JP2000183031A - Plasma etching equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the generation of SiO-based spatter from the periphery of a plasma region during an etching process, to reduce a dimensional conversion difference in a wafer surface, and to improve controllability of etching conditions by oxygen. A plasma etching apparatus is provided. SOLUTION: A reaction chamber 1 in which a plasma region is formed, electrodes 2 and 3 provided in the reaction chamber for forming the plasma region, a stage 4 on which a member to be etched 5 is mounted, and the electrode In the plasma etching apparatus provided with the electrode cover 12 covering the electrode cover 3, the electrode cover 1
2 was made of SiC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plasma etching apparatus. More specifically, the present invention relates to a plasma etching apparatus provided with an electrode cover for protecting an electrode for plasma generation.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor device such as an LSI, a plasma etching apparatus is used to pattern electrodes and various thin films. As one of such plasma etching apparatuses, a triode type plasma etching apparatus having an upper electrode for plasma generation and a side wall electrode, a permanent magnet on the back surface of each electrode, and high density of plasma is used. ing. In this triode type plasma etching apparatus, the front surface of the side wall electrode on the side of the plasma region is covered with an electrode cover made of quartz to protect the electrode.

[0003]

However, in the conventional triode type plasma etching apparatus, since the electrode cover is made of quartz (SiO), when the plasma is generated by capacitive coupling from the side wall electrode, the side wall electrode is not used. Of the electrode cover that covers the wafer is sputtered and adheres to the wafer surface. The quartz sputter adhered to the wafer surface, on the other hand, adheres to the side surface of the processed pattern of the wafer and has an effect of stabilizing the pattern shape to protect the pattern side surface. However, since the sputtered material is generated by being sputtered from the side wall electrode at the peripheral portion of the wafer, the amount of spatter attached to the peripheral portion of the wafer becomes excessive compared to the amount of spatter attached to the central portion of the wafer. For this reason, a difference in pattern size occurs between the central portion and the peripheral portion within the wafer surface, and the size conversion difference increases.

Further, in the processing of the gate electrode in the semiconductor device manufacturing process, the sputtering of the quartz electrode cover generates oxygen-based active species, which affects the processing state. When it is attempted to control the supply of oxygen, it becomes difficult to control the supply of oxygen.

[0005] Such a quartz sputter generated during the etching process is generated not only from the electrode cover, but also when the wafer peripheral parts such as a clamp for holding the wafer and a focus ring for defining a plasma region are formed of quartz or these. In the case where a quartz protective cover is provided to protect the peripheral parts described above, such a peripheral part such as the wafer peripheral parts and its protective cover is also generated.

The present invention has been made in consideration of the above-mentioned prior art, and has been described in connection with the related art.
It is an object of the present invention to provide a plasma etching apparatus which eliminates generation of O-based sputters, reduces a dimensional conversion difference in a wafer surface, and improves controllability of etching conditions by oxygen.

[0007]

According to the present invention, there is provided a reaction chamber in which a plasma region is formed, and an electrode provided in the reaction chamber for forming the plasma region. A plasma etching apparatus comprising a stage on which a member to be etched is mounted and an electrode cover for covering the electrode, wherein the electrode cover is made of SiC.

According to this configuration, since the electrode cover is made of SiC containing no oxygen component, no SiO-based spatter is generated unlike the prior art, and the dimensional conversion difference of the processing pattern of the member to be etched is reduced. Variation is reduced.

Further, since the electrode cover made of SiC does not contain an oxygen component, no oxygen-based active species is generated by sputtering of the electrode cover, and the oxygen supply amount is accurately controlled by adding oxygen to the etching gas. And high-precision pattern processing becomes possible.

In a preferred embodiment, the electrode comprises an upper electrode and a side wall electrode provided in the reaction chamber,
The stage is provided to face the upper electrode, permanent magnets are provided on the back surface of the upper electrode and the back surface of the side wall electrode, and the electrode cover is provided on the front surface of the side wall electrode.

According to this structure, the present invention is applied to a triode type plasma etching apparatus having a high plasma density, and generation of oxygen-based active species due to sputtering of an electrode cover of a side wall electrode is eliminated, so that etching can be performed. The pattern dimension conversion difference is suppressed, and high-precision pattern processing becomes possible.

In a further preferred configuration, the peripheral members of the member to be etched are made of SiC.

According to this structure, since the peripheral members such as the holding member of the member to be etched and the focus ring or its protective cover are made of SiC, no SiO-based spatter is generated and the processing pattern of the member to be etched is The variation of the dimensional conversion difference is reduced. Oxygen-based active species are not generated by sputtering of the peripheral member, and the amount of oxygen supply can be controlled with high accuracy by adding oxygen to the etching gas, so that highly accurate pattern processing can be performed.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a triode type plasma etching apparatus according to an embodiment of the present invention.

An upper electrode 2 and an annular side wall electrode 3 are provided in a reaction chamber 1. A stage 4 made of a conductive material is provided facing the upper electrode 2. A wafer 5 is mounted on the stage 4. The wafer 5 is fixedly held on the stage 4 by the clamp 6. A focus ring 7 is provided on the outer periphery of the wafer 5 on the stage 4 to regulate the range of plasma. A permanent magnet 8 is provided on the back of the upper electrode 2, and a permanent magnet 9 is also provided on the back of the side wall electrode 3. A high frequency power supply 10 for plasma generation is connected between the upper electrode 2 and the side wall electrode 3. A high-frequency power source 11 for bias is connected to the stage 4 on which the wafer 5 is mounted. Thereby, a plasma region is formed in a space surrounded by the upper electrode 2 and the side wall electrode 3 in the reaction chamber 1.

In the present embodiment, the front surface of the side wall electrode 3 is covered with an electrode cover 12 made of SiC to protect the electrode. As described above, the electrode cover 12 is made of S containing no oxygen component.
By using iC, oxygen-based active species generated by sputtering the electrode cover during the etching process can be eliminated, and the supply of oxygen by adding to the etching gas can be easily and accurately controlled. Of the pattern between the central part and the peripheral part of the pattern is reduced.

Further, in the present embodiment, the electrode cover 1
2 may be made of SiC, and the clamp 6 and the focus ring 7 of the wafer 5 may be made of SiC. When a protective cover for covering the clamp 6 and the focus ring 7 is provided, it is preferable that the protective cover is also made of SiC. Since the peripheral members of the wafer 5 are made of SiC in this manner, oxygen-based active species generated by sputtering the wafer peripheral members during the etching process are eliminated, and the supply control of oxygen by adding to the etching gas is easily performed with high accuracy. In addition to the above, the difference in dimensional conversion of the pattern between the central portion and the peripheral portion in the wafer surface is further reduced.

[0018]

As described above, according to the present invention, since the electrode cover is made of SiC containing no oxygen component, no SiO-based spatter is generated unlike the prior art, and the processing of the member to be etched is performed. Variation in the dimensional conversion difference of the pattern is reduced.

Since the electrode cover made of SiC does not contain an oxygen component, no oxygen-based active species are generated by sputtering of the electrode cover, and the oxygen supply amount is accurately controlled by adding oxygen to the etching gas. And high-precision pattern processing becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a plasma etching apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1: reaction chamber, 2: upper electrode, 3: side wall electrode, 4: stage, 5: wafer, 6: clamp, 7: focus ring, 8, 9: permanent magnet, 10, 11: high frequency power supply, 1
2: Electrode cover.

Claims (3)

[Claims] 1. A reaction chamber in which a plasma region is formed, an electrode provided in the reaction chamber for forming the plasma region, a stage on which a member to be etched is mounted, and an electrode cover that covers the electrode. A plasma etching apparatus comprising: the electrode cover made of SiC. 2. The electrode comprises an upper electrode and a side wall electrode provided in the reaction chamber. The stage is provided to face the upper electrode, and a permanent magnet is provided on a back surface of the upper electrode and a back surface of the side wall electrode. The plasma etching apparatus according to claim 1, wherein the electrode cover is provided on a front surface of the side wall electrode. 3. A member surrounding the member to be etched is made of SiC.
The plasma etching apparatus according to claim 1, wherein: