JPH03236484A - High-frequency etching device - Google Patents

Abstract

PURPOSE:To deposit metal of a metallic cathode on an anode in the intervals of etching and to prevent peeling of deposit thereon by replacing this movable metallic cathode with a base plate being an object of etching and arranging the said cathode at the etching position. CONSTITUTION:High-frequency electric power is impressed between an anode 2 and a cathodic plate 8 from an RF power source 6 in a treatment chamber 1. Gaseous Ar supplied from an introduction port 7 thereof is plasmaized. A base plate S arranged at the etching position A is etched by this plasma. In the high-frequency etching device, after etching is finished, the base plate S is retreated to the base plate carrier position B via a chuck 9 and replaced with a fresh base plate. In the intervals of sputtering thereof, a movable metallic cathode 10 positioned at the retreat position C is moved to the above-mentioned etching position A and etched. As this metallic cathode 10, Mo, Ti and Al, etc., which are good in adhesive properties to the anode 2 are preferably utilized. Thereby the etched metal thereof is built-up on the deposit of the anode 2 and peeling of this deposit is inhibited. Generation of dust in the treatment chamber 1 is prevented.

Description

[Detailed Description of the Invention] [Summary] Regarding RF etching equipment used in the manufacture of semiconductor devices, etc., it is possible to prevent deposits accumulating on the anode from becoming a source of dust even if the number of substrate etching processes increases. In order to make it difficult for anode deposits to peel off from the anode, a movable metal cathode is provided which can be placed in place of the substrate to be etched at the location where the substrate is to be etched. Further, the metal of the metal cathode is configured to be molybdenum, titanium, or aluminum.

[Industrial application field]

The present invention relates to a high frequency etching apparatus used for manufacturing semiconductor devices.

The above-mentioned radio frequency (RF) etching equipment is used mainly when the surface of the substrate to be etched is P etched in the manufacture of semiconductor devices.
It is used for etching insulators such as SG and SiO2.

It is also desired that the material removed by etching be treated so that it does not become dust inside the device.

[Conventional technology]

RF etching equipment applies high-frequency power between an anode and a cathode, and accelerates and collides ions such as Ar with the substrate to be etched, which is placed on the cathode side, thereby sputtering and etching the substrate surface. It is.

In the manufacturing of semiconductor devices, for example, when cleaning the substrate surface as a pretreatment for forming a wiring layer on the insulating film on the substrate surface, the substrate surface is mainly made of PSG or
Used for etching insulating materials such as iOz.

At this time, the material removed from the substrate by the etching is deposited on the surface of the anode, and the thickness of the deposit increases as the number of times the substrate is etched increases.

[Problem to be solved by the invention] By the way, the deposits on the anode are
In the case of glass such as No. 2, it has poor adhesion to the stainless steel or the like constituting the anode, so if it becomes thick, it will easily peel off and become a source of dust within the device.

This dust then impairs the cleaning process, e.g.
Prevents clean etching.

Therefore, the present invention provides R
An object of the present invention is to make it difficult for deposits on the anode to be peeled off from the anode so that the deposits deposited on the anode do not become a source of dust even when the number of substrate etching processes increases in an F etching apparatus.

[Means for Solving the Problems] The above objects are achieved by the RF etching apparatus of the present invention, which includes a movable metal cathode that can be placed at the position where the substrate to be etched is placed, alternating with the substrate. achieved.

According to the present invention, the metal of the metal cathode is molybdenum (MO), titanium (Ti), aluminum (Af),
It is desirable that it be one of the following.

[Function] In this RF etching apparatus, the metal cathode can be placed at the above position and etching can be performed after etching of the previous substrate is finished and while switching to the next substrate.

Therefore, the metal of the metal cathode can be deposited on the anode between the etching of the preceding and succeeding substrates, and since the metal has good adhesion with the anode, the anode of the anode deposited by the material removed from the substrate can be deposited on the anode. Even if the adhesion with the anode is poor, the deposit can be fixed on the anode by metal deposition before the deposit becomes thick.

This makes it difficult for the deposits on the anode to separate from the anode, and the deposits do not become a source of dust even if the number of substrate etching processes increases.

Note that MOTi and Af have particularly good adhesion with the anode, so if these metals are used for the metal cathode,
The above-mentioned adhesion is further strengthened, and the prevention of peeling of the deposit from the anode becomes extremely stable.

[Example] Hereinafter, an example of the RF etching apparatus according to the present invention will be described using the constituent countries shown in FIG.

In the same figure, this embodiment is based on an anode coupling method, where ■ is an RF etching chamber, 2 is an anode, 3 is an insulating ring, 4 is a coupling capacitor, and 5 is a matching circuit, 6 is RFii
Source, 7. 8 is an Ar gas inlet, 8 is a cathode plate, 9 is a substrate chuck for holding the substrate S to be etched, IO is a metal cathode according to the present invention, and 11 is a shield plate.

This RF etching equipment etches A2 on the insulating film on the surface of the substrate.
Since the processing chamber 1 is used exclusively for pretreatment when forming a wiring layer, the processing chamber 1 is connected to an AN film forming chamber (not shown) via a load rotor.

The anode 2 is made of stainless steel and has a cylindrical shape with a bottom.
It is insulated by a ceramic insulating ring 3, and high frequency power is supplied from an RF power source 6 via a capacitor 4 and a matching circuit 5.

Also, ^r gas is supplied into the cylindrical interior from the Ar gas introduction lower part.

The cathode plate 8 is made of stainless steel and has a plate shape, faces the anode 2 at the opening of the anode 2, and has an opening at the etching position A in the center.

The substrate chuck 9 has an etching position A and a substrate transfer position B.
and the substrate S at the etching position A.
The substrate S is held so that it faces the anode 2.

The metal cathode 10 is made of Mo, Ti, or Al, and is movable between an etching position A and a retracted position C, and faces the anode 2 at the etching position A. The metal of the metal cathode 10 is particularly preferably the one mentioned above, but other metals may be used.

The shield plate 11 confines the Ar plasma generated by the supply of the high-frequency power in a region surrounded by the anode 2 and the cathode plate 8.

When etching the substrate S, the substrate chuck 9 holding the substrate S is placed at the etching position A, and the surface of the substrate S is etched by applying high frequency power. At this time, the metal cathode 10 is retracted to the retracted position C. Thereafter, when transporting the substrate S for replacement, the substrate chuck 9 is placed at the substrate transport position B, the metal cathode 10 is placed alternately at the etching position A, and high frequency power is applied. Etching the metal cathode 10.

In this way, the anode 2 can be
Since the deposits accumulated on the substrate become difficult to peel off from the anode 2, even if the number of substrate etching processes increases, the deposits will not become a source of dust, and the substrate can always be etched cleanly.

When the deposit on the anode 2 becomes thicker as the number of consecutive substrate etching processes increases,
All you have to do is stop using the device and remove it.

Although this embodiment is based on an anode coupling method, the present invention can also be applied to a cathode coupling method, and similar results can be obtained.

[Effects of the Invention] As explained above, according to the configuration of the present invention, in an RF etching apparatus used for manufacturing semiconductor devices,
In order to prevent the deposits that accumulate on the anode from becoming a source of dust, the deposits on the anode can be made difficult to peel off from the anode, and even if the number of consecutive substrate etching processes increases, a clean substrate can always be etched. It has the effect of making it possible.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of the embodiment, It is. 6 is an RF power supply, 7 is an Ar gas inlet; 8 is a cathode plate, 9 is a substrate chuck, 10 is a metal cathode, 11 is a shield plate, A is the etching position, B is the board transfer position; C is the retreat position; S is the substrate to be etched, It is. In the figure, 1 is an RF etching processing chamber; 2 is an anode, 3 is an insulating ring, 4 is a coupling capacitor, 5 is a munching circuit,

Claims (1)

[Claims] 1) The etching target substrate can be placed at a position where the substrate is to be etched, alternating with the substrate.
A high-frequency etching device characterized by having a movable metal cathode. 2) The metal of the metal cathode is molybdenum, titanium,
The high-frequency etching apparatus according to claim 1, wherein the etching device is aluminum.