JP2002362966A - Ceramic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic material with excellent corrosion resistance to gaseous halogen and halogen plasma, further with high thermal conductivity and with excellent thermal shock characteristics. SOLUTION: The ceramic material contains >=5 wt.% and <=95 wt.% magnesium oxide and the balance is composed of an oxide or a compound oxide containing a rare earth element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic material having a high resistance under a halogen-based gas or a halogen-based plasma environment and suitably used for a semiconductor manufacturing apparatus and the like.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, there are many members used in a highly corrosive environment. For example, a bell jar, a chamber, a dome, a susceptor, a clamp ring, a focus ring, and the like are used in a dry etching process using a highly corrosive halogen-based gas. Materials used in such a corrosive environment include silica / quartz (SiO ₂ ) and alumina (Al
_{2 O 3)} has been the widely used but, because it can not be said corrosion resistance is sufficient under the halogen gas or halogen-based plasma environment, high corrosion-resistant material as yttria in place of these (Y 2 _{O 3)} Ya It has been proposed to use an oxide or composite oxide containing a rare earth element represented by YAG (yttrium aluminum garnet).

[0003]

However, a composite oxide containing a rare earth element such as YAG or Y ₂ O ₃ alone has a small thermal conductivity of about 10 W / m · K and a large thermal expansion. There was concern about damage due to thermal shock.

The present invention has been made in view of such circumstances, and has a high thermal conductivity and excellent thermal shock characteristics while maintaining good corrosion resistance to halogen-based gas and halogen-based plasma. An object is to provide a ceramic material.

[0005]

That is, according to the present invention, there is provided a ceramic material containing magnesium oxide in an amount of 5% by weight or more and 95% by weight or less, with the balance being an oxide or a composite oxide containing a rare earth element. You.

[0006] Such a ceramic material of the present invention comprises:
It is easy to densely sinter, exhibits excellent corrosion resistance at an etching rate of 15 nm / min or less in a halogen-based plasma environment, and has a thermal conductivity of 15 W / m at room temperature.
Excellent in thermal shock properties because it is at least K and 1.5 times or more larger than 10 W / m · K of conventional Y ₂ O ₃ or YAG.
Therefore, it is suitably used as a member used under such an environment in an apparatus using a halogen-based gas or a halogen-based plasma atmosphere, such as a semiconductor manufacturing apparatus.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The ceramic material of the present invention comprises an oxide or a composite oxide containing magnesium oxide (MgO) in an amount of 5% by weight to 95% by weight and a balance containing a rare earth element. If the content of MgO is less than 5% by weight, there is a problem that the thermal conductivity is small and sufficient thermal shock resistance cannot be obtained. On the other hand, when MgO exceeds 95% by weight,
For the sintered body is not sufficiently densified, since the plasma tends to concentrate in the pores, etc., fluorine (F ₂₎ gas or chlorine (Cl ₂₎ sufficient for halogen gas or halogen-based plasma such as a gas There is a problem that high corrosion resistance cannot be obtained. When the oxide or composite oxide containing a rare earth element is contained in an amount of 5% by weight or more, the corrosion resistance can be improved or maintained. A more preferred content of MgO is 20% by weight or more and 80% by weight or less.

The oxide or composite oxide containing a rare earth element may be in a stable form in a temperature range from room temperature to 1000 ° C. Specifically, yttria (Y ₂ O ₃ ), yttrium (Y) and aluminum Complex oxide containing (Al) (Y
AG, YAM (yttrium aluminum monoclinic) and YAP (yttrium aluminum perovskite).

5% to 95% by weight of MgO and Y
₂O₃Or an oxide containing a rare earth element such as YAG or
A ceramic material according to the present invention comprising a composite oxide
Is easy to sinter densely,
As shown in the figure, etching in a halogen-based plasma environment
Excellent corrosion resistance with a running speed of 15 nm / min or less
You. It has a thermal conductivity of 15 W / m · K or more at room temperature.
It has high thermal conductivity and excellent thermal shock characteristics. What
Here, the etching rate is F₂Gas plasma and Cl ₂
Obtained from the erosion depth of gas plasma in each environment
The thermal conductivity is measured at room temperature by laser flash.
This is a value measured by the Schott method.

[0010]

The present invention will be described in more detail with reference to the following examples. Y ₂ O ₃ , Al with a purity of 99.9% or more
Using powders of ₂ O ₃ and MgO, a total of 200 g was weighed for each sample so as to have the composition of each sample shown in Table 1, and each powder and methanol 200 were placed in a polyethylene pot.
g, and 250 g of nylon balls containing an iron core, and mixed for 16 hours. After the slurry thus obtained was dried under reduced pressure by a rotary evaporator, the obtained powder was
The mixture was mesh-passed with a nylon mesh of 100 to obtain a molding powder.

The molding powder is 15 mm in diameter and 6 mm in thickness.
, And then subjected to cold isostatic pressing to obtain a molded body. The formed compact was fired at 1600 ° C. for 3 hours using an air furnace. The thermal conductivity of the obtained sintered body was measured at room temperature using a laser flash method. Further, one side of the fired body is mirror-polished, a part of which is masked with a polyimide resin, and carbon tetrafluoride (CF ₄ ) +
Oxygen (O ₂ ) plasma (flow rate 50 sccm, CF ₄ : O
₂ = 40: 10) and boron trichloride (BCl ₃ ) + oxygen (O ₂ ) plasma (flow rate 50 sccm, BCl ₃ : O ₂₎
= 40: 10), respectively. By comparing the height of the exposed portion of the test sample after the etching test with the height of the portion previously masked with the polyimide resin, the erosion depth is examined,
The etching rate was calculated.

The test results are shown in Table 1. Comparative Example 1 and Comparative Example 3 both have a low MgO content of 3% by weight, so that the etching rate is as small as 1 to 2 nm / min and the corrosion resistance is good, but the thermal conductivity is 8 to 11 W / m ·. Since K is small, sufficient thermal shock characteristics cannot be obtained.
On the other hand, in both Comparative Examples 2 and 4, the thermal conductivity was 59 to 60 W / m since the MgO content was as large as 98% by weight.
・ K is large and good thermal shock characteristics can be expected, but it can be seen that the etching rate is as large as 19 to 31 nm / min and sufficient corrosion resistance is not obtained.

Examples 1 to 6 are ceramics made of MgO and Y ₂ O ₃ , but have an etching rate of 1 to 12 n.
m / min and good corrosion resistance is obtained.
The thermal conductivity was 16 to 47 W / m · K and 15 W / m · K or more, and showed high heat conductivity. Examples 7 to 12
Is a ceramic made of MgO and YAG, and has an etching rate of 2 to 12 nm / min and a thermal conductivity of 17 to 4
6 W / m · K, the same characteristics as in Examples 1 to 6 were obtained. As described above, it was confirmed that the ceramic material satisfying the composition conditions of the present invention had excellent corrosion resistance, high thermal conductivity, and excellent thermal shock characteristics.

[0014]

[Table 1]

In the above embodiment, the case where Y ₂ O ₃ or YAG is used as the rare earth oxide or the composite oxide is shown. However, the rare earth oxide or the composite oxide is not limited to the yttria compound. Erbium oxide (Er
₂ O ₃ ), ytterbium oxide (Yb ₂ O ₃ ), dysprosium oxide (Dy ₂ O ₃ ), and the like.
Further, since the atmosphere of the halogen-based gas not converted into plasma is considered to be less corrosive than the plasma atmosphere of the halogen-based gas, the ceramic material of the present invention shows that the halogen-based gas not converted into plasma is Even in a gas atmosphere, it is determined to have good corrosion resistance.

[0016]

As described above, according to the ceramic material of the present invention, the corrosion resistance to a halogen-based gas or a halogen-based plasma is good, and the thermal conductivity is large and the thermal shock characteristics are excellent. And so on. As a result, the replacement frequency of the used parts is reduced, and the accompanying maintenance cost is reduced. In addition, since contamination of the processing atmosphere by the corroded components is suppressed, various effects of improving the processing characteristics can be obtained.

Continuing from the front page (72) Inventor, Kazuyoshi Minamizawa 3--5, Ametsu, Izumi-ku, Sendai-shi, Miyagi Japan Inside the Ceratech headquarters and factory in Japan (72) Inventor Keisuke Sato 3-chome, Akari, Izumi-ku, Sendai, Miyagi No. 5 Inside the Japan Ceratec headquarters and factory (72) Yukio Kishi Inventor 3-Chome, Izumi-ku, Sendai-shi, Miyagi 5th F-term inside the Japan Ceratech headquarters and factory 4G030 AA07 AA12 AA36 BA21 BA23 BA33 GA19 4G031 AA03 AA08 AA29 BA21 BA23 BA26 GA06

Claims (2)

[Claims] 1. A ceramic material containing magnesium oxide in an amount of 5% by weight or more and 95% by weight or less, with the balance being an oxide or composite oxide containing a rare earth element. 2. The ceramic material according to claim 1, wherein the etching rate in a halogen-based plasma environment is 15 nm / min or less, and the thermal conductivity at room temperature is 15 W / m · K or more.