JPH0927495A - Manufacture of semiconductor device and semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing semiconductor devices, and a semiconductor manufacturing apparatus, capable of flattening even global level differences. SOLUTION: The manufacture has the steps of forming an coating film 10 by applying a solution to a substrate, forming a thin film 3 made out of an organic compound on the applied film, and applying pressure uniformly to the coating film from above the thin film. The thin film can also be removed by performing etching after the pressurizing process, or by performing etchback along with the applied film and an insulating film formed under the coating film after the pressurizing process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device and a semiconductor manufacturing apparatus, and more particularly, to manufacturing of a semiconductor device capable of flattening not only local steps on a surface of an interlayer insulating film but also global steps. A method and a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art With the recent increase in the integration of semiconductor devices, the space between wirings is becoming narrower and it is inevitable that the time constant of wirings will be larger. Under these circumstances, the performance required for devices such as high speed and low power consumption is increasing more and more, so it is unavoidable to cope with low resistance by thickening wiring. .

However, if the wiring is made thicker, a step corresponding to the film thickness is inevitably generated, so that it becomes difficult to secure a sufficient DOF (Depth of Focus) in the subsequent lithography process. Therefore, even if the wiring is thickened, the DOF
In order to avoid the shortage, it is necessary to flatten the wiring layers.

As a flattening technique of this kind, S has been conventionally used.
OG (Spin on Glass) and REB (Resist Etch Back)
Has been put into practical use, and a dummy pattern process and CPM (Chemical Mechanical Polishing) are also known.

[0005]

SUMMARY OF THE INVENTION However, SOG
And REB for flattening the space between lines (Line / S
is effective only for local steps up to a few μm, and achieves sufficient flattening for several steps of several mm level required to secure DOF. There was a problem that I could not do it.

On the other hand, the dummy pattern process and CPM
Although global flattening is possible, there is a problem in the dummy pattern process that it becomes difficult to perform defect analysis if a dummy pattern is formed in the wiring layer.If the dummy pattern is formed in the insulating layer, the number of processes increases. It has the drawback of high process costs. Moreover, CPM is still unknown technology, and it is not known whether it can be applied to all types of devices.

As described above, the dummy pattern process and CPM capable of global planarization have technical and cost problems, and it is unclear whether they can be put to practical use. Therefore, conventional planarization by SOG or REB is used. It has been desired to improve the technology to achieve flattening even for global steps.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a semiconductor device manufacturing method and a semiconductor manufacturing apparatus capable of flattening a global step. To do.

[0009]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention comprises a step of applying a coating liquid on an upper portion of a substrate to form a coating film, and an upper portion of the coating film. And a step of uniformly pressing the coating film on the thin film. The thin film is composed of, for example, an organic film. The thickness of the thin film is not particularly limited, but is, for example, about several hundred nm to several μm.

The pressurizing pressure is not particularly limited, but is, for example, 200 to 1000 g / cm ² . The thin film may be removed by etching after the pressing step, or may be removed by etching back with the coating film and the insulating film formed under the coating film after the pressing step.

The thin film is preferably made of a material which does not contaminate the semiconductor device, and more preferably porous. It is more preferable that at least the thin film laying step and the pressurizing step are performed in a solvent atmosphere of the coating liquid.

In order to achieve the above object, the semiconductor manufacturing apparatus of the present invention includes a base plate for mounting a substrate having a coating film formed on the surface thereof, and a base plate for uniformly pressing the coating film. And a pressure plate provided so as to be relatively close to and away from each other.

The coating film can be formed by dripping, but it is more preferably formed by a spin coating method. The base plate may be a rotatably provided rotary plate or a hot plate having a heating means. Alternatively, these rotating plate and hot plate may be combined.

Further, it is more preferable that the base plate and the pressure plate are provided in a chamber into which the solvent of the coating film is introduced.

[0015]

In the method of manufacturing a semiconductor device and the semiconductor manufacturing apparatus of the present invention, the coating liquid is applied on the substrate to form a coating film, and a thin film made of an organic compound is laid on the coating film. Since the coating film is uniformly pressed from above the film, the coating film has a global step (for example, the step width is several tens of μm or more, and the step height is 0.5 to 1.0 μm).
.mu.m), the coating film is flattened through the thin film. Since the method according to the present invention is basically a planarization method using a coating film, it is naturally possible to embed a local step.

If the thin film is made porous, the air that has entered between the coating film and the thin film can be discharged when pressure is applied. Further, if at least the thin film laying step and the pressurizing step are processed in the solvent atmosphere of the coating liquid, the solvent evaporation from the coating film is suppressed and the viscosity of the coating film is kept low during the pressing step. Therefore, more planarization is achieved.

If the base plate of the semiconductor manufacturing apparatus of the present invention is rotatable, the base plate can be used when forming a coating film. Moreover, after the coating film is formed, if the coating film is placed on the base plate and further rotated, the coating film is further stretched, and by quickly laying a thin film on the coating film, the coating film becomes flatter. Be converted.

Further, if the heating means is provided on the base plate of the semiconductor manufacturing apparatus of the present invention, the coating film can be heated, so that the viscosity of the coating film is lowered and the coating film easily flows, so that the flatness is further improved. .

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a semiconductor device manufacturing method and a semiconductor manufacturing apparatus capable of improving flatness by applying pressure to a wafer surface in thin film formation by spin coating or the like. Embodiments of a semiconductor device manufacturing method and a semiconductor manufacturing apparatus according to the present invention will be described below with reference to the drawings. Semiconductor Manufacturing Apparatus FIG. 1 shows a semiconductor manufacturing apparatus according to one embodiment of the present invention.
The semiconductor manufacturing apparatus of this embodiment has a base plate 1 on which a wafer is placed, and a pressure plate 4 is provided so as to be able to approach and separate from the base plate 1. The pressing surface 4a of the pressing plate 4 is polished to have a sufficient flatness so that the wafer 2 mounted on the base plate 1 can be pressed at a desired pressure by a pressing mechanism (not shown).

In the case of flattening various coating films such as SOG film and resist film formed on the surface of the wafer 2 by using such a semiconductor manufacturing apparatus, first, the wafer 2 after spin-coating the coating liquid is applied to the base plate 1 The thin film 3 having a thickness of about several hundred nm to several μm and made of an organic compound such as novolac resin is laid on the coating film, and then the pressure plate 4 is placed. The surface of the wafer 2 is uniformly lowered by the pressing surface 4a, for example, 500 g / cm.
Pressurize at a pressure of about ² . As a result, the coating film is flattened according to the pressing surface 4a of the pressing plate 4 and the thin film 3, and sufficient flattening can be achieved even if there is a global step. The thin film 3 adhered on the wafer 2 after the pressing is removed by dry etching such as O ₂ plasma or wet etching such as sulfuric acid / hydrogen peroxide mixture.

The semiconductor manufacturing apparatus of the present invention can be variously modified without being limited to the above embodiment.
FIG. 2 is a side view showing another embodiment of the semiconductor manufacturing apparatus of the present invention. In the semiconductor manufacturing apparatus of this embodiment, the base plate is composed of the rotatable plate 5 rotatably provided,
The other structure is the same as that of the embodiment shown in FIG.

In the case of flattening various coating films such as SOG film and resist film formed on the surface of the wafer 2 by using such a semiconductor manufacturing apparatus, first, the wafer 2 coated with the coating liquid is rotated on the rotating plate 5. After being placed on the substrate, the rotating plate 5 is rotated to further spread the applied coating liquid to a desired thickness. When the coating liquid is sufficiently spread, the rotation of the rotary plate 5 is stopped, and a thin film having a thickness of about several hundred nm to several μm formed of an organic compound such as novolac resin on the coating film. After the film 3 is laid, the pressure plate 4 is lowered to uniformly press the surface of the wafer 2 with the pressure surface 4a at a pressure of, for example, about 500 g / cm ² .

Although the coating liquid on the wafer after spin coating remains viscous, the solvent evaporates and solidifies with the passage of time, so it is necessary to quickly lay a thin film and apply pressure after coating. However, according to the semiconductor manufacturing apparatus of this embodiment, since the rotating plate 5 is rotatably provided, the thin film is quickly laid after the coating liquid on the wafer 2 is further spread to a desired thickness. And can be pressurized. It is also possible to directly spin-coat the coating liquid using the rotary plate 5.

FIG. 3 is a side view showing still another embodiment of the semiconductor manufacturing apparatus of the present invention. In the semiconductor manufacturing apparatus of this embodiment, the base plate is composed of the hot plate 6 having a heating means, and the other structure is the same as that of the embodiment shown in FIG. Recent SOGs have been developed that have flow characteristics by heating (100 ° C. to 200 ° C.) after spin coating by increasing the number of organic groups or forming Si—H bonds. For a coating film having such characteristics, a pressure plate 4 is placed on a hot plate 6 as shown in FIG. 3, and first, the wafer 2 after being spin-coated with this type of coating solution is hot. Place on plate 6. Next, while heating the wafer 2 at a desired temperature (200 ° C. or less), a film having a thickness of several hundred nm to several μm formed of an organic compound such as a novolac resin is formed on the coating film. After the thin film 3 is laid, the pressure plate 4 is lowered to uniformly press the surface of the wafer 2 with the pressure surface 4a, for example, 5
Pressurization is performed at a pressure of about 00 g / cm ² . Thereby, global flattening of the coating film can be achieved.

The hot plate 6 of this embodiment may be rotatably provided. FIG. 4 is a side view showing still another embodiment of the semiconductor manufacturing apparatus of the present invention. In the semiconductor manufacturing apparatus of this embodiment, the rotary plate 5 and the pressure plate 4 are provided in a closed chamber 7, and bubbling for introducing the same solvent as the solvent of the coating liquid into the chamber 7. A room 8 is provided. As described in the embodiment shown in FIG. 2, since the coating liquid on the wafer 2 after spin coating has a small thickness, the solvent is likely to evaporate and solidify. Therefore, in the present embodiment, the rotary plate 5 is sealed by the chamber 7, and the same solvent as the coating liquid contained in the bubbling chamber is bubbled with a gas such as N ² to form the chamber 7.
And the atmosphere in the chamber 7 is changed to the same solvent atmosphere as the coating liquid. As a result, evaporation of the solvent of the solution on the wafer 2 is suppressed, viscosity is maintained, and stable flatness can be obtained by pressurization.

The rotary plate of this embodiment can be applied to both the base plate shown in FIG. 1 and the hot plate 6 shown in FIG. Method of Manufacturing Semiconductor Device Next, a method of manufacturing a semiconductor device using the semiconductor manufacturing apparatus of the present invention described above will be described.

Example 1 FIGS. 5A to 5D are sectional views showing an example of a method for manufacturing a semiconductor device according to the present invention. In Example 1, the present invention is applied to planarization by SOG. It was done. First, FIG.
As shown in (a), SOG is formed on the insulating film 9 having a step of, for example, 500 nm formed by aluminum (AL) wiring or the like.
10 is a film thickness equal to or larger than the step (for example, 80 on a bare Si substrate
Spin coating to a film thickness of 0 nm). Then, several hundred nm formed by an organic compound such as novolac resin
The wafer is covered with the thin film 3 having a thickness of about several μm, and the pressure plate 4 uniformly covers the wafer surface.
Pressurization is performed with a pressure of about 0 g / cm ² .

The thin film 3 attached to the surface of the wafer 2 after the pressurization is, for example, gas flow rate ratio O ₂ / N ₂ =
3.75 slm / 0.375 slm, pressure 266 Pa,
It can be removed by O ₂ plasma treatment under the conditions of RF power of 1 kW and wafer temperature of 180 ° C. (FIG. 5).
(C)).

By removing the thin film 3 in this way, global planarization by the SOG 10 can be achieved as shown in FIG. Conventional S
With the flattening by the OG, it was almost impossible to flatten a global step having a step width of several tens of μm or more. However, according to the method for manufacturing a semiconductor device of the present embodiment, the step width is Even a global step difference of several tens of μm or more can be flattened.

[0030]Example 2 FIG. 6 shows another embodiment 2 of the method for manufacturing a semiconductor device of the present invention.
It is a cross-sectional view showing, Example 2 is a resist etch back
The present invention is applied to the flattening by the above. First, FIG.
As shown in (a), for example, 500n by AL wiring or the like.
A resist 11 is formed on the insulating film 9 having a step of m
Upper film thickness (for example, 800nm film thickness on bare Si substrate)
Spin coating on. Then, for example, novolac resin
Formed by various organic compounds, having a thickness of several hundred nm to several μm.
Cover the wafer 2 with a thin film 3 having a thickness and pressurize the film.
The surface of the wafer 2 is evenly covered by the coat 4 such as 500 g / cm.
^Two Pressurize with moderate pressure.

In order to simultaneously etch the thin film 3, the resist 11 and the insulating film 9 after applying pressure, for example, the gas flow rate ratio CHF ₃ / O ₂ = 75 sccm / 25 s.
Etch back is performed under the conditions of ccm, gas pressure of 5.3 Pa, and RF power of 600 W (FIG. 6C).

By thus etching the thin film 3, the resist 11 and the convex portions of the base insulating film 9, global flattening can be achieved by a resist etch back process. Similar to SOG, the flattening by the resist etch back cannot flatten a global step. However, according to the method for manufacturing a semiconductor device of this embodiment, as shown in FIG. Even a global step having a width of several tens of μm or more can be flattened.

[0033]

As described above, according to the present invention, after the thin film is laid on the coating film formed on the substrate, the coating film is uniformly pressed from above the thin film.
In particular, even if the coating film has a global level difference, the coating film can be flattened through the thin film. Since the method according to the present invention is basically a planarization method using a coating film, it is naturally possible to embed a local step.

[Brief description of drawings]

FIG. 1 is a perspective view showing a semiconductor manufacturing apparatus of the present invention.

FIG. 2 is a side view showing another embodiment of the semiconductor manufacturing apparatus of the present invention.

FIG. 3 is a side view showing still another embodiment of the semiconductor manufacturing apparatus of the present invention.

FIG. 4 is a side view showing still another embodiment of the semiconductor manufacturing apparatus of the present invention.

5A to 5D are sectional views showing a method for manufacturing a semiconductor device of the present invention.

6A to 6D are sectional views showing another embodiment of the method for manufacturing a semiconductor device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base plate 2 ... Wafer 3 ... Thin film 4 ... Pressurizing plate 5 ... Rotating plate 6 ... Hot plate 7 ... Chamber 8 ... Bubbling chamber 9 ... Insulating film 10 ... SOG film 11 ... Resist film

Claims (10)

[Claims] 1. A step of applying a coating liquid on an upper part of a substrate to form a coating film, a step of laying a thin film on the upper part of the coating film, and uniformly pressing the coating film on the thin film. A method of manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of etching the thin film after the pressing step. 3. The thin film after the pressing step,
The method of manufacturing a semiconductor device according to claim 1, further comprising a step of etching back the coating film and an insulating film formed under the coating film. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the thin film is porous. 5. The manufacturing of a semiconductor device according to claim 1, wherein at least the step of laying the thin film and the step of pressing are performed in a solvent atmosphere of the coating liquid. Method. 6. A base plate for mounting a substrate having a coating film formed on a surface thereof, and a pressure plate provided so as to be relatively close to and away from the base plate so as to uniformly press the coating film. And a semiconductor manufacturing apparatus. 7. The semiconductor manufacturing apparatus according to claim 6, wherein the coating film is formed by a spin coating method. 8. The semiconductor manufacturing apparatus according to claim 6, wherein the base plate is rotatably provided. 9. The semiconductor manufacturing apparatus according to claim 6, wherein the base plate has a heating means. 10. The base plate and the pressure plate are provided inside, and further comprising a chamber into which the solvent of the coating film is introduced.
The semiconductor manufacturing apparatus according to any one of 1.