JP2002222803A - Corrosion resistant member for manufacturing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrosion resistant member more excellent than SiO2, Al2O3 and AlN, etc. SOLUTION: A part to be exposed to fluorine-contained corrosion gas or its plasma is composed of oxide, nitride and carbide of group 3a elements in the periodic table and the complex. A fluoride layer is formed on the surface by reaction with the fluorine-contained corrosion gas or the plasma.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus used for manufacturing a semiconductor device, which requires high corrosion resistance to a fluorine-based corrosive gas or its plasma, an inner wall material in a film forming apparatus, The present invention relates to a corrosion-resistant member for semiconductor production suitable for a jig such as a support member for supporting a Si substrate.

[0002]

2. Description of the Related Art The use of plasma, such as a dry process for semiconductor manufacturing and plasma coating, has been rapidly advancing in recent years. For example, in a semiconductor manufacturing process, a fluorine-based halogen-based corrosive gas is frequently used in a plasma process, particularly for deposition, etching and cleaning, due to its high reactivity.

[0003] Further, in a portion of the apparatus which is in contact with the gas or plasma, such as an inner wall, a material mainly composed of SiO ₂ such as glass or quartz, stainless steel, or the like is conventionally used to prevent corrosion by the gas or plasma. Corrosion resistant metals such as Monel are used.

Further, in a semiconductor manufacturing apparatus, since a susceptor material for holding a Si wafer or the like also comes into contact with corrosive gas or plasma, alumina sintered body, sapphire, AlN sintered body, Is used on the surface of a substrate by CVD coating. Further, as a heater in the apparatus, a heater coated with graphite or boron nitride or the like is used.

[0005]

However, glass and quartz conventionally used have insufficient corrosion resistance in plasma and are intensely consumed. When they come into contact with fluorine, the contact surface is etched and the surface properties change. In a member requiring light transmissivity, there has been a problem that the surface gradually becomes cloudy and the light transmissivity is reduced.

[0006] Further, even a member using a metal such as stainless steel has insufficient corrosion resistance, so that the corrosion rate is high and a defective product which is mixed as impurities into a product is generated.
Also, alumina and AlN sintered bodies, which are being used as being excellent in corrosion resistance to fluorine-based corrosive gases, are corroded when exposed to plasma at high temperatures, causing crystal grains to fall off from the surface of the sintered body, After all, it causes contamination.

[0007]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of studying a semiconductor manufacturing material having excellent corrosion resistance to a fluorine-based corrosive gas or its plasma, fluoride is generated on the surface as the reaction with the fluorine-based corrosive gas or its plasma proceeds, and That the stability of the fluoride has a significant effect on corrosion resistance,
Further, as the fluoride, a fluoride of a Group 3a element of the periodic table has a high melting point and is stable at a high temperature, so it has been found that a Group 3a element of the periodic table is suitable as a corrosion-resistant member, and has led to the present invention. .

That is, the corrosion-resistant member for manufacturing a semiconductor according to the present invention has been completed based on the above-mentioned findings, and the portion exposed to the fluorine-based corrosive gas or its plasma is formed by oxidation of the Group 3a element of the periodic table. A fluoride layer is formed on the surface by reaction with the fluorine-based corrosive gas or its plasma.

Further, the element of Group 3a of the periodic table is Sc,
Being at least one selected from the group consisting of Y, La, Ce, Yb, Eu and Dy, in particular, the group 3a element of the periodic table is selected from the group consisting of Sc, La, Ce, Eu and Dy It is characterized by at least one kind.

[0010] At a portion exposed to a fluorine-based corrosive gas or its plasma, its surface becomes fluoride and evaporates,
Attrition is going on. According to the present invention, the member exposed to the fluorine-based corrosive gas or its plasma is made of an oxide, a nitride, a carbide, or a complex thereof of a Group 3a element of the Periodic Table. The group III element reacts with fluorine to form a fluoride layer having a high melting point, and the durability is improved in a severe fluorine-based corrosive gas atmosphere over a wide temperature range.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The corrosion-resistant member for manufacturing a semiconductor according to the present invention is a member exposed to a fluorine-based corrosive gas or a plasma containing a fluorine-based corrosive gas.
Gases such as SF ₆ , CF ₄ , CHF ₃ , ClF ₃ , and HF. When microwaves, high-frequency waves, or the like are introduced into the atmosphere in which these gases are introduced, these gases are turned into plasma.

According to the present invention, such a portion to be exposed to the fluorine-based corrosive gas or its plasma is composed of an oxide, nitride, carbide or a composite thereof of a Group 3a element of the periodic table. It is. Here, Periodic Table 3a
Group elements are Y, Sc and lanthanoid elements, among which Sc, Y, La, Ce, Yb, E
at least one selected from the group consisting of u and Dy, especially Sc,
At least one selected from the group consisting of La, Ce, Eu, and Dy
Species are most desirable because of their higher melting point as fluoride compared to other elements.

Further, as the compound of the Group 3a element of the periodic table, Sc ₂ O ₃ , Y ₂ O ₃ , Yb ₂ O ₃ , Ce ₂ O ₃ , Eu
Examples include oxides such as ₂ O ₃ and Dy ₂ O ₃ , nitrides such as ScN and YN, carbides such as YC, and fluorides such as YF ₃ and LaF ₃ . All of these compounds change to fluoride when exposed to a fluorine-based corrosive gas or plasma.

This corrosion-resistant member is preferably formed by coating a predetermined substrate surface with an oxide, nitride, carbide, or a composite thereof of the Group 3a element of the periodic table by a well-known thin-film forming method in terms of denseness. desirable. In this case, the substrate is preferably formed on the surface with a thickness of 5 to 500 μm, particularly 10 to 200 μm. This is because, if the thickness is too small, when the corrosion proceeds by the corrosive gas, the corrosion-resistant thin film disappears and the substrate is exposed. Such a dense film may be, for example, a thin film formed by applying and baking a liquid phase by a known sol-gel method, or a thin film formed by a known gas phase method such as a CVD method or a PVD method.

In addition, oxides of Group 3a elements of the periodic table,
Single crystals consisting of nitrides, carbides and their composites,
It is also possible to constitute from a dense sintered body. In this case, it is desirable that the relative density of each of these bulk bodies is 98% or more, particularly 99% or more. This is because the corrosion resistance decreases as the number of voids increases.
Such a sintered body includes an oxide of an element of Group 3a of the periodic table,
After molding into a predetermined shape using powders of nitrides, carbides, and composites thereof, it can be formed by firing the molded body. In general, oxides and nitrides of Group 3a elements of the periodic table can be used. Since carbides and their composites are difficult to sinter, they can be sintered by applying a high-pressure gas atmosphere by a hot isostatic pressing method or the like to achieve high density.

[0016]

EXAMPLES Various types of glass, sintered bodies, and single bonds as shown in Table 1
Crystal and PVD method using carbon as substrate
Oxides, nitrides, carbides of Group 3a elements of the Periodic Table and the same
These composite oxides, nitrides and carbides have a thickness of 20μ
m was formed. These are RIE plasma etches
Installed in the_FourAnd O_TwoMixed gas (CF _Four:
O_Two= 9: 1), Ar and SF₆Mixed gas (Ar: SF
₆= 2: 3) and 13.5
Plasma was generated by introducing a high frequency of 6 MHz. This
For up to 3 hours in the plasma of
Measure the weight loss, and from the value, etch
The thickness to be etched (etching rate) was calculated. Also,
The surface after the test was observed, and the results are shown in Table 1.

[0017]

[Table 1]

As is clear from the results in Table 1,
SiO used_TwoGlass, silicon nitride sintered body
Means that the etching rate exceeds 500Å / min
Is known as a material having excellent corrosion resistance._TwoO_ThreeBurning
Sintered body, AlN sintered body, AlF _ThreeThen, 150Å / min
The etching rate is reduced as follows, but based on the present invention,
Oxides, nitrides, and carbides of Group 3a elements of the periodic table
And their complexes, namely Sc, Y, La, Ce, Y
at least one oxidation selected from the group consisting of b, Eu and Dy
In materials, nitrides, carbides and their composites
Great corrosion resistance is dramatically improved to less than 20Å / min.
You can see that it goes up. Among these, Sc, L
a, Ce, Eu and Dy compounds were all 10 ° / min.
The following and more excellent characteristics were shown.

[0019]

As described in detail above, the corrosion-resistant member for semiconductor production of the present invention has high corrosion resistance as a member exposed to a fluorine-based corrosive gas and its plasma. The life of these members can be extended by using them as a clamp ring for fixing a Si wafer, a shield ring around an upper electrode, an inner wall material of an apparatus, or the like in a plasma processing apparatus or an etching apparatus used as an apparatus.

Claims (3)

[Claims] 1. A fluorine corrosive gas or a portion exposed to plasma thereof is made of an oxide, nitride, carbide, or a complex thereof of a Group 3a element of the periodic table, and said fluorine corrosive gas or plasma thereof. A corrosion-resistant member for semiconductor production, wherein a fluoride layer is formed on the surface by the reaction with 2. The element of Group 3a of the periodic table is Sc, Y, L.
The corrosion-resistant member according to claim 1, wherein the member is at least one selected from the group consisting of a, Ce, Yb, Eu, and Dy. 3. The element of Group 3a of the periodic table is Sc, La,
2. The corrosion-resistant member according to claim 1, wherein the member is at least one member selected from the group consisting of Ce, Eu, and Dy.