JPH11219944A - Etching gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain etching gas for etching a formed thin film, a formed thick film or the like by a method wherein gas containing a perfluoroalkylamine, a perfluoroalkylether or a perflyuorocyclicether is used as the etching gas. SOLUTION: A material film to be etched using etching gas is a B film, a P film, a W film, an Si film, a Ti film, a V film, an Nb film, a Ta film, an Se film, a Te film, an Mo film, an Re film, an Os film, an Ir film, an Sb film, a Ge film, an Au film, an Ag film, an As film or a Cr film and its compound film and in concrete terms, the material film is an oxide film, a nitride film or a carbide film and these alloy films. Moreover, as the etching gas, (CF3 )3 N gas, CF3 OCF3 GAS or C4 F8 O gas is specially preferable, but in consideration of the kind, the thickness and the like of the formed film, gas itself containing a perfluoroalkylamine, a perfluoroalkylether or a perfluorocyclicether is used or the above gas diluted with inert gas, such as nitrogen gas, argon gas and helium gas, and Hg gas, O2 gas, F2 gas, ClF3 gas, BrF3 gas, BrF5 gas or the like is used. These methods of using the etching gas has only to be property selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching gas for etching a thin film or a thick film formed by a CVD method, a sputtering method, a sol-gel method, or a vapor deposition method, cutting an ingot, and polishing a surface.

[0002]

2. Description of the Related Art Conventional technology and problems to be solved
In order to form a circuit pattern on various thin film materials constituting a circuit in an FT or the like, it is necessary to perform gas etching for partially removing the thin film material. Furthermore, in CVM (chemical vapor machining), it is necessary to cut a Si ingot or the like by gas etching.

[0003] The performance required of an etching gas for cutting such a material is that the reaction speed with respect to an etching object is high, the treatment of exhaust gas is relatively easy, and the gas is relatively unstable in the atmosphere. It is desired that the impact on global warming is small. At present, gases such as C ₂ F ₆ and CF ₄ are used to remove such unnecessary deposits and etch film materials. However, these gases are very stable compounds, and it is difficult to treat exhaust gas after etching.
In addition, a high temperature is required for processing, so that the running cost is relatively high. Furthermore, it has a slow decomposition rate in the atmosphere and a long life, and is stably present in the environment and has a high global warming potential.

[0004]

[Specific means for solving the problem]
As a result of intensive studies, a thin film formed by using a CVD method, a sputtering method, a sol-gel method, a vapor deposition method, etching of a thick film or cutting of an ingot, and an etching gas for polishing a surface, have reached the present invention. is there.

That is, the present invention relates to a perfluoroalkyl compound which is more easily dissociated than CF ₄ , C ₂ F _6, etc., is relatively easy to treat an exhaust gas, has a high decomposition rate in the atmosphere, and has little adverse effect on the global environment. By using a gas containing an amine, a perfluoroalkyl ether, or a perfluorocyclic ether, an etching gas for etching a formed thin film, thick film, or the like is provided.

The substances to be etched in the present invention include B, P, W, Si, Ti, V, Nb, Ta, and S.
e, Te, Mo, Re, Os, Ir, Sb, Ge, A
u, Ag, As, Cr and their compounds, specifically, oxides, nitrides, carbides and alloys thereof.

Further, the etching gas in the present invention is:
(CF_Three)_ThreeN [tri-trifluoromethy
lamine], (C_TwoF_Five)_ThreeN [tri-pentaf
fluoethylamine], (C_ThreeF₇)_ThreeN [t
ri-heptafluoropropylamine
e], C₆F₁₁NF_Two[Tridecafluorocy
Clohexylamine], C_FiveF_TenNF [und
ecafluoropiperidine], (C
_TwoF_Five)_TwoNC_ThreeF₇[N, N-di-pentafluor
oethyl-heptafluoropropila
mine], (i-C _ThreeF₇)_TwoNC_TwoF_Five[N, N-di-
heptafluoroisopropyl-pent
afluoroethylamine], CF_ThreeOCF_Three
[Di-trifluoromethyl ether
r], C_TwoF_FiveOC_TwoF_Five[Di-pentafluoro
ethyl ether], C_ThreeF₇OC_ThreeF₇[Di-h
eptafluoropropyl ether], C
_FourF₉OC_FourF₉[Di-nonafluorobutyl
 ether], C_FourF₉OCF_Three[Nonafluor
obbutyl-trifluoromethyl et
her], CF_ThreeOCF_TwoCF _TwoOCF_Three[Decaflu
oro-glycol dimethyl ethyl
r], C₆F₁₁OCF_Three[Undecafluorocy
Clohexyl-trifluoromethyl
ether], C_FourF₈O [octafluorotte
ramethylene oxide], C_FiveF_TenO
[Decafluoropentamethylene
 oxide]]. Particularly preferably, (C
F_Three)_ThreeN, CF_ThreeOCF_Three, C_FourF₈O.

The etching gas used in the present invention may be perfluoroalkylamine, perfluoroalkylether, or perfluorocyclic ether itself, or may be nitrogen, argon, helium, or the like, in consideration of the type and thickness of the formed film. And inert gas such as H ₂ , O ₂ , F
₂ , diluted with ClF ₃ , BrF ₃ , BrF _5, etc.
What is necessary is just to select suitably. The reaction conditions are not particularly limited, and are appropriately selected in consideration of the target material as described above.

[0009]

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 4 and Comparative Examples 1 to 2 Test pieces obtained by depositing a silicon oxide film of 20 μm on a silicon wafer (4 inches) by using a parallel plate type plasma CVD apparatus using tetraethyl orthosilicate as a main raw material. , And a test piece in which a silicon oxide film was deposited on a silicon wafer (4 inches) in a thickness of 20 μm by a sol-gel method using tetraethylorthosilicate as a main raw material. These test pieces were placed on the lower electrode of a plasma CVD apparatus, and (CF ₃ ) ₃ N, CF ₃
A gas pressure of 1 Torr is applied to three kinds of gases, OCF ₃ and C ₂ F _6.
r, a high-frequency power was applied to the lower electrode on which the test piece was installed under the conditions of a gas flow rate of 100 SCCM and room temperature (a high-frequency power frequency of 13.56 MHz and an applied power of 0.315 W /
(cm ² , distance between electrodes: 50 mm) for etching. Table 1 shows the measurement results of these etching rates.

[0011]

[Table 1]

Examples 5 to 6, Comparative Example 3 A silicon wafer was placed on an electrode of a CVD apparatus, and (CF)
₃ ) High-frequency power is applied to the lower electrode on which the test piece is installed under the conditions of a gas pressure of 760 Torr, a gas flow rate of 100 SCCM, and room temperature by using three kinds of gas of ₃ N, CF ₃ OCF ₃ and C ₂ F ₆ (high-frequency power Etching was performed at a frequency of 13.56 MHz, an applied power of 0.315 W / cm ² , and a distance between electrodes of 2 mm. Table 2 shows the measurement results of these etching rates.

[0013]

[Table 2]

Examples 7 to 9 and Comparative Example 4 A test piece was prepared by depositing a silicon oxide film of 20 μm on a silicon wafer (4 inches) using a parallel plate type plasma CVD apparatus using tetraethyl orthosilicate as a main raw material. did. These test pieces were placed on the lower electrode of a plasma CVD apparatus, and (CF ₃ ) ₃ N, CF ₃
The four gases of OCF ₃ , C ₄ F ₈ O and C ₂ F ₆ were diluted to 10 vol% with helium, and under the conditions of a gas pressure of 10 Torr, a gas flow rate of 100 SCCM and room temperature, the lower electrode on which a test piece was installed was placed. High frequency power is applied (high frequency power frequency 13.56 MHz, applied power 0.315 W / cm ² ,
Etching was performed with a distance between electrodes of 50 mm). Table 3 shows the measurement results of these etching rates.

[0015]

[Table 3]

[0016]

The etching gas of the present invention exhibits extremely excellent etching performance.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/304 341 H01L 21/304 341D

Claims (2)

[Claims] 1. A gas for etching a thin film or a thick film made of a metal or a compound thereof formed by a thin film forming apparatus, cutting an ingot, or polishing a surface, comprising perfluoroalkylamine, perfluoroalkylether, Alternatively, an etching gas containing a perfluorocyclic ether. 2. Perfluoroalkylamine, perful
Oroalkyl ether or perfluorocyclic ether
Is (CF_Three)_ThreeN, CF_ThreeOCF_ThreeOr C_FourF ₈In O
The etching gas according to claim 1, wherein the etching gas is provided.