Cleaning and liquid contact with solids – Processes – Using sequentially applied treating agents
Reexamination Certificate
2000-09-25
2003-12-16
Carrillo, Sharidan (Department: 1746)
Cleaning and liquid contact with solids
Processes
Using sequentially applied treating agents
C210S900000, C134S001100, C134S028000, C134S029000, C134S034000, C134S036000, C134S041000, C134S042000
Reexamination Certificate
active
06663722
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method of cleaning a fluorine-containing rubber molded article such as a sealing material for semiconductor production apparatuses, the cleaned molded article and semiconductor production apparatuses such as etching equipment which are equipped with the molded article.
BACKGROUND ART
In the field of semiconductor industries, sealing materials produced from a silicone material, fluorosilicone material, ethylene/propylene/diene terpolymer (EPDM), and the like have been used generally as molded articles such as sealing materials for semiconductor production apparatuses, and from the viewpoint of excellent heat resistance, plasma resistance and corrosive gas resistance, fluorine-containing rubber materials such as vinylidene fluoride/hexafluoropropylene copolymer rubber, vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene copolymer rubber, tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer rubber and tetrafluoroethylene/propylene copolymer rubber have been used for molded articles to be used under particularly strict conditions.
In a production process of semiconductors, there arise organic residues such as photoresist residue, organic solvent residue, synthetic wax and fatty acid derived from human body, inorganic contaminants such as sodium, potassium, gold, iron and copper, and particles. It is important to remove them and not to carry them into the following high temperature heat treating step. Attention is paid particularly to cleaning of a wafer, and strict control on chemicals to be used therefor is demanded.
However for example, since a minimum pattern of 64 Mbit DRAM is 0.35 &mgr;m, it is necessary to keep fine particles of as small as about 0.02 &mgr;m to about 0.03 &mgr;m under control, but the present situation is such that controlling of chemicals to be used for cleaning of wafer up to the above-mentioned level is technically difficult.
The present inventors supposed that only cleaning of semiconductor products such as silicon wafer (article to be processed) by etching and washing is not enough and paid attention to cleaning of molded members as components of semiconductor production apparatuses, particularly sealing materials thereof.
The reason why attention was paid to the molded articles such as sealing materials to be used on semiconductor production apparatuses was that particles and metal components are considered to possibly adhere to a surface of semiconductor, thereby causing lowering of yield.
As a method of cleaning the molded articles such as sealing materials, there have been usually employed, for example, a method of wiping them with an absorbent cotton impregnated with a solvent such as isopropyl alcohol. However it is still impossible to sufficiently reduce an amount of particles adhering to the molded articles and a content of metal components, and even if the above-mentioned chemicals used for cleaning of wafer, etc. are used, cleaning enough to cope with high integration of semiconductors and fine patterning has not yet been achieved.
In view of the above-mentioned fact, objects of the present invention are to provide a novel and effective cleaning method capable of giving cleaned fluorine-containing rubber molded articles for semiconductor production apparatuses, and further to provide semiconductor production apparatuses which can reduce sufficiently particles and metal components resulting from molded articles such as sealing materials.
DISCLOSURE OF INVENTION
The present invention relates to the method of cleaning a fluorine-containing rubber molded article for semiconductor production apparatuses, which comprises washing the fluorine-containing rubber molded article once or two or more times preferably at a temperature of not less than 80° C. with ultra pure water which has a metal content of not more than 1.0 ppm and does not contain fine particles of not less than 0.2 &mgr;m in an amount of more than 300 per 1 ml.
The present invention also relates to the method of cleaning a fluorine-containing rubber molded article for semiconductor production apparatuses, which comprises washing the fluorine-containing rubber molded article once or two or more times with an organic compound or inorganic compound which has a metal content of not more than 1.0 ppm, does not contain fine particles of not less than 0.5 &mgr;m in an amount of more than 200 per 1 ml and is in liquid form at a washing temperature.
Further the present invention relates to the fluorine-containing rubber molded article for semiconductor production apparatuses which is subjected to cleaning by dry etching.
Further the present invention relates to the method of cleaning a fluorine-containing rubber molded article for semiconductor production apparatuses, which comprises extraction cleaning.
Further the present invention relates to the method of cleaning a fluorine-containing rubber molded article for semiconductor production apparatuses, in which after a method of washing with an organic compound or inorganic compound having an oxidizing ability and a method of washing with an inorganic compound having a high ability of dissolving a metal are carried out in this order or in reverse order, washing with ultra pure water is conducted and then removal of water is carried out in a clean inert gas or air. Still further the present invention relates to the method of cleaning a fluorine-containing rubber molded article for semiconductor production apparatuses, in which after washing with an aqueous solution of a mixture of H
2
SO
4
and H
2
O
2
which has a metal content of not more than 1.0 ppm and does not contain fine particles of not less than 0.5 &mgr;m in an amount of more than 200 per 1 ml is carried out, washing with an aqueous solution of HF which has a metal content of not more than 1.0 ppm and does not contain fine particles of not less than 0.5 &mgr;m in an amount of more than 200 per 1 ml, washing with ultra pure water which has a metal content of not more than 1.0 ppm and does not contain fine particles of not less than 0.2 &mgr;m in an amount of more than 300 per 1 ml and then removing of water in a clean inert gas or air which does not contain fine particles of not less than 0.2 &mgr;m in an amount of more than 26 per 1 liter and has a content of organic component (TOC) of not more than 0.1 ppm are carried out.
Further the present invention relates to the fluorine-containing rubber molded article for semiconductor production apparatuses, in which the number of particles of not less than 0.2 &mgr;m being present on the surface thereof is not more than 200,000/cm
2
.
Further the present invention relates to the fluorine-containing rubber molded article for semiconductor production apparatuses, in which the molded article is subjected to cleaning by one of the above-mentioned cleaning methods or by a combination of two or more thereof and the number of particles of not less than 0.2 &mgr;m being present on the surface thereof is not more than 200,000/cm
2
.
The present invention also relates to the semiconductor production apparatuses equipped with the above-mentioned fluorine-containing rubber molded article, for example, etching equipment, washing equipment, exposure equipment, grinding equipment, film forming equipment and ion diffusion and implantation equipment.
BEST MODE FOR CARRYING OUT THE INVENTION
Firstly the fluorine-containing rubber constituting the fluorine-containing rubber molded article for semiconductor production apparatuses of the present invention is explained below.
Non-restricted examples of the fluorine-containing rubber constituting the fluorine-containing rubber molded article for semiconductor production apparatuses of the present invention are those which have been used for molding materials for sealing materials nd the like. For example, there are a copolymer rubber represented by the formula (1):
wherein m is from 85 to 60, n is from 15 to 40, or the formula (2):
wherein m is from 95 to 50, n is from 5 to 50, R
f
is a perfluoroalkyl group having 1 to 8 carbon atoms,
a terpolymer
Hasegawa Masanori
Higashino Katsuhiko
Kishine Mitsuru
Noguchi Tsuyoshi
Carrillo Sharidan
Sughrue & Mion, PLLC
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