JP2001181024A - Ceramic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic member having a high resistance to a halogen gas or a halogen gas plasma and high in resistance to thermal shock. SOLUTION: A part of this ceramic member exposed to a halogen gas or halogen gas plasma is composed of oxides including >=30 wt.% of yttrium oxide and porosity of the ceramic member is 3%-8%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic member having high resistance to a halogen-based gas or a halogen gas plasma, which is suitable for a member 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 an environment having high chemical corrosion. For example, a bell jar, a chamber, a susceptor, a clamp ring, a focus ring, and the like can be used. These are used in a dry etching process using a highly corrosive halogen-based gas.

As these materials, conventionally, quartz (Si
O ₂ ) and alumina (Al ₂ O ₃ ) have been frequently used,
These materials do not have sufficient corrosion resistance in a halogen gas or halogen gas plasma environment, and oxide materials containing rare earth elements have recently been proposed as alternative materials.

[0004]

However, such an oxide material containing a rare earth element has various problems, although it has high corrosion resistance in a halogen gas or halogen gas plasma environment. That Y ₂ O ₃ composite oxide including a rare earth oxide represented by and Y ₂ O ₃ oxide single ceramic Both low thermal conductivity, thermal expansion is large, thermal shock properties conventionally used It is worse than ceramics, and there is a concern that it may be damaged by thermal shock during use.

The present invention has been made in view of such circumstances, and has as its object to provide a ceramic member having high resistance to a halogen-based gas or a halogen gas plasma and having high thermal shock resistance.

[0006]

Means for Solving the Problems As a result of repeated studies to solve the above-mentioned problems, the present inventors have made a site exposed to a halogen-based gas or a halogen gas plasma a specific material containing yttrium oxide, and It has been found that by providing a certain degree of porosity, it is possible to increase the thermal shock resistance while maintaining good corrosion resistance to a halogen-based gas or a halogen gas plasma, thereby completing the present invention.

That is, the present invention provides that a portion exposed to a halogen-based gas or a halogen gas plasma is composed of an oxide containing 30 wt% or more of yttrium oxide and has a porosity of more than 3% and 8% or less. Provide a ceramic member characterized by the following.

[0008] At least a part of the ceramic member may be a composite oxide. Further, aluminum oxide may be contained in addition to yttrium oxide.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. In the ceramic member of the present invention, the portion exposed to the halogen-based gas or the halogen gas plasma is made of an oxide containing 30 wt% or more of yttrium oxide and has a porosity of more than 3% and 8% or less.

The ceramic member constituting the present invention may contain at least 30 wt% of yttrium oxide, and may contain other oxides or may be yttrium oxide alone.

The reason why the content of yttrium oxide is set to 30 wt% or more is that if yttrium oxide is less than 30 wt%, it does not have sufficient corrosion resistance to halogen-based gas and halogen gas plasma.

Since the corrosion resistance is improved by containing yttrium oxide in an amount of 30% by weight or more, the remaining compound is not particularly limited, and any compound capable of forming a sintered body having a porosity within the range of the present invention can be formed. However, it is preferable that at least a part of the composite oxide forms a complex oxide with yttrium oxide.

Other compounds include aluminum oxide,
Among them, silicon oxide and the like can be mentioned, and among them, aluminum oxide which can form a composite oxide having high corrosion resistance is preferable.

On the other hand, as described above, yttrium oxide has low thermal conductivity and large thermal expansion, and thus has poor thermal shock resistance, and the thermal shock resistance deteriorates as the content of yttrium oxide increases. Conventionally, a dense body has been used as a material containing yttrium oxide, and there has been a concern about breakage due to thermal shock during use. However, in the present invention, the thermal shock resistance is improved by providing a certain degree of porosity. In other words, the porosity is a particularly important factor with respect to the thermal shock resistance, and by setting the porosity to a certain degree, the thermal shock resistance is improved. If the porosity is 3% or less, the corrosion rate is small but the thermal shock characteristics are not improved. If the porosity is 8% or more, the thermal shock characteristics are improved but the corrosion resistance is insufficient. Therefore, the porosity range exceeds 3% to 8%.
% Or less.

In the ceramic member of the present invention, a portion exposed to a halogen-based gas or a halogen gas plasma is excellent in corrosion resistance to the same and has high thermal shock resistance.
It is suitable for a member for a semiconductor manufacturing device such as a bell jar, a chamber, a susceptor, a clamp ring, and a focus ring and a member for a liquid crystal display device manufacturing device.

[0016]

Embodiments of the present invention will be described below. 99.9% pure yttrium oxide (Y ₂ O ₃ ) and 9 pure
Using 9.9% or more of aluminum oxide (Al ₂ O ₃ ), these were weighed in a total of 200 g in the ratios shown in Table 1, and were put into a polyethylene pot together with 200 g of ion-exchanged water and 250 g of nylon balls containing an iron core. ,
Mix for 16 hours. After the obtained slurry was dried under reduced pressure by a rotary evaporator, the obtained powder was # 100
A mesh pass was performed using a nylon mesh. This powder is 15 mm in diameter, 6 mm in thickness, or 40 × 50
After molding to a size of × 6 mm, a molded product was obtained by cold isostatic pressing. The obtained molded body is placed in an electric furnace in the atmosphere,
It was baked at a predetermined temperature for 4 hours.

One side of the obtained sintered body was mirror-polished, placed in a chamber of a parallel plate type RIE etching apparatus, and subjected to a corrosion test using CF ₄ + O ₂ plasma.
At that time, plasma processing was performed by masking a part of the polished surface with a polyimide tape, and after removing the mask after the test,
The etching rate was calculated by measuring the level difference between the portion with and without the mask.

Further, bending specimens in accordance with JIS R1601 were prepared from the samples fired at the respective temperatures, poured into ice-cold water from an electric furnace maintained at a predetermined temperature, and then the bending strength of the specimen was measured. At this time, the electric furnace temperature was set to ΔT
And the flexural strength of the sample without pouring into hot ice water was 1
The value of ΔT at which the strength was / 2 was evaluated as thermal shock resistance. Table 1 shows the results.

[0019]

[Table 1]

As shown in Table 1, yttrium oxide (Y
_Although the content of ₂ O ₃ ) is within the range of the present invention, Comparative Example 1 having a porosity of 0.3%, which is smaller than the range of the present invention,
The etching rate is 3 nm / min. However, the thermal shock resistance ΔT was 100 ° C., which was smaller than that of a commonly used alumina ceramic (Al ₂ O ₃ ; Comparative Example 5 in Table 1). Although the content of yttrium oxide (Y ₂ O ₃ ) is within the range of the present invention, Comparative Example 2 having a porosity of 9% larger than the range of the present invention has a thermal shock resistance of 170 ° C.
And about the same as in Examples 1 to 3, but the etching rate was 15 nm / min. And the corrosion resistance was low.

On the other hand, yttrium oxide (Y
_In Examples 1 and 2 in which the content of ₂ O ₃ ) was 57 wt% and the porosity was 3.5% and 5%, both of which were within the range of the present invention, the etching rate was as small as 3 nm / min. 160 ° C each while maintaining the value
And 170 ° C., a value close to that of alumina ceramics. Yttrium oxide (Y ₂ O ₃ ) more than in Examples 1 and 2
Even in Example 3 where the content is small and the porosity is 3.5%, the etching rate is 4 nm / min and the thermal shock resistance is 170 ° C.
And a good value.

On the other hand, with respect to the sample of yttrium oxide alone, in Comparative Example 3 having a porosity of 0.3%, the thermal shock resistance was 90%.
° C and a porosity of 9% in Comparative Example 4 where the etching rate was 18 nm / min. And corrosion resistance was low.

Examples 4 and 5, which are samples of yttrium oxide alone and have a porosity of 3.5% and 4.5%, respectively, within the range of the present invention, have an etching rate of 3 nm / mi.
n. And the thermal shock resistance was 150 ° C. and 160 ° C., respectively, showing values close to those of alumina ceramics.

[0024]

As described above, according to the present invention,
Since the portion exposed to the halogen-based gas or the halogen gas plasma is made of an oxide containing 30 wt% or more of yttrium oxide and has a porosity of more than 3% and 8% or less,
A ceramic member having high resistance to halogen-based gas or halogen gas plasma and high thermal shock resistance can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiromichi Otaki 3-5 Amedori, Izumi-ku, Sendai-shi, Miyagi Japan Co., Ltd. Inside the plant of Japan Ceratech Co., Ltd. F-term (reference) in the Japan Ceratech headquarters and factory No.5 4G030 AA12 AA36 BA33 CA09 4G031 AA08 AA29 BA26 4G075 AA30 AA53 BC06 BD14 CA47 FB04

Claims (3)

[Claims] A portion exposed to a halogen-based gas or a halogen gas plasma contains 30 wt% of yttrium oxide.
A ceramic member comprising an oxide containing the above and having a porosity of more than 3% and 8% or less. 2. The ceramic member according to claim 1, wherein at least a part of the ceramic member is a composite oxide. 3. The method according to claim 1, wherein aluminum oxide is contained in addition to yttrium oxide.
2. The ceramic member according to 1.