JPS6098629A - Treating equipment - Google Patents

Abstract

PURPOSE:To treat a wafer uniformly by interposing a plurality of porous plates in a hollow section in an electrode and feeding a treating gas at uniform flow velocity, flow rate and pressure extending over the whole. CONSTITUTION:A hollow section 7 is formed to an upper electrode 2, and porous plates 9-11 are each mounted in parallel with a lower electrode 3 and detachably at mutually proper intervals to the hollow section 7. Circular through-holes 12-14 having different apertures are each bored to the plates 9-11. Consequently, pressure difference is reduced gently, a treating gas is diffused sufficiently in the hollow section 7, and a treating chamber is supplied with the treating gas uniformly extending over the whole under the state of proper flowing. Accordingly, a wafer is etched equally extending over the whole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to processing technology, particularly technology that performs processing using plasma reactions, such as dry etching processing, CVD processing, etc. used in the manufacture of semiconductor devices. Concerning techniques that can be used effectively.

BACKGROUND ART] When performing an etching process in the manufacture of semiconductor devices, it is conceivable to use a dry etching apparatus that utilizes a plasma reaction.

As such a dry enching device, parallel plate electrodes are provided in a processing chamber equipped with a gas introduction path and an exhaust path, and a wafer is placed on one of the electrodes and a high frequency voltage is applied to form a gas between the electrodes. A conceivable method is one in which the wafer is etched by a gas electrochemical reaction caused by plasma.

However, in such dry etching equipment, processing gas is not uniformly supplied over the entire surface of the wafer, resulting in a difference in the speed of etching progress between the center and the periphery of the wafer, resulting in non-uniform processing conditions. The present inventor has revealed that there is.

Therefore, a dry etching apparatus can be considered in which a plurality of processing gas channels are provided at the electrodes so that the processing gas is uniformly supplied over the entire surface of the wafer.

However, the present inventor has revealed that in such dry etching equipment, abnormal discharge may occur depending on the conditions, or gas may not be supplied evenly, resulting in uneven processing conditions. . This is particularly noticeable when the electrode spacing is narrow and the output is high.

[Object of the Invention] An object of the present invention is to provide a processing technique that allows uniform processing.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief summary of typical inventions disclosed in this application is as follows.

In other words, by inserting a plurality of porous plates in the hollow part of the electrode, the processing gas can be supplied with uniform flow velocity, flow rate, and energy throughout the electrode, so that the processing can be performed uniformly. It is.

[Example] Fig. 1 is a vertical cross-sectional view showing a dry etching apparatus according to an embodiment of the present invention, and Fig. 2 is a plan view showing each perforated plate thereof.

In this embodiment, this dry etching apparatus is equipped with a processing chamber 1 made of a quartz herger or the like, and the processing chamber 1 is constructed so as to be kept airtight. In the processing chamber I, a pair of parallel plate electrodes 2.3 are arranged above and below, respectively. A high frequency power source 4 is connected to the upper electrode 2, and the lower electrode 3 is grounded, and a wafer 5 as an object to be processed is connected to the upper electrode 2.
It is constructed so that it can be placed and held. Processing room 1
An exhaust passage 6 is connected to the bottom wall of the chamber so as to evacuate the interior of the chamber.

"A hollow part 7 is formed in the two-part electrode 2, and the hollow part 7
An introduction passage 8 for introducing an etching gas as a processing gas is connected to the ceiling wall of the apparatus approximately at the center thereof. Three perforated plates 9.10.11 are installed in the hollow part 7 in parallel with the lower electrode 3 at appropriate intervals, and are removably installed. As shown in Figures +a+, (bl, and (C)), circular through holes 12, 13, and 14 of different diameters are respectively opened.

That is, the first perforated plate 9 disposed most upstream has the largest diameter through-hole 12, and the second perforated plate 10 in the middle has a smaller-diameter through-hole I3 disposed most downstream. The third porous plate 11 is provided with through holes 14 having the smallest diameter, and in each case, the through holes are arranged so as to have as uniform a density as possible over the entire surface. Also, the first and second
The perforated plates 9 and 10 are made of an insulating material such as quartz, and the third perforated plate 14 is made of an electrode material such as aluminum (ΔI).

Next, the action will be explained.

The wafer 5 is placed on the lower electrode 3, the processing chamber 1 is evacuated and etching gas is introduced, and both electrodes 2.
When a high frequency voltage is applied between the wafers 3 and 3, plasma is formed, and the resulting gas electrochemical reaction causes the wafer 5 to undergo an etching process.

At this time, the etching gas introduced into the upper space of the hollow part 7 from the introduction path 8 receives some resistance from the first porous plate 9, so it diffuses throughout the entire first porous plate 9. It flows into the central space from the through hole 12. This through hole 12 has a large diameter and almost no resistance to passage is exerted, so that the flow is performed extremely gently or smoothly. The etching gas that has flowed into the central space is diffused so as to be uniform throughout, and flows into the lower space through the through holes 13 throughout the second holes #1tlO. The through hole 13 is the first through hole TL.
Although the gas flow is smaller than that of No. 12, the gas flow is almost uniform, so that the gas flows in slowly or smoothly. The etching gas that has flowed into the lower space is diffused so as to be completely uniform throughout, and the etching gas flows into the third perforated plate 11.
The water flows down ζ evenly over the entire surface of the wafer 5 from the entire through hole 14 . Although this through hole 14 has a small diameter, the gas flow is made uniform throughout the entire lower space, and the pressure difference between the upper and lower portions of the third perforated plate 11 is small.
The etching gas is gradually supplied to the entire surface of the wafer 5 with uniform flow rate, flow rate, and pressure throughout the through holes 14 of the third porous plate 11.

In this way, the etching gas is evenly and slowly supplied to the entire wafer 5, so that the etching process is uniformly applied to the entire wafer 5.

Further, since the third porous plate 11 closest to the lower electrode 3 has the substance of the upper electrode 2, it effectively contributes to plasma generation and induces an excellent gas electrochemical reaction.

Furthermore, since the first and second porous plates 9 and 10 are made of insulating material, unnecessary plasma is not generated.
No uncontrolled reactions are triggered in the hollow space 7.

In addition, prepare perforated plates of multiple standards: [Choose the most suitable one according to the conditions such as the flow rate, flow rate, pressure, exhaust volume of notching gas, power between electrodes, material to be etched, etc. Replacement is recommended.

Furthermore, it is desirable that the cut ends of each through hole in the perforated plate be rounded to avoid concentration of the electric field, and that the surface be finished.

Now, if only one perforated plate is provided in the hollow part of the electrode, and etching gas is supplied onto the wafer from each hole in this perforated plate, the following phenomenon will cause the etching process on the wafer to be delayed. becomes uneven.

However, if the holes in the perforated plate have a small diameter, the pressure difference between the hollow portion and the processing chamber will increase, and the flow rate of the etching gas through the holes will increase, resulting in a field lightning phenomenon.

In addition, when the holes in the perforated plate have large diameters, the pressure difference between the hollow part and the processing chamber is small, but the etching gas is not sufficiently diffused within the hollow part, so the etching gas flows out unevenly at each hole. A phenomenon occurs.

On the other hand, when multiple perforated plates each having through-holes of different diameters are provided in the hollow part of the electrode, as mentioned above,
Since the pressure difference is gradually reduced and the processing gas is sufficiently diffused in the hollow portion, the processing gas is supplied to the processing chamber evenly throughout the chamber in a suitable flow state. Therefore, the etching process on the wafer is uniformly performed over the entire wafer.

[Effects] By installing multiple perforated plates in the hollow part of the electrode, processing gas can be uniformly supplied throughout the processing chamber in an appropriate state, so it is possible to The ζ treatment can be applied uniformly over the entire surface.

(2) Plasma can be effectively generated by configuring the porous plate closest to the electrode to be processed to have an electrode structure, and the plasma can be generated in an uncontrolled manner between adjacent electrodes that fall into the hollow part of the electrode. Generation of unstable plasma can be prevented.

(31. By configuring the perforated plate to be replaceable, it is possible to install the most suitable one according to the processing conditions such as processing gas, exhaust volume, voltage applied between electrodes, and abrasive material of the object to be processed. A processing state can be created.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, there are no limitations on the number, arrangement interval, shape, etc. of the perforated plates.

The diameters and densities of the perforated holes in the perforated plate are not limited to being set the same; for example, they may be set to a small diameter and low density in the central region, and a large diameter and high density in the peripheral region. . In short, the settings may be made so that the processing gas is effectively and uniformly diffused and evenly flows into the processing chamber.

The perforated plate is not limited to being replaceable, but a plurality of hollow parts and electrodes to which the perforated plate is fixedly attached may be prepared in a plurality of specifications.

[Field of Application] In the explanation below, the invention made by the present inventor is mainly applied to a dry etching apparatus used in the manufacture of semiconductor devices, which is the field of application that forms the background of the invention, but the present invention is not limited thereto. For example, the present invention can be applied to processing equipment that utilizes a plasma reaction, such as a CVD equipment or an asher removal equipment.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing one embodiment of the present invention, and FIG.
l, (bl, tc+ are respective plan views showing each of the perforated plates. !- Processing chamber, 2.3... Electrode, 4... High frequency power supply, 5... Wafer (processed object) ), 6...exhaust path, 7
...Hollow part, 8...Gas introduction path, 9.10.11.
...Perforated plate, 12.13°14...Through holes. Agent Patent Attorney Akio Takahashi

Claims (1)

[Scope of Claims] 1. In a processing apparatus in which an object to be processed is arranged on one side of opposing electrodes provided in a processing chamber, and a gas is supplied to the processing chamber to perform processing, the gas is placed on the other side of the electrode. A hollow part is formed into which the gas is introduced, and a plurality of perforated plates are installed in this hollow part so that the introduced gas is uniformly diffused throughout and is evenly supplied to the processing chamber from each through hole in the final stage. A processing device characterized by: 2. Among the perforated plates, only the one closest to the object electrode is
2. The processing device according to claim 1, wherein the processing device has an electrode structure. 3. The processing apparatus according to claim 1, wherein the perforated plate is replaceable.