JP3265720B2 - Spin coating apparatus and semiconductor device manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to flattening of an interlayer insulating film, and more particularly to improvement of a spin coating apparatus and a method of manufacturing a semiconductor device.

2. Description of the Related Art Recent semiconductor devices have been rapidly miniaturized, and the depth of focus of an exposure apparatus has been rapidly reduced. Particularly, in a semiconductor device having a multi-layer wiring, a step of the entire substrate, that is, a global step has been reduced. It needs to be smaller.

In view of the above circumstances, there is a need for a spin coating apparatus and a semiconductor device manufacturing method capable of reducing the global step.

[0004]

2. Description of the Related Art A conventional spin coating apparatus will be described in detail with reference to FIG. 3, and a conventional method of manufacturing a semiconductor device will be described in detail with reference to FIG.

FIG. 3 is a view showing a conventional spin coating apparatus, and FIG. 4 is a side sectional view showing a conventional semiconductor device manufacturing method in the order of steps. As shown in FIG.
A spin chuck 11 for mounting and fixing an object to be coated, for example, a semiconductor substrate 5, is provided at the center of a cup 12, and a nozzle 13 for dropping a coating liquid is provided above the spin chuck 11.

In order to apply a coating solution to the surface of the semiconductor substrate 5 by using such a spin coating apparatus, first, the semiconductor substrate 5 is placed on a spin chuck 11 and fixed by suction in a vacuum, and a predetermined amount is fixed. After the coating liquid is dropped from the nozzle 13 onto the surface of the semiconductor substrate 5, the spin chuck 11 is rotated at a low speed to spread the coating liquid over the entire surface of the semiconductor substrate 5. This is an apparatus for forming a thick coating liquid on the surface of the semiconductor substrate 5.

When a thin film of a coating solution is formed on the surface of the semiconductor substrate 5 by using such a spin coating apparatus, the peripheral portion has a smaller thickness than the central portion. In the conventional method of manufacturing a semiconductor device, first, as shown in FIG. 4A, an insulating film 16a covering a wiring layer 17 formed on the surface of a semiconductor substrate 5 is formed.
Is formed, and a spin-on-glass film (hereinafter abbreviated as SOG film) 16b is applied to form a film.

Next, as shown in FIG. 4B, when the entire surface is back-etched by dry etching using carbon tetrafluoride (CF ₄ ) or wet etching using a hydrogen fluoride-based etching solution, the wiring layer is formed. SOG film 16 on the surface of 17
Since b and the SOG film 16b in the other region have the same etching rate, a step H occurs between the insulating film 16a on the surface of the wiring layer 17 and the SOG film 16b in the other region.

Next, as shown in FIG.
After the CVD film 18 is formed on the surface of b, a second insulating film 26a is formed on the surface of the second wiring layer 27 as shown in FIG.
After the second SOG film 26b is formed, if the etch back is performed in the same manner, the second insulating film 26a and the other second SOG film
A step 2H is formed between the film 26b.

[0010]

In the conventional spin coating apparatus described above, the semiconductor substrate is suction-fixed to the spin chuck by vacuum, and the spin chuck is rotated at a high speed to form a thin film of the coating solution. Therefore, there is a problem that the coating liquid in the peripheral portion is scattered and the film thickness distribution of the coating liquid becomes thicker in the central portion than in the peripheral portion. Further, since the etching rate of the SOG film is the same over the entire surface when the interlayer insulating film is back-etched, the step between the surface of the insulating film on the surface of the wiring layer and the surface of the SOG film of the interlayer insulating film in the other region is multi-layered. As shown in FIG. 6, there is a problem that the resist is accumulated in the wiring, and the resist in the low step portion used for patterning the upper wiring layer remains unexposed as shown in FIG.

In view of the above situation, the present invention makes it possible to easily and easily prevent a spin coating apparatus capable of making the film thickness distribution of a coating solution uniform and a large step of an interlayer insulating film from being generated. It is an object of the present invention to provide a method for manufacturing a semiconductor device that can be used.

[0012]

Spin coating apparatus of the present invention SUMMARY OF THE INVENTION comprises a suction unit for sucking and mounting the object to be coated, in and the suction portion has a substantially equal inner size as the outer shape of the object to be coated Adsorbed
A spin chuck including a frame having a height higher than the surface of the object to be coated and a supporting portion provided at the center of the frame and connecting the suction portion and the frame is provided.

[0013] The method of manufacturing a semiconductor device of the present invention, the scan <br/> pin-on-glass of the interlayer insulating film of a semiconductor device having a multilayer wiring with an interlayer insulating film formed by laminating an insulating film and the spin-on-glass film In a method of manufacturing a semiconductor device in which a film is etched back by etching, the wiring layer is formed.
Energy in the spin-on-glass film in the region other than the region
After the irradiation with the energy beam, the etch back is performed .

[0014]

According to the present invention, a semiconductor substrate (coated
A suction unit for sucking by placing an object), the has a substantially equal inner size as the outer shape of the semiconductor substrate and the sucked by the suction unit half
Using a tall than the surface of the conductive substrate of the frame, a spin coating apparatus characterized by comprising a spin chuck comprising a supporting portion for coupling the frame to the suction portion provided at the center of the frame Since the coating liquid is formed on the surface of the semiconductor device, the coating liquid that has been scattered from around the
The coating liquid is reflected by the inner peripheral surface of the coating liquid.
Since the it is possible to remain on the periphery of the semiconductor substrate, it is possible to reduce the film thickness variation of the coating solution of the central portion and the peripheral portion of the semiconductor substrate. In addition, the insulating film and S
Etching the SOG film of the interlayer insulating film of a semiconductor device having a multilayer wiring with an interlayer insulating film formed by laminating and OG film
In the method of manufacturing a semiconductor device which is etched back by etching , a region before the region other than the region where the wiring layer is formed is formed.
Etch back after irradiating the SOG film with energy rays
Since performing this energy rays is remarkably decreased etching rate of the region irradiated, also SOG film on the insulating film on the surface of the wiring layer is etched, the SOG film that the etching rate is lowered is hardly etched Therefore, the SOG film in the wiring layer region not irradiated and the SOG film in the region are not irradiated.
The difference in height from the film is reduced , and the surface of the interlayer insulating film as viewed from the entire substrate can be made flat.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a view showing a spin coating apparatus according to one embodiment of the present invention, and FIG. 2 is a side sectional view showing a method of manufacturing a semiconductor device according to one embodiment of the present invention in the order of steps.

FIG. 1 shows a spin coating apparatus according to an embodiment of the present invention.
As shown in FIG. 1, an adsorbing portion 1a on which an object to be coated, for example, a semiconductor substrate 5 is placed and adsorbed and fixed, and a semiconductor having an inner method substantially equal to the outer shape of the semiconductor substrate 5 and adsorbed by the adsorbing portion 1a
A spin chuck 1 including a frame 1b higher than the surface of the substrate 5 and a supporting portion 1c for connecting the suction portion 1a provided at the center of the frame 1b and the frame 1b is provided at the center of the cup 2. A nozzle 3 for dropping a coating liquid above the spin chuck 1
Is provided. Semiconductor substrate 5 due to reflection of coating liquid
Is provided with a cleaning nozzle 4 for cleaning contamination on the back surface of the substrate.

In order to apply a coating solution onto the surface of the semiconductor substrate 5 using such a spin coating apparatus, first, the semiconductor substrate 5 is placed on the spin chuck 1 and fixed by suction and fixed in a vacuum. After the coating liquid is dropped from the nozzle 3 onto the surface of the semiconductor substrate 5, the spin chuck 1 is rotated at a low speed to spread the coating liquid over the entire surface of the semiconductor substrate 5. A thick coating liquid is formed on the front surface of the semiconductor substrate 5, and the back surface of the semiconductor substrate 5 is cleaned with a resist removing liquid jetted from a cleaning nozzle.

When the coating liquid is applied to the surface of the semiconductor substrate 5 by such a spin coating apparatus, the coating liquid, which has been scattered from the periphery of the semiconductor substrate 5 in the related art, is reflected by the inner peripheral surface of the frame 1b , whereby the semiconductor substrate 5 Can be left at the peripheral portion of the semiconductor substrate 5, so that the variation in the film thickness between the central portion and the peripheral portion of the semiconductor substrate 5 can be reduced.

In the method of manufacturing a semiconductor device according to one embodiment of the present invention, first, as shown in FIG. 2A, an insulating film 6a covering the wiring layer 7 formed on the surface of the semiconductor substrate 5 is formed. The SOG film 6b is formed by coating.

Next, as shown in FIG. 2B, energy rays, for example, ultraviolet rays are irradiated using a mask 8 having the same pattern as that of the wiring mask. Then, as shown in FIG. 2C, when the entire surface was back-etched by dry etching using carbon tetrafluoride (CF ₄ ) or wet etching using a hydrogen tetrafluoride-based etching solution, ultraviolet rays were irradiated. Since the etching rate of the SOG film 6b in the region is extremely reduced, only the SOG film 6b on the surface of the insulating film 6a on the surface of the wiring layer 7 is removed.

As described above, since the etching rate is significantly reduced by irradiating the SOG film 6b in the region other than the SOG film 6b on the surface of the wiring layer 7 with the ultraviolet light, when the SOG film 6b is etched back, Only the SOG film 6b in the region not irradiated with is etched back, and the surface can be made flat.

In this embodiment, ultraviolet rays are used as energy rays, but SOG is performed using an electron beam other than ultraviolet rays.
It is also possible to reduce the etching rate of the film 6b.

[0023]

As is apparent from the above description, according to the present invention, it is possible to flatten an interlayer insulating film by improving a very simple spin coating apparatus and improving a method of manufacturing a semiconductor device. It is possible to provide a spin coating apparatus and a method for manufacturing a semiconductor device, which have advantages and can be expected to significantly improve the reliability.

[Brief description of the drawings]

FIG. 1 is a diagram showing a spin coating apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing a method of manufacturing a semiconductor device according to one embodiment of the present invention in the order of steps;

FIG. 3 shows a conventional spin coating apparatus.

FIG. 4 is a side sectional view showing a conventional method of manufacturing a semiconductor device in the order of steps (1).

FIG. 5 is a side sectional view showing a conventional method of manufacturing a semiconductor device in the order of steps (2).

FIG. 6 is a side sectional view showing a problem of a conventional method of manufacturing a semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spin chuck 1a Suction part 1b Frame 1c Support part 2 Cup 3 Nozzle 4 Cleaning nozzle 5 Semiconductor substrate 6 Interlayer insulating film 6a Insulating film 6b SOG film 7 Wiring layer 8 Mask

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-52-155058 (JP, A) JP-A-60-50939 (JP, A) JP-A-61-1027 (JP, A) JP-A-1- 164034 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/316 H01L 21/3065 H01L 21/3205 H01L 21/768

Claims (2)

(57) [Claims] An adsorbing section for mounting and adsorbing an object to be coated, an adsorbing section having an inner method substantially equal to an outer shape of the object to be applied, and
A frame having a height higher than the surface of the object adsorbed to the portion, and a support portion provided at the center of the frame and coupling the attraction portion and the frame, comprising a spin chuck comprising: Spin coating equipment. 2. A semiconductor device having a multilayer wiring including an interlayer insulating film in which an insulating film and a spin-on-glass film are stacked, wherein the spin-on-glass film of the interlayer insulating film is etched back by etching. In the manufacturing method, the spin in a region other than the region where the wiring layer is formed is formed.
After irradiating the on-glass film with energy rays,
A method for manufacturing a semiconductor device, comprising: performing chipback .