JPS6047419A - Multilayer level patterning method - Google Patents

Abstract

PURPOSE:To obtain the excellent double layer pattern by a method wherein when the first and second resist films are laminated on a semiconductor substrate and the second film is subjected to exposure and development to be made into the predetermined pattern which is used as a mask for patterning the first film by O2 plasma, the novolak-group resin silylated including Si is used for the second film and this is irradiated with ultraviolet rays. CONSTITUTION:On the semiconductor substrate 11 having a level difference, the first resist film 12 is spreaded so as to fill up said difference and to level the surface and then the film is heated at 150-200 deg.C for about 30min to be insolubilized to an alcoholic solvent. Next, the second resist film 13 including an Si- including silylating agent, N-phenylaminopropyltrimethoxysilazane is spreaded on the film 12 and is heated again at 80 deg.C for 10-30min. After that, the substrate is irradiated with the ultraviolet ray 14 through a mask 15 having the predetermined opening and is immersed in an alcoholic solution to make the film 13 into the predetermined pattern 16. Next, the exposed part of the film 12 is removed with using the pattern 16 as a mask to form the predetermined pattern 18 and the desired double-layer pattern can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a precision resist pattern for forming a fine I4 turn shape and a multilayer resist pattern Jung method, which is a turn Jung method.

[Prior art]

Conventional resist film and turn-jung methods use ultraviolet (UV), deep ultraviolet (DUV), and electron beam (
After exposure to light such as X-rays, the film was developed with a developer to obtain a Lennost pattern. However, in integrated circuit manufacturing, semiconductor substrates have uneven steps, and when resist is applied to these step substrates, molds of Lennost's thickness appear on the uneven portions, and the steps are Since materials with different properties are often used, the UV and EB exposure energy is reflected from the underlying substrate, creating unnecessary exposed areas in the renost layer and deteriorating the renost layer.

In order to improve this, the multi-level and turn-Jung method was devised. In the recent multilayer level Guternjung method, a renost containing St in the resist is used as the upper resist film, and after this is exposed and developed, the lower renost layer is etched with 02 plasma using the upper resist pattern as a mask. It is being considered. (For example, the 23rd Symponium on Semiconductor Integrated Circuit Technology P18). The inventors announced in October 1981 at the Society of Vultures that Renosto containing St is resistant to Zolazma 02. Therefore, it is easy to think that Si-containing renost can in principle be applied as a two-layer structure renost.

Here, the method using lenost containing S1 is 2
It is considered to be a promising method as it has the advantage of a simple process as a layered resist/♀turn-jung method, but the above-mentioned S1
Renost, which contains , is vinylbenzene-based and has a limited photosensitive wavelength. That is, the exposure energy irradiation ray of the resist is FB,! :I) It is limited to UV light, and has the drawback that UV light, which is currently the most commonly used radiant energy beam, cannot be used. Needless to say, this is impractical.

[Purpose of the invention]

It is an object of the present invention to provide a multilayer level Guternjung method using UV as the exposure energy radiation.

[Structure of the invention]

In the present invention, a Nozerac resin is applied on a semiconductor substrate in a first l/l/
After coating and heating as a cyst, further coating a silylated Nogilac resin containing Si as a second resist, and heating, the second resist is applied in a specific pattern.
A resist (p-turn) is obtained by etching the first resist with 02 plasma, using a resist (resist) pattern formed by exposing with V, developing, heating or heating and developing as a mask of the first resist with 9 turns. It's something you get.

〔Example〕

Figure 1 shows the 02 plasma resistance of a resin resist made of a resin containing silicone, which is the premise of the present invention, and the resistance to plasma of the resin. MP) 02 Zolazma resistance (residual film thickness rate) of Rennost, which is a mixture of 1 to 7 cc of silicon-containing Noryl and other agents N-phenylaminozologyltrimethoquinosilazane to 20CH
This is a comparison with 100% 1400-27 Renost. Note that the film thickness is 15 μm. As shown in FIG. 1, the resistance to 02 Zolazma of the resist mixed with the silylating agent improves as the amount of the silylating agent increases, and this tendency is shown up to 5 CC, but after 5 CC and 7 CC, the resistance to 02 Zolazma improves. Oxygen plasma resistance decreases. However, even in this case, almost 80% remained, indicating sufficient resistance.

On the other hand, MP1400- without the addition of the silylating agent
27 The 100% resist was etched proportionally to the 0270 plasma exposure time, indicating that a 1.4 μm thick resist was removed in approximately 13 minutes. MP 1 mixed with the above silylating agent
Since the 400-27 resist exhibits resistance to the 02 plasma, it can be seen that by applying it as a mask for the 02 plasma, it is possible to etch the underlying resist. 1 is a cross-sectional view of a semiconductor substrate showing a first embodiment; FIG. First, an MP is placed on a semiconductor substrate 11 having a step.
1400-27 Resost 12 is applied to a thickness of 2 μm.

(Fig. 2 (A)) Next, the semiconductor substrate was heated to 150 to 200°C.
Heat for 0 minutes to make it insoluble in alcohol solvents. Thereafter, an MP containing a silicon-containing silylating agent N-phenylaminoglobil trimethoxine lazan was applied on the semiconductor substrate.
1400-27 resist I:9 was applied to a thickness of 1.4 μm and heated again at 80°C for 10 to 30 minutes (see Figure 2 (B).
)) Thereafter, the semiconductor substrate is exposed to UVIJ through the nozzle turn mask 15. (Figure 2 (C))
Thereafter, it is developed by immersion in an alcoholic solvent developer or by the sdale method to obtain a resist/o-turn 16. The resist pattern 16 (in FIG. 2) is extremely less affected by reflections from the underlying semiconductor substrate, and a highly accurate pattern can be obtained. It has been confirmed that the MP 1400-27 Renost has the advantage that no deterioration in resolution is observed due to the addition of the silylation agent. Now,
100℃ to improve 02 plasma resistance after development.
1 at a temperature of ~180°C, in this example at 150°C.
Bake again for 0 minutes. Then, using a parallel plate type 02 grama device and using the upper layer resist as a mask, the lower resist layer is etched with 02 lazer 1'7. As a result, Renost Guturf 18-J was obtained, which had an extremely chassis-like profile.

(Figure 2 (odor)) In the first example, a heating step was performed after exposure and development in patterning the upper layer lenost, but in the second example, a pattern was obtained by heating immediately after exposure and then developing. The other steps were the same as in the first example, and as a result, a slight turn with the same chassis profile as in the first example was obtained.

In the first and second examples, N~phenylaminozolopyltrimethoxysilazane was used as the silylating agent, but in the third example, 1-trimethylsilylaniline was used as the silylating agent. When the same process as in the second embodiment was carried out, the same results as in the first and second embodiments were obtained.

Also, 1st. Second. In the third example, MP 1400-27 Renost was mainly used as the sost agent, while in the fourth example, 0FPR800 (trade name of Tokyo Ohka Chemical Co., Ltd.) was used, and the others were as follows. Second. As a result of carrying out the same process as in the third example, the same results as above were obtained.

〔Effect of the invention〕

In the present invention, by mixing a silylation agent containing 81 with a UV-sensitive novilac resin resist, an ultraviolet-sensitive renost with excellent 02 plasma resistance is obtained, and it is easy to use UV as the exposure energy irradiation. This results in an excellent two-layer resist patterning method that can be used in high-density integrated circuits.

[Brief explanation of the drawing]

Figure 1 shows MP1'400 with silicon-containing silyl and other agents added.
Explanatory diagram showing the 02 plasma resistance of -27 resist, Part 2
The figure is a cross-sectional view of a semiconductor substrate implementing the present invention. 11. Semiconductor substrate, 12. Lower layer renost, 13.
... Upper layer resist, 14... Ultraviolet ff1J, 15...
・Pattern mask, 16... Upper layer Renost pattern,
17...o2 plasma, 18...lower Renost Gutan. Figure 1 Figure 2

Claims (1)

[Claims] A first resist and a second resist are sequentially coated on a semiconductor substrate, and a specific renost Yaturn obtained by exposing and developing the second renost is used as a mask for the first renost using an 02f plasma. In the multilayer level patterning method for obtaining a resist film or a turn by etching, a step of applying a silylated resin containing Si as the second resist; A multilayer Lepernoc turning method characterized by including a step of exposing the material to ultraviolet light.