JP3243258B2 - Plasma CVD equipment - 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 CVD apparatus for producing, for example, a thin film transistor.

[0002]

Conventionally, for example, the production of thin film transistor used for the active matrix type liquid crystal display, is used continuously formed to Louis <br/> inline type plasma CVD apparatus a plurality of film type thin film on the substrate ing. As shown in FIG. 2, the plasma CVD apparatus includes a loading chamber 1,
It comprises a reaction chamber 2, an unloading chamber 3, and a tray transport section 4. Further, a substrate attaching / detaching section 5 is formed in the tray transport section 4.

[0003] In the substrate attaching / detaching section 5 provided in the tray transport section 4, a substrate is mounted on a tray, and the tray mounted on the substrate is transported to the loading chamber 1. In the loading room 1, the pressure in the room is reduced and the tray is heated to a predetermined temperature and transported to the reaction chamber 2. Further, the reaction chamber 2 is previously set in a vacuum heating state, and when the tray is conveyed, a reaction gas is introduced into the chamber and held at a constant pressure by a conductance valve or the like.
A thin film is formed on the substrate by high-frequency discharge, and after the discharge for a predetermined time is completed, the thin film is transferred to the carry-out chamber 3. Then, in the carry-out chamber 3, the tray is carried in a vacuum state, and after changing the room pressure to the atmospheric pressure state, the tray is carried out to the tray transport unit 4. The carried-out tray is returned to the substrate attaching / detaching portion 5 again, and the substrate is removed.

[0004]

However, in the above configuration, when the cumulative thickness of the thin film in the reaction chamber 2 exceeds a certain amount, the amount of dust taken in during the film formation on the substrate abnormally increases. Yield is significantly reduced. Therefore, it is necessary to clean the inside of the reaction chamber 2 before the cumulative thickness of the thin film in the reaction chamber 2 reaches a certain amount. However, the time required for this work has been a major factor in lowering the operation rate of the apparatus.

When a plurality of film types are successively formed in different reaction chambers 2 successively, the accumulated film thickness requiring cleaning differs depending on the film type, so that the cleaning execution time differs for each reaction chamber 2. Therefore, the apparatus must be stopped corresponding to the reaction chamber 2 each time.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a plasma CVD apparatus that reduces the frequency of cleaning, improves the operation rate of the apparatus, and suppresses a decrease in yield.

[0007]

Means for Solving the Problems Plasma CVD of the present invention
Device includes a predetermined number of reaction chambers for depositing the one film, the thickness of sedimentary
A cumulative film thickness management unit for managing the product, forming another film different from the one film, and requiring a higher frequency of cleaning than the reaction chamber for forming the one film, and The number of reaction chambers is larger than the predetermined number of reaction chambers for forming a film.

[0008]

According to the plasma CVD apparatus of the present invention, the number of reaction chambers for forming another film having a higher frequency of cleaning is made larger than the number of reaction chambers for forming another film having a higher frequency of cleaning. since the number of the reaction chamber for forming the high other film is large, the number of stops for cleaning the device less <br/> ing. Also, the cumulative film thickness tube of the reaction chamber for forming other films
In the control section, the deposition of other film thicknesses formed in this reaction chamber is monitored.
Ru can sense.

[0009]

An embodiment of the present invention will be described below with reference to the drawings using an in-line type plasma CVD apparatus for manufacturing a thin film transistor for an active matrix liquid crystal display, which is generally called a bottom gate type so-called inverted staggered structure. Will be explained.

As shown in FIG. 1, the plasma CVD apparatus includes a loading chamber 11, a heating chamber 12, a first reaction chamber 13, a first cooling chamber,
14, the second reaction chamber 15, the third reaction chamber 16, the fourth reaction chamber 17, the second
The cooling chamber 18, the unloading chamber 19, and the tray transport section 20 are sequentially arranged. Further, the tray transporting section 20 is provided with a substrate attaching / detaching section 21. Further, the second and third reaction chambers 15 and 16 are provided with accumulated cumulative film thickness control units 22 and 23, respectively. These cumulative cumulative film thickness control units 22 and 23 use a cumulative time counter of discharge time. are doing. Then, in the substrate attaching / detaching section 21 provided in the tray carrying section 20, the tray on which the substrate is loaded is carried into the carry-in chamber 11, changed from the atmospheric pressure state to the low-pressure state, and then carried to the heating chamber 12 in the low-pressure state. predetermined temperature, for example, heated at 300 ° C. until. afterwards,
Predetermined thickness of silicon nitride film (SiN _x) in the first reaction chamber 13, and for example from about 200n m film, the first cooling chamber 14
Cooled, amorphous silicon (α-Si) film a predetermined thickness in either of the second reaction chamber 15 or the third reaction chamber 16 was a at a low pressure atmosphere to about 250 ° C. In
And example, if about 50n m film, a fourth silicon nitride film in the reaction chamber 17 (SiN _x) a predetermined thickness, e.g., about 200n
m forming the membrane. Then, the substrate temperature is cooled down to about 150 ° C. or lower in the second cooling chamber 18, and the substrate is carried into the carry-out chamber 19 and is carried out.
After the inside is changed from a low pressure state to an atmospheric pressure state, it is carried out of the apparatus. The movement of the tray from the first reaction chamber 13 to the unloading chamber 19 is performed under low pressure.

In general, the more a film is formed in a reaction chamber, the more dust is generated, and when the film thickness exceeds a certain cumulative film thickness, the amount increases rapidly. When the equivalent film thickness on the substrate side is about 50 μm for silicon nitride and about 5 μm for amorphous silicon , dust generation increases and cleaning is required. Therefore, the first reaction chamber 13 and the fourth reaction chamber 17 are 50 μm /
200 nm = 250 times, second reaction chamber 15 and third reaction chamber
No. 16 requires cleaning when film formation is performed 5 times at 5 μm / 50 nm = 100 times.

In the above embodiment, since the reaction for amorphous silicon is constituted by the two reaction chambers of the second reaction chamber 15 or the third reaction chamber 16, the cleaning may be performed by 100 times × 2 = 200 times of film formation. . Therefore, the cleaning which has been performed once every 100 times can be reduced to once every 200 times. The amorphous silicon film is formed using the second reaction chamber 15 immediately after the cleaning of the apparatus by the accumulated film thickness management units 22 and 23 of the second reaction chamber 15 and the third reaction chamber 16. When the cumulative film thickness of the chamber 15 reaches 5 μm, the amorphous silicon film can be automatically formed in the third reaction chamber 16. Further, when the cumulative film thickness in the third reaction chamber 16 reaches 5 μm, a cleaning execution request can be displayed on a CRT or the like.

The heating may be performed in the loading chamber 11 without providing the heating chamber 12, or the cooling may be performed in the unloading chamber 19 without providing the second cooling chamber 18. The type of film is not limited to silicon nitride and amorphous silicon , but may be silicon oxide (SiO _x ) or the like.

Further, the accumulated cumulative film thickness management unit is provided in the second reaction chamber.
The present invention is not limited to the case where it is provided in the first and third reaction chambers 16 and may be in another reaction chamber.

The number of reaction chambers for forming the same film may be set based on the relationship between the film thickness accumulated until dust generation sharply increases and the film thickness required for the product.

[0016]

According to the plasma CVD apparatus of the present invention,
By increasing the number of reaction chambers for forming other films with higher frequency of cleaning than the reaction chamber for forming one film, the number of reaction chambers with higher frequency of cleaning is required. The number of stoppages for cleaning can be reduced, the operation rate can be improved, and the total number of reaction chambers for forming other films can be increased.
Films of other films to be formed in this reaction chamber by the product integrated film thickness management unit
Ru can manage the deposition of thickness.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a plasma CVD apparatus of the present invention.

FIG. 2 is a block diagram showing a conventional plasma CVD apparatus.

[Explanation of Signs] 13 First reaction chamber 15 Second reaction chamber 16 Third reaction chamber 17 Fourth reaction chamber 22 , 23 Cumulative accumulated film thickness management unit

Continuation of front page (56) References JP-A-4-147614 (JP, A) JP-A-59-41470 (JP, A) JP-A-2-224242 (JP, A) JP-A-63-35778 (JP) , A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) C23C 14/00-14/58 C23C 16/00-16/56 H01L 21/205 H01L 21/3065 H01L 21/31-21 / 32

Claims (2)

(57) [Claims] 1. A method according to claim 1, further comprising a predetermined number of reaction chambers for forming one film, and a cumulative integrated film thickness management unit for managing the deposition of film thickness, wherein another film different from the one film is formed. A plasma CVD apparatus, comprising: a plurality of reaction chambers, the number of which requires higher frequency of cleaning than the reaction chamber for forming the one film and the number of reaction chambers for forming the one film. . 2. A reaction chamber for forming the other film, a plasma CVD apparatus according to claim 1, wherein the this that provided on the rear step from the reaction chamber for forming the one film.