JPS6013090A - Copper plating bath composition and method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to plating bath compositions and methods for electrodepositing copper onto conductive substrates, and more particularly to plating bath compositions and methods thereof for electrodepositing copper on conductive substrates, and more particularly to Aqueous/acidic improved copper plating bath consisting of
The present invention relates to an improved bath for producing a slightly smoother and brighter copper plating with less ductility, particularly in the four-part region of low current densities.

[Conventional technology]

- A wide variety of bath compositions and methods are used to electrodeposit bright, smooth, and ductile copper films.

and has been proposed. Representative of such prior art is U.S. Patent No. 2,704166;
Publication No. 7; Publication No. 2,738,318; Publication No. 2,8
Publication No. 82,209; Publication No. 6,267.010;
Publication No. 5,328,273 2 Publication No. 3,770,59
Publication No. 8; Publication No. 4,110,176 and Publication No. 4,
This is described in Publication No. 272,335. U.S. Patent No. 4,272,335 V was substituted as a brightener 7
Aqueous acidic copper plating baths are provided that contain talocyanine groups and, in preferred embodiments, further contain auxiliary secondary brighteners such as polysulfides, sulfides and/or polyether compounds. This U.S. patent describes improvements in brightness, smoothness, and ductility of copper plating within a certain range of operating parameters and compositions; In the density recessed region, the best brightness of copper plating has not yet been achieved.

However, even if aposafranin brightness compound is used alone or in combination with polysulfide, organic sulfide, and/or polyether compound, under certain conditions, the brightness and smoothness of the plating film will decrease in the low current density region. I'm not getting anything that satisfies me. In order to solve this problem in the low current density region, when the concentration of this aposafranin brightening compound is increased, dark stripes occur in the low current density region, making it impossible to obtain a satisfactorily glossy film.

[Problem that the invention seeks to solve]

Therefore, there remains room for further improvements in aqueous/acidic plating baths that can impart significant brightness to copper coatings even in low current density recessed regions of plated articles, and bath composition and operation. There remains a need for improvements that consistently yield good results even under widely varying conditions. The aqueous acidic plating baths of this invention involve combinations of brighteners that exhibit additive brightening effects, over a relatively wide range of concentrations and bath operating conditions, particularly in recessed regions of low current densities. Shows an extra gloss effect.

[Structure of the invention]

SUMMARY OF THE INVENTION An advantage and inventive step of this invention is to provide a gloss compound that combines an amount of bath-soluble substituted 7-talocyanine groups with an amount of an apot-7 lanine compound in its gloss amount. This is achieved by electrodepositing copper from an aqueous/acidic plating bath and using the plating bath composition.

More specifically, this aqueous/acidic plating bath is preferably of the copper sulfate or copper fluoroborate type, and contains a sufficient amount of copper to deposit copper and a substituted 7 talocyanine residue represented by the general formula %. This is a plating bath that contains an amount of gloss in combination with one compound as shown in the general formula.

The 7-talocyanine brighteners may be metal-free or contain stable divalent or trivalent metals such as cobalt, nickel, chromium, iron or copper, and mixtures thereof, with copper being the most preferred. It is a preferred metal. The 7 thalocyanine brighteners preferred in this invention are those having a bath solubility of at least about Ojmy/Z.

In a preferred embodiment of the invention, secondary brighteners such as aliphatic polysulfides, organic sulfides and/or polyethers are added to the p-cyanino-based brightener and the aposafranine brightener. By reinforcing it, the brightness and physical properties of the copper plating will be further strengthened.

[Bath operating conditions]

In the proposal of this invention, the bath temperature is about 15 to about 50°C, and the current density is about 0.5 to 400 ASF (0.05 to 43 A
/Ikn2).

[Description of preferred actual IM mode]

In the practice of this invention, from about 180 to about 2150117
A typical sulfate-based aqueous acid bath is used, such as one containing 500 t of sulfuric acid steel and about 30 to 30 SOP/l of sulfuric acid. As a variation, a typical 7-fluoroborate bath containing about 200 to about 600 Pat of copper fluoroborate and about 60 Pat of fluoroboric acid may be prepared; Using only about an equivalent amount of steel.

The bath may be acidified with an equivalent amount of phosphoric acid, nitric acid or sulfuric acid. The preferred embodiment of this invention uses a sulfate type copper bath.

This aqueous plating bath contains halogen ions such as chlorine and/or bromide ions in an amount of about 0.5 P/l.

When a substituted phtatecyanine residue brightener and an aposafranine brightener are used in combination at a constant concentration and a constant ratio, a complementary brightness effect appears and a #1 or excellent brightness is obtained in the low current density recessed region. However, at this time, it is preferable to further combine an auxiliary organic brightener.

Substituted phthalocyanine residues are preferably metal-free, including cobalt, nickel, chromium, and iron.

Metals selected from the group consisting of copper and mixtures thereof, including stable divalent or trivalent metals, such as those bonded by coordination of the isoindole nitrogen atoms of the molecule. Of these, copper is typically the preferred metal. 1C preferred talocyanine compounds for use in the present invention have bath solubility of at least about 0.111
9/J! , which corresponds to the general formula ().

Substituted 7-talocyanine compounds suitable for use in the practice of the present invention further include U.S. Patent No. 4,272,33
No. 5 includes those disclosed in Publication No. 5. A particularly preferred 7-thalocyanine compound is Alcimanp #-(Alc
ian Blue).

The combination brighteners with general formula and substituted phthalocyanine-based brighteners are used at bath concentrations of from about 0.0005 P/l to about 11/l, preferably from about 0,02 pit to about 0.01 pt. This substituted 7 talocyanine residue brightener is
Approximately 35 to approximately 80 Jt amount % based on the total amount of the two types of brighteners
need to be occupied. A particularly preferable combination is substitution 7
31μ “Methic” as a talocyanine brightener
Turquise J is used in combination with an aposafranine brightener 3-Vt, denoted by General 2A, where 几 is ethyl.

In addition to the substituted 7-thalocyanine and aposafranine brighteners, at least one known auxiliary brightener of the present invention is added to enhance the brightness, smoothness and ductility of the electrodeposited steel. It turns out that it is advantageous to improve it. Such auxiliary brighteners include polyether compounds, laminated products and disulfide compounds.

Suitable organic polyether compounds have an average molecular weight of about 180 to 1,000 containing at least 4 etheric oxygen atoms.
,000 bath-soluble and compatible polyether. Particularly satisfactory results are obtained with polyglopylene glycols and hyperpolyethylene glycols, as well as mixtures thereof, having an average molecular weight of about 600 to about 6,000, and aromatic alcohol alkoxylates having an average molecular weight of about 300 to 2,500.

Examples of polyether brighteners that produce suitable results include average molecular weights from about 400 to about 1,000. ODD polyethylene glycol; 7-tol ethoxylate containing 5-45 moles of ethylene oxide groups; 5-45 moles of propylene oxide groups
15-e: Mnathol probooxalate containing fluorine; nonylphenol ethoxylate containing 5 to 30 ethylene oxide groups; propylene glycol with an average molecular weight of about 350 to about 1.000; average molecular weight of about 350 to 250.
000 polyoxyethylene/polyoxypropylene glycol block polymer; 5 to 1 ethylene oxyto groups
．． Phenol propoxylate containing 5 to 15 moles of propylene oxide groups and an average molecular weight of about 1600 to about 30,000
Examples include ethylenediamine block polymers. Other polyether compounds include U.S. Pat.
There are those disclosed in Japanese Patent No. 72,335], which are also useful.

The amount of polyether brightener used is about 0.001 to about 5! /
Generally, foods with high molecular weights are used at low concentrations.

Organic sulfide brightening compounds useful in the baths of the present invention include:
Various sulfonate organic sulfide compounds such as those described in US Pat. No. 5,264,010 are included, but in particular those listed in Table 1 of the specification; US Pat. No. 4,181,582 Organic sulfur compounds such as those listed in Table 1: and U.S. Patent No. 5,328,2
The organic polysulfide compounds of Table 1 of No. 73 are included.

Organic sulfide compounds having sulfonic or phosphonic groups can also contain organic sulfides in their molecules, especially their aromatic and aromatic sulfides.
Various substituents may be included on the sulfonic or phosphonic acid, such as methyl, chlor, tetrame, methoxy, ethoxy, carboxy or hydroxy. These compounds are free acids.

Used as alkali metal salts, organic amine salts or other forms.

Among other suitable organic divalent sulfur compounds, moss, HO, P-(
CH2), -8-8-(CI(2), -PO,BH%
Average price: Kaftan, thiocarbamate, thiol carbamate.

Included are thiozensates and thiocarbonates having at least one sulfonic or phosphonic group.

A particularly preferred group of organic divalent sulfur compounds described in U.S. Pat. No. 5,328,273 includes the general formula %
(B and EL2 are the same or different alkylene groups having 1 to 6 carbon atoms, X is hydrogen, 80.H or PO3H,
n is a number from about 2 to 5]. These organic divalent sulfur compounds have at least two divalent sulfur atoms in 8 contact, and t in the molecule.
It is an aliphatic polysulfide having one or two sulfonic acid groups or phosphonic acid groups. The alkylene parts of the molecule are methyl, ethyl, and chlorine.

It may also be substituted with mercury, ethoxy, hydroxy and other groups. These compounds can be added as free acids or alkali metal or amine salts.

The organic sulfide brightening compound or mixture thereof is included in the bath at a concentration ranging from about 0.0005 to about I Pit.

In the proposed method of the present invention, a conductive substrate is immersed in an aqueous/acidic steel plating bath having the above composition, and electrolysis is performed using this as a cathode until a desired thickness of copper is deposited on the substrate. During operation, the bath temperature is about 15 to about 50°C, and the cathode current density is about 0.5 to about 400 ASF (0.05 to 43 A/Dm
2), preferably about 10 to about 100 ASF (1,1 to 1
1 A/Dm2). Bath temperature 20~36℃,
Current density 10~50A8F (1j~5,4 A/Dm
) Particularly satisfactory results are obtained here.

〔Example〕

Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples unless it departs from the gist of the present invention.

Example 1 Sulfuric acid pentahydrate is about 165 to about 225 Pit, and sulfuric acid is about 42 to about 75! / and chlorine ion about 0.0
Aqueous acidic steel plating baths containing from 4 to about Q, 15 F/Z were prepared. Into this aqueous solution, rMetbic Turquoise J 3 Mg consisting of a 7-talo-7-anine brightener was added.
ζ was added together with 3 my/l of diethyl aposafranine. The bath further contains 50 η/l of polypropylene glycol with an average molecular weight of 700 as an auxiliary brightener.
di-Na salt].

Current density 0.5~100A8F (0.05~11A
/Dm2) Bath temperature: 70-80°F (21-b) An extremely smooth, fine-grained copper plating was obtained without any defects.

Example 2 About 165 to about 2251! /l copper sulfate pentahydrate, approx.
2 to 751 P/l of sulfuric acid and about 165 to about 0.1. F/
717) An aqueous acidic steel plating bath containing chloride ions was prepared.

This aqueous solution contains 3 q/l of 7 talocyanine brightener.
``Methic Turquoise J'' was added at the same time as an auxiliary brightener with 6019/l of ethylene propylene oxide pro-polymer C (molecular weight 4000),
20Vt bis(3-sulfoprobyl disulfide-2N
a salt) and 1.5 mμ of the reaction product of polyethyleneimine (molecular weight 600) and benzyl chloride were added.

Bath temperature about 70° to about 807F (21° to 2-7°C), current density about 20 to about 80 ASF (2,1 to B, 6 A/D
By operating the bath under conditions m2), a bright and smooth copper plating was obtained. During this bath an additional 3 my/
The addition of Z diethyl aposafranine surprisingly improved the smoothness of the plated film, while also substantially improving the brightness in the low current density portion of the specimen using the same plating parameters.

Example 3 Copper sulfate pentahydrate of about 165 to about 225 Pit, about 4
An aqueous acidic steel plating bath containing 2 to about 75 pits of sulfuric acid and about 0.04 to about 0.1 pits of chloride ions was prepared.

In this plating bath, 2 my/L of diethyl aposafranine was added to 20 II μ of bis(3-sulfopropyl disulfide.
2 Na salt) - 120011μ polyethylene oxide (molecular weight 6000) and polyethyleneimine (molecular weight 6
00) with benzoyl chloride 1.5 Q/l
It was added with an auxiliary brightener consisting of: Average current density 5
OA8F (5,4A/Dm) r(for 15 minutes,
When the J-shaped specimen was plated, a shiny and smooth copper plating was deposited, but streaks appeared in the low current density area. 311μ “Meth” consisting of a substituted 7 talocyanine based brightener
When ic Turquoise J was added to the bath, the stripes in the low current density region of the J-shaped specimen plated under the same conditions disappeared without loss of brightness and smoothness.

It is clear that a wide range of different embodiments may be constructed without departing from the spirit and scope of the invention, and this invention is not limited to the specific embodiments thereof except as limited in the scope of the following claims. It is not restricted by ζ.

493-

Claims (1)

[Scope of Claims] (1) An aqueous/acidic plating bath containing a copper component in an amount sufficient to form copper plating on a substrate, (a) represented by the general formula % (%); substituted 7 talocyanine residues and (b)
Appointment indicated by general formula? An improved bath comprising a composite brightener comprising a 792 compound in an amount sufficient to precipitate a bright, smooth, ductile copper plating. A method according to claim 1, characterized in that the 7-talocyanine residue brightener consists of 35 to 80% by weight of the total amount of brighteners (b) and (i) present in the bath. Bath with bath. B) The total amount of brightener m) and (b) is 0.0005 to 1
The plating bath according to claim 1 VC, characterized in that the plating bath is within the range of f/l. (4) The total amount of brighteners (al and (b) is 0.002
The plating bath according to claim 1, wherein the plating bath is within the range of ~0.01//; 6) The 7 talocyanine residue brightening agent (ω is brightening agent (2)
and To) in an amount of 35 to 80% by weight of the total amount of plating bath according to claim 3. b) The 7 thalocyanine residue brightener (a) is a brightener)
and 35 to 80% by weight of the total amount of (b).
A plating bath according to claim 4, Vζ. (7) The plating bath according to claim 1, further comprising an auxiliary brightener consisting of a bath-soluble/compatible polyether compound having a coating weight of 0.001 to 5 tons. [F]) The plating bath according to claim 1, characterized in that it contains an auxiliary brightener consisting of a bath-soluble and compatible organic sulfide compound in an amount of from 0,000 to 111/l. (91 The 7 talocyanine residue brightener is MethicTu
The plating bath according to claim 1, characterized in that it is made of rquoise. (10) The plating bath according to claim 1, wherein the aposafranine compound brightener comprises diethyl aposafranine. (11) The 7 thalocyanine residue brightener is MethicT
2. The plating bath according to claim 1, wherein the plating bath is urquoise and the aposafranine compound brightener is diethyl aposafranine. (12) The plating bath according to claim 1, further containing halogen ions of 0.5P/Z. (13) An aqueous/acidic bath containing a copper component in an amount sufficient to produce copper plating on a substrate, wherein (a) a substituted 7-talocyanine residue represented by the general formula % (); and (bl
A conductive substrate is placed in a modified bath comprising a composite brightener comprising an aposafranine compound having the general formula in an amount sufficient to deposit a bright, smooth, ductile copper plating. A method for electrodeposition of a bright, smooth copper plating film on a conductive substrate, comprising the steps of dipping as a cathode and then depositing copper plating on the substrate to a desired thickness. (14) The method according to claim 13, 1ζ, further comprising the step of controlling the plating bath temperature within the range of 15° to 50°C. C15) The method according to claim 13, further comprising the step of controlling the plating bath temperature within the range of 20 to 36°C. (16) During the process of electrodepositing copper on the substrate, the current density is 0.5~a 00A8F (0.05~43 A/i)
Claims d I Z+ Jjj which include the process of controlling within the range of m2)
The method described in kC. (17) iE*During the process of electrodepositing steel on the substrate, the current density was j O~100A8F (1,1~11 A/1
) tn2) The method according to claim 13, further comprising the step of controlling the temperature within the range of tn2). (18) During the electrodeposition of the steel plating on the substrate, Temperature 20~
Within the range of 36℃, the current density is 10 to 50 ASF (
14. The method according to claim 13, further comprising the step of controlling within a range of 1,1 to 5,4 A/Dm2).