JP3106690B2 - Film formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming method suitable for forming a film in various semiconductor devices.

[0002]

2. Description of the Related Art As a method of forming a film, a chemical vapor deposition method (CVD method), a vapor deposition method, a sputtering method and the like are used. In order to obtain a high-quality film by these film forming methods, it is necessary to heat the substrate on which the film is to be deposited to a high temperature to form a film. For this reason, there is a problem that a large stress is generated between the film and the substrate.

In the case of using a plasma CVD method or an ECR (electron cyclotron resonance) plasma CVD method,
Although low-temperature film formation is possible, there is a problem that the impact of ions generated by the plasma results in deterioration of the film quality.

[0004]

SUMMARY OF THE INVENTION The present invention provides a film forming method capable of forming a film with good film quality without causing stress between a substrate and a film formed thereon.

[0005]

According to the film forming method of the present invention, a solid film 2 containing a volatile substance is formed on a substrate 1 as shown in FIGS. A material layer 3 to be formed is deposited on the solid film 2, and a film-forming body 4 is placed so as to face the material layer 3, and the back surface 1 </ b> R
Then, the material layer 3 is separated from the solid film 2 by irradiating an energy beam absorbed by the solid film 2 to form a film 5 made of the material layer 3 on the film-formed body 4.

Further, according to the present invention, in the above-mentioned film forming method, as shown in FIG.
The material layer 3 to be formed into a film is formed thereon via the separation layer 14.

[0007]

As described above, according to the present invention, once the material layer 3 is formed on the base 1 via the solid film 2 containing a volatile substance, the energy beam is irradiated from the back side of the base 1. Not only causes the volatile substance in the solid film 2 to evaporate, thereby causing the material layer 3 on the solid film 2 to be peeled off, but also causing the material layer 3 on the solid film 2 to face while being formed on the solid film 2. The film 5 was able to be formed by being deposited thereon. This will be described below.

First, as shown in FIG. 3A, a hydrogenated amorphous Si film (a-Si: H) 12 is entirely deposited on a substrate 1 made of quartz glass by a plasma CVD method to a thickness of 50 nm.
The film was formed at about 0 °. The a-Si: H film 12 contains a large amount of hydrogen of about 10% in the film. On the other hand, a half surface of the substrate 1 was irradiated with a XeCl excimer laser to be crystallized to form a polycrystalline Si (poly-Si) film 13. Since hydrogen evaporates at the time of laser heating, the polycrystalline Si film 13 does not contain hydrogen. Thereafter, a material layer 3 of Al or the like is entirely formed on the Si films 12 and 13.
Is deposited at a thickness of 3000 °, and the width w and the interval s are set to 20.
Patterning was performed by anisotropic etching such as RIE (Reactive Ion Etching) or the like with μm. Thereafter, a film-forming object 4 made of glass is opposed to the material layer 3 so as to maintain an interval L of about 1 mm from the upper surface of the solid film 2.
Were placed facing each other and placed in a vacuum chamber.

Then, an energy beam pulse such as a XeCl excimer laser was irradiated from the back surface 1R side of the substrate 1 in a vacuum as shown by an arrow E. 20 for a-Si: H film 12
When a laser having an energy density of 0 mJ / cm ² is irradiated, the material layer 3 is peeled off as shown by an arrow a, and the pattern of the material layer 3 is transferred to the object to be formed 4 as shown in FIG. 3B. The film 5 was formed. In contrast, polycrystalline Si
The material layer 3 on the film 13 was not peeled off by laser irradiation.

In addition, the film 5 thus formed is
It was confirmed that the transfer was formed with sufficient adhesiveness without being peeled off from the film-forming target 4 even when the acetone ultrasonic treatment was performed.

That is, from this result, by irradiating the solid film with an energy beam such as a laser, the internal pressure of the heated volatile substance, in this case hydrogen, in the solid film increases,
Due to the pressure at which the hydrogen evaporates, the material layer 3 in this case Al
It is considered that the film is peeled off, adhered to the object to be film-formed 4 and transferred and formed with sufficient adhesion.

In another embodiment of the present invention, as shown in FIG. 2, a material layer 3 to be formed is deposited on a solid film 2 via a separation layer 14, and then the substrate 1 has a back surface 1R side. The separation layer 14 and the material layer 3 thereon can be transferred to the film formation object 4 by irradiating an energy beam as shown by an arrow E from FIG. In this case, even when the material layer 3 to be formed and the solid film 2 containing a volatile substance are made of the same material, the material layer 3 can be reliably separated from the solid film 2.

As described above, according to the present invention, the material layer 3 formed on the separate substrate 1 is transferred and formed without forming the film directly on the object 4 to be formed. Therefore, the film-forming body 4 itself is not heated to a high temperature, and the occurrence of stress between the film 5 and the film-forming body 4 can be avoided. In this case, impact due to plasma ions or the like can be avoided, and a film can be formed with good film quality.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for forming a film of the present invention will be described below in detail with reference to the drawings. The method of the present invention firstly, as shown in FIG.
On a substrate 1 made of quartz glass or the like, a solid film 2 containing a volatile substance, for example, a solid film 2 made of hydrogenated amorphous Si containing about 10% of hydrogen in the film is entirely formed by a plasma CVD method or the like. A film having a thickness of about 500 ° was formed, and a material layer 3 of a predetermined pattern made of Al or the like was formed thereon. This material layer 3 is deposited, for example, with a thickness of 3000 °, and then RIE with a width w and an interval s of 20 μm
It was formed by performing patterning by anisotropic etching such as (reactive ion etching).

Then, as shown in FIG. 1B, a film-forming body 4 made of glass is opposed to the material layer 3 so as to maintain a distance L of about 1 mm from the upper surface of the solid film 2. And placed in a vacuum chamber. Then, as shown by an arrow E from the back surface 1R side of the base 1 in a vacuum, Xe
Pulse irradiation was performed with an energy beam such as a Cl excimer laser.

When the material layer 3 is irradiated with a laser having an energy density of 200 mJ / cm ² ,
1C, the material layer 3 having the same pattern as the pattern formed on the solid film 2 was transferred onto the opposed film-forming target 4 as shown in FIG. 1C to form a film 5. .

In such a transfer, the material of the film 5 is SiO ₂
In other cases such as this, the same could be done. Further, as the solid film 2, for example, P which can contain a large amount of hydrogen
A metal film such as d can also be used.

For example, when the material layer 3 made of Si is formed by using hydrogenated amorphous Si as the solid film 2 as described above, the solid film 2 and the material layer 3 are formed as shown in FIG. By providing a separation layer 14 having a higher melting point than the solid film 2 of, for example, SiO _2,
A film can be formed by simultaneously transferring 4 and the material layer 3 thereon.

Next, a case where a thin film transistor is formed by applying such a film forming method will be described in detail with reference to manufacturing process diagrams of FIGS. 4A to 4C. In this case, first, as shown in FIG. 4A, an impurity-containing semiconductor layer 15 made of Si or the like is formed on a substrate 21 made of glass or the like constituting a thin film transistor by a CVD method or the like. Is removed and patterning is performed, and a semiconductor layer 16 made of Si or the like is entirely deposited thereon. Then, the entire surface of the semiconductor layer 16 is irradiated with a pulsed laser to perform crystallization.

The semiconductor layers 15 and 16 are patterned into a predetermined pattern by applying photolithography or the like to form source and drain regions 22S and 22D, on which source and drain electrodes are formed by the film forming method of the present invention. Transfer formation. That is, as shown in FIG. 4B, a solid film 2 made of hydrogenated amorphous Si or the like and a material layer 3 formed by patterning an electrode material made of Al or the like are formed on a substrate 1 made of quartz glass or the like. This material layer 3 forms the source / drain region 22S
And 22D, and irradiates an energy beam such as a XeCl excimer laser in a vacuum from the back surface 1R side of the base 1 in a vacuum as shown by an arrow E, and the material layer 3 is moved by an arrow a. As shown by, transfer formation is performed on the source / drain regions 22S and 22D. As described above, by applying the method of the present invention, an electrode can be patterned without forming a metal layer on the channel region 22, so that metal contamination of the channel region 22 can be avoided. The characteristics of the thin film transistor can be improved.

Further, an insulating layer made of SiO ₂ or the like is entirely transferred and formed thereon by using the film forming method of the present invention. That is, as shown in FIG. 4C, a solid film 2 containing a volatile substance and a material layer 17 such as SiO ₂ are sequentially deposited on a substrate 1, which is likewise formed on a source / drain electrode 2.
The substrate is brought onto the 3S and 23D and similarly irradiated with an energy beam such as a pulsed laser from above the back surface 1R of the substrate 1, thereby covering the entire material layer 17 to form a gate insulating film. Usually, when an insulating layer such as SiO _{2 is applied,} the insulating layer is applied using a plasma CVD method or the like. However, by applying the film forming method of the present invention, it is necessary to heat the base 21 to a high temperature. Thus, a favorable gate insulating film can be formed while avoiding contamination by plasma ions.

Thereafter, as shown in FIG. 5, a gate electrode 25 made of Al or the like is formed on the gate insulating film 24 on the channel region 22 by applying, for example, the film forming method of the present invention as described above. A thin film transistor can be formed.

As described above, when the method of the present invention is applied to the manufacturing process of a thin film transistor, the source / drain electrode 2
3S and 23D, gate insulating film 24, and gate electrode 25
Since the formation and patterning of each thin film can be performed in parallel as a separate step from the step of manufacturing the transistor, the transistor creation step can be simplified.

In each of the above embodiments,
A case where a film is formed by transferring a single material layer 3 is shown,
Two or more material layers can be transferred by one laser irradiation. As a material layer, a pattern or a film can be similarly transferred as described above.

The present invention is not limited to the above-described embodiment, but can adopt various other material constitutions and transfer modes. The present invention is not limited to the thin film transistor manufacturing process, and is applicable to the manufacture of various semiconductor devices. It goes without saying that it can be done.

[0026]

According to the present invention, a film can be formed without heating a film-forming body to a high temperature, stress between the film-forming body and the film can be avoided, and plasma ion Deterioration of the film quality due to the above can be avoided.

Further, according to another aspect of the present invention, since the material layer is formed on the solid membrane via the separation layer, the material layer is transferred together with the separation layer, whereby the solid membrane containing a volatile substance is transferred. Even when the material described above is the same as the material of the film to be transferred, the material layer can be surely peeled off and transferred to the film formation object to form a film.

Further, when the present invention is applied to the manufacture of a thin film transistor, it is possible to avoid metal contamination in a channel region and a heat treatment step for forming a gate insulating film, thereby improving transistor characteristics. Furthermore, the process of forming electrodes, gate insulating films, and the like can be performed in parallel as a separate process from the process of forming transistors, and the manufacturing of various semiconductor devices such as thin film transistors can be simplified. It has a great effect.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of an example of a film forming method of the present invention.

FIG. 2 is a manufacturing process diagram of another example of the film forming method of the present invention.

FIG. 3 is an explanatory view of a film forming method of the present invention.

FIG. 4 is a manufacturing process diagram of the thin film transistor.

FIG. 5 is a schematic enlarged cross-sectional view of an example of a thin film transistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Solid film 3 Material layer 4 Deposition object 5 Film 14 Separation layer

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Setsuo Usui 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-2-34916 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/205 H01L 21/203

Claims (6)

(57) [Claims] 1. A solid film containing a volatile substance is formed on a substrate, and a material layer to be formed is formed on the solid film. Is installed, the material layer is separated from the solid film by irradiating an energy beam absorbed by the solid film from the back surface of the substrate, and a film made of the material layer is deposited on the object to be formed. A film forming method characterized by forming. 2. The film forming method according to claim 1, wherein a material layer to be formed is formed on the solid film via a separation layer. 3. The film forming method according to claim 1, wherein said energy beam is an excimer laser. 4. The method according to claim 1, wherein the solid film is made of hydrogenated amorphous Si.
The film forming method according to claim 1, wherein the film is a film. 5. The method according to claim 1, wherein the solid film is a hydrogen-containing metal film. 6. The method according to claim 1, wherein the material layer is made of Al.