JP3720391B2 - Semiconductor device and manufacturing method of semiconductor device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device.
[0002]
[Prior art]
With the recent increase in the density of semiconductor devices, the development of multi-layered semiconductor elements has been promoted. In recent semiconductor devices, a wiring layer is generally used as a buffer between a semiconductor chip and a sealing resin. A polyimide film is used as an interlayer insulating film when stacked. 12 to 16 are cross-sectional views illustrating a manufacturing process of a conventional semiconductor device using a polyimide film as a buffer between the semiconductor chip and the sealing resin. FIG. 17 is a flowchart showing the manufacturing process. First, as shown in FIG. 12, a bonding pad 2 and an insulating film 3 are formed on a semiconductor substrate 1 made of silicon or the like (step S1 in FIG. 17), and a polyimide film 4 is entirely formed thereon. The resist 5 is applied on the polyimide film 4. Next, after exposure using a photomask or the like, it is immersed in a solvent to leave only the necessary portion of the resist 5 as shown in FIG. 13, and thereafter, the portion of the polyimide film 4 not covered with the resist 5 is removed from the organic alkali. It melt | dissolves with developing solutions, such as a solution, and removes as shown in FIG. 14, Furthermore, a polyimide pattern is formed by removing the remaining resist 5 as shown in FIG. 15 (step S2 of FIG. 17).
[0003]
At this time, the polyimide film 4 melted with the developer is not blown away, and the polyimide residue 4 a remains on the bonding pad 2 and the insulating film 3. Alternatively, for the purpose of protecting the bonding pad 2 from the developing solution at the time of forming the polyimide pattern, a polyimide film (not shown) having a thickness of about several μm is formed on the bonding pad 2 and the insulating film in the same manner as the polyimide residue 4 in FIG. In some cases, it may remain on the film 3. The polyimide film 4 thus patterned is then heated and cured at about 350 ° C. (step S3 in FIG. 17). After curing, a polyimide residue 4a existing on the bonding pad 2 and the insulating film 3 or a thin polyimide film (not shown) left for protecting the bonding pad 2 is transformed into an oxygen plasma 6 as shown in FIG. It removes with the asher using (step S4 of FIG. 17). At this time, the surface of the polyimide film 4 is roughened by the asher, and the damage layer 4b is generated.
[0004]
[Problems to be solved by the invention]
In the semiconductor device manufactured by the conventional manufacturing method as described above, since the damage layer 4b has a weak adhesion with the polyimide film 4, an external electrode (not shown) is connected to the bonding pad 2 as shown in FIG. When resin sealing is performed with the resin 8 after bonding the wire 7 for connection, the sealing resin 8 may be peeled off from the polyimide film 4 together with the damaged layer 4b. There was a problem that the adhesiveness was poor and the reliability was poor.
[0005]
Further, when the protruding electrode 9 is formed on the bonding pad 2 (see FIG. 10), or when the polyimide film 4 is used as an interlayer insulating film (see FIG. 11), a metal film is formed on the damaged layer 4b by sputtering or the like. However, in that case, the problem that the adhesion between the metal film and the polyimide film 4 is deteriorated by the damage layer 4b, or the damage layer 4b and the metal film form a mixed layer. The mixed layer does not completely dissolve in the solvent at the time of etching, and there remains a problem that etching failure occurs.
[0006]
The present invention has been made to solve the above-described problems. The damage layer 4b generated on the surface of the polyimide film 4 is completely removed, and the adhesion between the polyimide film 4 and the sealing resin and metal film is improved. It is an object of the present invention to improve a semiconductor device and a method for manufacturing the semiconductor device with high reliability by preventing peeling of a sealing resin and a metal film.
[0007]
[Means for Solving the Problems]
In view of the above-mentioned object, the invention of claim 1 is provided by a semiconductor substrate and a ashing treatment after being provided on the semiconductor substrate and being heated and cured after being formed on the semiconductor substrate. And a polyimide pattern having a surface subjected to a heat treatment for removing the damaged layer and a sputter etching process, wherein the heat treatment for removing the damaged layer is performed at 300 to 500 ° C. in all SANYO performed 1 hour or more, the sputter etching process is carried out subsequent to the heat treatment.
[0008]
According to a second aspect of the present invention, there is provided a semiconductor device comprising a semiconductor substrate and a polyimide pattern provided on the semiconductor substrate and having a surface subjected to an acid cleaning and a sputter etching process for removing a damaged layer. Thus, the sputter etching process is performed following the acid cleaning process.
[0009]
Moreover, according to invention of Claim 3, the sealing resin which seals the surface of a semiconductor substrate with a polyimide pattern is provided.
[0010]
According to the invention of claim 4, the metal film provided on the polyimide pattern and the semiconductor substrate is provided.
[0011]
According to invention of Claim 5, the process of forming the polyimide pattern which consists of a polyimide film on a semiconductor substrate, the process of hardening the said formed polyimide pattern by heating, and removing the polyimide residue which remained in the unnecessary part by ashing A method of manufacturing a semiconductor device, comprising: a step of heating the polyimide pattern to reduce a damaged layer; and a step of sputter etching the surface of the polyimide pattern to remove the damaged layer. the heating for reducing the damaged layer, have rows over 1 hour at 300 to 500 ° C., the sputter etching process is performed subsequent to the heat treatment for reducing the damaged layer.
[0013]
According to invention of Claim 6, the process of forming the polyimide pattern which consists of a polyimide film on a semiconductor substrate, the process of removing the polyimide residue which remained in the unnecessary part by ashing, and acid cleaning the surface of the said polyimide pattern a step of reducing the damaged layer, and sputter etching the surface of the polyimide pattern, I manufacturing method der of a semiconductor device having a step of removing the damaged layer, the sputter etching process, the damaged layer This is followed by the above acid cleaning treatment to reduce the amount.
[0014]
According to a seventh aspect of the invention, there is provided a step of resin-sealing the surface of the semiconductor substrate together with the polyimide pattern.
[0015]
According to invention of Claim 8 , it has the process of providing a metal film on a polyimide pattern and a semiconductor substrate.
[0016]
[Action]
According to the first aspect of the present invention, the damaged layer generated on the surface of the polyimide pattern is completely removed by the heat treatment and the sputter etching treatment.
[0017]
According to the invention of claim 2, the damage layer generated on the surface of the polyimide pattern is completely removed by acid cleaning and sputter etching.
[0018]
According to invention of Claim 3, the adhesiveness of a polyimide pattern and sealing resin is high.
[0019]
According to invention of Claim 4, the adhesiveness of a polyimide pattern and a metal film is high.
[0020]
According to the invention of claim 5, the damage layer generated in the ashing process on the surface of the polyimide pattern is completely removed by the heat treatment and the sputter etching treatment.
[0022]
According to the sixth aspect of the present invention, the damaged layer generated in the ashing process on the surface of the polyimide pattern is completely removed by the acid cleaning and the sputter etching process.
[0023]
According to invention of Claim 7 , since the damage layer is removed, the adhesiveness of a polyimide pattern and sealing resin becomes high.
[0024]
According to invention of Claim 8 , since the damage layer is removed, the adhesiveness of a polyimide pattern and a metal film becomes high.
[0025]
【Example】
Example 1.
Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are cross-sectional views showing a method for manufacturing a semiconductor device in Embodiment 1 of the present invention. FIG. 5 is a flowchart showing this. Steps S1 to S4 in FIG. 5 are the same as the above-described manufacturing process of the conventional semiconductor device. That is, first, similarly to the conventional semiconductor device, as shown in FIG. 1, after forming the bonding pad 2 and the insulating film 3 on the semiconductor substrate 1 (step S1 in FIG. 5), the polyimide pattern by the polyimide film 4 is formed. It forms (step S2 of FIG. 5). Next, after the polyimide pattern is heated and cured (step S3 in FIG. 5), the polyimide residue 4a is removed by an asher using oxygen plasma 6 as shown in FIG. 2 (step S4 in FIG. 5). At that time, a damaged layer 4 b, which is damaged by the oxygen plasma 6, is formed on the surface of the polyimide film 4.
[0026]
In this embodiment, in order to remove the damaged layer 4b, next, as shown in FIG. 3, the semiconductor substrate 1 on which the polyimide film 4 is formed is heated in a nitrogen atmosphere at 350 ° C. for about 90 minutes. At this time, the damage layer 4b existing on the surface of the polyimide film 4 is caused to undergo a cyclization reaction or a polymerization reaction, and the damage layer 4b damaged by the oxygen plasma 6 is repaired and reduced (step S5 in FIG. 5). . The heating temperature and time in the nitrogen atmosphere are not limited to those described above, and an effect can be obtained by heating at about 300 to 500 ° C. for 1 hour or longer.
[0027]
However, since only the process of heating in a nitrogen atmosphere cannot be completely repaired by reducing the damaged layer 4b, sputter etching using Ar plasma 14 is further performed in this embodiment (see FIG. Step S6 of 5), the damaged layer 4b can be completely removed by physically removing the remaining damaged layer 4b.
[0028]
As described above, in this embodiment, after the damage layer 4b on the surface of the polyimide film 4 roughened by the oxygen plasma 6 used for removing the polyimide residue 4a is reduced by heating in a nitrogen atmosphere. Since the remaining damaged layer 4b is completely removed by the sputter etching process using the Ar plasma 14, the damage layer 4b and the resin layer are sealed even when resin-sealed as shown in Example 3 (see FIG. 9) described later. Since the sealing resin 8 does not peel off due to poor adhesion to the polyimide layer 4, a highly reliable semiconductor device can be obtained.
[0029]
Example 2
This embodiment shows another method for removing the damaged layer 4b. FIG. 8 is a flowchart showing the manufacturing process in this embodiment. Steps S1 to S4 in FIG. 8 are the same as those in the first embodiment described above, and thus the description thereof is omitted here. In this embodiment, the damaged layer 4b generated in step S4 is firstly treated with sulfuric acid / hydrogen peroxide (mixed solution of H ₂ SO ₄ and H ₂ O ₂ ), sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl), or Then, acid cleaning is performed with phosphoric acid (H ₃ PO ₄ ) or the like, and as shown in FIG. 6, the damaged layer 4b is dissolved and reduced by acid (step S5A in FIG. 8). However, since the damaged layer 4b cannot be completely removed only by acid cleaning, the surface of the polyimide film 4 is sputter-etched with Ar plasma 14 as shown in FIG. The damaged layer 4b is physically removed (step S6 in FIG. 8). By doing so, also in this embodiment, a highly reliable semiconductor device from which the damaged layer 4b has been completely removed can be obtained.
[0030]
Example 3 FIG.
In the following examples, application examples of the semiconductor device of Example 1 or Example 2 described above are described. FIG. 9 shows a partial cross section of the semiconductor device in this example in which the damage layer 4b generated on the surface of the polyimide film 4 was removed by the manufacturing process shown in Example 1 or Example 2 and then resin sealing was performed. FIG. In the figure, 1 to 4 are the same as those in FIG. In this embodiment, a wire 7 for connecting to an external electrode (not shown) is electrically connected to the bonding pad 2 and is entirely resin-sealed by a resin 8. Since there is no damage layer 4b (see FIG. 18) on the surface of the polyimide film 4, the adhesion between the polyimide film 4 and the sealing resin 8 is improved, and the sealing resin 8 is formed together with the damage layer 4b as in the conventional example described above. Damage such as peeling can be prevented, and the reliability of the semiconductor device can be improved.
[0031]
Example 4
In this embodiment, another application example of the semiconductor device of Embodiment 1 or Embodiment 2 will be described. In this embodiment, the case where the protruding electrode 9 is formed as shown in FIG. 10 will be described. In the figure, 1-4 are the same as FIG. First, after removing the damaged layer 4b by the method of Example 1 or Example 2, the entire surface of the semiconductor substrate 1 is covered with a metal layer by sputtering or the like so as to cover the bonding pad 2, the insulating film 3 and the polyimide film 4. 10 is formed. On the bonding pad 2, a protruding electrode 9 made of gold or the like is provided via a metal layer 10. Here, the protruding electrode 9 is formed by plating or the like after applying a resist (not shown) or the like to a portion where the protruding electrode 9 is not formed, but the metal layer 10 is formed when the protruding electrode 9 is formed by plating. Used as a cathode electrode. The metal layer 10 is composed of a multi-layered metal layer, and examples of the material thereof include Cr / Cu / Au in order from the lower layer, and TiW / Au, TiN / TiW / Au in the same order from the lower layer. Alternatively, Ti / Ni / Au or the like is used. FIG. 10 is a cross-sectional view after forming the protruding electrodes 9 by plating or the like and removing the resist. Further, the protruding electrode 9 is completed by removing the metal layer 10 other than the lower portion of the protruding electrode 9 by wet etching, dry etching or the like using the protruding electrode 9 as an etching mask.
[0032]
Also in this embodiment, since there is no damage layer 4b (see FIG. 2), the metal layer 10 peels off on the polyimide film 4 during the formation process of the protruding electrode 9, or the damage layer 4b and the metal layer 10 It is possible to prevent defective etching due to the mixed layer, and the protruding electrode 9 can be formed satisfactorily.
[0033]
Example 5 FIG.
Also in this embodiment, another application example of the semiconductor device of Embodiment 1 or Embodiment 2 will be described. In this embodiment, as shown in FIG. 11, the polyimide film 4 is applied to an interlayer insulating film of a semiconductor device. In this embodiment, as shown in FIG. 11, a first wiring layer 11 is formed on a semiconductor substrate 1, and a polyimide film 4 is formed on the first wiring layer 11. In the polyimide film 4, the damaged layer 4 b (see FIG. 2) is completely removed by the manufacturing process of Example 1 or 2. A second wiring layer 12 made of a metal film is formed on the polyimide film 4 by using the polyimide film 4 as an interlayer insulating film. Also in this embodiment, the damage layer 4b is completely removed as in the above-described embodiment 4, so that the adhesion between the polyimide film 4 and the second wiring layer 12 is improved, and the damage layer 4b. Since no mixed layer of the wiring layer 12 and the wiring layer 12 is formed, it is possible to prevent etching defects.
[0034]
【The invention's effect】
As described above, according to the invention of claim 1 or claim 2, the surface of the polyimide film 4 is subjected to heat treatment and sputter etching treatment, or acid cleaning and sputter etching treatment, so that the surface of the polyimide film is completely removed. Since the damaged layer 4b is removed, even when resin sealing is performed in a later process or when a metal film is provided on the polyimide film 4, the adhesion between the sealing resin or metal film and the polyimide film 4 is high. It can improve and can prevent that they peel from the polyimide film 4, and can improve the reliability of a semiconductor device.
[0035]
According to the invention of claim 3, since the damage layer 4b on the surface of the polyimide film 4 is removed, it is possible to improve the adhesion between the polyimide pattern and the sealing resin, and from the polyimide pattern of the sealing resin. Separation can be prevented and a highly reliable semiconductor device can be obtained.
[0036]
According to the invention of claim 4, since the damaged layer 4b on the surface of the polyimide film 4 is removed, the adhesion between the polyimide pattern and the metal film can be improved, and the metal film can be peeled off from the polyimide pattern. Thus, a highly reliable semiconductor device can be obtained.
[0037]
According to the invention of claim 5, since the damage layer generated in the ashing process on the surface of the polyimide pattern is completely removed by the heat treatment and the sputter etching process, the sealing resin and the metal film provided in the subsequent process are polyimide. A highly reliable semiconductor device that does not peel from the pattern can be manufactured.
[0039]
According to the invention of claim 6 , since the damage layer generated in the ashing process on the surface of the polyimide pattern is completely removed by the acid cleaning and the sputter etching process, the sealing resin, the metal film, etc. provided in the subsequent process A highly reliable semiconductor device can be manufactured without peeling from the polyimide pattern.
[0040]
According to invention of Claim 7 , since the damage layer is removed, the adhesiveness of a polyimide pattern and sealing resin becomes high, and the reliability of a semiconductor device improves.
[0041]
According to invention of Claim 8 , since the damage layer is removed, the adhesiveness of a polyimide pattern and a metal film becomes high, and the reliability of a semiconductor device improves.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a semiconductor device in a state where a polyimide pattern is formed in Example 1 of the present invention.
2 is a cross-sectional view showing an ashing process for removing polyimide residues of the semiconductor device of FIG. 1;
3 is a cross-sectional view showing a state in which heating is performed in a nitrogen atmosphere in order to remove a damaged layer generated by the ashing process of FIG. 2;
4 is a cross-sectional view showing a state in which a sputter etching process using Ar plasma is performed to remove a damaged layer that could not be removed in the process of FIG. 3;
5 is a flowchart showing manufacturing steps of Example 1. FIG.
6 is a cross-sectional view showing a state where acid cleaning for removing a damaged layer in Example 2 is performed. FIG.
7 is a cross-sectional view showing a state in which a sputter etching process using Ar plasma is performed to remove a damaged layer that could not be removed in the process of FIG. 6;
8 is a flowchart showing manufacturing steps in Example 2. FIG.
9 is a cross-sectional view showing a semiconductor device in Example 3. FIG.
10 is a cross-sectional view showing a semiconductor device in Example 4. FIG.
11 is a cross-sectional view showing a semiconductor device in Example 5. FIG.
FIG. 12 is a cross-sectional view showing a manufacturing process in a conventional semiconductor device.
FIG. 13 is a cross-sectional view showing a manufacturing process in a conventional semiconductor device.
FIG. 14 is a cross-sectional view showing a manufacturing process in a conventional semiconductor device.
FIG. 15 is a cross-sectional view showing a state in which a polyimide residue remains after a polyimide pattern is formed in a conventional semiconductor device.
16 is a cross-sectional view showing an ashing process for removing polyimide residue in FIG.
FIG. 17 is a flowchart showing a manufacturing process of a conventional semiconductor device.
FIG. 18 is a cross-sectional view showing a state in which a conventional semiconductor device is sealed with resin.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor substrate, 2 Bonding pad, 3 Insulating film, 4 Polyimide film, 4a Polyimide residue, 7 Wire, 8 Sealing resin, 9 Projection electrode, 10 Metal film, 11 1st wiring layer, 12 2nd wiring layer

Claims (8)

A semiconductor substrate;
Provided on the semiconductor substrate, formed on the semiconductor substrate, heated and cured, and subjected to heat treatment and sputter etching treatment for removing a damage layer generated by the ashing treatment after the heating. A semiconductor device comprising a polyimide pattern having a curved surface,
The heat treatment for removing the damaged layer state, and are not carried out for 1 hour or more at 300 to 500 ° C.,
The semiconductor device according to claim 1, wherein the sputter etching process is performed subsequent to the heat treatment . A semiconductor substrate;
A semiconductor device comprising: a polyimide pattern provided on the semiconductor substrate and having a surface subjected to acid cleaning and sputter etching treatment for removing a damaged layer ;
The semiconductor device, wherein the sputter etching process is performed subsequent to the acid cleaning process .   3. The semiconductor device according to claim 1, further comprising a sealing resin for sealing the surface of the semiconductor substrate together with the polyimide pattern.   3. The semiconductor device according to claim 1, further comprising a metal film provided on the polyimide pattern and on the semiconductor substrate. Forming a polyimide pattern made of a polyimide film on a semiconductor substrate;
A step of curing the formed polyimide pattern by heating;
Removing polyimide residue remaining in unnecessary parts by ashing;
Heating the polyimide pattern to reduce the damage layer;
A method of manufacturing a semiconductor device comprising: a step of sputter etching the surface of the polyimide pattern to remove the damaged layer,
The heating for reducing the damaged layer, have rows over 1 hour at 300 to 500 ° C.,
The method of manufacturing a semiconductor device, wherein the sputter etching process is performed subsequent to the heat treatment for reducing the damaged layer . Forming a polyimide pattern made of a polyimide film on a semiconductor substrate;
Removing polyimide residue remaining in unnecessary parts by ashing;
Acid cleaning the surface of the polyimide pattern to reduce the damage layer;
A method of manufacturing a semiconductor device comprising: a step of sputter etching the surface of the polyimide pattern to remove the damaged layer ,
The sputter etching process is performed subsequent to the acid cleaning process for reducing the damaged layer.
A method for manufacturing a semiconductor device.   7. The method of manufacturing a semiconductor device according to claim 5, further comprising a step of resin-sealing the surface of the semiconductor substrate together with the polyimide pattern.   7. The method of manufacturing a semiconductor device according to claim 5, further comprising a step of providing a metal film on the polyimide pattern and on the semiconductor substrate.

Images