JP2002252216A - Plasma processing method and plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly process a thin film over the entire substrate. SOLUTION: The processing apparatus comprise gas change-over means (valves 15, 16) which can exhaust gas individually from each of a plurality of regions into which a gas guiding plate 5 is divided. This allow gas flow to be changed during the plasma processing of a substrate 7 so that the thin film on the substrate 7 can be uniformly etched over the entire substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method and a plasma processing apparatus for performing plasma processing on a substrate using plasma generated by exciting a gas in a processing chamber using electromagnetic waves, and more particularly to a plasma processing apparatus. The present invention relates to a plasma processing method and a plasma processing apparatus for performing dry etching of a substrate used for manufacturing an electronic device such as a semiconductor or a liquid crystal.

[0002]

2. Description of the Related Art FIG. 4 shows a schematic diagram of a conventional plasma processing apparatus. In FIG. 4, in a state where the residual gas in the vacuum processing chamber 1 is exhausted by using the vacuum exhaust means 2, the valve 8 is then closed and opened, and the reaction gas is supplied from a gas tank (not shown) to the gas introduction path 3 and the gas introduction path 3. A plurality of gas outlets 1 provided on the surface of the gas introduction plate 5 through the reservoir 4
After 0, a reaction gas is introduced in a shower shape onto the substrate stage 6 in the vacuum processing chamber 1. In this state, a high-frequency power is applied to the substrate stage 6 also having an electrode function to excite the reaction gas in the vacuum processing chamber 1 by the generated electromagnetic wave, and plasma processing is performed on the substrate 7 placed on the substrate stage 6.

[0003]

However, in the above-described conventional plasma processing method and apparatus, when performing plasma processing, in order to perform uniform plasma processing of a thin film on a substrate over the entire surface of the substrate, processing conditions must be maintained during processing. In many cases, the processing is performed while switching between. Generally, this type of switching in a conventional plasma processing apparatus has been dealt with by changing conditions such as the flow rate of a reaction gas and the output of a high frequency applied to an electrode.

[0004] However, it is sometimes impossible to uniformly process the thin film on the substrate over the entire surface of the substrate only by changing the conditions such as the flow rate of the reaction gas and the output of the high frequency applied to the electrode.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a plasma processing apparatus capable of uniformly processing a thin film on a substrate over the entire surface of the substrate.

[0006]

In order to achieve the above object, a first aspect of the present invention is to provide a gas switching means capable of individually blowing gas from a plurality of divided regions of a gas introduction plate. Features.

Further, the gas switching means includes a plurality of gas reservoirs provided on the gas supply side of the gas introduction plate, a gas introduction path individually connected to the plurality of gas reservoirs, and a valve provided on the gas introduction path. Even if it comprises, it may be comprised by the switching plate which can open and close the gas outlet provided in the gas introduction plate, and the drive means which drives the said switching plate.

According to a second aspect of the present invention, during plasma processing, gas is blown out from at least a part of a combination of the plurality of divided regions of the gas introduction plate, and a region different from the region 1 from which the gas is blown out. Gas is blown out from the area 2 which is a combination of

According to these inventions, a thin film on a substrate can be uniformly processed over the entire surface of the substrate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plasma processing apparatus according to the present invention will be described below with reference to FIGS. The same parts as those of the conventional plasma processing apparatus are denoted by the same reference numerals, and description thereof will be omitted.

(First Embodiment) FIG. 1 is a schematic configuration diagram of a plasma processing apparatus according to a first embodiment of the present invention. In FIG. 1, while the residual gas in the vacuum processing chamber 1 is exhausted using the vacuum exhaust means 2, the valves 15 and 16 are opened from the closed state, and the reaction gas is supplied from a gas tank (not shown) to the gas introduction path 11 and 12, through the gas reservoirs 13 and 14 separated by the partition 9, from the entire surface (area 1) of the gas introduction plate 5 provided with the plurality of gas outlets 10, and from the substrate stage 6 in the vacuum processing chamber 1 A reaction gas is introduced in a shower shape on the top. In this state, high-frequency power is applied to the substrate stage 6 to excite the reaction gas in the vacuum processing chamber 1 by the generated electromagnetic waves, and the substrate 7 placed on the substrate stage 6 is subjected to dry etching (plasma processing). Then, a desired amount of etching is performed on the substrate 7.
After a lapse of a predetermined time, application of high-frequency power to the substrate stage 6;
The introduction of the reaction gas is stopped, and the dry etching of the substrate 7 is terminated.

Here, when the etching amount of the substrate 7 after the dry etching process is not uniform, for example, when the etching amount near the center of the substrate 7 is large and the etching amount around the periphery is small, It is necessary to make the etching amount of the peripheral portion of the substrate 7 larger than that of the central portion.

In such a case, the unprocessed substrate 7 is first placed on the substrate stage 6, and the residual gas in the vacuum processing chamber 1 is exhausted by the vacuum exhaust means 2, and the valve 15 is opened.
And 16 are closed to open, and the reaction gas is supplied from a gas tank (not shown) to the gas introduction paths 11 and 12 and the partition 9.
Through the gas reservoirs 13 and 14 separated from each other, and from the entire surface (area 1) of the surface of the gas introduction plate 5 provided with a plurality of gas outlets 10 onto the substrate stage 6 in the vacuum processing chamber 1 by a shower. A reaction gas is introduced into the device (step S1). In this state, high-frequency power is applied to the substrate stage 6 to excite the reaction gas in the vacuum processing chamber 1 with the generated electromagnetic wave, and the substrate 7 placed on the substrate stage 6 starts dry etching (plasma processing). (Step S2). During this dry etching process, the valve 15 is closed while the valve 16 is open. As a result, the reaction gas is not supplied to the gas reservoir 13 and the gas introduction plate 5
The reaction gas does not blow out from the vicinity of the center. On the other hand, since the reaction gas is continuously supplied to the gas reservoir 14, the reaction gas is continuously blown out from the vicinity (area 2) of the surface of the gas introduction plate 5 (step S3). That is, the reaction gas is blown out from a part of the plurality of divided regions of the gas introduction plate 5. After etching the substrate 7 for a predetermined time in this state, the application of the high-frequency power to the substrate stage 6 and the introduction of the reaction gas are stopped, and the dry etching of the substrate 7 is completed (step S4). In this step S3, more excited reaction gas is brought into contact with the peripheral portion than in the central portion of the substrate 7, and as a result, the amount of etching in the peripheral portion is increased as compared with the central portion of the substrate 7. Can be done. Thereafter, the dry-etched substrate and the unprocessed substrate are exchanged (Step S4), and the process returns to Step 1 to perform the dry-etching process on the substrate in the same procedure.

The number and shape of the divided regions of the gas introduction plate 5 are not limited to those of the first embodiment, but may be any number and shape depending on the etching amount of the substrate. Good.

Embodiment 2 FIG. 2 is a schematic configuration diagram of a plasma processing apparatus according to Embodiment 2 of the present invention. The difference from the first embodiment is that a switching plate 21 that can open and close a gas outlet provided in a gas introduction plate 5;
Cylinder (drive means) 23 for driving the switching plate 21
And that was provided.

In FIG. 2, similarly to the first embodiment, when it is necessary to increase the etching amount in the peripheral portion of the substrate 7 compared to the central portion, first, the cylinder (drive means) 23 is moved upward. The contact between the switching plate 21 and the gas introduction plate 5 is released by driving. Next, as in the first embodiment, the valve 8 is opened in a state where the residual gas in the vacuum processing chamber 1 is exhausted by using the vacuum exhaust means 2, and a reaction is performed on the substrate stage 6 in the vacuum processing chamber 1 like a shower. Introduce gas.
After a certain period of time, the cylinder 23 is driven downward to bring the switching plate 21 into contact with the gas introduction plate 5 so that the reaction gas does not blow out from the contact portion between the switching plate 21 and the gas introduction plate 5. Switching plate 2 from this time
An O-ring 22 is arranged on the contact surface of the switching plate 21 in order to increase the adhesion between the contact portion of the gas introduction plate 5 and the gas introduction plate 1.

As a result, the reactive gas does not blow out from the vicinity of the center of the gas introduction plate 5 but blows out only from the peripheral portion. Can be done.

In the second embodiment, a single switching plate is used, but a plurality of switching plates may be used.
Further, the operation of the switching plate is not limited to the present embodiment, and can be arbitrarily set according to the characteristics of the etching process, such as the switching plate operation direction and the number of operations.

Further, in addition to controlling the gas flow according to the present embodiment, etching may be performed by changing conditions such as the gas flow rate and the output of the high frequency applied to the electrodes.

Also, when a multilayer film on a substrate is etched by a single plasma process, the type of reactive gas and
If the flow of the gas is controlled in addition to changing the flow rate and the output of the high frequency applied to the electrode, a uniform etching process can be performed.

[0021]

According to the plasma processing apparatus of the present invention, by providing gas switching means capable of individually blowing out gas from a plurality of divided regions of the gas introduction plate, during the plasma processing of the substrate, The flow of gas can be switched, and the thin film on the substrate can be uniformly etched over the entire surface of the substrate.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a step diagram showing a procedure according to the embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum processing chamber 5 Gas introduction plate 6 Substrate stage (electrode) 7 Substrate 9 Partition wall 10 Gas outlet 11 Gas introduction path 12 Gas introduction path 13 Gas reservoir 14 Gas reservoir 15 Valve 16 Valve 21 Switching plate 23 Driving cylinder ( Driving means)

Claims (5)

[Claims] 1. A plasma for blowing a gas from a gas introduction plate into a vacuum processing chamber to radiate an electromagnetic wave from an electrode in the vacuum processing chamber to generate plasma in the vacuum processing chamber and performing plasma processing on a substrate in the vacuum processing chamber. In the processing apparatus, a gas switching unit capable of individually blowing gas from a plurality of divided regions of the gas introduction plate is provided. 2. The gas switching means includes: a plurality of gas reservoirs provided on a gas supply side of a gas introduction plate; a gas introduction path individually connected to the plurality of gas reservoirs; 2. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus includes a valve. 3. The gas switching means, comprising: a switching plate provided on a gas introduction plate, which can open and close a gas outlet, and a driving means for driving the switching plate. 2. The plasma processing apparatus according to 1. 4. A plasma for blowing a gas from a gas introduction plate into a vacuum processing chamber to radiate an electromagnetic wave from an electrode in the vacuum processing chamber to generate plasma in the vacuum processing chamber, and performing plasma processing on a substrate in the vacuum processing chamber. In the processing method, during the plasma processing, a gas is blown out from at least a part of the plurality of regions 1 of the plurality of regions of the gas introduction plate, and a region 2 that is a combination of regions different from the region 1 that blows the gas. A plasma processing method characterized by blowing gas from a substrate. 5. The area 1 is an entire surface of the gas introduction plate, and the area 2 is a peripheral surface of a region obtained by dividing the gas introduction plate into a peripheral part and a central part. Plasma treatment method.