JP2563689B2 - Plasma reactor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma reactor for depositing a reaction gas on a substrate housed in a vacuum chamber by utilizing a plasma reaction. Specifically, it can be used to form a metal film or a resist film on a substrate.

[0002]

BACKGROUND ART As shown in FIG. 5, a manufacturing process of a semiconductor integrated circuit (LSI) includes a sputtering step (A) of depositing a thin film 2 such as a semiconductor film or a metal film on a surface of a substrate 1 such as silicon or glass. A resist coating step (B) of coating a resist film 3 on the thin film 2, an exposure step (C) of irradiating the resist film 3 with light, an electron beam, a laser beam 4 or the like to draw a required pattern, a resist film. Developing step (D) for developing No. 3 and the resist film 3 remaining in the developing step
The etching step (E) of partially removing the thin film 2 with the mask as a mask and the ashing step (F) of finally removing the resist film 3 used as the mask.

By the way, conventionally, in the above-mentioned resist coating step (B), as a method for coating the resist film 3 on the thin film 2, the substrate 1 is rotated at a high speed while the polymer coating material for resist is liquefied. In addition to the spin coating method in which the resist film 3 is coated on the surface of the substrate 1 by dropping it, a spray method in which the polymer coating material for resist is sprayed in a mist form to coat on the substrate 1, the polymer coating for resist Known are a dipping method in which the substrate 1 is immersed in the film material solution, a laminating method in which the resist polymer coating material is formed into a thin sheet, and the thin sheet is superposed on the substrate 1. In particular, the spin coating method is often used for semiconductors.

[0004]

Among the conventional coating methods, the spin coating method, which is widely used for semiconductors, is a method of coating the resist film 3 by utilizing the centrifugal force generated by the rotation of the substrate 1. The surface of the substrate 1 is limited to a flat surface. Further, the film thickness of the resist film 3 to be formed is mainly determined by the rotation speed of the substrate 1 and the viscosity of the resist polymer coating material, but it is also changed by the underlying material, temperature, humidity, etc. It is extremely difficult to accurately control the film thickness of No. 3.

Since these coatings are performed in the atmosphere, dust in the air is likely to adhere to the coated resist film 3, and as a result, the resist film 3 is formed.
There is a problem that pinholes occur in the. Moreover,
After coating the resist film 3 on the surface of the substrate 1,
Since it is necessary to heat and dry at a predetermined temperature in order to increase the adhesiveness between the resist film 3 and the base material, post-treatment is required.

Therefore, as a method for solving these problems, a method of depositing the resist film 3 on the surface of the substrate 1 using a plasma reactor has been proposed. FIG.
And FIG. 4 shows a plasma reactor. In FIG. 3, reference numeral 11 denotes an openable / closable reaction container, in which a vacuum chamber 13 having a plasma generation chamber 12 is formed. An exhaust system (not shown) is connected to the vacuum chamber 13 through an exhaust port 14, and a substrate electrode 15 to which the substrate 1 is attached is arranged inside.

A plasma generating electrode 17 connected to a high frequency power source 16 is arranged outside the plasma generating chamber 12, and a plasma state is generated by the plasma generating electrode 17 on the upper end side thereof. A carrier gas introducing port 18 for introducing an inert carrier gas CG such as argon is provided in a region to be filled therein, and a reaction gas introducing pipe 19 for introducing a reaction gas G is provided at a lower end side thereof. The plasma reactor shown in FIG. 4 has the same basic configuration as that of FIG. 3 except that it has two reaction gas introduction pipes 19a and 19b for introducing two kinds of reaction gases Ga and Gb. is there.

Therefore, the inside of the vacuum chamber 13 is exhausted to a predetermined vacuum pressure through the exhaust port 14 and the exhaust system, and then an inert carrier gas CG such as argon is introduced into the vacuum chamber 13 through the carrier gas inlet port 18. Subsequently, when high frequency power is applied from the high frequency power supply 16 to the plasma generation electrode 17, plasma is generated in the plasma generation electrode 17. In this state, the reaction gas introducing pipes 19, 19a,
When the reaction gas G, Ga, Gb is introduced into the vacuum chamber 13 from 19b, the reaction gas G, Ga, Gb is excited and ionized and deposited on the substrate 1.

In the method of forming the resist film 3 using such a plasma reactor, the film thickness can be easily controlled, and since the processing is performed in the vacuum chamber 13, there is no problem such as pinholes. Further, since the heating and drying step after coating the resist film 3 can be eliminated, there is an advantage that all the drawbacks of the conventional wet type resist film forming method can be eliminated. Moreover, there is an advantage that not only the flat surface but also the uneven surface can be uniformly coated with the resist film 3.

However, in the conventional plasma reactor shown in FIGS. 3 and 4, the number of plasma generating electrodes 17 is one, and therefore the plasma generating region is narrow. Therefore, it cannot be applied to the substrate 1 having a large resist coating area. By the way, in the conventional plasma reactor, the diameter is about 25 mm. Therefore, in recent years, in the field of semiconductors, with an increase in the diameter of substrates for the purpose of improving production efficiency, there has been a demand for the development of a plasma reactor capable of coping with this.

It is an object of the present invention to maintain the advantages of such a conventional plasma reactor, to eliminate the drawbacks thereof and to uniformly deposit a reaction gas on a large area on a substrate. It is to provide a reactor.

[0012]

Therefore, in the plasma reactor of the present invention, in the plasma reactor for depositing the reaction gas on the substrate housed in the vacuum chamber by utilizing the plasma reaction, the plasma reactor communicates with the vacuum chamber. Plasma generation chamber
Are provided along the deposition surface of the substrate.
Placing plasma generation electrodes outside the generation chamber
At the same time, an inert carrier gas is introduced into each plasma generation chamber.
It is characterized in that a carrier gas introduction port for entering is provided.

[0013]

[Function] The plasma generation chamber communicating with the vacuum chamber deposits the substrate.
A plurality are provided along the surface and outside each plasma generation chamber.
Each of the plasma generation electrodes is placed in the
For introducing an inert carrier gas into the plasma generation chamber
Since the carrier gas inlet is provided, plasma can be uniformly and efficiently generated over a wide range. In this state, the reaction gas is introduced into the vacuum chamber
And the reaction gas is excited by the generated plasma.
And ionized and deposited on the substrate,
The reaction gas can be uniformly deposited on the substrate .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the description of these drawings, the same components as those in FIGS. 3 to 5 described above will be denoted by the same reference numerals, and the description thereof will be omitted or simplified.

FIG. 1 shows a vacuum lithographic apparatus. In the figure, CB is a spare room, TR is a transfer room, and SP.
Is a sputtering chamber for forming the thin film 2 on the substrate 1 in vacuum, PP is a plasma polymerization chamber for forming the resist film 3 on the thin film 2 in vacuum, and EB is the plasma polymerization chamber for forming the resist film 3 in vacuum. An electron beam drawing chamber for exposing and drawing a required pattern, RIE is an etching chamber for partially etching the thin film 2 using the developing resist film 3 as a mask in vacuum, and RP is the pattern in vacuum. The developing / ashing chamber doubles as a developing chamber for developing the resist film 3 after drawing and a removing chamber for removing the resist film 3 used as the mask.

Each of these rooms CB, TR, SP, PP, RI
E, RP, and EB are respectively connected to the exhaust system pump P, and each of the E, RP, and EB is formed so that the exhaust system pump P can independently hold a vacuum. Among the chambers, the sputtering chamber SP, the plasma polymerization chamber PP, the etching chamber R
The IE and the developing / ashing chamber RP are connected to the transfer chamber T via partition valve devices V2, V3, V4 and V5, respectively.
Each is connected to R. Further, the electron beam drawing chamber EB is connected to the auxiliary chamber CB via a partition valve device V6. The preliminary chamber CB and the transfer chamber TR are connected to each other via a partition valve device V1.

Each of the partition valve devices V1, V2, V3
V4, V5, and V6 are configured to be openable and closable, and when opened, the substrate 1 is held in a size capable of being taken in and out of each chamber, and when closed, each chamber is isolated to a vacuum state. It is configured to be possible. The opening and closing of these partition valve devices V1, V2, V3, V4, V5 and V6 are automatically controlled according to a predetermined order.

A partition valve device V11 for loading the substrate 1 is attached to the spare chamber CB on the side opposite to the partition valve device V1. The transfer chamber TR is
It has a length extending over the plasma polymerization chamber PP, the etching chamber RIE, and the developing / ashing chamber RP. Transport room TR
Inside each of the chambers, transfer robots R1, R2, and R3 are provided at positions corresponding to the chambers PP, RIE, and RP, respectively.
Substrate receivers S1 and S2 are provided between R2 and R3, respectively.

FIG. 2 shows the plasma polymerization chamber PP. The plasma polymerization chamber PP is communicated Mr to the vacuum chamber 13
Further, it is provided with three plasma generation chambers 12A, 12B, 12C arranged in parallel along the deposition surface of the substrate 1 . Each of the plasma generation chambers 12A, 12B and 12C has a plasma generation electrode 17A, 17B connected to a high frequency power source 16 outside thereof.
17C is arranged and carrier gas inlets 18A, 18 for introducing an inert carrier gas CG such as argon into a region where a plasma state is generated by the plasma generating electrodes 17A, 17B, 17C on the upper end side.
B and 18C are provided respectively.

Next, the operation of this embodiment will be described. In advance
Each room TR, SP, PP, RIE, R except the spare room CB
P and EB are evacuated to a predetermined vacuum pressure by the exhaust system pump P and kept in a state ready for process processing. In this state, after the substrate 1 is loaded into the preliminary chamber CB, the preliminary chamber CB is evacuated and set to a predetermined vacuum pressure. here,
The partition valve device V1 between the preliminary chamber CB and the transfer chamber TR is opened, the transfer robot R1 is operated to load the substrate 1 in the preliminary chamber CB into the transfer chamber TR, and then the process is performed according to a predetermined procedure. Proceed.

First, the substrate 1 in the transfer chamber TR is loaded into the sputtering chamber SP, where the thin film 2 of chromium or the like is deposited on the surface of the substrate 1. Then, after returning to the inside of the transfer chamber TR, it is carried into the plasma polymerization chamber PP, where the reaction gas is deposited by utilizing the plasma reaction to form the resist film 3 on the thin film 2.

For this purpose, the substrate 1 is set on the substrate electrode 15 in the reaction vessel 11, the inside of the vacuum chamber 13 is evacuated to a predetermined vacuum pressure, and then the carrier gas inlets 18A to 18A.
An inert carrier gas CG such as argon is introduced into the vacuum chamber 13 through C. Then, the plasma generation electrode 1
When high frequency power is applied to the 7A to 17C from the high frequency power supply 16, plasma is generated in the plasma generating electrodes 17A to 17C. In this state, when the reaction gas G is introduced into the vacuum chamber 13 through the reaction gas introduction pipe 19, the reaction gas G is excited and ionized and deposited on the substrate 1.

At this time, a vacuum is placed in the plasma polymerization chamber PP.
Plasma generation chambers 12A, 12B, 12 communicating with the chamber 13
A plurality of Cs are provided along the deposition surface of the substrate 1, and each C
Plasma generation outside the Zuma generation chambers 12A, 12B, 12C
The production electrodes 17A, 17B, 17C are respectively arranged,
Moreover, each plasma generation chamber 12A, 12B, 12C
Carrier gas guide for introducing active carrier gas CG
Since the entrances 18A, 18B, 18C are provided,
It is possible to generate plasmas uniformly and efficiently over a wide range.
Can be. Therefore, since the reaction gas G can be uniformly deposited over a wide area of the substrate 1, the resist film 3 can be uniformly formed on the large-area substrate 1.
Then, the substrate 1 is returned into the transfer chamber TR.

Next, the substrate 1 in the transfer chamber TR is once returned to the preliminary chamber CB and then carried into the electron beam drawing chamber EB, where the resist film 3 is irradiated with an electron beam to form a pattern. draw. After that, it is carried into the developing / ashing chamber RP through the preliminary chamber CB and the transport chamber TR, where the resist film 3 is developed and then returned into the transport chamber TR. Then, it is carried into the etching chamber RIE, where it is etched and then returned to the transport chamber TR. Finally, the resist film 3 was carried into the developing / ashing chamber RP, where it was no longer needed.
Are removed and then taken out to the atmosphere through the transfer chamber TR and the preliminary chamber CB.

Therefore, according to this embodiment, in the plasma polymerization chamber PP, the plasma generation chamber communicating with the vacuum chamber 13 is formed.
A plurality of 12A, 12B, 12C along the deposition surface of the substrate 1
Of each plasma generation chamber 12A, 12B, 12C
The electrodes 17A, 17B, 17C for plasma generation are placed outside.
The plasma generation chambers 12A and 1A are arranged respectively.
To introduce an inert carrier gas CG into 2B and 12C
Carrier gas inlets 18A, 18B, 18C of
Therefore, the plasma generation region can be expanded as compared with the single plasma generation chamber and the plasma generation electrode. Therefore, the reaction gas G can be uniformly deposited over a wide range of the substrate 1, so that the resist film 3 can be uniformly formed on the large-area substrate 1.

Further, the transfer chamber TR is connected to the sputter chamber SP, the plasma polymerization chamber PP, the etching chamber RIE and the developing / ashing chamber RP, and the electron beam drawing chamber EB is connected to the preliminary chamber CB connected to the transfer chamber TR. With this configuration, the lithography process from the deposition of the thin film 2 on the substrate 1 to the removal of the resist film 3 can be continuously performed in a vacuum. During this time, since the substrate 1 is not exposed to the atmosphere, it is possible to reduce contamination by dust in the atmosphere.

In addition, each room SP, PP, RIE, RP, E
B is formed so as to be able to hold a vacuum independently of each other, and the transfer chamber TR is provided via partition valve devices V1 to V6.
It is connected to each room SP, PP, RIE, R
P and EB can be independently maintained in a vacuum state. Therefore, the influence of other chambers is small, and the atmosphere in each chamber can be maintained constant, so that the processing conditions in each process can be stabilized.

In the transfer chamber TR, three transfer robots R1 to R3 are provided corresponding to the plasma polymerization chamber PP, the etching chamber RIE, the sputtering chamber SP and the developing / ashing chamber RP, respectively. Since the substrate receivers S1 and S2 are provided between them, the transfer robots R1 to R1
By R3, the substrate 1 can be automatically carried in and out of each chamber SP, PP, RIE, RP.

In addition, the loading and unloading of the substrate 1 is carried out in the preliminary chamber C.
Since the process is performed from B, only the preliminary chamber CB needs to be opened to the atmosphere when the substrate 1 is loaded and unloaded, that is, all the chambers are opened again as compared with the conventional one in which all the chambers are released to the atmosphere. Since it is not necessary to set a predetermined vacuum pressure, process processing can be performed efficiently and it is economical.

Although the present invention has been described with reference to the preferred embodiment, the present invention is not limited to this embodiment, and various improvements and design changes can be made without departing from the scope of the present invention. Of course it is possible.

For example, the number of plasma generating electrodes is not limited to the three described in the above embodiment, but may be two.
The number may be four or more. Further, the arrangement is not limited to the arrangement of the above embodiment. In short, the number and arrangement of the plasma generating electrodes may be selected according to the size and shape of the substrate 1.

[0032]

As described above, according to the present invention, while maintaining the advantages of the conventional plasma reactor, eliminating the drawbacks thereof, it is possible to uniformly deposit the reaction gas over a wide area on the substrate. A reactor can be provided.

[Brief description of drawings]

FIG. 1 is a plan view showing a vacuum lithographic apparatus to which the present invention has been applied.

FIG. 2 is a cross-sectional view showing the plasma polymerization chamber of FIG.

FIG. 3 is a sectional view showing a conventional plasma reactor.

FIG. 4 is a sectional view showing another conventional plasma reactor.

FIG. 5 is an explanatory diagram showing a manufacturing process of the semiconductor integrated circuit.

[Explanation of symbols]

1 substrate 3 resist film 11 reaction container 12A, 12B, 12C plasma generation chamber 13 vacuum chamber 17A, 17B, 17C plasma generation electrodes 18A, 18B, 18C carrier gas inlet G reaction gas CG inert carrier gas

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 61-56279 (JP, A) JP-A 1-230782 (JP, A) JP-A 2-170530 (JP, A) Actual development Sho-61- 82958 (JP, U)

Claims (1)

(57) [Claims] 1. A plasma reactor in which a reaction gas is deposited on a substrate housed in a vacuum chamber by utilizing a plasma reaction, and a plasma generation chamber communicating with the vacuum chamber is provided in front of the plasma chamber.
A plurality of plasma generators are provided along the deposition surface of the substrate to generate each plasma.
Placing the plasma generation electrodes outside the chamber
Introduce an inert carrier gas into each plasma generation chamber.
A plasma reaction apparatus having a carrier gas inlet for charging .