JP3281140B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly, to a multilevel metal wiring technology, which improves the reliability of metal wiring in an LSI operating at high speed and high frequency and a signal generated by capacitance between wirings. It is used for delay improvement.

[0002]

2. Description of the Related Art FIG. 10 is a sectional view showing a conventional semiconductor device. A first metal wiring 2 is provided on the surface of the silicon substrate 1, and a first TEOS oxide film 3 is deposited on the metal wiring 2 and the silicon substrate 1. This TEO
On the S oxide film 3, a second TEOS oxide film 4 is deposited, and on the TEOS oxide film 4, a third TEOS oxide film 5 is deposited. The first to third TEOS oxide films 3 to 5 are provided with a via hole 5a located above the first metal wiring 2, and the via hole 5a and the third T
On EOS oxide film 5, second metal wiring 6 is provided.

In the semiconductor device manufactured as described above, the second TEOS oxide film 4 as an interlayer insulating film has
Many impurities such as i-F, Si-OH and Si-H are contained. Due to the influence of these impurities, the metal wirings 2, 6
Is liable to be corroded, and there is a problem that a wiring disconnection defect 6a as shown in FIG. 10 occurs.

FIGS. 11 and 12 are cross-sectional views showing another conventional method for manufacturing a semiconductor device which solves the above-mentioned problem. The same parts as those in FIG. 10 are denoted by the same reference numerals, and only different parts will be described. I do.

As shown in FIG. 11, the first to third TEs
After the OS oxide films 3 to 5 are provided with via holes 5a located on the first metal wiring 2, the TEOS oxide film 3 is formed.
Energy -7 due to heat at a temperature of 300 [deg.] C. or higher is applied to. Thereby, impurities such as Si-F, Si-OH, and Si-H in the TEOS oxide films 3 to 5 are removed outside the TEOS oxide films 3 to 5 and are divided. As a result, the concentration of the impurities in the TEOS oxide films 3 to 5 is reduced.

Thereafter, as shown in FIG. 12, a second metal wiring 6 is provided in the via hole 5a and on the third TEOS oxide film 5. By the way, in the other conventional method for manufacturing a semiconductor device, since the concentration of the impurity in the TEOS oxide films 3 to 5 is reduced, the metal wiring 2,
6 is less likely to be corroded, thereby preventing the occurrence of wiring disconnection defects. However, when the concentration of the impurities in the TEOS oxide films 3 to 5 is reduced, the TEOS oxide films 3 to 5
And the capacitance between the first and second metal wires 2 and 6 increases. As a result, when operating the semiconductor device at high speed and high frequency, signal delay occurs due to the increase in the capacitance.

[0007]

In the above-mentioned other conventional method for manufacturing a semiconductor device, the second TEOS oxide film 4 has a Si-
If a large amount of impurities such as F, Si—OH, and Si—H are contained, the wiring disconnection failure 6 a shown in FIG. 10 occurs, so that the concentration of the impurities in the TEOS oxide film 4 is reduced. However, when the impurity concentration is reduced, the capacitance between the first and second metal wirings 2 and 6 increases when operating the semiconductor device at high speed and high frequency, which causes a problem that a signal delay occurs. .

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to prevent the occurrence of wiring disconnection defects and to prevent the occurrence of signal delay during high-speed, high-frequency operation. And a method of manufacturing the same.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a first metal wiring and a region provided on the first metal wiring and containing a Si--F bonding group at a low concentration. An insulating film having a region containing Si—F bonding groups at a high concentration, and a via hole located on the first metal wiring provided in the region containing the Si—F bonding groups at a low concentration. And a second metal wiring provided on the insulating film in the via hole and in the vicinity of the via hole.

Further, in the insulating film, the Si-
It is characterized in that the dielectric constant of the region containing the F-bond group at a low concentration is higher than that of the region containing the Si-F bond group at a high concentration.

A first metal wiring and a region provided on the first metal wiring and containing a Si—F bonding group, a Si—OH bonding group, and a Si—H bonding group at a low concentration are formed. An insulating film having a region containing an F bonding group, a Si—OH bonding group, and a Si—H bonding group at a high concentration;
a via hole located on the first metal wiring provided in a region containing a low concentration of an i-OH bond group and a Si-H bond group, and a via hole in the via hole and in the vicinity of the via hole. And a second metal wiring provided on the insulating film.

Further, in the insulating film, the Si-
The dielectric constant of the region containing the F-bonding group, the Si-OH bonding group and the Si-H bonding group at a low concentration is the above-mentioned Si-F bonding group, Si-O
It is characterized by being higher than that of the region containing a high concentration of H-bonding group and Si-H bonding group.

A step of providing an insulating film having a Si—F bonding group, a Si—OH bonding group and a Si—H bonding group on the first metal wiring; and forming the first metal wiring on the insulating film. Providing a via hole located on the substrate, providing an infrared absorber in the via hole and on the insulating film in the vicinity of the via hole, and irradiating the infrared absorber with infrared light. Removing the infrared absorber, and providing a second metal wiring in the via hole and on the insulating film.

Further, the infrared absorber is made of carbon. A step of providing an insulating film having a Si—F bonding group, a Si—OH bonding group, and a Si—H bonding group on the first metal wiring; and forming an insulating film on and in the vicinity of the first metal wiring. Selectively irradiating a microwave having a wavelength of 10 nm or less; and providing a via hole located on the first metal wiring in the insulating film in a portion irradiated with the microwave, Providing a second metal wiring in the via hole and on the insulating film.

A step of providing an insulating film having a Si—F bonding group, a Si—OH bonding group and a Si—H bonding group on the first metal wiring; and forming an insulating film on the first metal wiring and in the vicinity thereof. Selectively irradiating the insulating film with an electromagnetic wave obtained by stimulated emission; and providing a via hole positioned above the first metal wiring to the insulating film in a portion irradiated with the electromagnetic wave.
A step of providing a second metal wiring in the via hole and on the insulating film.

[0016]

According to the present invention, an insulating film is provided on a first metal wiring, and a via hole located on the first metal wiring is provided on the insulating film. An infrared absorber is provided on the film. Next, by irradiating the infrared ray to the infrared ray absorber, the temperature of the infrared ray absorber is increased, and the Si-
Decomposes the F-bond group and diffuses it out of the insulating film. As a result, the Si film is placed near the via hole in the insulating film.
A region having a reduced -F bonding group can be formed. Therefore, it is possible to prevent the occurrence of a disconnection failure in the first and second metal wirings. Further, the Si-F
Since the region where the bonding groups are reduced is selectively formed in the insulating film near the via hole, the dielectric constant of the insulating film is low only in the vicinity of the via hole. Therefore, it is possible to prevent an increase in capacitance between the first and second metal wirings, and to prevent a signal delay when operating at high speed and high frequency.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 7 are sectional views showing a method for manufacturing a semiconductor device according to a first embodiment of the present invention. First, as shown in FIG. 2, a thermal oxide film 22 having a thickness of about 8000 Å is formed on the surface of a silicon substrate 21. On this thermal oxide film 22, for example, an Al—
A Cu-Si film 23 is deposited. This Al-Cu-Si
By processing the film 23, a first metal wiring 24 is formed on the thermal oxide film 22. On the first metal wiring 24 and the thermal oxide film 22, a first TEOS oxide film 25 formed at a temperature of, for example, 350 ° C. and having a thickness of about 3000 Å is deposited.

Next, as shown in FIG. 3, the first TE
On the OS oxide film 25, for example, a second TEOS film formed at 250 ° C. and having a thickness of about 12,000 angstroms.
An oxide film 26 is deposited. This TEOS oxide film 26
It contains at least any one of Si—F, Si—OH, and Si—H bonding groups, and has a dielectric constant of ε.
_Is one. After this, the second TEOS oxide film 26
Unillustrated planarization resist and etch-back RIE (React
ive Ion Etching). Next, the second
A third film having a thickness of about 3000 Å formed at a temperature of, for example, 350 ° C. on the TEOS oxide film 26 of FIG.
Of TEOS oxide film 27 is deposited. At this time, the dielectric constant of the second TEOS oxide film 26 has a constant value ε ₁ in the oxide film 26, for example, 2.6 × 10 ⁻¹¹ F / m. Thereafter, via holes (connection holes) 26a located above the first metal wiring 24 are provided in the first to third TEOS oxide films 25 to 27.

Thereafter, as shown in FIG.
A material which easily absorbs infrared energy, for example, a thickness of 1
Carbon 28a of about 000 angstroms is deposited by sputtering. Next, the carbon 28a is patterned by an anisotropic etching technique so as to remain on the third TEOS oxide film 27 in and near the via hole 26a. As a result, a card is formed in the via hole 26a and on the third TEOS oxide film 27.
An infrared absorber 28 composed of a bon 28a is formed.

Next, as shown in FIG. 5, the infrared ray absorber 28 is irradiated with infrared rays 19 having energy -hv for 60 seconds. Thereby, the temperature of the infrared absorber 28 is set to, for example, 350 ° C. As a result, the via hole 26a
In the second TEOS oxide film 26 in the vicinity of
Impurities such as F, Si—OH, and Si—H bonding groups are decomposed and diffused out of the oxide film 26. As a result, in the vicinity of the infrared absorber 28, a region in which each of the bonding groups is reduced, that is, a region 26b in which the impurity concentration is reduced is formed.
The dielectric constant of this region 26b is ε ₂ , for example, 4.5 × 10
⁻¹¹ F / m, and this ε ₂ is a higher value than the aforementioned ε ₁ . That is, in the second TEOS oxide film 26, the dielectric constant has a location dependency, and the distribution of the dielectric constant is 2.6 × 1.
0 ⁻¹¹ F / m to 4.5 × 10 ⁻¹¹ F / m.

Thereafter, as shown in FIG. 6, the infrared absorber 28 is removed by, for example, O ₂ plasma. Next, as shown in FIG. 7, for example, a thickness of 800 is formed on the via hole 26a and on the third TEOS oxide film 27.
An Al-Cu-Si film 29a of about 0 Å is deposited by a sputtering method. By processing the Al-Cu-Si film 29a, a second metal wiring 29 is formed in the via hole 26a and on the third TEOS oxide film 27. As a result, the second metal wiring 29 is electrically connected to the first metal wiring 24.

Thereafter, as shown in FIG. 1, a passivation film made of, for example, a TEOS oxide film having a thickness of about 7000 Å is formed on the second metal wiring 29 and the third TEOS oxide film 27. A film 30 is deposited.

According to the first embodiment, the via hole 2
6a and on the third TEOS oxide film 27, an infrared absorber 28 made of carbon 28a is formed.
Irradiate for seconds. As a result, the temperature of the infrared absorber 28 is set to 350 ° C., and the Si—F, Si—OH, S in the second TEOS oxide film 26 in the vicinity of the via hole 26a.
Impurities such as i-H bonding groups are decomposed and diffuse out of the oxide film 26. As a result, a region where each of the bonding groups is reduced, that is, a region 26b where the concentration of impurities is reduced is formed near the infrared absorber 28. For this reason, the first and second metal wirings 24 and 29 are less likely to be corroded in the via hole 26a, and the occurrence of wiring disconnection failure can be prevented.

At the same time, the region 26 is
This is selectively formed on the second TEOS oxide film 26 near the hole 26a. That is, the concentration of the impurity in the second TEOS oxide film 26 only in the vicinity of the via hole 26a is reduced. Therefore, the dielectric constant of the TEOS oxide film 26 is reduced only in the vicinity of the via hole 26a. Therefore, it is possible to prevent an increase in capacitance between the first and second metal wirings 24 and 29. Thereby, when operating the semiconductor device at a high speed and a high frequency, it is possible to suppress a signal delay unlike a conventional product.

FIGS. 1, 2 and 6 to 9 are cross-sectional views showing a method for manufacturing a semiconductor device according to a second embodiment of the present invention. Only different parts will be described.

As shown in FIG. 8, after a third TEOS oxide film 27 is deposited on the second TEOS oxide film 26,
A mask material 31 is formed above the third TEOS oxide film 27.
Is fixed. The mask material 31 is, for example, a glass plate 3
A metal layer 31b containing Cr and having an opening 31c formed thereon is deposited on 1a. The opening 31
c is located above the first metal wiring 24.

Next, as shown in FIG.
1 as a mask, the second and third TEOS oxide films 2
For example, microwaves 20 having a wavelength of 1.5 nm
Is irradiated. As a result, Si-F, S in the second TEOS oxide film 26 near the first metal wiring 24
Impurities such as i-OH and Si-H bonding groups are decomposed and diffused out of the oxide film 26. As a result, the second TE
In the OS oxide film 26, a region in which each of the bonding groups is reduced, that is, a region 26b in which the impurity concentration is reduced is formed. The dielectric constant epsilon ₂ next to the region 26b, the epsilon ₂ is higher than the epsilon ₁ value.

Thereafter, as shown in FIG. 6, the mask material 31 is removed, and the first to third TEOS oxide films 25 are removed.
To 27 are via holes located on the first metal wiring 24.
26a is provided.

The same effects as those of the first embodiment can be obtained in the second embodiment. Although the second and third TEOS oxide films 26 and 27 are irradiated with the microwave 20 having a wavelength of 1.5 nm in the second embodiment, the second and third TEOS oxide films 26 and 27 are irradiated with the microwave 20 having a wavelength of 1.5 nm. Other wavelengths can be used as long as the wavelength of the microwave applied to 27 is 10 nm or less.

FIGS. 1, 2 and 6 to 9 are sectional views showing a method of manufacturing a semiconductor device according to a third embodiment of the present invention. Only different parts will be described.

As shown in FIG. 9, the second and third TEOS oxide films 26 and 27 are formed by using the mask material 31 as a mask.
Is irradiated with an electromagnetic wave obtained by stimulated emission, for example, a laser 18 having an electron beam current density of 60 A / cm @ 2. In the third embodiment, the same effects as in the first embodiment can be obtained.

[0032]

As described above, according to the present invention,
An insulating film having a region containing a Si—F bonding group at a low concentration and a region containing a Si—F bonding group at a high concentration is provided over the first metal wiring. Therefore, it is possible to prevent the occurrence of the disconnection of the wiring and to prevent the occurrence of the signal delay at the time of performing the high-speed and high-frequency operation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to a first, second, or third embodiment of the present invention and illustrating a step subsequent to FIG. 7;

FIG. 2 is a cross-sectional view showing a method for manufacturing a semiconductor device according to the first, second, or third embodiment of the present invention.

FIG. 3 is a sectional view illustrating the method for manufacturing the semiconductor device according to the first embodiment of the present invention, and illustrating a step subsequent to FIG. 2;

FIG. 4 is a cross-sectional view showing the method of manufacturing the semiconductor device according to the first embodiment of the present invention, showing a step subsequent to FIG. 3;

FIG. 5 is a sectional view illustrating the method of manufacturing the semiconductor device according to the first embodiment of the present invention, and illustrating a step subsequent to FIG. 4;

FIG. 6 shows a method of manufacturing a semiconductor device according to the first, second, or third embodiment of the present invention, and FIG.
Sectional drawing which shows the next process.

FIG. 7 is a cross-sectional view showing the method of manufacturing the semiconductor device according to the first, second, or third embodiment of the present invention, and showing a step subsequent to FIG. 6;

FIG. 8 is a cross-sectional view showing the method of manufacturing the semiconductor device according to the second or third embodiment of the present invention, and showing a step subsequent to FIG. 2;

FIG. 9 is a sectional view illustrating the method for manufacturing the semiconductor device according to the second or third embodiment of the present invention, and showing the step subsequent to FIG. 8;

FIG. 10 is a cross-sectional view illustrating a conventional semiconductor device.

FIG. 11 is a sectional view showing another conventional method for manufacturing a semiconductor device.

FIG. 12 is a cross-sectional view illustrating another conventional method of manufacturing a semiconductor device and illustrating a step subsequent to FIG. 11;

[Explanation of symbols]

18 ... Laser, 19 ... Infrared ray having energy hv, 20
… Microwave, 21… silicon substrate, 22… thermal oxide film, 23…
Al-Cu-Si film, 24 first metal wiring, 25 first TEOS oxide film, 26 second TEOS oxide film, 26a via hole (connection hole), 26b lower impurity concentration Region (region where each bonding group is reduced), 27... Third TEOS
Oxide film, 28: infrared absorber, 28a: carbon, 29: second
Metal wiring, 29a ... Al-Cu-Si film, 30 ... passivation film, 31 ... mask material, 31a ... glass plate, 31b ... C
metal layer containing r, 31c ... opening, epsilon ₁ ... second TEOS
Dielectric constant of oxide film, ε ₂ ... Dielectric constant of region where impurity concentration is reduced.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-94539 (JP, A) JP-A-58-92235 (JP, A) JP-A-63-131543 (JP, A) JP-A-7-97 37980 (JP, A) JP-A-2-156538 (JP, A) JP-A-1-198050 (JP, A) JP-A-63-76331 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/3205 H01L 21/321 H01L 21/3213 H01L 21/768

Claims (8)

(57) [Claims] A first metal wiring, a region provided on the first metal wiring and containing a Si—F bonding group at a low concentration and a region containing a Si—F bonding group at a high concentration; An insulating film; a via hole located on the first metal wiring provided in a region containing the Si-F bonding group at a low concentration; and a via hole in the via hole and in the vicinity of the via hole. A semiconductor device, comprising: a second metal wiring provided on an insulating film; and a multilayer wiring having the following. 2. In the insulating film, a dielectric constant of the region containing the Si—F bonding group at a low concentration is higher than that of a region containing the Si—F bonding group at a high concentration. 2. The semiconductor device according to 1. 3. A first metal wiring, provided on the first metal wiring, a Si—F bonding group,
An insulating film having a region containing a Si—OH bonding group and a Si—H bonding group at a low concentration and a region containing a Si—F bonding group, a Si—OH bonding group and a Si—H bonding group at a high concentration; A via hole located on the first metal wiring provided in a region containing the -F bonding group, the Si-OH bonding group and the Si-H bonding group at a low concentration; A second metal wiring provided on the insulating film in the vicinity of the via hole; and a multi-layer wiring having the following. 4. In the insulating film, the dielectric constant of a region containing the Si—F bonding group, the Si—OH bonding group, and the Si—H bonding group at a low concentration is equal to the Si—F bonding group, the Si—OH bonding group. 4. The semiconductor device according to claim 3, wherein the semiconductor device is higher than that of a region containing a group and a Si—H bonding group at a high concentration. 5. A Si—F bonding group on the first metal wiring,
Providing an insulating film having a Si-OH bonding group and a Si-H bonding group; providing a via hole located on the first metal wiring on the insulating film; Providing an infrared absorber on the insulating film in the vicinity of the via hole; irradiating the infrared absorber with infrared light; removing the infrared absorber; Providing a second metal wiring on the insulating film. A method of manufacturing a semiconductor device, comprising: 6. The method according to claim 5, wherein the infrared absorber is made of carbon. 7. A Si—F bonding group on the first metal wiring,
Providing an insulating film having a Si-OH bonding group and a Si-H bonding group; and forming an insulating film on the first metal wiring and in the vicinity thereof.
Selectively irradiating a microwave having a wavelength of 10 nm or less; and providing a via hole located on the first metal wiring in the insulating film in a portion irradiated with the microwave; Providing a second metal wiring in the via hole and on the insulating film. 8. A Si—F bonding group on the first metal wiring,
Providing an insulating film having a Si-OH bonding group and a Si-H bonding group; and forming an insulating film on the first metal wiring and in the vicinity thereof.
Selectively irradiating an electromagnetic wave obtained by stimulated emission; and providing the first portion on the insulating film in a portion irradiated with the electromagnetic wave.
Providing a via hole located on the metal wiring of step (a), and providing a second metal wiring in the via hole and on the insulating film. Production method.