JPH06216502A - Process of photosensitive polyimide precursor pattern - Google Patents

Abstract

PURPOSE:To form a photosensitive polyimide precursor pattern by coating a copper pattern formed on a substrate with silane adherence improving agent and baking, exposing and developing it after applying photosensitive polyimide precursor on the silane adherence improving agent. CONSTITUTION:A copper pattern 2 is formed on a substrate 1. A silane adherence improving coat layer 3 is formed on the copper pattern 2. A photosensitive polyimide precursor coat layer 4 is formed on the silane adherence improving coat layer 3. Then, a via hole 5 is formed. As for the formation of the via hole 5, ultraviolet rays are applied on the substrate 1 whereupon the photosensitive polyimide precursor coat layer 4 is formed through a glass mask provided with a desired patterning and the substrate 1 is exposed. Since the light shielding part of the glass mask is square, the part of the photosensitive polyimide precursor coat layer 4 whereupon ultraviolet rays are not applied dissolves in developing liquid at the developing process and the square via hole 5 is formed. Then, a conductive layer 6 is formed on the photosensitive polyimide precursor coat layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive polyimide precursor pattern as an insulating layer formed on a copper pattern used as a conductor layer on a ceramic substrate, a glass substrate or a wafer used in electronic equipment such as a computer. Regarding processing method.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view showing an example of a conventional method for processing a photosensitive polyimide precursor pattern in the order of steps.

A conventional method for processing a photosensitive polyimide precursor pattern as an insulating layer formed on a copper pattern used as a conductor layer on a ceramic substrate, a glass substrate or a wafer used in electronic equipment such as a computer is shown in FIG.
As shown in (a), first, the conductor layer 92 is formed on the substrate 91. The conductor layer 92 is formed by forming a thin film of chromium or palladium on the substrate 91 by a vapor deposition method or a sputtering method, applying a photoresist varnish thereon by a spin coating method or the like, and drying it with a hot plate oven or the like. To do. Then, it is exposed to light and developed by a dip development method or the like to obtain a desired pattern. Next, after forming a conductor pattern by plating gold or nickel or copper on it, peel off the photoresist,
The conductive layer 92 is formed by removing the chromium or palladium thin film by etching with an ion beam or the like.

An insulating layer is formed on the conductor layer 92. The insulating layer is formed by spin coating on the conductor layer 92 formed on the substrate 91 as shown in FIG. 8B. The photosensitive polyimide precursor 93 is applied by a method or the like, and is dried in a hot plate oven or the like. Next, it is exposed to ultraviolet rays through the glass mask 94 and developed by a dip developing method or the like. As a result, FIG.
As shown in (c-1), the photosensitive polyimide precursor 93
A via hole 95 for exposing the conductor layer 92 is formed in a portion where the ultraviolet ray is not exposed. By baking this in an oven in a nitrogen atmosphere, an insulating layer of polyimide is formed.

Next, as shown in FIG. 8 (d-1), when a second conductor layer 98 is formed on this insulating layer, the conductor layer 98 comes into contact with the conductor layer 92 through the via hole 95. , These two conductor layers are electrically conducted.

In the above series of processes, FIG.
-2), when the first conductor layer is the copper pattern 96, the surface of the copper pattern 96 is oxidized in air at room temperature and is more chemical than divalent copper oxide (CuO). It is a stable monovalent copper oxide (C _u2 O).

As described above, when the photosensitive polyimide precursor is applied to the copper pattern 96 whose surface is oxidized and dried, exposed and developed, monovalent copper oxide (C _u2 O) on the surface of the copper pattern 96 is applied. And the photosensitive polyimide precursor cause a chemical reaction, and as shown in FIG. 8C-2, the copper polyimide complex 9
Form 7. Since this is insoluble in the developing solution, it remains as a residual film on the copper pattern in the via hole portion, making it impossible to process the photosensitive polyimide precursor pattern.

Therefore, when the conductor layer 99 is formed thereon, the open portion 1 is formed between the conductor layer 99 and the copper pattern 96.
00 is formed, electrical connection between them cannot be obtained.

[0009]

As described above, in the conventional method of processing a photosensitive polyimide precursor pattern, the photosensitive polyimide precursor is applied on the copper pattern and the conductor layer is formed thereon. At this time, since a monovalent copper oxide film is formed on the surface of the copper pattern to form a copper-polyimide complex, an open portion 100 is formed between the conductor layer and the copper pattern, and electrical conduction cannot be obtained. It has the drawback of

[0010]

A first method for processing a photosensitive polyimide precursor pattern according to the present invention is to apply a silane-based adhesion improving agent onto a copper pattern formed on a substrate,
The method includes coating a photosensitive polyimide precursor on the silane-based adhesion improver and then performing baking, exposure and development to form a photosensitive polyimide precursor pattern.

A second method for processing a photosensitive polyimide precursor pattern according to the present invention is to apply a temperature of 100 ° C. or more to a copper pattern formed on a substrate in the presence of oxygen to form the copper pattern. Forming an oxide layer of divalent copper oxide on the surface of, and applying a photosensitive polyimide precursor on the oxide layer, followed by baking, exposure and development to form a photosensitive polyimide precursor pattern. It is a waste.

The third method for processing a photosensitive polyimide precursor pattern of the present invention is to irradiate a copper pattern formed on a substrate with ultraviolet rays in the presence of oxygen to expose the surface of the copper pattern. Forming an oxide layer of divalent copper oxide,
The method includes applying a photosensitive polyimide precursor on the oxide layer, followed by baking, exposure and development to form a photosensitive polyimide precursor pattern.

A fourth method for processing a photosensitive polyimide precursor pattern according to the present invention is that the surface of a copper pattern formed on a substrate is etched with an ion beam to make the surface of the copper pattern a primitive copper, The method includes applying a photosensitive polyimide precursor on the copper pattern, baking, exposing and developing to form a photosensitive polyimide precursor pattern.

[0014]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of the present invention in the order of steps, and FIG. 4 is a schematic view showing the constitution of a photosensitive polyimide precursor coating apparatus used in the embodiment of FIG.

The first embodiment of the present invention is first shown in FIG.
As shown in, the copper pattern 2 is formed on the substrate 1 which is the workpiece by the method described above. The copper pattern 2 is
It is formed by copper plating to have a thickness of 10 μm and a width of 30 μm. The surface of the copper pattern 2 is oxidized in air at room temperature, and XPS (X-RAY PHOTOELECTORON SPECTROS
COPY) According to the analysis, 82% of the surface is monovalent copper oxide (C
_u2 O).

Next, as shown in FIG. 1B, a silane-based adhesion improving agent coating layer 3 is formed on the copper pattern 2. The method for forming the silane-based adhesion improving agent coating layer 3 is as follows: 100% hexamethyldisilazane, which is an adhesion improving agent, is applied onto the substrate 1.
5 g per cm ^{2 is} dropped, the substrate 1 is rotated at a rotation speed of 3000 RPM for 30 seconds, and hexamethyldisilazane is spread and applied on the entire surface of the substrate 1 by a spin coating method. As a result, a silane-based adhesion improving agent coating layer 3 having a film thickness of 1 μm or less
Is formed.

Next, as shown in FIG. 1C, a photosensitive polyimide precursor coating layer 4 is formed on the silane-based adhesion improving agent coating layer 3. The photosensitive polyimide precursor coating layer 4 is formed by dropping 7 g of the photosensitive polyimide precursor on 100 cm ^{2 of} the substrate 1 on which the silane-based adhesion improving agent coating layer 3 is formed, and rotating the substrate 1 at a rotation speed of 700 RPM. After rotating for 30 seconds, the rotation speed is 2000 RPM for 1 second. At this time, the viscosity of the photosensitive polyimide precursor is 30
It is Poise. Subsequently, the substrate 1 is placed on a hot plate oven and baked at 80 ° C. for 90 minutes to evaporate the solvent in the photosensitive polyimide precursor. As a result, the photosensitive polyimide precursor coating layer 4 having a film thickness of 20 μm is formed.

Next, as shown in FIG. 1D, a via hole 5 is formed. The method for forming the via hole 5 is as follows. The substrate 1 having the photosensitive polyimide precursor coating layer 4 formed thereon has a wavelength of 36 via a glass mask on which desired patterning is performed.
It is irradiated with ultraviolet rays of 5 nm and exposed at an exposure amount of 150 millijoules per cm ² . The photosensitive polyimide precursor has negative type photosensitivity. The light-shielding portion of the glass mask is a square with one side of 40 μm. Therefore, the portion of the photosensitive polyimide precursor coating layer 4 which has not been irradiated with ultraviolet rays is dissolved in a developing solution in the next developing step, and a square via hole 5 having a side of 40 μm is formed. The development was carried out in a dimethylacetamide developer solution at a liquid temperature of 21 ° C.
It is performed by soaking for 0 seconds.

At the time of this development, since the silane-based adhesion improving agent coating layer 3 is interposed between the surface of the copper pattern 2 and the photosensitive polyimide precursor coating layer 4, the surface of the copper pattern 2 and the photosensitive polyimide are coated. Does not come into direct contact with the precursor coating layer 4,
Therefore, it does not form a copper-polyimide complex. Therefore, it becomes possible to form a pattern of the photosensitive polyimide precursor on the copper pattern 2.

Next, as shown in FIG. 1E, a conductor layer 6 is formed on the photosensitive polyimide precursor coating layer 4 having the via holes 5 formed therein. The conductor layer 6 is formed by baking the substrate 1 on which the via holes 5 are formed at 380 ° C. for 20 minutes in a nitrogen atmosphere so that the photosensitive polyimide precursor is used as a polyimide insulating layer, and a known series of conductors is used. The conductor layer 6 is formed by the layer forming step. As a result, the copper pattern 2 and the conductor layer 6 are directly connected, and electrical conduction is obtained.

FIG. 4 is a schematic diagram showing the construction of the photosensitive polyimide precursor coating apparatus used in the above-mentioned embodiment.

The substrate 1 of the workpiece on which the copper pattern 2 is formed is mounted on the substrate holder 32 which is rotated by the motor 31. The silane-based adhesion improver 37 is N ₂
It is placed in a pressure tank 36 which is pressurized by, and is dropped onto the substrate 1 from a silane-based adhesion improving agent dropping nozzle (nozzle) 33 by opening a valve 35 of a pipe 34. When the motor 31 is subsequently rotated, the substrate 1
The silane-based adhesion improving agent 37 dropped onto the substrate is spin-coated to form the silane-based adhesion improving agent coating layer 3 on the substrate 1.

The photosensitive polyimide precursor 42 is placed in a pressure tank 41 which is pressurized with N ₂ .
By opening the valve 40 of the pipe 39, the photosensitive polyimide precursor dropping nozzle (nozzle) 38 is dropped onto the substrate 1 on which the silane-based adhesion improving agent coating layer 3 is formed. Subsequently, when the motor 31 is rotated, the photosensitive polyimide precursor 42 dropped on the substrate 1 is spin-coated.

Next, the substrate 1 is transferred from the substrate holder 32 onto the hot plate oven 44 by the transfer arm 43, and baking is performed by the hot plate oven 44. As a result, the solvent in the photosensitive polyimide precursor is evaporated and the photosensitive polyimide precursor coating layer 4 is formed.

The substrate 1 on which the photosensitive polyimide precursor coating layer 4 has been formed by the coating apparatus of FIG. 4 is moved to the next step.

FIG. 2 is a sectional view showing the second and third embodiments of the present invention in the order of steps, and FIG. 5 is a schematic diagram showing the construction of a photosensitive polyimide precursor coating apparatus used in the second embodiment of the present invention. It is a figure.

The second embodiment of the present invention is first shown in FIG.
As shown in, a copper pattern 12 is formed on a substrate 11 which is a workpiece. Next, the copper pattern 12 of this substrate 11
An oxide layer 13 is formed thereon as shown in FIG. The oxide layer 13 is formed by baking the substrate 11 in a hot plate oven in the atmosphere at 200 ° C. for 30 minutes to forcibly form the oxide layer 13 of divalent copper oxide (Cu 2 O 3) on the surface of the copper pattern 12. Form.

Next, as shown in FIG. 2C, the oxide layer 1
3 is coated with a photosensitive polyimide precursor coating layer 14. The method for forming the photosensitive polyimide precursor coating layer 14 is as follows.
This is the same as the first embodiment shown in FIG.

Next, as shown in FIG. 2D, a via hole 15 is formed. The method of forming the via hole 15 is also shown in FIG.
This is the same as the first embodiment shown in (d). At this time,
Since the oxide layer 13 is interposed between the surface of the copper pattern 12 and the photosensitive polyimide precursor coating layer 14, the surface of the copper pattern 12 and the photosensitive polyimide precursor coating layer 14 do not come into direct contact with each other. Does not form a copper-polyimide complex.

Next, as shown in FIG. 2E, a conductor layer 16 is formed on the photosensitive polyimide precursor coating layer 14 in which the via hole 15 is formed. The method of forming the conductor layer 16 is also the same as that of the first embodiment shown in FIG.

FIG. 5 is a schematic diagram showing the construction of the photosensitive polyimide precursor coating apparatus used in the above-mentioned examples.

The substrate 11 of the workpiece on which the copper pattern 12 is formed is first mounted in the hot plate oven 60 and heat-treated in the atmosphere. As a result, the surface of the copper pattern 12 is forcibly oxidized by divalent copper oxide (CuO).

The substrate 11 having the oxide layer 13 formed thereon is mounted on a substrate holder 52 which is rotated by a motor 51 by a transfer arm 58, and the photosensitive polyimide precursor 5
7 to form the photosensitive polyimide precursor coating layer 14. The means for forming the photosensitive polyimide precursor coating layer 14 is
It is the same as the coating apparatus of FIG.

FIG. 6 is a schematic diagram showing the structure of a photosensitive polyimide precursor coating apparatus used in the third embodiment of the present invention.

In the third embodiment of the present invention, the formation of the oxide layer is replaced by heat treatment in a hot plate oven,
This is performed by irradiating ultraviolet rays from a high pressure mercury lamp, and therefore the process diagram is the same as that of the second embodiment shown in FIG.

The photosensitive polyimide precursor coating apparatus used in the third embodiment comprises an ultraviolet irradiation stage 61 and a high pressure mercury lamp 62, as shown in FIG. The substrate 11 of the workpiece on which the copper pattern 12 is formed is first mounted on the ultraviolet irradiation stage 61 and irradiated with ultraviolet rays by the high pressure mercury lamp 62. By this ultraviolet irradiation, the surface of the copper pattern 12 is forcibly oxidized by divalent copper oxide (Cu 2 O 3).

The substrate 11 having the oxide layer 13 formed thereon is mounted on a substrate holder 52 which is rotated by a motor 51 by a transfer arm 58, and the photosensitive polyimide precursor 5
7 to form the photosensitive polyimide precursor coating layer 14. The means for forming the photosensitive polyimide precursor coating layer 14 is
It is the same as the coating apparatus of FIG.

FIG. 3 is a sectional view showing a fourth embodiment of the present invention in the order of steps, and FIG. 7 is a schematic view showing the constitution of a photosensitive polyimide precursor coating apparatus used in the embodiment of FIG.

In the fourth embodiment of the present invention, as shown in FIG. 3A, first, a copper pattern 22 is formed on a substrate 21 which is a workpiece. Next, the copper pattern 2 of this substrate 21
2 to the ion beam 2 as shown in FIG.
Irradiate 3. The ion beam 23 is irradiated with an argon ion beam until the surface of the copper pattern 22 is etched by 0.5 μm by an ion generation source and a focusing accelerator. As a result, the entire surface of the copper pattern 22 becomes primitive copper (Cu).

Next, as shown in FIG. 3C, a photosensitive polyimide precursor coating layer 24 is formed on the copper pattern 22 whose surface is made of primitive copper (Cu). The method for forming the photosensitive polyimide precursor coating layer 24 is the same as that of the first embodiment shown in FIG.

Next, as shown in FIG. 3D, a via hole 25 is formed. The method of forming the via hole 25 is also shown in FIG.
This is the same as the first embodiment shown in (d). At this time,
Since the surface of the copper pattern 22 is all primitive copper (Cu), the copper pattern 22 does not form a copper polyimide complex.

Next, as shown in FIG. 3E, a conductor layer 26 is formed on the photosensitive polyimide precursor coating layer 24 having the via holes 25 formed therein. The method of forming the conductor layer 26 is also the same as that of the first embodiment shown in FIG.

FIG. 7 is a schematic diagram showing the structure of a photosensitive polyimide precursor coating apparatus used in the above-mentioned examples.

The photosensitive polyimide precursor coating apparatus used in the fourth embodiment is, as shown in FIG. 7, a copper pattern 22.
A vacuum chamber 80 for primordial copper (Cu) by irradiating the surface of the substrate with an argon beam for etching.
Is equipped with. The vacuum chamber 80 includes an etching stage 81 for mounting the substrate 21, an ion source 83 for irradiating the substrate 21 mounted on the etching stage 81 with an ion beam, and an argon gas for the ion source 83. It has a gas introduction port 84 for supply, and an ion focusing accelerator 82 that focuses argon ions from the ion source 83 as a beam on the substrate 21 on the etching stage 81 to accelerate the ions.

The substrate 21 of the workpiece on which the copper pattern 22 is formed is first mounted on the etching stage 81 in the vacuum chamber 80, and an argon beam is applied to the surface of the copper pattern 22 by the ion source 83 and the ion focusing accelerator 82. It is irradiated and etched. As a result, the entire surface of the copper pattern 22 becomes primitive copper (Cu).

The substrate 21 in which the surface of the copper pattern 22 is made of primitive copper (Cu) is transferred to the motor 71 by the transfer arm 78.
The photosensitive polyimide precursor coating layer 24 is formed from the photosensitive polyimide precursor 77 by being mounted on the substrate holder 72 which is rotated by. The means for forming the photosensitive polyimide precursor coating layer 24 is the same as that of the coating apparatus of FIG.

[0048]

As described above, according to the method for processing a photosensitive polyimide precursor pattern of the present invention, a silane-based adhesion improving agent coating layer is provided on a copper pattern formed on a substrate of a workpiece. Alternatively, an oxide layer of divalent copper oxide (CuO) formed by heating in a hot plate oven or ultraviolet irradiation is provided, or the surface of the copper pattern is exposed to an original beam (Cu) by irradiation of an ion beam.
Then, a photosensitive polyimide precursor coating layer is formed thereon to form a via hole, thereby forming a copper polyimide complex by a chemical reaction between the monovalent copper oxide on the surface of the copper pattern and the photosensitive polyimide precursor. The effect is that it can be prevented, and therefore, the processing of a complete photosensitive polyimide precursor pattern is possible.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention in the order of steps.

FIG. 2 is a cross-sectional view showing the second and third embodiments of the present invention in the order of steps.

FIG. 3 is a sectional view showing a fourth embodiment of the present invention in the order of steps.

FIG. 4 is a schematic diagram showing a configuration of a photosensitive polyimide precursor coating apparatus used in the example of FIG.

FIG. 5 is a schematic diagram showing the configuration of a photosensitive polyimide precursor coating apparatus used in the second embodiment of the present invention.

FIG. 6 is a schematic diagram showing the configuration of a photosensitive polyimide precursor coating apparatus used in the third embodiment of the present invention.

FIG. 7 is a schematic diagram showing a configuration of a photosensitive polyimide precursor coating device used in the example of FIG.

FIG. 8 is a cross-sectional view showing an example of a method of processing a conventional photosensitive polyimide precursor pattern in process order.

[Explanation of symbols]

1 ・ 11 ・ 21 ・ 91 Substrate 2 ・ 12 ・ 22 ・ 96 Copper pattern 3 Silane-based adhesion improver coating layer 4 ・ 14 ・ 24 ・ 93 Photosensitive polyimide precursor coating layer 5 ・ 15 ・ 25 ・ 95 Via hole 6 ・ 16・ 26 ・ 92 ・ 98 ・ 99 Conductor layer 13 Oxide layer 23 Ion beam 31 ・ 51 ・ 71 Motor 32 ・ 52 ・ 72 Substrate holder 33 ・ 73 Silane-based adhesion improver dropping nozzle (nozzle) 34 ・ 39 Piping 35 ・ 40 Valve 36/41 Pressurized tank 37 Silane-based adhesion improver 38 Photosensitive polyimide precursor dropping nozzle (nozzle) 42/57/77 Photosensitive polyimide precursor 43/58/78 Transfer arm 44/60 Hot plate oven 61 UV irradiation stage 62 High Pressure Mercury Lamp 80 Vacuum Chamber 81 Etching Stage 82 Ion Focus Accelerator 83 Io Source 84 gas inlet 94 glass mask 97 copper polyimide complex 100 open part

Claims (4)

[Claims] 1. A silane-based adhesion improving agent is applied onto a copper pattern formed on a substrate, and a photosensitive polyimide precursor is applied onto the silane-based adhesion improving agent, followed by baking, exposure and development. A method of processing a photosensitive polyimide precursor pattern, comprising: performing the method to form a photosensitive polyimide precursor pattern. 2. A copper pattern formed on a substrate is heated to a temperature of 100 ° C. or higher in the presence of oxygen to form an oxide layer of divalent copper oxide on the surface of the copper pattern, A method of processing a photosensitive polyimide precursor pattern, comprising: forming a photosensitive polyimide precursor pattern by applying a photosensitive polyimide precursor on the oxide layer and then baking, exposing and developing the photosensitive polyimide precursor pattern. 3. A copper pattern formed on a substrate is irradiated with ultraviolet rays in the presence of oxygen to form an oxide layer of divalent copper oxide on the surface of the copper pattern. A method for processing a photosensitive polyimide precursor pattern, comprising: forming a photosensitive polyimide precursor pattern by applying a photosensitive polyimide precursor on the surface and then performing baking, exposure and development. 4. The surface of a copper pattern formed on a substrate is etched by an ion beam to make the surface of the copper pattern a primitive copper, and a photosensitive polyimide precursor is applied onto the copper pattern. A method of processing a photosensitive polyimide precursor pattern, comprising: performing baking, exposing and developing to form a photosensitive polyimide precursor pattern.