JPS61215286A - Forming of pattern of semiconductor film - Google Patents

Abstract

PURPOSE:To enable the accurate deposition of an Si or Ge film to the exposed part of a substrate, by forming a fine pattern of an Si or Ge film accurately to the desired part of a substrate. CONSTITUTION:An SiO2 film 5 is formed on the surface of an Si (100) single crystal substrate 4, and a square opening is opened to the SiO2 film 5 by photolithography or reactive ion-etching process to expose the surface of the Si substrate 4. Si is deposited to the substrate by electron beam evaporation apparatus to form a deposited Si film 6 until the thickness of the deposited film becomes equal to that of the SiO2 film 5. The Si film 6 is formed exclusively between the SiO2 films and there is no generation of polycrystalline Si on the SiO2 film.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method of forming a thin film, particularly a method of selectively depositing a Si or Ge single crystal or polycrystalline film at a desired location on a substrate. Regarding.

[Background of the invention]

Conventionally, a thin film such as 81 or Qe was applied to a desired location on the board. a
When forming T-layers, it is common practice to once form these thin films and then process them into a desired shape, which is rare. This sword U process is processed into the desired shape by exposing and developing the photoresist spin-coated on the 4-layer film, and using this as a mask, processing is performed using methods such as 81 or Gei reactive ion etching, ion milling, wet etching, etc. Become by doing. Additionally, there is a method called a lift-off method which is the opposite of this method. That is, before forming a desired thin film, a mask made of photoresist is formed on the substrate using the above-mentioned method, and a mask of 81 or dGeJll is applied on this mask.
l-form. Then, when the photoresist is removed, the Si or Gem deposited on the photoresist is removed together with the photoresist, and a Si or ()E film with a desired shape is formed on the plate where the photoresist was not present. .

However, these conventional methods have been difficult to process Si or Ge films into fine patterns. That is, in the former method, using photoresist as a mask, 81 or Ge! fj! - Due to the phenomenon of over-etching and under-etching occurring during processing, it is not possible to transfer the mask pattern to 81 or Geg with good reproducibility, and 141! S on the fine pattern that zes
i or Qei processing was not possible. Maku,
In the latter method, since there is no photoresist film that is stable at 400 C or higher once heated when depositing Si or Ge, patterning of the Sl or ()e film was impossible.

Furthermore, a pattern of Minx film is formed on the substrate.
However, it is difficult to accurately form (ie, embed) the 81 or ()e film only on the exposed portion of the underlying layer where the dich film is not present, which is difficult to do using the conventional method using photoresist.

As described above, in the conventional method, problems arose when selectively forming a Si or Ge film at a desired location on the base, especially when the desired location was microscopic or embedded between SiO□ films.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to form a fine pattern of Si or Ge film accurately on a desired part of the base, and to form a fine pattern of Si or Ge film.
Si or
The purpose of the present invention is to provide six selective deposition methods.

[Summary of the invention]

In order to achieve the above object, in the present invention, a SiO rich film is conveniently used as a mask instead of a photoresist mask, and S+02
A film pattern is formed in advance, and Si or G is deposited on top of this.
E-film was applied. However, 4 layers coated with Si or Ge film by the usual method have a rate of 8! 02) 5!
A film is deposited.

As a result, even if we try to remove Si or Gag deposited on the 5ift film by using Siftkm analysis, the Si or Ge film is uniformly SjO*dt-4
Therefore, it is easy to remove S as in the case of photoresist.
iOzMk? ! It is impossible to understand. Therefore, in the present invention, Si or Gea! After studying the selective vapor deposition method of I
This method applies a method of depositing a Si or ()e film in an atmosphere containing water X of 0-''L'orr or more.

According to this method, Si or Qe is not coated on 5iChji1, but selectively 4 is applied only to the exposed portion of the base.
To form a film. As a result, the 5i02 film is not covered with Si or Ge, and can be easily removed, allowing a desired pattern of 81 or Gem to be formed on the base. At this time, if the 5ins film is thin, it is possible to accurately form a fine pattern using a photoresist, so that an accurate fine pattern of the 81 or Ge film can be obtained. Furthermore, according to this selective vapor deposition method, the film can be selectively deposited on the base, so that the periphery of the exposed base is 810. Even if the hollow is surrounded by 81 or Ge
can be embedded by Thereby, an inter-element insulation structure can be formed.

In the present invention, Si or Ge refers to Si.

In addition to ()e, it also includes a solid solution consisting of 3i and Ge. (9) The 3i or Ge film to be grown includes not only single crystal but also polycrystal.

[Embodiments of the invention]

Example 1 Figure m1 shows the steps of one example of the present invention. As shown in the figure, after forming a Sin film 2 with a thickness of 300A on the surface of a 3j (100) single crystal substrate 1 by the 4&a method,
By photolithography method and C) (reactive ion etching method using F3 gas)
A pattern of Il+@0.5 am was formed (a).

Then, it was loaded directly onto the electron beam evaporator, and 2 x 10
” After vacuuming to Torr, 5X10-'gor
Hydrogen was introduced up to r, and # layer of Ge film was formed at a substrate temperature of 700C. As a result, Ge was deposited to a thickness of 1.2 μm only where Si was formed, and on 810* film 2 (
) e film was not formed (b).

As a result, using the Sigh film as a mask on the Ge film, the minimum line I11! It was revealed that a fine pattern of 0.5 .mu.m was formed, and that the formed 9-Ge film stood up almost perpendicularly to the substrate and was in the form of a single-crystalline haze. Next, by removing Sin using a 5-hydrofluoric acid aqueous solution, a fine pattern of a Ge nest crystal film could be formed on the Si substrate (C).

This result shows that GeR can be produced by vapor deposition in a hydrogen atmosphere.
It is based on the selective deposition of lX, which allows the 5ICh film to form GeBI! , and can be easily removed using a hydrofluoric acid aqueous solution. Also%
It is clear that GeM grows perpendicularly to the substrate, and this results in a thick G film despite the fine pattern.
A pattern could be formed on ea.

Example 2 Implementation/IJ In 1, the pressure fr of hydrogen introduced into the vapor deposition apparatus: 1×10−? TOrr to I x 10-'
The effect of hydrogen pressure on selective deposition was investigated by changing between Tort and Tort. As a result, when the substrate temperature is 700C,
In ()e, hydrogen was selectively coated on the Si substrate under pressure conditions of I x 10-' forr or higher, and when the hydrogen pressure was low, island-like Ge polycrystalline grains were formed on top. In this study, it was not possible to perform electron beam evaporation of Ge by introducing hydrogen at a pressure exceeding I x 10-' Torr, but it is expected that selectivity would be achieved even at I x 10-' Torr or higher. However, in the case of vacuum evaporation, the practical upper limit of the pressure is considered to be Fi1×101Port.

Example 3 In Example 1, Si was deposited by electron beam evaporation instead of Ge. The substrate temperature at this time is 1000C
And so. As a result, it was found that Si was deposited with a thickness of 0.8 .mu.m only on the exposed portions of the Si substrate, and it was revealed that Si could be selectively deposited in a hydrogen atmosphere in the same manner as Ge04. It was also revealed that the 6i film is a single crystal film that stands up almost perpendicular to the substrate, and the S
It was possible to form an ijlE-4ILsA pattern.

Furthermore, as a result of examining the influence of hydrogen pressure on the selective vapor deposition of Si, it is certain that selectivity can be obtained under the same conditions as in the case of Ge! la! It was done.

Example 4 Figure 1Xz shows the steps of another embodiment of the invention.

After forming a 1.1 μm 840* film on the narrow side of a 3i (100) single crystal substrate 4 in the same manner as in Example 1, a SjOz film was formed by photolithography and reactive ion etching.
Make a square opening in M and let the four underlying Si substrates 4 come out. The length of one side of the square is 5 μm, and the shallow depth is 9 SiO! The line width is 2 μm (a).

Then, using an electron beam evaporator, a hydrogen pressure of 1 x
81 4-metal evaporation was carried out under the conditions of 10-56 Torr and 4-plate temperature of 950 tll'. FIG. 2(b) shows a stage in the middle of depositing Si. The thickness of the B+ evaporated film 6 is
The vapor deposition was completed at a thickness of 1.1 μm, which is the same as the film thickness of -1iOz5. As a result, Si genus 6 is SiQ! Si polycrystalline grains grew only in fi5, and no Si polycrystalline grains were observed on the 5i01 film (C). That is, Si is embedded in a lattice made of SiO2, and this method
Enables isolation between elements by separating and insulating them by z.

〔Effect of the invention〕

As explained above, according to the method of the present invention, it is possible to form a fine pattern of Si or Ge film having a fine pattern, and furthermore, a Si or (Je film) can be formed in the next region surrounded by the 5i02 film. Can be selectively deposited and embedded.

In addition, in the present invention, a solid bath consisting of Si and Qe can also obtain the same effect as 5i-Qe.

[Brief explanation of drawings]

Fig. 1 is a process diagram of forming a fine pattern of Ge by selective vapor deposition, and Fig. 2 is a process diagram of forming a fine pattern of Ge by selective vapor deposition. FIG. 3 is a process diagram of embedding Sam into the exposed area of the Si substrate from the film. 1.4...Si substrate, 2,5...SiO2 film, 3.
...Ge single crystal film, 6...S4 single crystal film. day l

Claims (1)

[Claims] 1. SiO_2 on a substrate partially covered with SiO_2
1. A method for forming a pattern of a semiconductor film, the method comprising at least the step of selectively depositing at least one of Si, Ge, and a solid solution of Si and Ge on portions where the pattern does not exist. 2. A semiconductor film pattern forming method according to claim 1, wherein the vapor deposition step is performed in an atmosphere containing hydrogen at 1×10^-^6 Torr or more. 3. A method for forming a pattern of a semiconductor film according to claim 1 or 2, wherein the base is a Si single crystal, and the film deposited on the base is a single crystal. 4. A method for forming a pattern of a semiconductor film according to any one of claims 1 to 3, characterized in that the vapor deposition step is performed by an electron beam evaporation method.