FR2489848A1 - PROCESS FOR PRODUCING COPPER ALLOY LAYERS AND CONFIGURATIONS, PRODUCTS THEREFORE OBTAINED AND SOLUTION FOR CARRYING OUT SAID METHOD - Google Patents

Abstract

PROCESS AND SOLUTION FOR THE DEPOSIT, WITHOUT CURRENT, OF COPPER PRESENTING AN IMPROVED DUCTILITY, BY INCORPORATION OF AT LEAST ONE OF THE METALS NI, CO, FE, PT, PD, RH, RU AND IR, WHICH MAKES A TRAINER OF COMPLEXES IS CHOSEN SUCH THAT IF, NI, CO OR FE SERVES AS AN ALLOY COMPONENT, IT COMPLEXES CUPRIC IONS MORE STRONGLY THAN THE IONS OF THESE ALLOY COMPONENTS AND COMPLEX THE LATTER MORE STRONGLY THAN CUPRIC IONS IN THE CASE OF 'USE OF THE REST OF THE METAL SADITS. APPLICATION: LAYERED COPPER DEPOSIT.

Description

"Process for making layers and configurations of alloys

  of copper, thus obtained products and solution

  for the implementation of this method ".

  The invention relates to a method for producing

  layers and configurations formed by alliances

  copper ions on catalytic substrates for deposition

  of copper without electricity. It also concerns

  products thus obtained and a solution for the implementation

of this process.

  According to such a method, catalytically active seeds for deposition of electroless copper are, if necessary, first deposited on a substrate. This can be done from

  several ways that are described in the literature.

  Thus, US Pat. No. 3,011,920 discloses a method in which a colloidal metal solution, which serves as a catalyst for the deposition of copper among others, is contacted with the substrate

  with a collo! of protector. The United States patent of

  No. 3,674,485 discloses a photoresist which

  can be used as a substrate or

  on another substrate and which contains a semi-

  scattered photosensitive driver. After exposure, this photosensitive oxide is able to reduce a salt of a metal

  catalyst for the deposition of copper, in particular

  in a metal in the form of germs.

  British Patent No. 1,283,715, describes, for the purposes of

  electroless copper deposit, a process for obtaining

  copper, the appearance of which is improved, as

  properties of flexibility or elasticity. In addition to adding the salt of a Group VIII metal of the Periodic Table of Chemical Elements as a measure to obtain improved copper, mention is made of the addition of an agent capable of forming a compound with formaldehyde, a , composed of organic srlicium and an agent facilitating the

  formation of hydrogen bubbles, so as to prevent the

  clusion of hydrogen during the formation of the deposit. According to

  the examples described in this patent, effects

  readable are obtained mainly by combinations of these measures. As is customary for the examination of the

  quality of the deposited copper without current, the name of the

  many times that the copper layer can be folded, after

  what the fold is smoothed and then the copper is folded.

  The invention provides a method for depositing

  be copper alloys, in which the formation of hy-

  to a lesser extent than in

  the known process, so that when training the

  However, the inclusion of hydrogen is reduced and the deposition rate can be significantly increased at the given temperature without affecting the flexibility properties and / or

elasticity of the deposit.

  According to the invention, the method for producing layers and configurations of copper alloys on catalytic substrates for deposition of electroless copper by contacting the substrate with

  a solution with a pH of 11.5 to 13.5 containing cupric ions

  a complex-forming compound or a combination of compounds forming metal ion complexes,

  formaldehyde, alkali hydroxide and. a salt of the

  of alloy or alloying constituents, is essential

  characterized in that the alloy constituent or the

  alloys are / are constituted by at least one of Ni, Co, Fe, Pt, Pd, Ru, Rh and Ir metals, the alkali hydroxide solution in a concentration <0.25 M and the formaldehyde in a concentration <0.20 M, whereas a complex-forming compound or esV complex-forming compounds are chosen (s) .when in the case where Ni, Co or Fe is used as the alloy component, they are confined ( nt) the cupric ions more strongly than the ions of these metals, whereas in the case where Pt, Pd, Rh, Ru or Ir is chosen as the alloying constituent, they complex (nt) this

  latter metals more strongly than cupric ions.

  The invention is based on the idea that formaldehyde

  hyde is dehydrogenated on a metal surface and that it

  chemisorption of the formed atomic hydrogen occurs.

  Depending on the metal on the surface of which the reaction is taking place, the hydrogen atoms can react in two ways: 1) H + H-> H21t 2) H + OH-H20 + e From these reactions two metallization reactions result different crude: A) 2n CH 2 O + 4nOH + 2Mn + 2Mi + 2nHCOO + 2nH 2 O + nH 2 I B) n CH 2 + 3O H - 2M '- n + B) n CH 2 O + 3nOH + 2Mn 2 - 2M 2 + nHCOO + 2nH 2 O on a surface of copper it only happens the

  reaction A, since the reaction rate 1) exceeds

  it is notably that of the reaction 2). The incorporation of a

  on the surface of which the reaction 2) occurs much

  more quickly than the reaction 1), significantly reduces the hydrogen separation and, therefore, its incorporation for a constant deposit of formaldehyde. The

  speed at which the alloy can be deposited is thus

  greater than that to which

  pure copper without the properties of flexibility and elasticity

  ticity of the depAt are affected.

  To obtain a stable solution

  Laying alloy layers with a thickness of at least 1 μm, it is first necessary that the concentration of alkali hydroxide remains less than 0.25 M and that of formaldehyde less than 0.20 M. Moreover, during the development of the invention, the Applicant found that the choice of the compound forming

  complex used in the bath working without

  rant also plays an essential piece.

  In the case where Ni, Co or Fe is used as a com-

  As an alloying agent, it is necessary to choose a complex-forming compound capable of complexing cupric ions more strongly than the ions of the alloy. On the other hand, when

  3- we use Pt, Pd, Ir, Rh or Ru, we must choose a

  At, sqA complex trainer or a combination of complex compounding compounds, such as it is precisely the ions of the last metals which are complexed more strongly.

than the cupric ions.

  The complex formation equilibrium constant K given by the relation K = FLX (n-xm) [Mn] [Lm] x

  is decisive. The literature mentions in

  values of this constant for a large number of multi-metal complex-forming compounds, including Critical Stability Constants by A. E. Martell and R. M. Smith, as shown in the table below, in which log

  K is mentioned for several metals and several

complex.

w uln o W

: 2+:

: FE o

2+: 2+

CO: Ni

(:::

(Cyanide ,: 35.4: 30.2

(:::

(triethanolamine: 1.7: 3.1

(:::

  (Ethylenediamine: 9.7: 14.1: 18.4

(:::

  (nitrilotriacetic acid: 12.8: 14.4: 16.4

(:::

(glycine: 7.6: 10.8: 14.0

(:::

  (Ethylenediamine-N, N ':: 11.2: 13.6 (diacetic acid: :: (ethylene-diaminetra-) acid: 14.3: 16.3: 18.6 (acetic acid::

(: ::

  (Tetrahydroxypropylethylene :: 10.2: 11.2 (diamine (ethylenediamine-isopropyl) :: 11.4: 11.1 (pylphosphonic acid: (ethylenediamine) NN'- (dimethylphosphonic acid (: (acid Ethylenediaminetetra- (methylphosphonic acid:

(cyclohexano-1,2-dia-

  minptntrammthul -nhnqrh.nin ,. _, 2 17.4 11.7 17.0

: 3.3: 3.9:

o o: :)

2+: 2+: 2+)

  Cu: Pd: Pt) :-) Unstable: 45.3 :): :)) 6.0 :): :))

, 2: 18,4: 36,5)

: :))

17.4: 19.3 :)

: :))

, 0: 27,5 :)

16.2:: :)): :))

18.8: 18.5 :)

: :)): :))

9.0: :)

): :)), 3: :): :)): :))

17.5: :)

: :)):.:)

23.0: :)

::): :))

9.7::.

he cro o co -, 0 Co

. 1 M, Ir'e-

, F. -

  The Applicant empirically determined that complex-forming compounds frequently used, such as

  ethylene-diamine-tetra-acetic acid and tetra-hydroxy-

  propylene-diamine, do not cause any improvement in the ductility in the copper plating solution in the presence of Ni and Co salts, which can be explained from the constant

  balance by the fact that it does not occur

  Ni or Co. Substances becoming at the simultaneous separation of

  Ni or Co with copper are triethanolamine and ni-

  trilo-tri-2-propanol, whereas ethylene-diamine-

  diacetic compounds and phosphorus compounds according to the

  tannic N 1 425 298 may also be used for this purpose.

-:.-effect.

  Moreover, we note that if the cupric ions are

  complexed, for example by ethylene diamine tetra-

  acetic, cyanide is a very suitable complex-forming agent for palladium ions, because the complex of cupric ions with cyanide is very unstable and the equilibrium constant of the formation of ethylene-diamine complexes tetra-acetic with Pd is significantly more

  weak than that of cyanide with palladium.

  The invention will be explained hereinafter with the aid of several

some examples.

Example 1

  Glass plates, 5 x 1 cm in size, are subjected to the following treatments:

  a) both sides of the platelets are roughened with the help of

  of carborundum so as to reach a roughness (Ra) of

0.8 to 1.0 μm.

b) washing with cold water.

  c) the platelets are immersed for 10 seconds in a 4% HF solution at normal room temperature

d) washing with cold water.

  (e) the platelets are defatted by immersion for at least 24 hours in a 5% solution of "Decon 90"

  at normal room temperature.

  f) wash in cold deionized water.

  (g) platelets are immersed for 1 minute at

  normal room temperature in a solution containing,

  per liter, 100 mg of SnCl 2 and 0.1 ml of concentrated HCI.

  h) immersing for 1 minute in the deionized ion of the

normal room temperature.

  i) immersion for 1 minute in a solution of the temperature

  normal room temperature containing, per liter, 1 g of AgNO3. j) immersion for 1 minute in the deionized of the

normal room temperature. -

  k) immersion for 1 minute in a solution at room temperature

  normal room temperature containing, per liter, 100 mg of

PdCl2 and 3.5 ml concentrated HCl.

  1) immersion for 1 minute in deionized water at

normal room temperature.

  m) immersion for 1 minute in deionized water of 900.

  n) the platelets are kept in a solution of

  electroless plating until a layer is obtained

alloy of the required thickness.

  The temperature of the solution is maintained at a constant value. o) The platelets are dried and the deposition rate is weighed by weighing the deposited metal and measures the duration of the metallization. The ductility of the metal layer is determined by local peeling of this layer of the glass plate, folding, application in its position

  initial and pressure following the fold to flatten it.

  This test is repeated until the sample is

crease.

  p) during step n), for several examples the

  amount of hydrogen released in order to determine the

  port between the quantity of metal deposited and the quantity

hydrogen released.

  (q) analytically determines the percentage-of

incorporated alloying light.

COMPOSITIONS OF THE BATH.

  Cu0S4 5H 2 0.08 mole PdC12 0.006 tetrasodium salt of ethylenediamine acid 0.096 "tetraacetic NaOH 0.11"

HCHO 0,10 "

KCN X "

water up to 1 liter

bath temperature 50 C.

  In these copper plating baths, the palladium ions are complexed by reaction of a predetermined amount of

  solution of 0.02 mole of PdCl2 per liter, for 10 minutes

  at 50 ° C. with the required amount of a solution of 0.30 mol / l KCN. The amount of KCN is variable so as to obtain a range of KCN: PdC12 ratios between 3

  and 6. The following table mentions the results.

(: (bath: report

(: KCN /

(: PdCl2 (((

(1: 3.0

(

(2: 4.0

(

(3: 4.25

(

(4: 4,5

(

(5: 5.0

(

(6: 6.0

  (: stabili-: velocity: number:% of Pd: part of: de2t: of: in: bath: mgtcm: flexions: layer: ratio * H2 / M :: h- ::: 1 Min .:

: <1 min .: -: -: -

:::::

: 55 min .: 3.4:> 5: 0.3: -

  :::::: 75 min .: 3,4:> 5: 0,3: 0,69 2 uur: 3,3: 5: 0,15: 0,82 :::::> 2 uur: 3 , 1:]: O: 1,00 2 uur 0,0 ::::> 2 uur: 0, O - :. :::: Of the aforesaid range of if the palladium is incorporated, is not slowed down and that compositions it appears that

the development of hydro-

the flexibility of filing in

  , is significantly improved. In these cases, the speed of

  metal deposit is kept constant. From the table

  - that the improvement can not be attributed to the ir'-

  ))))))))))))))))) Sense of cyanide in the bath The Pd2 ions are more strongly complexed as the cyanide concentration increases.

-2 2+

  increases. In the case of a CN / Pd ratio higher than

  4.5, the incorporation of Pd into the deposit decreases sharply.

  As a result, hydrogen development increases, which affects flexibility. In the case of a CN / Pd2 ratio greater than 5, the copper plating bath is polluted as a result of

  the presence of uncomplexed cyanide.

Example 2

  Glass plates are made rough and

  cleaned as described in Example 1. Germination

  tion is carried out by two treatments g to m of Example 1.

  The glass plates containing the seeds are metallized

  with an aqueous solution containing, per liter CUSO4 5H2O 0.02 mole NiSO4. 6H20 0.0008 mole triethanolamine 0.065 mole NaOH 0.20 mole formaldehyde 0.10 mole Metallization solutions are refreshed at

  several times to avoid exhaustion.

  In the case of a bath temperature of 250 the vi--

  deposition rate is 1.0 mg / cm 2 per hour and after 4 1/2 hours the ductility is 1 flexion. The ratio H2 / m is 0.67, while an analysis reveals the presence of 3.8%

  of nickel in the metal layer. When metallisation

  tion is carried out at a bath temperature of 450C, the

  deposition rate is 2.0 mg / cm 2 hours. After 3 hours, a layer having a ductility of 2 to 3 flexions was obtained. The percentage incorporated in nickel is about 2%. When a metal layer is formed in a solution containing no nickel ions, but having the same composition as mentioned above, no compact metal layer is obtained at 250C

  only at 450C, but only a powdery copper deposit.

2489848 '

Example 3

  Platelets are roughened and sprouted

  the manner described in Example 1. The metallization is carried out

  * kills at 45 C in one of the solutions composed as follows: a) CuSO4. 5H20 0.02 mole nitrilo-tri-2-propanol 0.065 mole formaldehyde 0.10 mole NaOH 0.20 mole

water up to 1 liter.

  b) as a) + 0.0004 moles of CoSO4.7H20 c) as a) + 0.0004 moles of NiSO 4.6H20 The table below gives the results:) (: -dM / d .: number :: M (: mg / cm /: of: H2 / M: incorporated (: hour: flexion :: t :::: È

  (- - - - - - - - - - - - --- - - - - - - -

  (a: metal layer: 1.00 - -) (: porous :) () (b: 2.0: 2-4 1/2: 0, 59: 0.04)

(::: :)

  (c: 1.9: 2-4: 0.47: 1.5) Equilibrium constants for Cu complexes

  and Ni with 2-nitrilo-propanol were determined

  in alkaline medium 10-29 and 10-16 respectively in an alkaline medium at 10 and 10_

* I11

Claims (6)

CLAIMS:   Process for producing layers and   confiuration of copper alloys on substrates   Talytics for electroless copper deposition by contacting the substrate with a pH solution of 11.5 to 13.5   containing cupric ions, a compound-forming compound   plexes or a combination of complex-forming compounds   of metal ions of formaldehyde, alkali hydroxide   lin and a salt of the alloying constituent or alloy components, characterized in that the alloying constituent or the alloying constituents is / are constituted by at least one of Ni, Co, Fe, Pt, Pd, Ru, Rh and Ir, the solution of alkaline hydroxide in a concentration <0.25 M and formaldehyde in a concentration <0.20 M, while a compound-forming complexes or compounds forming complexes are / are chosen such that, in the case where Ni, Co or Fe is used as alloying component, they complex (nt) the cupric ions more strongly than the ions of these metals whereas in the case o Pt, Pd, Rh, Ru or Ir is chosen as alloy constituents, it complex (s) these latter metals   more strongly than the cupric ions.   2. Process for producing layers and confi   formed by a copper alloy with Ni, Co or one of them according to claim 1, characterized in that   that the trainer of compile is made up of ethanolamine.   3. Process for producing layers and confi   gurations constituted by a copper alloy with Ni, Co or one of them according to the rendication 1, characterized in that   that the complex trainer consists of nitrilo   2-propanol. 4. Process for producing layers and configurations of a copper alloy containing at least one of the metals Pt, Pd, Rh, Ru and Ir according to claim   1, characterized in that the complex trainer is constituted   a combination of cyanide and ethylene-dia- minetetraacétique.   5. Products obtained by the implementation of the   die according to one of claims 1 to 4.   6. Solution for electroless deposition of copper alloys on catalytic substrates with pH   from 11.5 to 1.3.5 containing cupric ions, formaldehyde   dehydrogen, an alkali metal hydroxide, a strong compound   complex matrix or a combination of complex-forming compounds for metal ions and at least one of the salts of the alloy component or alloy components,   lo characterized in that the alloy constituent or the   alloys are (are) selected from Ni, Co, Fe, Pt, Pd, Rh, Ru and Ir, the alkali hydroxide solution in   concentration <0.25 M and formaldehyde in a   0.20 M center, while the compound forming the   complexes or complex-forming compounds if Ni, Co or Fe act as alloying constituent (s), complex (nt) more strongly the cupric ions than the ions of these metals whereas if Pt, Pd, Rh , Ru and Ir are chosen, they complex (nt) the ions of these last metals more strongly than the cupric ions.