ is supplied at a flow rate of 1000 to 2000 sccm, and the reaction is performed at a pressure of 0.1 to 0.2 torr and a temperature of 750 to 800 K. It is preferable to be carried out in a deposition of a thickness of 50 to 100um.

At this time, if the reaction pressure is increased or the temperature is increased to increase the Ti (OC ₃ H ₇ ) ₄ feed rate, the growth rate of the TiO ₂ layer is increased, but the crystal structure and orientation are not changed, and the Ti (OC ₃ H ₇ ) _{4 is increased.} When too much is supplied, the active concentration of the reaction is increased, particles are generated by the gas phase reaction, and thus the deposition rate is reduced, which may cause contamination of the plasma etching chamber.

3A and 3B are views illustrating a reaction process of a focus ring lower layer in a plasma etching chamber according to the present invention.

Referring to FIG. 3A, electrons (e−) and holes (h +) are generated as light having energy above a band gap generated during plasma etching is irradiated onto the TiO ₂ surface of the focus ring lower layer. At this time, the light irradiated onto the TiO ₂ layer surface preferably has a wavelength of 400 nm or less.

See Figure 3b If, the radical electron (e-) and holes (h +) is reacted with O ₂ and H ₂ O in each chamber OH radicals and ₀₂ radicals is ² to create the OH radical and 0 ₂ ² The oxidation reaction of the polymer decomposes the organic material on the surface of the TiO ₂ layer.

The plasma etching chamber according to the present invention is coated with a TiO ₂ layer under the focus ring in the chamber so that the polymer generated during the plasma etching process and deposited on the wafer backside is decomposed by the photocatalytic action of the TiO ₂ layer, thus eliminating the need for an additional cleaning process. Therefore, the manufacturing cost is reduced, and there is no problem of polymer deposition during the plasma etching process, so that the etching characteristics can maintain a stable chamber state, thereby increasing the reliability of the semiconductor device. In addition, there is an effect that the yield of the device is improved by preventing the generation of particles by the polymer.

In addition, a preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, substitutions and additions through the spirit and scope of the appended claims, such modifications and changes are the following claims It should be seen as belonging to a range.

Claims (5)

In a chamber used for a plasma etching process having an electro static chuck (ESC), an electrode and a focus ring, And the focus ring has a TiO ₂ layer coating the surface thereof. The method of claim 1, Plasma etching chamber and focus ring coating method characterized in that the TiO ₂ is coated with a lower portion of the focus ring 1 to 2mm below the upper portion of the ESC. In the focus ring coating method in the plasma etching chamber, Coating Ti (OC ₃ H ₇ ) ₄ and O ₂ as a source gas and Ar as a carrier gas to react Ti (OC ₃ H ₇ ) ₄ and O ₂ with TiO ₂ on the lower portion of the focus ring in the plasma etching chamber. Plasma etching chamber and focus ring coating method comprising a. The method of claim 3, wherein The Ti (OC ₃ H ₇ ) ₄ is supplied at a flow rate of 1000 to 2000sccm, the reaction is carried out at a pressure of 0.1 to 0.2torr, the temperature of 750 to 800K plasma etching chamber and focus ring coating method. The method of claim 3, wherein The TiO ₂ is a plasma etching chamber and focus ring coating method characterized in that the deposition to a thickness of 50 to 100μm.

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