Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Forming nonplanar surface
Reexamination Certificate
2000-08-07
2002-02-26
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Forming nonplanar surface
C134S001300
Reexamination Certificate
active
06350560
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of removal of polymeric materials from a substrate. In particular, the present invention relates to compositions and methods as rinse compositions for polymer removers.
Numerous materials containing polymers are used in the manufacture of electronic devices, such as circuits, disk drives, storage media devices and the like. Such polymeric materials are found in photoresists, solder masks, antireflective coatings, and the like. For example, modern technology utilizes positive-type resist materials for lithographically delineating patterns onto a substrate so that the patterns can be subsequently etched or otherwise defined into the substrate material. The resist material is deposited as a film and the desired pattern is defined by exposing the resist film to energetic radiation. Thereafter the exposed regions are subject to a dissolution by a suitable developer liquid. After the pattern has been thus defined in the substrate the resist material must be completely removed from the substrate to avoid adversely affecting or hindering subsequent operations or processing steps.
It is necessary in such a photolithographic process that the photoresist material, following pattern delineation, be evenly and completely removed from all unexposed areas so as to permit further lithographic operations. Even the partial remains of a resist in an area to be further patterned is undesirable. Also, undesired residue between patterned features can have deleterious effects on subsequent film depositions processes, such as metallization, or cause undesirable surface states and charges leading to reduced device performance.
The semiconductor industry is moving toward sub-quarter micron geometry features. As the geometry of the features gets smaller and pattern density increases, plasma etching, reactive ion etching, ion milling and the like are required for the lithographic process. During such plasma etching, reactive ion etching and ion milling processes, the polymeric material is subjected to conditions that make the removal of such polymeric material difficult. During the plasma etch process a photoresist film forms a hard to remove organometallic polymeric residue on the sidewalls of the various features being etched. Furthermore, the photoresist is extensively cross-linked due to the high vacuum and high temperature conditions in the etch chamber.
The difficulty of removing post plasma etch polymers depends upon the plasma etch gas used. For example, when chlorine-type gas is used, such as BCl
3
or Cl
2
, the resulting organometallic polymer can be removed by conventional strippers. However, when fluorine-type etch gas is used, such as CF
4
or CHF3, then the resulting organometallic polymer is fluorinated and the conventional strippers do not sufficiently remove such residue. Fluorine containing strippers are typically used to remove such fluorinated organometallic polymer residue.
Numerous polymer stripper compositions have been developed to remove photoresists, antireflective coatings and post plasma etch polymeric residue. One class of such removers is based on fluoride, such as hydrofluoric acid, ammonium fluoride or ammonium bifluoride. For example, U.S. Pat. No. 5,320,709 (Bowden et al.) discloses compositions for the selective removal of organometallic residues remaining after plasma etching of materials including anhydrous ammonium fluoride salt selected from anhydrous ammonium fluoride or anhydrous ammonium bifluoride in a polyhydric alcohol, wherein the composition contains less than 4% by weight added water. Such fluoride based stripping compositions are particularly suitable for use in the removal of post plasma etch polymeric residue.
In general, after a substrate has been treated with a stripping composition, it is rinsed, typically with water or isopropanol. Isopropanol is generally preferred as it removes any residue from the stripping compositions, such as water and organic components, and dries quickly. Also, many of the metals used in the manufacture of electronic devices are sensitive to corrosion, such as by water. Thus, it is desirable to limit the contact of such metal layers with large amounts of water. Such isopropanol rinses are effective in removing fluoride-based stripping composition residues, however, such rinses form precipitate. Precipitate formation creates problems in subsequent processing steps by clogging the fine features in the electronic devices itself. Such precipitant formation may also clog tubes or filters used in filtering such rinse solutions prior to disposal of such rinses.
Methods for increasing the effectiveness of polymer removers have been proposed. For example, U.S. Pat. No. 4,786,578 (Neisius et al.) discloses a rinse solution used after a photoresist stripper. This rinse solution contains a nonionic surfactant and an organic base, such as an alkanolamine, that will form a water-soluble salt with alkylbenzenesulfonic acids. U.S. Pat. No. 4,824,762 (Kobayashi et al.) discloses a photoresist stripper post rinse containing a glycol ether and an aliphatic amine. In both patents, the compositions contain amines which tend to cause corrosion of copper present in the electronic devices. Further, these compositions will not avoid the precipitate problem when used to rinse fluoride-based stripping compositions.
There is thus a continuing need to effectively remove stripping composition residue from electronic devices in ways that are environmentally compatible, that do not damage the features and geometries of the electronic devices, that do not cause corrosion of the substrate, particularly thin metal films, that do not etch dielectric layers in the substrate, and that do not form precipitate when removing fluoride-based stripping composition residues.
SUMMARY OF THE INVENTION
It has been surprisingly found that stripping composition residues may be effectively and easily removed from a substrate, such as an electronic device, without the formation of a precipitate by rinsing the electronic device with a composition of the present invention.
In one aspect, the present invention provides a composition including water and two or more solvents, wherein at least one solvent is selected from polyol compounds or glycol ethers.
In a second aspect, the present invention provides a method of removing stripping composition residue from a substrate including the step of contacting the substrate with a composition described above.
In a third aspect, the present invention provides a method for manufacturing an electronic device including: a) contacting polymeric material disposed on a substrate with a stripping composition for a period of time sufficient to at least partially remove the polymeric material; and b) then contacting the substrate with a composition including water and two or more solvents, wherein at least one solvent is selected from polyol compounds or glycol ethers.
DETAILED DESCRIPTION OF THE INVENTION
As used throughout this specification, the following abbreviations shall have the following meanings unless the context clearly indicates otherwise: ° C.=degrees Centigrade; % wt=percent by weight; mL=milliliter; DI=deionized; DPM=dipropylene glycol monomethyl ether; and PME=propylene glycol monomethyl ether. All percentages and ratios are by weight, unless otherwise indicated. All numerical ranges are inclusive and combinable.
The terms “stripping” and “removing” are used interchangeably throughout this specification. Likewise, the terms “stripper” and “remover” are used interchangeably. “Alkyl” refers to linear, branched and cyclic alkyl. The term “substituted alkyl” refers to an alkyl group having one or more of its hydrogens replaced with another substituent group, such as halogen, cyano, nitro, (C
1
-C
6
)alkoxy, mercapto, (C
1
-C
6
)alkylthio, and the like. The term “glycol” refers to dihydric alcohols. Thus, the term “glycol ether” refers to ethers of dihydric alcohols.
The compositions of the present invention incl
Cairns S. Matthew
Le Hoa Van
Shipley Company L.L.C.
LandOfFree
Rinse composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rinse composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rinse composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2945569