JPS59113627A - Forming method of metallic layer being patterned - Google Patents

Abstract

PURPOSE:To form the metallic layer patterned easily, minutely, with excellent reproducibility and with high accuracy by electrolytically etching a metallic layer while using a mask layer patterned as a mask up to a point of time when currents flowing from a DC constant voltage source reduce suddenly. CONSTITUTION:An insulating substrate 3 in which an insulating layer 2 is formed on a substrate 1 is prepared, and the metallic layer 4 is formed as a layer consisting of an Al layer with 1mum thickness through evaporation. The mask layers 5 are formed on the metallic layer 4 as the Al layer as layers consisting of a photo-resist through exposure using a photo-mask and development treatment. The substrate body 6 is dipped in a tank 12 encasing an electrolyte 11 consisting of an aqueous solution using phosphoric acid in 85% concentration as a solute so that the metallic layer 4 extends on approximately a vertical surface, an electrode 13 in platinum is dipped oppositely, and connected to the positive pole side of a DC power supply 14 as the DC constant voltage source in a region not masked with the mask layers 5, and the metallic layer 4 is etched electrolytically up to the point of time when currents (I) flowing from the DC power supply 14 reduce suddenly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a patterned metal layer on an insulating substrate, particularly when forming a wiring layer of a semiconductor integrated circuit device, and when manufacturing a semiconductor integrated circuit device. This is suitable for use when forming a mask layer to be used.

The wiring layer of a semiconductor integrated circuit device is formed of a metal layer such as an A1 layer, an A1-8i alloy layer, an Al-Cu alloy layer, or a Cu layer, and the above-mentioned mask layer is formed of a metal layer such as an Or layer. Conventionally, a metal layer to be patterned is formed on a semiconductor substrate, a mask layer of a patterned photoresist is then formed on the metal layer, and then a patterned metal layer is formed on the metal layer. A patterned metal layer is formed by chemically etching the metal layer using an etching solution capable of etching the metal layer to be patterned using the mask layer as a mask for a predetermined period of time. as a wiring layer or mask layer,
It was normal for them to form.

However, in such conventional methods, an etching solution capable of etching the metal layer to be patterned is applied to the metal layer to be patterned using a patterned mask layer as a mask. In the process of covering the chemical etching used in J3, the patterned metal layer is etched from the side by an amount corresponding to the predetermined period of time described above, that is, it is obtained as a so-called side-etched layer. be forced to. Therefore, the patterned metal layer is formed to have a smaller pattern around the mask layer pattern by an amount that is side-etched.

Incidentally, it is desirable that the patterned metal layer be obtained in the same pattern as the pattern of the mask layer.

The reason is that by simply forming the mask layer in the same pattern as the desired pattern of the patterned metal layer to be formed, the patterned metal layer can be formed with the desired pattern. This is because it can be formed as

However, even if the patterned metal layer is formed with a smaller pattern around the mask layer pattern by an amount that is side-etched, the metal layer will not be overly etched during the chemical etching process described above. If the amount to be etched is predicted, the mask layer can be
To account for the anticipated rapid etching of the patterned metal layer, the patterned metal layer is pre-formed in a pattern that is larger in circumference than the intended pattern of the patterned metal layer to be formed. The metal layer can be formed with a desired pattern.

However, in the case of the above-mentioned conventional method, even if the above-mentioned chemical etching is performed for the above-mentioned scheduled fixed time, in the above-mentioned chemical etching process, the above-mentioned side-etched amount is less than the etching amount used for chemical etching. It depends on the temperature of the solution, the flow of the etching solution to the metal layer to be patterned, etc.
It was extremely difficult to predict the length of the side etching described above.

Therefore, in the case of the conventional method described above, it is extremely difficult to form a patterned metal layer with a desired pattern with good reproducibility, fineness, and high precision. It had

The invention therefore seeks to propose a new method for forming patterned metal layers that does not have the above-mentioned disadvantages.

The present inventor prepared in advance an insulating substrate 3, as shown in FIG. 1A, in which an insulating layer 2 made of silicon oxide (SfO2) is formed on a substrate 1 made of silicon, for example, and
Then, as shown in FIG. 1B, a metal layer 4 to be patterned is formed on the insulating layer 2 of the insulating substrate 3 by a method known per se, for example, by vapor deposition. As shown in FIG. 1C, a patterned mask layer 5 made of, for example, photoresist is formed on the metal layer 4 to be processed, and a photoresist layer is formed on the metal layer 4 on the insulating substrate 3. The metal layer 4 to be patterned on the insulating substrate 3 is formed by a method known per se, by first exposing the photoresist layer to light using a mask and then developing it. A substrate body 6 is obtained in which a patterned mask layer 5 is formed on the metal layer 4.

Ta.

In this case, the metal layer 4 is an A1 layer that can become a wiring layer, an Al
It can be a -8i alloy layer, an Al-C0 alloy layer, a C1 layer, or it can be a Cr layer that can serve as the mask layer described above.

Then, as shown in FIG. 2, the above-mentioned substrate body 6 is placed in a tank 12 containing an electrolytic solution 11 made of an acidic or alkaline aqueous solution so that the metal layer 4 extends substantially vertically. An electrode 13 made of, for example, platinum is immersed in the tank 12 so as to face the metal layer 4 of the substrate 6, and the metal layer to be patterned on the substrate 6 is immersed in the bath 12. 4 is connected to the positive electrode side of the DC power supply 14 in a region not masked by the mask layer 5,
In addition, the electrode 13 is connected to the negative electrode side of the DC power supply 14,
Electrolytic etching was performed on the metal layer 4 using the mask layer 5 as a mask and using an electrolytic solution 11 made of an acidic or alkaline aqueous solution.

However, in this case, when the metal layer 4 is an A1 layer, the electrolytic solution 11 made of an acidic or alkaline aqueous solution is 50 to 80%
% concentration of phosphoric acid as the main solute, 15 to 20 volume parts of 50 to 80% concentration of phosphoric acid and 1 to 4 volume parts of 30 to 60% concentration of nitric acid as the main solutes. an acidic aqueous solution consisting of 15-20 parts by volume of 50-80% phosphoric acid, 1-4 parts by volume of 30-60% nitric acid, and 1-4 parts by volume of 70-100% acetic acid.
An acidic aqueous solution consisting of an aqueous solution whose main solute is a 4-volume suspension, an aqueous solution whose main solute is hydrochloric acid at a concentration of 5 to 40%, and an aqueous solution consisting of an aqueous solution whose main solute is potassium hydroxide at a concentration of 10 to 50%. and an alkaline aqueous solution consisting of an aqueous solution containing sodium hydroxide as a main solute at a concentration of 10 to 50%.

In addition, when the metal layer 4 is an Al-3i alloy layer, the electrolytic solution 11 made of an acidic or alkaline aqueous solution is
% concentration of phosphoric acid as the main solute; a mixed aqueous solution of 15 to 20 volume parts of 50 to 80% concentration of phosphoric acid and 1 to 4 volume parts of 30 to 60% concentration of nitric acid; an acidic aqueous solution, and 1 of phosphoric acid with a concentration of 50-80%
5 to 20 parts by volume, 1 to 4 parts by volume of nitric acid at 30 to 6011 degrees Celsius, and 1 to 4 parts by volume of 70 to 100% concentration in an acidic aqueous solution consisting of the main solutes. or1
It was.

Furthermore, an electrolytic solution 11 made of an acidic or alkaline aqueous solution
is 50 to 8 when the metal layer 4 is an Al-Cu alloy layer.
An acidic aqueous solution containing 0% phosphoric acid as the main solute, 15-20 parts by volume of 50-80% phosphoric acid and 1-4 parts by volume of 30-60% nitric acid as the main solute. an acidic aqueous solution consisting of an aqueous solution of 50 to 8
15 to 20 volume parts of 0% m degree phosphoric acid, 1 to 4 volume parts of 30 to 60% concentration nitric acid, and 1 to 4 volume parts of 70 to 100% concentration acetic acid as main solutes. One of the following acidic aqueous solutions was used.

Furthermore, when the metal layer 4 is a Cu layer, the electrolytic solution 11 made of an acidic or alkaline aqueous solution has a content of 40 to 96% a.
An acidic aqueous solution containing sulfuric acid as the main solute was used.

Further, when the metal layer 4 is a Cr layer, the electrolyte 11 made of an acidic or alkaline aqueous solution is an acidic aqueous solution containing hydrochloric acid as a main solute at a concentration of 5 to 40%.

In such a case, the area of the metal layer 4 that is not masked by the mask layer 5 acts as an anode, and the electrode 13 acts as a cathode, so that the area of the metal layer 4 that is not masked by the mask layer 5 acts as an anode, and the electrode 13 acts as a cathode. , from the unetched state shown in FIG. 3A, through the state of being etched from the surface, as generally shown in FIG. 3B, to the fully etched state, as shown generally in FIG. 3G. It has now been confirmed that a patterned metal layer 7 is etched through the thickness and formed under the mask layer 5. However, in this case, the electrode 13 was made of platinum.

The present inventor also carried out the above-mentioned electrolytic etching by using the DC power supply 14 connected between the metal layer 4 to be patterned and the electrode 13 as a DC constant voltage source, and using the DC constant voltage source to pattern the pattern. The current I (mA) flowing through the metal layer 4 to be oxidized was measured using an ammeter 16.

In such a case, the relationship between the voltage ■ and the time t (minutes) is as shown in FIG. 4 at the time t. ′, the current I increases little by little with time t, but from time point (l) the current I suddenly decreases.

Furthermore, as a result of investigating the relationship between the current (2) and the time t described above and the etching state of the region of the metal layer 4 that is not masked by the mask layer 5, the inventor found that the current I
Until the time tcL' when the metal layer 4 is gradually rising with time t, the area of the metal layer 4 that is not masked by the mask layer 5 is etched from the surface with time t, but when it reaches the time tl , the areas of the metal layer 4 not masked by the mask layer 5 are etched through their entire thickness, resulting in a patterned gold R layer 7, as generally shown in FIG. 3C. I have come to confirm that it is.

Furthermore, the present inventor has proposed that the above-mentioned electrolytic etching,
When forming the metal layer 7 patterned by the mask layer 5 at the point tl when the above-mentioned current (2) suddenly decreases, that is, the metal layer 4, the patterned aluminum layer 7
It has been determined that the side surfaces of the mask layer 5 are generally obtained as lead etched, as shown in FIG. .

Further, the present inventor carried out the above-mentioned electrolytic etching by using the DC type m14 as a DC constant voltage source as described above, and setting the temperature T ('C) of the electrolytic solution 11 as a constant temperature Te (°C). A current 1 (III
A) and therefore the density J( of the current flowing through the metal layer 4)
mA/cm') until the point t' when the above-mentioned current I suddenly decreases, that is, the mask layer 5 of the metal layer 4.
to the point where the unmasked areas are etched through their entire thickness to form the patterned metal layer 7 described above, and the metal layer 7 is side-etched. (6) That is, the side etching amount Y (μ) was measured.

In such cases, the above-mentioned relationship between the side etching mY and the current density J, with the temperature {circle around (2)} of the electrolytic solution 11 as a parameter, was generally obtained as shown in FIG. In addition, the fifth
The warm spaces 1-1 and T2 shown in the figure have a relationship of T, <T.

Therefore, from the measurement results shown in FIG. 5, if the temperature T of the electrolytic solution 11 is a constant dryness level ('C), and the current density UJ is equal to the current density UJ, then the above-mentioned side etching (6) Y is I have confirmed that it will be smaller.

In addition, if the current flowing through the electrolyte 11 is increased so that the current density J becomes equal to the current density J, the side etching ti
The reason why lY is small is that when the current density J is increased, the electric field strength between the metal layer 4 and the electrode 13 is mainly related to the direction connecting the metal layer 4 and the electrode 13. ,
For this IC, the etching speed of the region not masked by the mask layer 5 of the metal layer 4 in the thickness direction is the ratio of the etching speed in the surface direction. W1 has come to accept that this is because it becomes large.

Furthermore, when the current density J is kept constant, if the temperature T of the electrolytic solution 11 is lowered, the above-mentioned side etching ff1Y
We have now confirmed that the value is small.

Furthermore, it has been confirmed that in order to obtain the above-mentioned side etching ff1Y at the same value, if the temperature T of the electrolytic solution 11 is increased, the current density J can be increased accordingly.

Furthermore, from the measurement results shown in FIG. 5, the relationship between the current density J and the temperature T of the electrolytic solution 11 when the value of the one-noid etching ff1Y described above becomes zero is as shown in FIG. is T1 and T2, the current density J is obtained by the values of Jl and J2, respectively;
And as mentioned above, when the temperature T of the electrolytic solution 11 is constant, if the current density 1ffi J is increased, the above-mentioned side etching amount Y becomes smaller. The temperature T of the electrolytic solution 11 is expressed as the temperature Te('C
), and the current density J is Te = a −Je+b・・・・・・・・・・・・・・・
・(1a) a = ((T2-T,) / (J2-J
l) )×(1±0.1)・・・・・・・・・・・・(
1b) b = [(T, J2- T2J,) / (J
2- J,) )×(1±0.1)・・・・・・・・・
...Current density Je (m A) given by (1C)
/cm' ) or more, the patterned metal layer 7 described above has the above-mentioned 1' deetching ratio Y of approximately zero, as shown in FIG. 7. We have also confirmed that it is formed.

Furthermore, the relationship between the current density J and the temperature T of the electrolytic solution 11 is obtained as shown in FIG.
m'), if the temperature T of the electrolytic solution 11 is lowered, the above-mentioned side etching ff1Y becomes smaller.
A/cm' ), and the temperature T of the electrolytic solution 11 is Te =
a −Je +b・・・・・・・・・・・・・・・(2
a) a = ((T2-T,) / LJ2-Jl)
)×(1±0.1)・・・・・・・・・・・・(2b)
b = (('T,, J2--I2J,)/ (J2-
J,))x(1±0.1)・・・・・・・・・・・・
- If etching is carried out at a temperature lower than the temperature given by (2C) -re (°C), the above-mentioned patterned metal layer 7 will be etched by the above-mentioned 1-noid etching ff, as shown in FIG.
It has also been confirmed that 1Y is formed as approximately zero.

Therefore, the present inventor has proposed the invention described in the claims as an invention according to the present invention.

The method of forming a patterned metal layer according to the invention has now been clarified.

According to the method according to the present invention, in the step of electrolytically etching a metal layer to be patterned using a patterned mask layer as a mask, the electrolytic etching is performed from a direct current constant voltage source. Since the current flowing through the target metal layer suddenly decreases, the amount of side etching of the patterned metal layer to be formed can be controlled by electrolytic etching, as shown in FIG. Depending on the liquid temperature T and current density J,
Can be predicted.

On the other hand, the point at which the current flowing from a DC constant voltage source through the metal layer to be patterned becomes suddenly small is called
It can be easily detected by various current detectors, and the output of the current detector turns off the DC constant voltage source connected between the gold FS layer as anode and the cathode electrode thereto. The above-mentioned electrolytic etching can be carried out from a DC constant voltage source to the metal layer to be patterned by a simple means of cutting the line between the DC constant voltage source and the metal layer as an anode or the cathode electrode. It can be quickly and easily terminated at the point where the current flowing through it suddenly decreases.

Therefore, according to the method for forming a patterned metal layer according to the present invention, in the step of forming a patterned mask layer on a metal layer to be patterned, a warped patterned mask can be predicted. By taking into account the side etching ff1Y to be etched, it is possible to easily form a patterned metal layer with good reproducibility, fineness, and high precision as the desired pattern. Has characteristics.

Further, according to the method for forming a patterned metal layer according to the present invention, in the above-mentioned electrolytic etching step, the electrolytic etching is performed by changing the temperature of the electrolyte solution to a temperature of T.
e ('C) and the current density J is as described above (1a).
~Current density Je (m A/
cm') or higher, or by setting the current density J to the current density Je (nl A/am'), the temperature of the electrolytic solution -' is given by the above equations (2a) to (2C). The Gf1 patterned metal layer is formed at a temperature below the temperature Te ('C) where the side etching IfiY is approximately zero.

Therefore, according to the method for forming a patterned metal layer according to the present invention, in the step of forming a patterned mask layer, the mask layer is applied to the desired area of the patterned metal layer to be formed. In addition, in the electrolytic etching process described above, when the temperature T of the electrolytic solution is the temperature Te, the current density J is the current density given by the above equations (1a) to (1C). J
When the current density is equal to or higher than e, or when the current density J is set to the current density Jc, the temperature T of the electrolytic solution is set to the above (2a) to
By keeping the temperature below II T 8 given by equation (2C), the patterned metal layer can be easily formed into the desired pattern with good reproducibility, fineness, and high precision. It has the characteristic that it can be formed.

Further, the patterned metal layer formed by the method for forming a patterned metal layer according to the present invention includes:
It functions as a distribution PA layer or a mask layer.

Therefore, the present invention has the characteristic that it is extremely suitable for application to forming wiring layers of semiconductor integrated circuit devices and forming mask layers used in manufacturing semiconductor integrated circuit devices. do.

Next, an example of the present invention will be described.

Example 1-1 As described above with reference to FIG. 1A, an insulating substrate 3 having an insulating layer 2 formed on the substrate 1 was prepared in advance. However, in this case, the substrate 1 was made of silicon and had a surface area of about 40.0 cm'. Further, the -insulating layer 2 was made of silicon oxide (Si0.2>).

A metal layer 4 to be patterned was then formed on the insulating layer 2 of the insulating substrate 3 in the same manner as described above with reference to FIG. 1B. However, in this case, the metal layer 4 is deposited to a thickness of 1 μm.
It was formed of an A1 layer having a thickness of .

Next, a patterned mask layer 5 was formed on the metal layer 4 made of the A1 layer in the same manner as described above with reference to FIG. 1C. However, in this case, the mask layer 5 can be formed from a photoresist by forming a photoresist layer on the metal layer 4 made of the A1 layer, exposing the photoresist layer to light using a photomask, and then performing a development process. It was formed as something.

In this way, the metal layer 4 consisting of the A1 layer to be patterned on the insulating substrate 3, as described above in FIG. 1C.
A substrate body 6 was obtained in which a patterned mask layer 5 was formed on a metal layer 4 made of the A1 layer.

Next, the substrate body 6 is heated to 85% as described above in FIG.
In a tank 12 containing an electrolytic solution 11 made of an aqueous solution containing only vA acid as a solute, which is made of a phosphoric acid solution of m degrees, a metal layer 4 made of an A1 layer extends substantially on a vertical plane. soaked u
An electrode 13 made of platinum is immersed in the tank 12 every once in a while so as to face the metal layer 4 made of the A1 layer of the substrate 6, and the metal layer to be patterned on the substrate 6 is immersed. 4 in the area not masked by the mask layer 5, and connected to the positive electrode side of the DC power source 14, which is a DC constant voltage source, and connected the electrode 13 to the negative electrode side of the DC power source 14. The metal layer 4 made of a layer A1 is electrolytically etched using the electrolytic solution 11 made of an aqueous solution containing phosphoric acid as a solute.
up to the point where the current I flowing through it suddenly becomes small,
A metal layer 7 consisting of a patterned A1 layer was obtained.

However, in this case, the temperature of the electrolytic solution 11 is 20.0°C,
Also, the current flowing through the electrolytic solution 11 is 50. OmA, and therefore, the current density passing through the metal layer 4 made of the A1 layer is 1.2
5 (=50.0m A/40.0cm'>mA/
0111'.

In that case, the metal layer 7 made of the patterned A1 layer was formed with approximately zero side etching amount.

Example 1-2 Metal layer 4 consisting of A1 layer to be patterned on insulating substrate 3, similar to the case of Example 1-1 of the present invention described above.
A substrate body 6 was obtained in which a patterned mask layer 5 was formed on a metal layer 4 made of the A1 layer.

Next, the electrolytic solution 11 in the case of Example 1-1 of the present invention described above was mixed with phosphoric acid consisting of 16 parts by volume of an 85% phosphoric acid solution and nitric acid consisting of 1 part by volume of a 60% concentration nitric acid solution. Except for changing it to an aqueous solution with and as a solute,
The same electrolytic etching as in Example 1-1 of the present invention described above was carried out in the same manner as in Example 1-1 of the present invention described above to obtain the metal layer 7 made of the patterned A1 layer. Ta.

However, in this case, the temperature of the electrolytic solution is 33.0°C, the current flowing through the electrolytic solution 11 is 240.0 mA, and the current density passing through the metal layer 4, which is the A1 layer, is 6.0 (=240.0 mA).
0 mA/40.0 cm') mA/cm'.

In this case, as in the case of Examples 1 to 1 of the present invention described above, the tanned metal layer 7 was formed of the patterned A1 layer so that the amount of side etching was approximately zero.

Example 1-3 Similar to the case of Example 1-1 of the present invention described above, metal layer 4 made of A1 layer to be patterned on insulating substrate 3
A substrate body 6 was obtained in which a patterned mask layer 5 was formed on the metal layer 4.

Next, the electrolytic solution 11 in the case of Example 1-1 of the present invention described in F was mixed with phosphoric acid consisting of 16 parts by volume of 85% 81 degree phosphoric acid solution and 1 part by volume of 60% concentration nitric acid solution. with nitric acid,
Electrolytic etching was carried out in the same manner as in Example 1-1 of the present invention described above, except that the aqueous solution was changed to an aqueous solution containing 1 part by volume of 96% acetic acid as a solute. A metal layer 7 made of a patterned A1 layer was obtained in the same manner as in Example 1-1 of the present invention described above.

In such a case, as in the case of Example 1-1 of the present invention described above, the metal layer 7 made of the patterned A1 layer was formed with the amount of side etching being approximately zero. .

Example 1-4 Similar to the case of Example 1-1 described above, a metal layer 4 made of the A1 layer to be patterned is formed on an insulating substrate 3, and a pattern is formed on the metal layer 4. A substrate body 6 was obtained.

Next, in the case of Example 1-1 of the present invention described above, except that the JUG-pulling electrolyte 11 was changed to an aqueous solution containing hydrochloric acid (HCI) with a concentration of 5 to 40% as a solute. The same electrolytic etching as in Example 1-1 of the present invention described above was carried out in the same manner as in Example 1-1 of the present invention described above to form the metal layer 7 made of the patterned A1 layer. Obtained.

However, in this case, the temperature of the electrolytic solution 11 is 33.0°C,
Further, the current flowing through the electrolytic solution 11 is 200.0 IIIA, and therefore the current density flowing through the metal layer 4 made of AIFl is 5.0 (= 200.Om A/4o, ocm'
)mA/cm'.

In that case, the patterned aluminum layer 7 was formed with approximately zero side etching.

Example 1-5 Similar to the case of Example 1-1 described above, a metal layer 4 made of the A1 layer to be patterned is formed on an insulating substrate 3, and a pattern is formed on the metal layer 4. The board body 6 was removed.

Next, the electrolytic solution 11 in the case of Example 1-1 of the present invention described above was mixed with 10 to 50% concentrated potassium hydroxide (KO).
The same electrolytic etching as in Example 1-1 of the present invention described above was carried out in the case of Example 1-1 of the present invention described above, except that the etching was changed to an aqueous solution containing H> as a solute. Similarly, gold R made of patterned A1 layer
Layer 7 was obtained.

However, in this case, the temperature of the electrolytic solution 11 is set to 33.0°C,
In addition, the current flowing through the electrolyte 11 is 160. oIllA, and therefore the current density passing through the aluminum layer 4 is 4,0
(= 160.0m A/40.0cm+') m
A/am'.

In that case, the patterned aluminum layer 7 was formed with approximately zero side etching.

Example 1-6 Similar to the case of Example 1-1 described above, a metal layer 4 made of the A1 layer to be patterned was formed on an insulating substrate 3, and a pattern was formed on the metal layer 4. A substrate body 6 was obtained.

Next, in the case of Example 1-1 of the present invention described above, the electrolyte solution 11 was mixed with sodium hydroxide (10 to 50% concentration).
The same electrolytic etching as in Example 1-1 of the present invention described above was carried out in Example 1 of the present invention described above, except that the etching was changed to an aqueous solution containing NaOH) as the solute.
In the same manner as in the case of -1, a metal layer 7 made of a patterned A1 layer was obtained.

However, in this case, the temperature of the electrolytic solution 11 is 33.0°C,
In addition, the current flowing through the electrolyte 11 is 180.0 mA,
Therefore, the current density passing through the aluminum layer 4 is set to 4.5(
= 180.0m A/40. Ocm') m
A/cm'.

In that case, a patterned aluminum layer 7 was formed with side etching m of approximately zero.

Example 2-1 Example 1 of the present invention described above except that the metal layer 4 of the substrate body 6 in Example 1-1 of the present invention described above was changed to one made of an Al-3i alloy layer. A substrate body 6 similar to that in case -1 was obtained.

Next, the patterned Al-3i alloy layer was subjected to electrolytic etching similar to that in Example 1-1 of the present invention described above. A metal layer 7 was obtained.

In such a case, the patterned Al-8i alloy layer 7
It was formed so that the amount of side etching was approximately zero.

Example 2-2 Similar to the case of Example 2-1 of the present invention described above, a gold Ff& layer 4 made of an Al-8i alloy layer to be patterned is formed on an insulating substrate 3, and the Al- A substrate body 6 was obtained in which a patterned IC mask layer 5 was formed on a metal layer 4 made of a 8i alloy layer.

Next, the electrolytic solution 11 in the case of Example 2-1 of the present invention described above is made of phosphoric acid consisting of 16 volume parts of an 85% concentration phosphoric acid solution and nitric acid consisting of 1 volume part of a 60% concentration nitric acid solution. Except for changing it to an aqueous solution with and as a solute,
The same electrolytic etching as in Example 2-1 of the present invention described above was performed to form a metal layer made of a patterned AI-8i alloy layer. I got a 7.

In this case, as in the case of Example 2-1 of the present invention described above, the metal layer 7 made of the patterned AI-8i alloy layer is formed so that the amount of side etching is approximately zero. Ta.

Example 2-3 Similar to the case of Example 2-1 of the present invention described above, a metal layer 4 made of an Al-8i alloy layer to be patterned was formed on an insulating substrate 3, and the Al-8i A substrate body 6 was obtained in which a patterned mask layer 5 was formed on a metal layer 4 made of an alloy layer.

Next, the electrolytic solution 11 in the case of Example 2-1 of the present invention described above is made of phosphoric acid consisting of 16 parts by volume of 85% phosphoric acid solution and nitric acid consisting of 1 part by volume of 60% amlff nitric acid solution. And 96% F! Electrolytic etching was carried out in the same manner as in Example 2-1 of the present invention described above, except that the aqueous solution was changed to an aqueous solution containing acetic acid as a solute. A metal layer 7 made of a patterned AI-8i alloy layer was obtained in the same manner as in Example 2-1 of the present invention described above.

In this case, as in the case of Example 1 of the present invention described above, the metal M7 made of a patterned Al-8i alloy layer was formed with approximately zero side etching amount.

Example 3-1 The present invention described above except that the metal layer 4 of the substrate body 6 in Example 1-1 of the present invention described above was changed to one made of an Al-Cu metal layer. A substrate body 6 similar to that in Example 1-1 was obtained.

Next, the same electrolytic etching as in Example 1-1 of the present invention described above was performed on the patterned Al-Cu alloy layer. A metal layer 7 is obtained.

However, in this case, the temperature of the electrolytic solution 11 is 33.0°C,
Further, the current flowing through the electrolytic solution 11 is 240.0 mA, and therefore the current density flowing through the AI-CLI alloy layer 4 is 6.0 mA.
(= 240.0+e A/40.0cm') l
It was set to 1lA/c+a'.

In such a case, the patterned Al-8i alloy layer 7
It was formed so that the amount of side etching was approximately zero.

Example 3-2 Similar to the case of Example 3-1 of the present invention described above, a metal layer 4 made of an Al-Cu alloy layer to be patterned is formed on an insulating substrate 3, and the Al-Cu A substrate body 6 was obtained in which a patterned mask layer 5 was formed on a metal layer 4 made of an alloy layer.

Next, the electrolytic solution 11 in the case of Example 3-1 of the present invention described above was replaced with phosphoric acid consisting of 16 parts by volume of a 85% concentration phosphoric acid solution and nitric acid consisting of 1 volume part of a 60% concentration nitric acid solution. Except for changing it to an aqueous solution with solute.
The same electrolytic etching as in the case of Example 3-1 of the present invention described above was carried out in the same manner as in the case of Example 2-1 of the present invention described above to form a metal layer made of a patterned AI-CU alloy layer. I got a 7.

In this case, as in the case of Example 3-1 of the present invention described above, the metal layer 7 made of the patterned AI-Cu alloy layer is formed so that the amount of side etching is approximately zero. Ta.

Example 3-3 Similar to the case of Example 3-1 of the present invention described above, a metal layer 4 made of an Al-Cu alloy layer to be patterned is formed on an insulating substrate 3, and the Al-Cu A substrate body 6 was obtained in which a patterned mask layer 5 was formed on a metal layer 4 made of an alloy layer.

Next, the electrolytic solution 11 in the case of Example 3-1 of the present invention described above was mixed with phosphoric acid consisting of 16 parts by volume of a phosphoric acid solution having a concentration of 85% and nitric acid consisting of 1 part by volume of a nitric acid solution having a concentration of 60%. and 9
Electrolytic etching was carried out in the same manner as in Example 3-1 of the present invention described above, except that the aqueous solution was changed to an aqueous solution containing 1 part by volume of 6% acetic acid solution and acetic acid as a solute. A gold F4 layer 7 made of a patterned AI-CU alloy layer was obtained in the same manner as in Example 3-1 of the present invention described above.

In this case, as in the case of Example 1 of the present invention described above, the metal layer 7 made of the patterned Al--Cl alloy layer was formed so that the amount of side etching was approximately zero.

Example 4 Similar to the case of Example 1-1 described above, a gold i layer 4 made of a Cu layer to be patterned is formed on an insulating substrate 3, and a patterned mask is formed on the metal layer 4. A substrate body 6 on which the layer 5 was formed was obtained.

Next, except that the electrolytic solution 11 in the case of Example 1-1 of the present invention described above was changed to an aqueous solution containing sulfuric acid at a concentration of 5 to 40% as a solute, The same electrolytic etching as in Example 1-1 was carried out in the same manner as in Example 1-1 of the present invention described above to obtain a metal layer 7 made of a patterned Cu layer.

However, in this case, the temperature of the electrolytic solution 11 is 33.0°C,
In addition, the current flowing through the electrolyte 11 is 160. OIA, and therefore the current density passing through the metal layer 4 made of Cu layer is 4.0.
(= 160.0+++ A/40.0cm') mA
/Cl1l+Toshita.

In that case, a metal layer 7 consisting of a patterned Cu layer was formed with a lead etching m of approximately zero.

Example 5 Similar to the case of Example 1-1 described above, a metal layer 4 made of a Cr layer to be patterned is formed on an insulating substrate 3, and a patterned mask layer is formed on the metal layer 4. Eight substrates 6 on which 5 was formed were obtained.

Except for changing to one consisting of a quality aqueous solution.
The same electrolytic etching as in the case of Example 1-1 of the present invention described above was carried out in the same manner as in the case of Example 1-1 of the present invention described above to obtain the metal layer 7 consisting of the patterned 01 layer. Ta.

However, in this case, the temperature of the electrolytic solution 11 is 33.0°C,
In addition, the current flowing through the electrolyte 11 is 240. OraA,
Therefore, the current density passing through the metal layer 4 consisting of the 01 layer is set to 6.
0(=240.0+nA/40.Ocm')+1
It was set to 1A/cm'.

In that case, the patterned metal layer 7 made of Crff1 was formed with approximately zero side etching amount.

[Brief explanation of drawings]

FIGS. 1A, B, and C illustrate the sequential steps of forming a patterned mask layer on a metal layer to be patterned, illustrating a method for forming a patterned metal layer according to the present invention. It is a sectional view along the route. FIG. 2 shows the step of forming a patterned metal layer by electrolytic etching on the metal layer to be patterned, likewise illustrating the method of forming a patterned metal layer according to the invention. , is a route map. FIG. 3 also shows the step of forming a patterned metal layer by electrolytic etching on the metal layer to be patterned, which serves to illustrate the method of forming a patterned metal layer according to the invention. () is a cross-sectional view of the route. FIG. 4 also illustrates the process of forming a patterned metal layer by electrolytic etching on the metal layer to be patterned, illustrating the method of forming a patterned metal layer according to the invention. Time t (minutes)
FIG. 3 is a diagram showing the relationship between current 1 (lA) flowing from a DC constant voltage source through a metal layer to be patterned, and FIG. 5 also shows the formation of a patterned metal layer by electrolytic etching of the metal layer to be patterned, illustrating the method of forming a patterned metal layer according to the invention. Current density J (mA/cm') with the temperature of the electrolyte as a parameter in the step of
FIG. 3 is a diagram showing the relationship between the 1 nide etching ff1Y (μm) of a patterned metal layer formed according to the present invention and FIG. 6 similarly illustrates the process of forming a patterned metal layer according to the invention by electrolytic etching of the metal layer to be patterned. This is a diagram showing the relationship between the current density J (mA/cm') and the temperature T (°C) of the electrolytic solution when the side etching amount Y of the patterned metal layer formed according to the present invention becomes zero. be. FIG. 7 is a cross-sectional view showing an example of a patterned metal layer obtained by the method of forming a patterned aluminum layer according to the present invention. １・・・・・・・・・・・・・・・Substrate 2・・・・・・
・・・・・・・・・Insulating layer 3・・・・・・・・・・・・
・・・Insulating substrate 4・・・・・・・・・・・・Metal layer to be patterned 5・・・・・・・・・・・・Patterned mask Layer 6......Substrate body 7...
・・・・・・・・・・・・Patterned metal layer 1
1...... Electrolyte 12...
・・・・・・・・・・・・Tank 13・・・・・・・・・・・・
・・・・Electrode 14・・・・・・・・・・・・・・・DC power source 16・・・・・・・・・・・・・・・Ammeter Applicant Tokyo Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] forming a metal layer to be patterned on an insulating substrate;
forming a patterned mask layer on the metal layer, then using the mask layer as a mask for the metal layer;
The gold to be patterned ff1 is subjected to electrolytic etching using an electrolytic solution consisting of an acidic or alkaline aqueous solution.
PJ is used as an anode, and a direct current constant voltage source is connected between the metal layer to be patterned as the anode and the corresponding cathode electrode, and the gold T to be patterned as the anode is connected.
A method for forming a patterned metal layer, characterized in that the patterned metal layer is formed by performing the process until the voltage between the A layer and the cathode electrode suddenly decreases.