JPH0897327A - Manufacture of multi-layer wiring board - Google Patents

Abstract

PURPOSE: To make it possible to form a through hole with a stable taper angle in a multi-layer wiring board, by forming a contact through hole in an insulating film in a patterning step, and carrying out etching after an insulating material is applied again to the through hole. CONSTITUTION: A forward-tapered through hole 4 or a reverse-tapered through hole 5 is drilled in a first insulting film 3 that is formed previously. An insulating material 6 is applied thinly at a second time and an etching step is carried out. Then, there is an etching remnant between a reverse-tapered part with an acute angle and a base part at the through hole, but there is no remnant at a forward-tapered part with an obtuse angle at the through hole so that a forward-tapered through hole can be formed stably. As a result, there is an obtuse angle between an upper face of the insulating film and a side face of the through hole, and this state is effective in preventing a break in metallic wiring formed on the upper face.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing a multilayer wiring electronic component having an insulating film, a metal wiring film, etc. on a substrate.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a semiconductor or a multilayer wiring board has been performed by forming an insulating film or a metal wiring on the board. As a method of opening a through hole such as a contact through hole with a metal wiring in an insulating film, generally, an insulating material such as polyimide resin is applied on the metal wiring, a through hole pattern is formed with a photoresist, and etching is performed to form a through hole. There is a method of opening a through hole or a method of exposing and developing using a photosensitive insulating material to open a through hole. In addition, Japanese Patent Laid-Open No. 5-198
As in Japanese Patent No. 687, a through hole-shaped pattern is formed with photoresist by overexposure at a site where a through hole is opened, covered with a polyimide resin, and etched by oxygen plasma or the like until the resist pattern is exposed. After that, there is a method of opening the through hole by removing the exposed resist.

[0003]

When an insulating material is applied on a substrate, a pattern is formed with a photoresist, and etching is performed, the taper angle of the through hole may change depending on the baking condition and the etching condition of the insulating material. In some cases, it is difficult to control the taper angle such that the taper angle opens in the opposite direction. As the angle between the upper surface and the side surface of the through hole becomes smaller, the step coverage when the metal wiring is formed on the upper surface of the insulating film deteriorates, and the possibility of disconnection increases. Further, the adhesion between the insulating film and the underlying metal wiring may be deteriorated and peeling may occur. Furthermore, when forming a through-hole pattern with photoresist,
When a pattern is formed by overexposure, the contact area with the underlying metal film is small and the adhesion is poor.Therefore, peeling may occur when forming a through hole with a small diameter or a thick insulating film. is there. An object of the present invention is to form a through hole having a small taper angle variation by making the reverse taper a forward taper even if an inverse taper occurs due to a variation in taper angle or the like that occurs when forming a through hole in an insulating film. An object of the present invention is to provide a method for forming a multilayer wiring by the method.

[0004]

In order to achieve the above object, in addition to a conventional method of forming an through hole by applying an insulating material on a substrate or a base metal wiring formed on the substrate, An insulating material is applied and etching is performed by the applied film thickness. As a result, in the portion where the taper angle is reverse taper, the smaller the angle between the side surface of the through hole opened at the first time and the base, the more easily the insulating material applied at the second time remains and the forward taper occurs. In addition, since the insulating material applied the second time is less likely to remain in the forward taper portion as the angle between the side surface of the through hole and the base becomes larger, the forward taper through hole with less variation in taper angle is formed.

[0005]

By the above means, when the insulating material is applied again to the opened through hole and etching is performed by the film thickness of the applied insulating material, the etching rate changes depending on the taper angle of the first opened through hole. As the taper angle has a smaller inverse taper, the insulating material applied the second time is more likely to remain, so that a forward taper through hole with less variation in taper angle can be formed and a stable through hole can be formed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1A to 1C are process sectional views of a multilayer wiring board according to an embodiment of the present invention. In FIG. 1, 1 is a substrate, 2 is metal wiring, 3 is a first insulating material,
Reference numeral 4 is a forward tapered through hole, 5 is a reverse tapered through hole, and 6 is a second insulating material.

First, as shown in FIG. 1, a metal wiring 2 is formed on a substrate 1, an insulating material 3 is applied and formed on the metal wiring 2 for the first time, and a photoresist is applied, exposed, developed, and etched. The tapered through hole 4 or the reverse tapered through hole 5 is opened. After that, as shown in FIG. 1B, the insulating material 6 for the second time is applied again slightly thinly thereon. Then, the insulating material is etched without photoresist processing. By this etching, the base on the bottom surface of the through hole is exposed. As a result, as shown in FIG. 1C, etching residue is generated in the insulating material 6 for the second time in the gap between the reverse tapered through hole 5 and the underlying metal wiring 2 at an acute angle. Further, since the forward taper through hole 4 and the underlying metal wiring 2 have an obtuse angle, the second insulating material 6 is unlikely to remain. Therefore, in the first insulating film through hole formation, the taper angle is varied in the substrate. Also, through-holes and through-holes having tapered angles that vary from batch to batch can be collectively formed at a stable angle.

In another embodiment, the forward tapered through hole 4 and the reverse tapered through hole 5 are formed in the insulating film, and the negative type photosensitive organic insulating film is used as the second insulating material 6 to be applied. Development is performed without performing. By this development,
The base of the bottom of the through hole is exposed. Residual development occurs at the acute angle portion of the gap between the reverse taper through hole 5 and the underlying metal wiring 2. Residual development hardly occurs between the forward tapered through hole 4 and the underlying metal wiring 2.

[0010]

In the past, when forming a through hole in an interlayer insulating film in the formation of a multilayer wiring, after applying an insulating agent, patterning by photoresist coating, exposure and development, etching of an insulating film, resist stripping, etc. It went through the process. However, it is difficult to control the variation of the taper angle of the through hole depending on the conditions such as exposure, development, and etching. When an inverse tapered through hole occurs, the angle between the upper surface of the insulating film and the side surface of the through hole becomes an acute angle. Therefore, the step coverage with the metal wiring formed on this becomes poor, and there is a possibility that cracks and the like will occur from the acute-angled portions, causing disconnection. In the present invention, in addition to the steps described above, a forward tapered through hole can be stably formed by applying and forming an insulating agent and etching, and the processing accuracy is improved.

[Brief description of drawings]

FIG. 1 is a process sectional view of a multilayer wiring board.

[Explanation of symbols]

1 ... Substrate, 2 ... Metal wiring, 3 ... First insulating material, 4 ... Forward tapered through hole, 5 ... Reverse tapered through hole, 6 ... Second insulating material.

Claims (3)

[Claims] 1. A multi-layer wiring having an insulating film, characterized in that a through hole is formed in a forward taper by forming a through hole in an insulating material applied on a substrate and then applying the insulating material again and etching. Substrate manufacturing method. 2. The method for manufacturing a multilayer wiring board according to claim 1, wherein variations in the taper angle on the side surface of the through hole formed in the insulating material are corrected to form a through hole having a stable taper angle. Of manufacturing a multi-layer wiring board having the above insulating film. 3. The method according to claim 1, wherein a negative photosensitive polyimide resin is used as an insulating material to be applied again, application and development are performed to correct variations in taper angle on the side surface of the through hole, and to stabilize the taper angle. A method for manufacturing a multilayer wiring board having an insulating film, which is characterized by forming through holes.