JPH01293520A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form resist films by an ordinary photolithography method in which a reactive ion etching method is not included and manufacture a high quality semiconductor device in a simple process by a method wherein, after a light is applied to the whole surface of a thick film of first photoresist material to reform the first photoresist material to be soluble, a thin film of second photoresist material is built up and selectively exposed. CONSTITUTION:In order to form a resist film 5 selectively on the surface of a substrate 1, a thick film of first photoresist material 2 is uniformly formed on the substrate 1 surface and a light having a wavelength in a predetermined range is applied to the thick film so as to reform the first photoresist material to be soluble to predetermined developer. Then a light having a wavelength in the other range is applied to the whole surface for a short time to cure the surface part and a thin film of second photoresist material 3 is uniformly built up on it. Then the light having the wavelength in the predetermined range is selectively applied to the thin film to reform the exposed parts of the second photoresist material 3 to be soluble to the predetermined developer. After that, the whole surface is brought into contact with the predetermined developer and the reformed parts of the second photoresist material 3 and the parts of the first photoresist material 2 under those reformed parts of the material 3 are dissolved and removed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves sequentially forming constituent members such as an ion diffusion layer, an electrical insulating layer, various electrodes, and wiring portions on predetermined portions of a substrate. This method relates to a method for manufacturing a semiconductor device in which a plurality of semiconductor devices are arranged, and in particular, a resist film is selectively formed on the substrate surface by photolithography, and the resist film marks the formation site of each component. The present invention relates to a method of manufacturing a semiconductor device in which multiple constituent members are sequentially formed at predetermined locations in a controlled manner.

[Prior Art] For example, as shown in FIG. 2, a semiconductor device is formed by using a p-type substrate (a) and implanting phosphorus (P), arsenic (As), etc. into the surface of this substrate (a). n+ region na)
(na) and electrical insulation 11 (i) on the surface of the substrate (a).
MO consisting of a source electrode (st), a gate electrode (at), a drain electrode (dt), etc. formed through the
3 type semiconductor device or a p type substrate (a) as shown in Figure 3.
And the n+ region na) to ( formed on this substrate (a)
na), p+ regions pa) to (1)a), a base electrode (bt), an emitter electrode (et), and a collector electrode formed on the surface of the substrate (a) via an electrical insulating layer (is). (ct) and the like are generally known.

When manufacturing these semiconductor devices, an n+ region na), a p+ region p
a) Ion diffusion Jl (id), electrical insulation layer (is) etc.
, and various electrodes (1), etc., the substrate (a) is formed by photolithography.
A method is adopted in which a resist film is selectively formed on the surface, and the formation portions of each component are sequentially controlled by this resist film.

Incidentally, in these semiconductor devices, the above-mentioned constituent members are stacked and the surface shape is minutely uneven, so the fourth step is to form the resist film so that the surface is flat. As shown in Figure (a), it was necessary to set the film thickness of the photoresist II(r) to be large.

However, if the thickness of the photoresist film (r) is set to be large, it will naturally occur that the thickness of the photoresist film (r) is set to be large.
) Since the exposure time required to irradiate the surface is also long,
As shown in FIG. 4(b), there is a drawback that the exposed area (α) expands due to the light diffusion effect, and even when a part of the photoresist film (r) is dissolved and removed using a developing material. , the photoresist film (r) becomes too dissolved in the vertical and horizontal directions due to the long time required for its development, so that the resist film (r) on the substrate (a) side is removed as shown in FIG. 4(C).
There was a drawback that I(r') became thinner, and the resolution was significantly lowered.

Therefore, in the past, another 111g photoresist film was layered on top of the above photoresist film to shorten the exposure time, and a reactive ion etching (RIE) method was adopted, which caused less lateral etching. Methods have been adopted to overcome the above-mentioned drawbacks.

That is, as shown in FIG. 5(a), a thick first photoresist II (rl) is formed on the surface of the substrate (a), and
The bond on which the second photoresist l1l (r2) is formed is exposed to light through a glass mask (m) as shown in FIG.
As shown in Figure (C), the second photoresist III (r2
) is selectively removed. In this case, since the second photoresist film (r2) is thinner than in the conventional method described above, exposure time and development time can be shortened.

Next, as shown in FIG. 5(d), after forming an oxygen-impermeable polysilicon film (EIS) on the second photoresist II (r2) surface in a silane (SiH4) atmosphere,
In this method, the first photoresist film (rl) exposed by the RIE method using oxygen gas is removed, and a resist film (r) as shown in FIG. 5(e) is formed.

In this method, the exposure time is short, and
Since the RIE method with less lateral etching is adopted, the resolution is high and the resist film (r) can be etched with high precision.
It has the advantage that it can be formed.

On the other hand, other methods shown in FIGS. 6(a) to 6(e) have also been developed.

That is, in this method, as shown in FIG. 6(a), the substrate (
A first photoresist film (rl) is formed as a thick film on the surface a), and as shown in FIG.
After forming the oxygen-impermeable intermediate 1gI(so) composed of 2, a second photoresist film (2) is formed on its surface.

Next, as shown in FIG. 6(C), a glass mask (m
＞ through exposure processing and development processing to form the sixth
The second photoresist MW (r2) as shown in figure (d)
After selectively removing the intermediate layer (Sg), the intermediate layer (Sg) was removed by RIE using fluorine gas, and then RIE using oxygen gas.
The first photoresist Is (rl
), as well as the second photoresist g! (r2) is removed to form a resist film (r) as shown in FIG. 6(e).

Also in this method, the second photoresist II
Because (r2) is a thin film, the exposure time is short, and the RIE method with less lateral etching is used, so the resolution is high and the above resist film (r) can be formed with high precision. It has the advantage of

[Problems to be Solved by the Invention] However, while the conventional improved method described above has the advantage of being able to form a resist film with high accuracy,
There are problems in that the formation process is complicated and requires a lot of man-hours, such as the adoption of the IE method.Moreover, one of the formation steps is to use a polysilicon film or SiO2 film by CVD method to prevent the permeation of etching gas. Since the step of forming a film is essential, an apparatus for carrying out this CVD method is required, resulting in a problem that the equipment cost is relatively high.

[Means for Solving the Problems] The present invention has been made by focusing on the above-mentioned problems, and its object is to form a resist film by a normal photolithography method that does not incorporate RIE method, and to An object of the present invention is to provide a method for manufacturing a semiconductor device that can easily manufacture a high quality semiconductor device.

That is, the present invention provides an ion diffusion layer,
A method of manufacturing a semiconductor device comprising forming constituent members such as an electrical insulating layer, various electrodes, or wiring parts, and arranging a plurality of semiconductor elements made of these constituent members, the method comprising: forming a plurality of semiconductor elements made of these constituent members; A method for manufacturing a semiconductor device is based on a semiconductor device manufacturing method in which a resist film is selectively formed on the substrate surface and the formation portion of each component is controlled by the resist film. A thick film forming step for uniformly forming a photoresist material; and irradiating the entire thick film of the first photoresist material with light in a predetermined wavelength range, changing the photoresist material into a property that can be dissolved by a predetermined developer. a light irradiation alteration step in which the thick surface of the altered first photoresist material is irradiated with light in another wavelength range for a short period of time to harden the surface portion; on a thick film of first photoresist material;
a resist lamination step of uniformly laminating a thin film of the second photoresist material, and selectively irradiating the thin film surface of the laminated second photoresist material with light in a predetermined wavelength range to irradiate the irradiated area of the film. A partial irradiation alteration step in which the property is changed to a property that can be dissolved by a predetermined developing material, and a predetermined developing material is brought into contact with the entire surface of the laminated second photoresist material to affect the altered portion of the second photoresist material and the second photoresist material on the lower surface thereof. 1) a development step of dissolving and removing the photoresist material;

In such technical means, the first photoresist material in the thick film forming step must be modified to a property that can be dissolved by a predetermined developing material in the next light irradiation modification step, and generally For example, a phototransposition resist material, which is called a positive resist material and whose main portion is composed of a novolak phenol resin and a nondiazide, can be used. Note that this first photoresist material is irradiated over the entire surface and is altered to be soluble before the partial irradiation alteration process, so it does not need to be a high-resolution positive type material and can be used as an inexpensive ordinary positive type material. Mold materials can be used.

In addition, in the light irradiation alteration process, the light source that alters the first photoresist material to be soluble is appropriately selected depending on the type of photoresist material to be applied, and has a wavelength range of a predetermined wavelength that decomposes the applied photoresist material. A light source is used that emits light.

Furthermore, the light source used in the surface hardening process is different from the light source used in the photo-irradiation modification process, and a light source that emits light in a wavelength range that promotes photopolymerization of the photoresist material can be used.

Note that this surface hardening treatment is a treatment performed to harden the first photoresist material surface and reliably laminate the second photoresist material on that surface.

Further, as the second photoresist material in the resist lamination step, it is desirable to use the same material as the first photoresist material in principle from the viewpoint of simplifying the development process. However, in order to form a high-resolution resist film when a positive-tone material with normal resolution is used as the first photoresist material, it is necessary to use a high-resolution positive-tone photoresist material as a second photoresist material. Selected as photoresist material,
A method may be adopted in which the photoresist material is laminated on the first photoresist material surface. Furthermore, a negative type 7 photoresist material may be selected as the second photoresist material, although the development process is somewhat complicated.

Next, in the development process, the developing material that dissolves and removes the altered parts of the second photoresist material and the first photoresist material on the lower surface thereof is appropriately set according to the type of photoresist material applied. For example, in the case of a positive photoresist material, an alkaline solution such as KOH or tetramethylammonium hydroxide can be used; on the other hand, if a negative material is selected as the second photoresist material, toluene or xylene can be used. etc. can be used.

Here, it is not necessary to form all the resist films formed when manufacturing a semiconductor device by the above-mentioned steps, and it is only necessary to apply them when it is necessary to form a thick resist film. That is, in the initial stage of manufacturing, in which ions are implanted into a predetermined portion of the substrate to form an ion diffusion layer in the n+ region and the p+ region, the resist film is set to be thick because the surface of the substrate is substantially flat. There's no need. Therefore, there is little need to apply each of the above steps at the initial stage of manufacturing.

However, in the later stages of manufacturing when various electrodes, wiring parts, etc. are formed on the substrate surface, various parts are arranged on the substrate surface and the surface becomes uneven. Film formation is required.

Note that there is no particular restriction on the scope of application of this technical means, and it can be applied, for example, to the manufacture of MO8 type semiconductor devices, bipolar type semiconductor devices, etc.

[Function] According to the above-mentioned technical means, the thickness of the second photoresist film formed on the first photoresist film in the resist lamination process is set to be thin, so that the exposure in the partial irradiation alteration process is The development time can be shortened, and since the entire first photoresist film has been altered in advance so as to be soluble by the developer in the light irradiation alteration step, the development time in the development step can be shortened.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. For convenience of explanation, ions are implanted into the substrate.
A description of the initial stage of oil manufacturing for forming the ion diffusion layer in the "region" and the p+ region will be omitted, and the process of forming a resist film in the final stage of manufacturing the semiconductor device will be mainly described.

That is, as shown in FIG. 1(a), on the surface of the substrate (1) on which constituent members such as an ion diffusion layer and an electrical insulating layer are formed,
A first photoresist material (positive resist material manufactured by Tokyo Ohka Co., Ltd., trade name 0FPR-800) is applied to a thickness of about 1 to 2 μm by slowing down the rotation speed using a spinner device to form a first photoresist film (2). , and this first photoresist film (2) is prebaked by heating at about 90° C. for 10 minutes.

Next, as shown in FIG. 1(b), the entire surface of the substrate (1) is irradiated with ultraviolet light for about 30 seconds using a projection aligner to photodecompose and develop the first photoresist film (2). Changes the property to be soluble depending on the material.

Further, while heating the substrate (1), the entire surface thereof is irradiated with deep ultraviolet light (wavelength λ × 300 rv) for about 20 seconds, and the first
As shown in Figure (C), the surface portion of the first photoresist film (2) is cured by crosslinking reaction, and the first photoresist film (2) is cured by crosslinking reaction.
2) Form a thin cured film of about 1000 angstroms on the surface.

Then, the first photoresist film (2
) surface, the rotational speed is increased using the spinner device, and a high-resolution second photoresist material (positive resist material manufactured by Tokyo Ohka Co., Ltd., trade name TSHR-8700) is applied at approximately 0.
．． 5-1. czm to form a second photoresist film (3) as shown in FIG. 1(d). in this case,
Since a hardened film is formed on the surface of the first photoresist film (2) and the first and second photoresist materials do not mix, the second photoresist film (3) is formed on the first photoresist GL (2) surface. can be formed uniformly. Also,
In addition to the above-mentioned high-resolution 7-photoresist materials, there is also a positive resist material manufactured by Tokyo Ohka Co., Ltd. (trade name: TSHR-88).
00 is available. Note that, of course, the same 7 photoresist material as the first photoresist material may be used.

Next, as shown in FIG. 1(e), a glass mask (4
) through a reduction projection stepper device.
After exposing the surface to a pattern of ultraviolet light for about 30 seconds to change the irradiated area of the second photoresist film (3) to a property that can be dissolved by a developer, the second photoresist film (3) is
3) and the first photoresist film (2) on the lower surface thereof are dissolved and removed using a developing material (Non-metal developer product name: NHD-3 manufactured by Tokyo Ohka Co., Ltd.), and then the substrate is removed using a rinsing material (water). (1) Rinse the surface as shown in Figure 1 (f)
Resist films (5) to (5) are formed as shown in FIG.

Thereafter, a metal film such as aluminum is formed on the exposed surface of the substrate (1) according to normal processing steps, various electrodes are formed through predetermined processing steps, and other components are formed to form a semiconductor. It manufactures equipment.

In the method for manufacturing a semiconductor device according to this embodiment, the entire surface of the first photoresist film (2) is irradiated with ultraviolet light to make the first photoresist film (2) soluble in a developing material in advance. The second photoresist film (3), which has been altered in quality and is laminated on the surface of the first photoresist film (2), is made of a high-resolution photoresist material, and the film thickness is set to be thin. are doing.

Therefore, the irradiation time for irradiating pattern exposure of ultraviolet light onto the second photoresist l1l(3) surface can be significantly shorter than in the past, and even if the development time with the RFL image material is short, the first photoresist film can be Since (2) has been altered in advance to be soluble, it is possible to reliably remove the altered portion of the resist film to the second film 1 as well as the first photoresist film on the lower surface thereof.

Therefore, it is possible to selectively form a resist film on the substrate surface with high precision using a normal photolithography apparatus that does not incorporate the RIE method, which has the advantage of easily manufacturing high-quality semiconductor devices. ing.

[Effects of the Invention] As described above, in the present invention, since the film thickness of the first photoresist film is set to be thin, the exposure time in the partial irradiation alteration process can be shortened, and furthermore, the entire first photoresist film can be Since it has been altered in advance so that it can be dissolved by the developing material, it is possible to shorten the developing time in the developing process.

Therefore, a resist film can be selectively formed on a substrate surface with high precision using a normal photolithography apparatus that does not incorporate the RIE method, which has the effect of easily manufacturing high-quality semiconductor devices. There is.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and FIG.
FIG. 1(f) is a process explanatory diagram showing the manufacturing process of the semiconductor device according to the example, FIGS. 2 and 3 are schematic partial cross-sectional views of the semiconductor device, and FIGS. 4(a) to 4. (C) is an explanatory diagram of the resist film formation process in the conventional method, FIGS. 5(a) to 5(e), and FIGS. 6(a) to 6(l) Diagrams explaining the formation process of the resist film are shown respectively. [Explanation of symbols] (1)...Substrate (2)...First photoresist film (3)...Second photoresist film (4)... ...Glass mask (5)...Resist film patent Applicant Fuji Xerox Co., Ltd. Representative Patent attorney Tomohiro Nakamura (3 others) Figure 1. 5-resist film Fig. 2 Fig. 4 +lilil Fig. 5 Fig. 6 Fig. 6 JillJ

Claims (1)

[Scope of Claims] A semiconductor in which constituent members such as an ion diffusion layer, an electrically insulating layer, various electrodes, or a wiring section are formed at predetermined portions of a substrate, and a plurality of semiconductor elements each made of these constituent members are arranged. A method for manufacturing a semiconductor device, wherein a resist film is selectively formed on the surface of the substrate by a photolithography method, and a formation site of each component is controlled by the resist film, the method comprising: At least one of the steps includes: forming a thick film of the first photoresist material uniformly on the substrate surface; and irradiating the entire thick film of the first photoresist material with light in a predetermined wavelength range to form a thick film of the photoresist material. A light irradiation alteration step in which the material is altered to a property that can be dissolved by a predetermined developing material, and the entire thick film of the altered first photoresist material is irradiated with light in another wavelength range for a short period of time to remove the surface area. a surface hardening step of curing, and a surface hardened thick film of the first photoresist material;
a resist lamination step of uniformly laminating a thin film of the second photoresist material; and selectively irradiating the thin film surface of the laminated second photoresist material with light in a predetermined wavelength range, and irradiating the irradiated portion of the thin film in a predetermined manner. A partial irradiation alteration step in which the property is changed to a property that can be dissolved by a developer, and a predetermined developer is brought into contact with the entire surface of the laminated second photoresist material, and the altered portion of the second photoresist material and the first layer on the lower surface thereof are A method for manufacturing a semiconductor device, characterized in that the semiconductor device is formed in each of the following steps: a developing step of dissolving and removing a photoresist material.