JP2000195841A - Method and apparatus for etching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a cleaning cycle for an apparatus, relating to an etching device used for manufacturing a semiconductor device, by reducing changes in etching rate and etching selection ratio according to the increase in the number of processed sheets, processing, while the etching rate and the etching selection ration to a base material and mask material are kept stable, and suppressing the release of deposit sticking to the inside wall of a chamber. SOLUTION: This apparatus is provided with a wafer mounting stage 12, on which a wafer W is placed, a chamber 14 provided with an inner wall comprising a plasma region away from the wafer placement stage 12 and a part which does not face the wafer W or plasma region, an inductively coupled antenna 16 provided on the outer periphery of the chamber 14, and a high-frequency power source 18 for supplying power to the antenna 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an etching apparatus and an etching method, and more particularly, to an etching apparatus and an etching method used for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art PZT (lead zirconate titanate (Pb (Zr _x Ti _1-x ))
O ₃ )), a ferroelectric thin film of an oxide such as PLZT ((Pb, Li) (Zr, Ti) O), or BST (bismuth strontium titanium oxygen (BiSrTiO)), STO (strontium titanium oxygen (SrTiO) )), Or an etching apparatus used for etching a thin film of a material having a low vapor pressure such as platinum (Pt) or a high dielectric thin film of an oxide.
The parallel plate type, the ECR type, the helicon type, and the ICP (inductive coupling) type are increasingly used.

[0003] In particular, ICP type etching apparatuses are widely used because the apparatus structure is relatively simple. General I
FIG. 1A schematically shows the structure of the CP type etching apparatus.

In FIG. 1A, a coiled antenna 2 is provided around a bell jar (also called a chamber) 1 made of quartz.
Is wound. Then, power for plasma generation is supplied from the high-frequency power supply 4 to the antenna 2 via the matching circuit 3, whereby plasma is generated in the bell jar 1 filled with the etching gas. A wafer W is fixed on a stage 5 in the bell jar 1. The wafer W includes a blocking capacitor 6 and a matching circuit 7.
Is connected to the wafer bias power supply 8 via an AC.

The power for plasma generation supplied from the high frequency power supply 4 is hereinafter referred to as source power. The power supplied from the wafer bias power supply 8 is hereinafter referred to as a bias power.

The bias power supplied from the wafer bias power supply 8 is important for obtaining a high etching rate and high anisotropy in etching. That is,
The anisotropy of the etching is achieved by adjusting the bias power to pull the ions generated by the plasma perpendicular to the wafer 4. Also, the magnitude of the bias power determines the etching rate and the etching selectivity of the etching target with respect to the base and the mask material.

[0007] Wafer processing using plasma is performed using the above-described apparatus and the like, and etching conditions such as etching gas flow rate, chamber pressure, stage position, source power, and bias power are the same each time the wafer is replaced. , So that always the same etching rate,
An etching selectivity is obtained.

[0008]

However, when a wafer is processed using the above-described general etching apparatus or the above-described general etching method, as the number of processed wafers increases, the etching rate and the etching selectivity increase. May fluctuate.

An example of an etching rate of a platinum film and an example of an etching selectivity of a platinum film to a resist when a platinum film on a wafer is etched using a resist as a mask in the conventional ICP apparatus shown in FIG. Is shown in FIG. As is clear from FIG. 2, the etching rate and the etching selectivity of the platinum film change as the number of processed films increases.

It is considered that the cause is dirt on the inner wall of the chamber 1. Causes of contamination of the inner wall of the chamber 1 are adhesion of the etched material, adhesion of the etched (sputtered) mask material, and etching (sputtering).
Adhesion of a base material, or deposition of radical elements generated by plasma.

In particular, in the case of an apparatus such as an ordinary ICP type etching apparatus which supplies electric power from outside the chamber to generate plasma in the chamber, as shown in FIG. Since the contamination 9 prevents the supply of electric power into the chamber 1, it becomes difficult to continuously generate the plasma in the same state.

In particular, if the contamination is due to a conductive substance, the power consumption due to the contamination increases, and the fluctuations in the etching rate and the etching selectivity increase.

[0013] Since such a stain on the inner wall of the chamber can be removed by cleaning the chamber, the initial etching rate can be recovered by cleaning the chamber, or the etching selectivity of the film to be etched with respect to the base and the mask material can be recovered. be able to.

However, since the etching process must be stopped during the cleaning of the chamber, the longer the cleaning cycle of the apparatus and the shorter the cleaning time, the better. The cycle of chamber cleaning is normally managed based on the processing time or the accumulated data of the number of processed wafers. According to such a management method, the margin of the cleaning cycle must be widened, and the cleaning operation is performed even when cleaning is not necessary, which is problematic from the viewpoint of efficient operation of the etching apparatus.

If the inner wall of the chamber is contaminated with an organic film, there is a so-called plasma cleaning method in which oxygen plasma is blown in the chamber. However, removal of a substance having a low vapor pressure, such as platinum, by plasma cleaning has no effect. For this reason, after etching a film made of a substance having a low vapor pressure such as platinum, the chamber is generally wet-cleaned.

However, wet cleaning requires more time than plasma cleaning, and has a problem from the viewpoint of efficient operation of the apparatus.

On the other hand, dirt on the inner wall of the chamber causes particles to be generated. It is considered that particles are generated by removing the dirt accumulated on the inner wall of the chamber. The smaller the number of particles, the lower the yield of semiconductor device manufacturing. Since dirt on the inner wall of the chamber can be removed by cleaning the chamber, if the chamber is cleaned before peeling of the dirt occurs, the yield of semiconductor device manufacturing does not decrease.

However, as described above, since the processing of the product must be stopped during the cleaning of the apparatus, the longer the cleaning cycle of the apparatus, the better. That is, it is preferable that the amount of dirt on the inner wall of the chamber be as small as possible, and it is preferable that the dirt once adhered can be prevented from peeling off.

An object of the present invention is to reduce fluctuations in the etching rate and etching selectivity as the number of substrates increases in the step of etching a substance having a low vapor pressure or in the step of etching a film made of a substance that cannot be plasma-cleaned. An etching apparatus and an etching apparatus capable of performing processing while maintaining an etching rate and an etching selectivity with a base material and a mask material stably, and suppressing the peeling of deposits adhered to the inner wall of the chamber and extending the cleaning cycle of the apparatus. The aim is to provide a method.

[0020]

Means for Solving the Problems (1) The above-mentioned problems are:
As illustrated in FIG. 3, FIG. 9, FIG. 10, or FIG. 12, it has a wafer mounting table 12 on which a wafer W is mounted, and a plasma generation area separated from the wafer mounting table 12, and A chamber 14 (14a, 24, 26) having an inner wall having a portion not facing the wafer W or the plasma generation region, and an inductive coupling type disposed on the outer periphery of the plasma generation region in the chamber 14 And an RF apparatus 18 for supplying power to the antenna 16.

The above-described etching apparatus is characterized in that irregularities 15 are formed on the inner wall of the chamber 14 around the plasma generation region.

In the above-described etching apparatus, the inner wall around the plasma generation region of the chamber 14 exists between the antenna 16 and the wafer W or exists between the antenna 16 and the plasma region. It is characterized by being present.

In the above-described etching apparatus, the inner wall of the chamber 24 around the plasma generation region is covered by a deposition-inhibiting plate 25 having a hole 25a. In this case, it is preferable that the hole 25a of the attachment-preventing plate 25 has a portion not facing the wafer W or the plasma region.

In the above-described etching apparatus, the inner wall of the chamber 14a around the plasma generation region is
It is characterized by having a surface with a roughness equal to or more than 1.6S mechanical finish.

In the above etching apparatus, at least the inner wall of the chamber 14 around the plasma generation region is made of quartz or covered with quartz. (2) As shown in FIG. 12, the above-described problem has a wafer mounting table 12 on which a wafer W is mounted, a plasma region separated from the wafer mounting table 12, and the area around the plasma generation region. A chamber 26 having an inner surface made of aluminum in a region to be removed, an inductively-coupled antenna 16 arranged on the outer periphery of the plasma generation region of the chamber 26, and a high-frequency power supply 18 for supplying power to the antenna 16; The problem is solved by an etching apparatus characterized by having the following. (3) The above-described problem has a wafer mounting table on which a wafer is mounted, and a plasma generation region separated from the wafer mounting table, and does not face the wafer or the plasma generation region around the plasma generation region. Using a device having a chamber having an inner wall having a portion, an inductively coupled antenna disposed on the outer periphery of the plasma generation region of the chamber, and a high-frequency power supply for supplying power to the antenna. The wafer is mounted on the wafer mounting table, and the maximum temperature of the inner wall of the chamber is set to 100 ° C.
The problem can be solved by an etching method characterized by setting the temperature below or setting the difference between the temperature of the inner wall at the time of etching and the temperature at the time of standby to 70 ° C. or less, and starting the etching of the wafer or the film thereon. (4) The above-described problem has a wafer mounting table on which a wafer is mounted and a plasma generation region separated from the wafer mounting table, and does not face the wafer or the plasma generation region around the plasma generation region. Using a device having a chamber having an inner wall having a portion, an inductively coupled antenna disposed on the outer periphery of the plasma generation region of the chamber, and a high-frequency power supply for supplying power to the antenna. The wafer is mounted on the wafer mounting table, and the object to be etched is platinum, iridium, ruthenium, copper, or a film made of a compound of any one of the elements formed on the wafer, or an oxide high dielectric substance. The problem is solved by an etching method characterized by being a film or an oxide ferroelectric film.

The figures and reference numbers cited in (1) and (2) are for facilitating the understanding of the present invention, and the present invention is not limited thereto.

Next, the operation of the present invention will be described.

According to the present invention, in an inductively coupled etching apparatus, an inner wall of a chamber having a plasma region is provided with irregularities, a surface having a roughness of 1.6S mechanical finish or more is provided, or the inner wall is provided. It is made to cover with a deposition prevention plate in which a plurality of holes were formed.

As a result, there is a portion on the inner wall of the chamber where dirt is unlikely to adhere. Therefore, it is possible to suppress the interruption of power supply from the antenna due to the dirt on the inner wall, thereby stabilizing the plasma state and maintaining the same state. , Plasma processing can be performed, and etching with good reproducibility can be achieved.

According to the present invention, the maximum temperature of the inner wall of the etching apparatus is set to 100 ° C. or lower, or the inner wall is set to have a temperature difference of 70 ° C. or lower.
The thermal stress applied to the dirt attached to the inner wall of the chamber is sufficiently reduced, so that the dirt is not easily peeled off, and the amount of particles generated due to the dirt peeling is reduced. As a result, the cleaning cycle of the apparatus becomes longer, so that the etching apparatus can be operated efficiently.

According to still another invention, a chamber is used in which aluminum is exposed from a region other than the periphery of the plasma generation region. Experiments have shown that the use of such an apparatus makes it possible to reduce peeling of contaminants from the inner wall of the chamber as compared with a conventional plasma dry etching apparatus, and the cleaning cycle of the apparatus can be lengthened.

[0032]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. (First Embodiment) FIG. 3 is a configuration diagram of an IPC type etching apparatus according to a first embodiment of the present invention.

In FIG. 3, a conductive wafer mounting table 12 on which a wafer W such as a semiconductor substrate is mounted is mounted inside a wafer storage chamber 11. Further, an exhaust port 13 is provided below the wafer storage chamber 11, and the exhaust port 1 is provided.
The gas is exhausted through the wafer storage chamber 1
1 and a bell jar 14, which will be described later, are decompressed.

Further, a bell jar (chamber) 14 having a plasma generation area therein removably covers the opening 11a on the upper part of the wafer storage chamber 11. Belja 14
Is formed of quartz, and the inner wall of the side is formed with irregularities 15, and a part of the inner wall of the bell jar 14 does not face the wafer W due to the presence of the concave portion 15a. 14 so as not to face the plasma generated within. Further, the gas inlet 10 is provided in the bell jar 14. FIG. 4 shows a state in which the dirt D adheres to the irregularities 15 on the inner wall of the bell jar 14.

Further, a coil-shaped antenna 16 is wound around the outer periphery of the bell jar 14, and both ends thereof are matched with the matching circuit 1.
The antenna 16 is connected to a high-frequency power supply 18 via a power source 7 so that a source power having a frequency of 13.56 MHz can be supplied to the antenna 16.

The wafer mounting table 12 is connected via a blocking capacitor 19 and a matching circuit 20 to a wafer bias power supply 21 having an output frequency of 100 kHz to 13.56 MHz.

The cooler 22 is provided outside the bell jar 14.
Is attached, and the bell jar 14 can be selectively cooled.

Next, the results of an experiment in which the platinum film was etched using the ICP type etching apparatus of the present invention shown in FIG. 3 and the platinum film was etched using the conventional ICP type etching apparatus shown in FIG. Compare the results of the etching experiment. Table 1 shows the etching conditions at this time.

[0039]

[Table 1]

From the experimental results of FIG. 2 obtained by etching a platinum film on a wafer using a resist as a mask by using the conventional ICP apparatus shown in FIG. It can be seen that the amount of change in the etching rate and the etching selectivity of the platinum film is large.

On the other hand, the platinum film on the wafer is etched using the resist as a mask by using the ICP apparatus of the present embodiment shown in FIG. 3, and the etching rate of the platinum film and the etching selectivity of the platinum film with respect to the resist. As a result, a result as shown in FIG. 5 was obtained.
As is clear from the graph shown in FIG. 5, it can be seen that the change in the etching rate and the etching selectivity of the platinum film is smaller as the number of processed films is increased. That is, FIG.
According to the experimental results, the change in the etching rate and the etching selectivity of the platinum film is small as compared with the experimental results in FIG. 2, and the cleaning cycle of the chamber can be made longer.

Next, the principle of an inductively coupled plasma (ICP) type etching apparatus will be described with reference to FIG.

The antenna 1 wound around the bell jar 14
6 is supplied with source power to generate plasma. When a high-frequency current flows through the antenna, a high-frequency magnetic field is generated,
An induced electric field is generated. The electrons are driven by the induced electric field, and the plasma P is generated and maintained in the bell jar 14. Note that a sheath S exists between the plasma P and the wafer W.

In the mechanism in which electrons are driven by the induced electric field, the antenna 16 corresponds to the primary coil of the transformer and the plasma P corresponds to the secondary coil. FIG. 7 shows an equivalent circuit of the inductively coupled plasma. A high-frequency current flows from the high-frequency power supply 18 to the coiled antenna 16 via the matching circuit 17. This high-frequency current creates a high-frequency magnetic field,
An electric field is generated in the plasma P linked to this magnetic field. This electric field becomes a driving force, and a current is generated in the plasma.

In FIG. 7, the plasma in the bell jar 14 is represented by an equivalent circuit in which the coil L and the resistor Zp are connected. The matching circuit 17 connected to the antenna 16 is a T-shaped coupling of three variable capacitors.

Here, the case where the bell jar 14 is contaminated is considered. If the inner surface of the bell jar 14 is contaminated, even if the high-frequency magnetic field B generated from the antenna 16 is maintained the same, the magnetic field which the plasma P senses from the antenna 16 is weakened by the contamination. Even if the source power is maintained at the same level, the electric field applied to the plasma P is reduced. This allows
The density of the plasma in the bell jar 14 decreases. This is equivalent to the mutual inductance M of FIG. 7 being reduced.

If the dirt on the inner surface of the bell jar 14 is due to a conductive film such as platinum, the current generated in the plasma P is further reduced due to the shielding effect. As a result, the plasma density decreases. When the plasma density decreases, a large bias voltage is applied to the wafer W even with the same bias power.

The principle will be described with reference to FIG.

Most of the voltage Vpp generated by the wafer bias power supply 21 is supplied to the blocking capacitor 19 (Cb).
And the sheath capacitance Cs. Here, the voltage applied to the sheath capacitance Cs corresponds to the bias voltage Vcs, and the voltage applied to the blocking capacitor Cb corresponds to the wafer bias voltage Vcb.

Accordingly, the wafer bias voltage Vpp, the sheath bias voltage Vcs, the blocking bias voltage Vcb, and the impedance voltage Vr have the following relationship.

Vpp = Vcb + Vcs + Vr (1) Here, since the impedance Zp of the plasma shown in FIG. 6 is small, the voltage Vpp of the wafer bias power supply 21 is applied to the blocking capacitor Cs and the sheath S between the plasma and the wafer. Equation (1)
Is represented by the following equation (2).

Vpp = Vcb + Vcs (2) When the density of the plasma P in the bell jar 14 decreases, the distance between the sheaths S between the plasma wafers increases, so that the capacitance of the sheath capacitance Cs decreases. As a result, the voltage division ratio between the blocking capacitor Cb and the sheath capacitance Cs changes, and the bias voltage Vcs increases. Plasma density and wafer bias voltage V
When cb changes, the etching rate and the etching selectivity change.

By the way, in the above-described ICP type etching apparatus according to the present embodiment, as shown in FIG. 4, the concave portion 15a of the unevenness 15 on the inner wall of the bell jar 14 is less likely to be stained than other portions. .

On the other hand, as shown in FIG. 1 (b), the inner wall of the conventional ICP type etching apparatus is almost uniformly contaminated on the entire inner wall of the bell jar.

Therefore, in the ICP type etching apparatus according to the present invention, the loss of the source power is reduced as compared with the conventional apparatus. As a result, even if the same number of processes are performed,
In the ICP apparatus according to the present invention, the fluctuation of the etching rate, the etching selectivity of the film to be etched with respect to the base and the mask material is reduced.

As shown in FIGS. 3 and 6, the bell jar 14 made of quartz is exposed to the plasma P during the wafer processing, so that the inner surface of the bell jar 14 during the wafer processing is smaller than when the apparatus is on standby. It gets hot. As a result, the dirt D deposited on the inner wall of the bell jar 14 is subjected to thermal stress due to the temperature difference between during the wafer processing and during the standby of the apparatus.

Therefore, after the bell jar 14 has been cleaned, the cumulative number of wafers processed by the ICP apparatus increases, and as the dirt D on the inner wall of the bell jar 14 becomes thicker, the thermal stress applied to the dirt D film also increases. It is considered that the contaminants are easily peeled off from the inner wall of the bell jar 14.

Therefore, the temperature difference between the wafer processing and the apparatus standby is set to 70 ° C. or less, or the maximum temperature of the inner wall of the bell jar (chamber) 14 during the wafer processing is set to 1
Experiments have shown that by setting the temperature to 00 ° C. or lower, the thermal stress applied to the dirt attached to the inner wall of the bell jar 14 can be sufficiently reduced, and as a result, the generation of particles can be reduced.

For example, when the Pt is etched using the resist as a mask while the cooler 22 is operated with the addition to the quartz bell jar 14 of the ICP apparatus shown in FIG. When a particle inspection was performed, experimental results as shown in Table 2 below were obtained.

[0060]

[Table 2]

As is apparent from Table 2, the bell jar 14 was cooled, and the temperature reached during the etching was set to 100 ° C. or less.
It can also be seen that by setting the temperature change in the chamber during etching and in standby to 70 ° C. or less, it is possible to prevent contaminants from peeling off from the inner wall of the bell jar 14 and to prevent generation of particles. Thereby, the cleaning cycle of the apparatus can be lengthened.

The above-described etching apparatus can be used for performing sputter etching.

When using the above-described ICP etching apparatus, at least one of the material to be etched, the mask material, and the base material must be at least one of platinum (P) having a low vapor pressure.
t), iridium (Ir), ruthenium (Ru), ruthenium oxide (RuO), or a conductive film such as copper (Cu) or a compound of the element thereof, the conductive film easily adheres to the bell jar 14. Since the conductive contamination causes a large fluctuation of the wafer bias voltage Vcb due to the above-described phenomenon, the etching apparatus of the present invention is a very effective means for performing a continuous wafer processing.

The material to be etched is PZT, PLZ
Ferroelectric thin film of oxide such as T, or BST, STO
And a high dielectric thin film of an oxide such as (Second Embodiment) As shown in FIG. 9, the inner surface of a quartz bell jar 14a is made to have a roughness equal to or more than 1.6S mechanical finish as shown in FIG. 9, instead of the inner surface irregularities 15 of the bell jar 14 of the CIP device shown in FIG. May be the irregularities 15b obtained by the treatment described above. In FIG. 9, the same reference numerals as those in FIG. 3 indicate the same elements.

Here, the 1.6S machine finish means that the surface has a smoothness of ± 0.6 / 100 mm. Therefore,
The roughness equal to or more than 1.6S mechanical finish means that the surface has a smoothness of ± 0.6 / 100 mm or more. 1.6 The mechanical finishing is performed by, for example, blast processing of $ 300 to 400, and as a result, the surface irregularities are Ra = 1.
It becomes about μm.

Next, using a device in which the inner surface of the quartz bell jar 14a was machine-finished by 1.6S and a device in which the inner wall of the quartz bell jar was baked and finished with extremely small irregularities, the resist was controlled by each device. The state of the inner wall of the chamber when the platinum film was etched using the mask as a mask and the particle inspection were performed. As a result, the results shown in Table 3 were obtained.

[0067]

[Table 3]

As is apparent from Table 3, the quartz bell jar 1
The inner wall of 4a is machined by 1.6S and the roughness 15
It can be seen that by using the bell jar 14a having b, the peeling of the contaminant from the inner wall of the bell jar 14a can be prevented and the generation of particles in the bell jar 14a can be prevented. This indicates that the cleaning cycle of the apparatus can be lengthened. (Third Embodiment) Next, the third embodiment of the ICP apparatus according to the present invention will be described.
The embodiment will be described with reference to FIG.

In FIG. 10, inside the bell jar 24, there is a cylindrical quartz-made protection plate 2 covering the inner surface of the bell jar 24.
5 are arranged. A large number of holes 25
a is open. The outer peripheral surface of the deposition preventing plate 25 and the bell jar 2
It is preferable that the distance between the inner peripheral surface of the bell jar 24 and the inner peripheral surface of the bell jar 24 be in contact with each other.

The inner peripheral surface of such a protection plate 25 and the hole 25a
Has the same function as the unevenness 15 on the inner wall of the bell jar 14 shown in FIG. 3, and is equivalent to the fact that a concave portion having a depth at least equal to the thickness of the protection plate 25 is formed in the protection plate 25.

The ICP device shown in FIG. 10 differs from the device of the first embodiment in that the unevenness 15 on the inner wall of the bell jar 14 is formed directly on the inner wall of the bell jar 24 or along the inner wall of the bell jar 25. Is provided, and the other structure is the same as that of FIG.

In such an ICP apparatus, the inner wall of the bell jar 24 hidden by the deposition-preventing plate 25 does not face the plasma or the wafer W. For this reason, the inner surface of the bell jar 24, which is a portion of the inner wall of the bell jar 24 that is hidden by the deposition-inhibiting plate 25, is less likely to be stained than the inner wall of the conventional chamber.

FIG. 11 shows a state in which dirt D has adhered to the inner surface of the attachment-preventing plate 25 and the inner wall of the bell jar 24.

According to this, the region where the ions in the plasma reach is the inner surface of the deposition-preventing plate 25 and the hole 25a of the deposition-preventing plate 25.
Thus, the adhered dirt is reduced on the inner wall of the bell jar 24. As described above, the region facing the plasma generated in the bell jar 24 is the deposition-preventing plate 25, and the deposition-preventing plate 25
The dirt is reduced by the area of the hole 25a. As a result,
According to the same principle as in the first embodiment, the increase in the sheath capacitance Cs is suppressed even if the cumulative number of wafers processed after cleaning the bell jar 24 increases, and the loss of source power can be reduced.

When Pt is etched using the resist as a mask in the CIP apparatus shown in FIG. 10, the result is almost the same as that shown in FIG. 5, that is, the change in the etching rate and the etching selectivity of the platinum film becomes small, and The result that the cleaning cycle can be lengthened was obtained.

The device of the third embodiment is different from the device of the first embodiment in that the irregularities 15 are formed directly on the inner wall of the bell jar 14 or that the quartz has a plurality of holes 25a along the inner wall of the bell jar 24. Is provided. Therefore, the device shown in FIG. 10 has the same operation and effect as the first embodiment. Further, in the present embodiment, since the area to which the dirt D mainly adheres is the inner wall of the quartz-made protection plate 25, the bell jar 24 itself can be easily cleaned. Moreover, if a plurality of the attachment-preventing plates 25 are prepared in advance,
The bell jar 24 returns to the initial clean state only by replacing the deposition-preventing plate 25.

In FIG. 10, a large number of holes 25a are provided in the attachment-preventing plate 25, but a structure having a large number of concave portions may be employed. In this case, the same operation as in the first embodiment is performed. The effect is obtained. Fourth Embodiment In the first to third embodiments, the ICP apparatus using the chambers 14, 14a, and 24 made of total quartz has been described. In this embodiment, an ICP apparatus using a chamber in which the periphery of the plasma generation region is made of quartz and the other region is made of aluminum will be described with reference to FIG.

The chamber 26 shown in FIG. 12 has a side portion made of quartz, and other regions (for example, a ceiling portion and a lower portion) made of aluminum. That is, inside the chamber 26, the quartz surface is exposed from the inner wall around the side of the plasma generation region, and the aluminum surface is exposed from other regions. FIG.
2, the same reference numerals as those in FIG. 3 indicate the same elements.

Next, the inner wall of the chamber excluding the side of the plasma generation region in the chamber is anodized as in the prior art, and the inner wall of the chamber except the side of the plasma generation region in the chamber 26 is removed as in the present embodiment. Using aluminum exposed without anodizing the inner wall of the area,
In each chamber, the platinum film was etched using the resist as a mask. Table 4 shows the state of the inner wall of the chamber obtained by this experiment and the result of the particle inspection of the inner wall of the chamber.

[0080]

[Table 4]

As is evident from Table 4, exposing the aluminum in regions other than the quartz surface can prevent the dirt from peeling off with a bell jar and prevent the generation of particles. That is, it is understood that the cleaning cycle of the apparatus can be lengthened. (Other Embodiments) Although the results of the above-described embodiment are based on the ICP device, the present invention is not limited to the ICP device. If it is a device that generates plasma by supplying power from outside the chamber like an ICP device,
There is a problem that the input of power is hindered by contamination on the inner wall of the chamber and it is difficult to continuously generate plasma in the same state.

In this device, as in the above-described embodiment, the "inner wall of the structure where the contamination is partially reduced" is formed in the bell jar (chamber) so that the plasma state can be maintained substantially constant. To be generated.

[0083]

As described above, according to the present invention, in an inductively-coupled etching apparatus, unevenness is provided on the inner wall of a chamber having a plasma region, or a surface having a roughness of 1.6S mechanical finish or more is provided. Or the inner wall of the chamber is covered with a shield plate having a plurality of holes, so that a portion that is hardly contaminated exists on the inner wall of the chamber, and in that portion, the supply of power from the antenna is facilitated. By
The plasma processing can be performed in the same state by stabilizing the plasma state. As a result, etching with good reproducibility can be achieved.

According to the present invention, the maximum temperature of the inner wall of the etching apparatus is set to 100 ° C. or lower, or the inner wall is set to have a temperature difference of 70 ° C. or lower.
The thermal stress applied to the dirt attached to the inner wall of the chamber is sufficiently reduced, and the amount of particles generated due to the dirt peeling can be reduced. As a result, the cleaning cycle of the apparatus becomes longer, and the etching apparatus can be operated efficiently.

According to still another aspect of the present invention, in a chamber partially formed of aluminum, aluminum is exposed without subjecting the inner wall of the aluminum to alumite treatment. Experiments have shown that the separation of contaminants from the chamber inner wall can be reduced
The cleaning cycle of the device can be lengthened.

[Brief description of the drawings]

FIG. 1 (a) is a configuration diagram of a conventional ICP etching apparatus, and FIG. 1 (b) is a partial cross-sectional view of a chamber of the etching apparatus.

FIG. 2 is a diagram showing a change in an etching rate and a selectivity when platinum is etched by a general ICP apparatus.

FIG. 3 is a configuration diagram of an apparatus according to the first embodiment of the present invention.

FIG. 4 is a partially enlarged sectional view of a bell jar of the device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing changes in an etching rate and a selectivity when platinum is etched by the ICP apparatus according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a plasma generation state in the ICP etching apparatus according to the first embodiment of the present invention.

FIG. 7 is an equivalent circuit diagram of an antenna system in the ICP etching apparatus according to the first embodiment of the present invention.

FIG. 8 is an equivalent circuit diagram of a wafer bias system in the ICP etching apparatus according to the first embodiment of the present invention.

FIG. 9 is a configuration diagram of an apparatus according to a second embodiment of the present invention.

FIG. 10 is a configuration diagram of an apparatus according to a third embodiment of the present invention.

FIG. 11 is a partially enlarged sectional view of a bell jar according to a third embodiment of the present invention.

FIG. 12 is a configuration diagram of an apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Gas inlet, 11 ... Wafer storage chamber, 12 ... Wafer mounting table, 13 ... Exhaust port, 14, 14a ... Bell jar (chamber), 15, 15b ... Concavo-convex, 15a ... Concave, 16 ... Antenna, 17 ... Matching circuit , 18 ... High frequency power supply, 1
9: blocking capacitor, 20: matching circuit,
Reference numeral 21: wafer bias power supply, 22: cooler, 24: bell jar (chamber), 25: anti-adhesion plate, 25a: hole, 26:
Chamber.

Continued on the front page F term (reference) 5F004 AA15 AA16 BA20 BB11 BB13 BB18 BC08 CA06 DA04 DA23 DB00 DB08

Claims (10)

[Claims] 1. A wafer mounting table on which a wafer is mounted, and a plasma generation region separated from the wafer mounting table,
A chamber having an inner wall having a portion not facing the wafer or the plasma generation region around the plasma generation region; and an inductively-coupled antenna disposed on the outer periphery of the plasma generation region in the chamber. An etching apparatus comprising: a high-frequency power supply for supplying power to the antenna. 2. The etching apparatus according to claim 1, wherein an unevenness is formed on an inner wall of the chamber around the plasma generation region. 3. The plasma processing apparatus according to claim 2, wherein an inner wall of the chamber around the plasma generation region exists between the antenna and the wafer or between the antenna and the plasma region. 2. The etching apparatus according to 1. 4. The etching apparatus according to claim 1, wherein an inner wall of the chamber around the plasma generation region is covered by a deposition plate having a hole. 5. The etching apparatus according to claim 1, wherein said hole of said deposition-preventing plate has a portion not facing said wafer or said plasma region. 6. The etching apparatus according to claim 1, wherein an inner wall of the chamber around the plasma generation region has a surface having a roughness equal to or more than 1.6S mechanical finish. 7. The etching apparatus according to claim 1, wherein at least an inner wall of the chamber around the plasma generation region is made of quartz or covered with quartz. 8. A chamber having a wafer mounting table for mounting a wafer thereon, a chamber having a plasma region remote from the wafer mounting table, and having an inner surface made of aluminum in a region except around the plasma generation region. An etching apparatus comprising: an inductively-coupled antenna disposed on an outer periphery of the plasma generation region of a chamber; and a high-frequency power supply for supplying power to the antenna. 9. A wafer mounting table on which a wafer is mounted, a plasma generation region separated from the wafer mounting table, and a portion around the plasma generation region that does not face the wafer or the plasma generation region. The wafer mounting is performed by using an apparatus having a chamber having an inner wall, an inductively coupled antenna disposed on the outer periphery of the plasma generation region of the chamber, and a high frequency power supply for supplying power to the antenna. Placing the wafer on a mounting table, setting the maximum temperature of the inner wall of the chamber to 100 ° C. or lower, or setting the difference between the temperature of the inner wall during etching and standby to 70 ° C. or lower, An etching method characterized by initiating etching of a wafer or a film thereon. 10. A wafer mounting table on which a wafer is mounted, a plasma generating region remote from the wafer mounting table, and a portion not facing the wafer or the plasma generating region around the plasma generating region. The wafer mounting is performed by using an apparatus having a chamber having an inner wall, an inductively coupled antenna disposed on the outer periphery of the plasma generation region of the chamber, and a high frequency power supply for supplying power to the antenna. The wafer is placed on a mounting table, and an object to be etched is a film made of platinum, iridium, ruthenium, copper, or a compound of any one of the elements formed on the wafer, or an oxide high dielectric film or an oxide. An etching method characterized by being a ferroelectric film.