KR100272143B1 - Dry cleaning method - Google Patents

Abstract

The present invention relates to a semiconductor manufacturing apparatus for generating plasma by an ECR phenomenon, in which a reaction product deposited on the entire inner wall of a chamber is removed by dry cleaning to suppress generation of dust and shorten the time required for dry cleaning .

A microwave waveguide 12 for introducing a microwave into a plasma chamber, and a semiconductor wafer 1 to be processed, which is a magnetic coil 13 provided outside of the plasma chamber, in a plasma chamber 10 (an ion source) A sample chamber 17 provided in the reaction chamber for mounting a semiconductor wafer thereon and a high frequency power source 23 for applying an RF bias to the chamber side wall of the reaction chamber .

Description

Semiconductor manufacturing apparatus and dry cleaning method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly, to a semiconductor manufacturing apparatus having a dry cleaning function for removing deposits on the inner wall of a chamber and a dry cleaning method thereof.

As an example of a semiconductor manufacturing apparatus using ions drawn out from a plasma generated by an electron cyclotron resonance (ECR) type ion source by a divergent magnetic field, an ECR etching apparatus for reactive ion etching (RIE) of a semiconductor wafer in a reaction chamber ECR-RIE device).

FIG. 4 schematically shows the structure of a conventional ECR etching apparatus.

In this ECR etching apparatus, the ion source and the reaction chamber are different from each other, and the semiconductor wafer is etched by drawing out the ions generated from the ion source to the reaction chamber according to the magnetic field.

That is, an etching gas is introduced into the plasma chamber 10 from the gas inlet 11 and a microwave is introduced from the microwave waveguide 12 through the microwave waveguide 10a. And generates an ECR phenomenon by interaction with a magnetic field formed by the plasma. The directional ions are extracted from the plasma drawing window 15 of the plasma chamber 10 (ion source) to the reaction chamber 14 side using the electric field generated by the magnetic field gradient by the divergent magnetic field to etch the semiconductor wafer 1 .

In this case, the energy of the ions can be relatively freely controlled by applying RF bias from the RF power source 19 to the sample table 17 on which the semiconductor wafer 1 is mounted. The ions drawn out from the plasma drawing window 15 toward the reaction chamber 14 are in the form of a stream and ions are irradiated directly to the side wall of the plasma drawing window 15 or the chamber side wall of the reaction chamber 14 The plasma non-irradiating unit 30 is present.

Further, in the fourth step 16, an exhaust port 16 of the reaction chamber, 18a and 18b a cold water pipe, 20 a matching box, 21 a DC power source, and 22 a choke coil.

However, etching of Si, Mo, W, or the like using the above ECR etching apparatus deposits a reaction product having a low vapor pressure on the inner wall of the chamber of the reaction chamber 14, Dry cleaning is performed using this high gas.

However, in the conventional dry cleaning, the reaction product deposited on the plasma non-irradiating portion 30 is not completely removed, and the remaining deposits of the plasma non-irradiating portion 30 are peeled off in the subsequent processing step, (Source of dust) is becoming.

Further, since the conventional dry cleaning is performed by etching the main body of the chemical reaction by the neutral active species (radicals) in the plasma which is not dependent on the electric field generated by the magnetic field gradient, the etching rate is slower than physical sputtering by ions The cleaning time becomes longer.

As described above, in the conventional ECR etching apparatus, there is a problem that the reaction product deposited on the plasma non-irradiated portion by etching is not completely removed by dry cleaning and the remaining sediment becomes an oscillation source.

In addition, since dry cleaning is performed by etching of the chemical reaction main body by latices in the plasma, the etching rate is slowed, and there is a problem that the time required for dry cleaning becomes long.

Disclosure of the Invention The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a semiconductor manufacturing apparatus which can reduce the time required for dry cleaning while suppressing oscillation by removing reaction products deposited throughout the chamber inner walls of the reaction chamber by dry cleaning, And a dry cleaning method.

It is another object of the present invention to provide a semiconductor manufacturing apparatus and a dry cleaning method thereof in which deposits on the inside of a window of a chamber having a window for introducing laser light are removed.

FIG. 1 schematically shows an example of the configuration of an ECR etching apparatus according to a first embodiment of the present invention,

FIG. 2 is a schematic view of an example of a semiconductor manufacturing apparatus according to a second embodiment of the present invention. FIG.

Fig. 3 schematically shows a modification of the semiconductor manufacturing apparatus of Fig. 2; Fig.

FIG. 4 is a view schematically showing a configuration of a conventional ECR etching apparatus.

DESCRIPTION OF THE REFERENCE NUMERALS

1: semiconductor wafer 10: plasma chamber (ion source)

10a: microwave wave window 11: gas introduction tube

12: microwave waveguide 13: magnetic coil

14: reaction chamber 15: plasma withdrawal window

16: exhaust port of the reaction chamber 17:

18a, 18b: cold water pipe 19: first high frequency power source

23: Second high frequency power source

According to a first aspect of the present invention, there is provided a semiconductor manufacturing apparatus including a plasma chamber for generating a plasma by an ECR phenomenon, a microwave waveguide for introducing a microwave into the plasma chamber, a magnetic coil provided outside the plasma chamber, And a high frequency power source for applying a high frequency bias to a chamber side wall of the reaction chamber, the sample chamber being disposed in the reaction chamber and accommodating the semiconductor wafer, the high frequency power source being provided in the reaction chamber, .

A semiconductor manufacturing apparatus according to a second aspect of the present invention includes a plasma chamber for generating a plasma by an ECR phenomenon, a microwave introduction tube for introducing the microwave into the plasma chamber, a magnetic coil provided outside the plasma chamber, A first RF power source for applying a high frequency bias of the sample stage for a first predetermined period of time, and a second RF power source for applying a high frequency bias of the sample stage for a first predetermined period; And a second high frequency power source for cleaning the chamber side wall by applying a high frequency bias to the chamber side wall of the reaction chamber for a second predetermined period.

According to a third aspect of the present invention, there is provided a dry cleaning method for a semiconductor manufacturing apparatus which generates an ECR phenomenon by interaction between a microwave introduced by a microwave waveguide and a magnetic field formed by a magnetic coil to generate a high density plasma in the plasma chamber, Wherein the ion exchange membrane is formed in the reaction chamber, and the ion exchange membrane is formed in the reaction chamber, and the ion exchange membrane is formed in the reaction chamber, And cleaning is performed in a state in which a high-frequency bias is applied to the chamber side wall of the chamber.

A semiconductor manufacturing apparatus according to a fourth aspect of the present invention includes a chamber accommodating a semiconductor wafer therein, a laser light introducing window capable of irradiating the semiconductor wafer with laser light through a laser light incident from the outside of the chamber, A ring-shaped electrode provided on a circumference of the outside of the laser introduction window, a high-frequency supply source provided for applying a high-frequency bias to the electrode, gas for introducing a predetermined gas into the chamber from the outside of the chamber, And an introduction port.

A semiconductor manufacturing apparatus according to a fifth aspect of the present invention includes a chamber capable of accommodating a semiconductor wafer therein, a laser light introducing window capable of irradiating the semiconductor wafer with laser light through the laser light incident from the outside of the chamber, A high frequency supply source for applying a high frequency bias to the electrode, and a high frequency supply source for supplying a predetermined gas from the outside of the chamber to the inside of the chamber. And a gas inlet.

[Example]

Hereinafter, embodiments of the present invention will be described in detail with reference to exemplary drawings.

FIG. 1 schematically shows an example of the configuration of an ECR etching apparatus according to the first embodiment of the present invention.

In this ECR etching apparatus, reference numeral 10 denotes a plasma chamber for generating plasma by ECR phenomenon, reference numeral 12 denotes a gas inlet for introducing an etching gas into the plasma chamber, reference numeral 12 denotes a microwave introduction tube connected to a microwave power source (not shown) Reference numeral 10a denotes a microwave guide window for introducing a microwave into the plasma chamber from the microwave waveguide. Reference numeral 13 denotes a magnetic coil provided outside the plasma chamber and a part of the microwave waveguide. Reference numeral 14 denotes a reaction chamber for accommodating the semiconductor wafer 1 to be processed, 15 is a plasma drawing window for drawing out ions from the plasma chamber to the reaction chamber side, and 16 is an exhaust port of the reaction chamber and connected to an external vacuum pump.

Reference numeral 17 denotes a sample chamber for mounting the semiconductor wafer, 18a and 18b are cold water pipes for introducing cold water for cooling the plasma chamber and the sample chamber, 19, A matching box for impedance matching between the first RF power supply and the sample band, 21 a DC power supply for applying a DC bias to the sample stage, 22 a first high frequency power source for applying RF bias to the sample band, A choke coil 23 inserted into the output side of the power source, and a second high frequency power source 23 for applying an RF bias of 13.56 Hz to the chamber side wall of the reaction chamber.

In the ECR etching apparatus having the above configuration, when performing normal wafer etching (ECR etching), RF bias is applied to the sample table 17 by operating the first RF power supply 19, The RF bias is not applied. (For example, the second high frequency power supply 23 is not operated).

The ECR phenomenon is caused by the interaction between a microwave of, for example, 2.45 GHz and a magnetic field of, for example, 875 gauss composed of the magnetic coil 13, introduced from the microwave waveguide 12, A plasma is generated and ions are drawn out from the plasma drawing window 15 of the plasma chamber 10 (ion source) toward the reaction chamber 14 in accordance with an electric field generated by a magnetic field gradient by a divergent magnetic field, Etching can be performed. In this case, since the RF bias is applied to the sample table 17 on which the semiconductor wafer 1 is mounted, the energy of the ions can be controlled with relative freedom.

On the other hand, when dry cleaning is performed, RF bias is applied to the chamber side wall of the reaction chamber 14 by operating the second high frequency power supply 23, but the RF band is not applied to the sample stage 17 , The first RF power supply 19 is not operated).

As a result, plasma irradiation can be performed so as to perform plasma etching (specifically, ions) over the entire inner wall of the chamber, and the reaction product deposited on the entire inner wall of the chamber (including the residual reaction product of plasma non- Can be removed by dry cleaning, so that oscillation can be suppressed.

In the case of performing the dry cleaning, physical sputtering is performed by ion irradiation over the entire inner wall of the chamber, so that the etching rate of the reaction product is improved compared to the cleaning in which the chemical reaction by the conventional radical is the main subject. Can be shortened.

Furthermore, the present invention is not limited to the ECR etching apparatus of the above-described embodiments, but may be applied to other semiconductor manufacturing apparatuses in which reaction products are deposited on the inner wall of the chamber, for example, a CVD film (vapor deposition film) An ECR-CVD apparatus for applying a metal film to an ECR sputtering apparatus or the like for depositing a metal film on a semiconductor wafer in a reaction chamber.

FIG. 2 schematically shows an example of the configuration of a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

In the semiconductor manufacturing apparatus shown in FIG. 2, a chamber 40 in which a semiconductor wafer 1 can be accommodated is provided with a window 41 for introducing a laser beam using, for example, quartz on one side (for example, And a laser beam incident from the upper part of the chamber is introduced into the chamber through the window 41 to irradiate laser light onto the wafer 1 inside the chamber.

The chamber 40 is provided with a gas inlet 44 and a ring-shaped electrode 42 is provided on the periphery of the outer surface of the window 41. The RF source 43 The RF power of 13.56 MHz, for example, can be applied to the electrode 42, and the ground potential of the chamber 40 is applied.

The window 41 for introducing laser light using quartz is provided in a structure that maintains airtightness with respect to the chamber 40. The presence of the window 41 for introducing the laser light causes the electrode 42 The chamber 40 is electrically insulated.

A predetermined gas (for example, Ar gas or chlorine gas) is introduced from the outside of the chamber into the chamber through the gas inlet 44 and the RF power is applied to the electrode 42, And has a sputtering function (dry cleaning function) capable of sputtering the inside of the window 41 by radiating plasma.

According to the semiconductor manufacturing apparatus shown in FIG. 2, when a metal material is buried in a groove such as a hole or a wiring groove in a contact hole or the like formed in an insulating film on the semiconductor wafer 1 by a laser-melt method in a manufacturing process of a semiconductor device, Even if the metallic material is adhered to the inside of the window 41, the above-described sputtering function can be performed to remove the deposit. In this case, since the electrode 42 for RF power application is provided in a ring shape over the outer periphery of the window 41, the sputtering function can be generated without interfering with the irradiation of the laser beam.

FIG. 3 schematically shows a modified example of the semiconductor manufacturing apparatus according to the second embodiment. The semiconductor manufacturing apparatus shown in FIG. 3 differs from the semiconductor manufacturing apparatus shown in FIG. 2 in that the front surface (upper surface) of the laser light introducing window 41 of the chamber 40 The same reference numerals as those in FIG. 2 are given because they are the same in that the electrodes 42a are formed so as to be freely attachable and detachable.

The electrode 42a is provided in a state of being detached from the outer surface side of the laser light introduction window 41 during the period of irradiating the semiconductor wafer 1 with laser light, And is mounted on the outer surface side of the laser light introduction window 41 in an arbitrary period within the period.

3, it is possible to irradiate laser light in a state in which the electrode 42a is separated from the window 41. When the laser light is not irradiated, for example, the chamber 40 and the outside wafer When the wafer 1 is taken out and carried in between the transfer mechanism (not shown) and the electrode 42a is mounted on the window 41, Can be removed.

It is to be noted that the drawings are not intended to limit the technical scope of the present invention to the embodiments shown in the drawings, in order to facilitate understanding of the present invention.

Industrial Applicability As described above, according to the present invention, it is possible to realize a semiconductor manufacturing apparatus and its dry cleaning method that can reduce the time required for dry cleaning while suppressing oscillation by removing the reaction products deposited over the entire inner wall of the chamber by dry cleaning .

Further, according to the present invention, a semiconductor manufacturing apparatus and its dry cleaning method capable of removing a metal material or the like attached to the inside of a chamber window provided with a laser light introduction window can be realized.

Claims (6)

A microwave waveguide 12 for introducing a microwave into the plasma chamber 10; a magnetic coil 13 provided outside the plasma chamber 10; a plasma chamber 10 for generating plasma by an electron cyclotron resonance phenomenon; A reaction chamber 14 accommodating a semiconductor wafer to be etched and connected to a plasma drawing window of the plasma chamber 10; a sample table 17 installed in the reaction chamber 14 for mounting the semiconductor wafer; A first high frequency power source 19 for applying a high frequency bias to the sample stage 17 for a first predetermined period and a high frequency power source 19 for applying a high frequency bias to the chamber side wall of the reaction chamber 14 for a second predetermined period, And a second high frequency power source (23) for generating a second high frequency power. Density plasma is generated in the plasma chamber 10 by causing an electron cyclotron resonance phenomenon by interaction between a microwave introduced by the microwave waveguide 12 and a magnetic field formed by the magnetic coil 13, When dry cleaning is performed to remove reaction products deposited on the inner wall of the chamber of the reaction chamber 14, ions are introduced into the reaction chamber 14 by using an electric field generated by a magnetic field gradient by a divergent magnetic field from the plasma chamber 10, (10) while applying a high-frequency bias to the side wall of the reaction chamber (10). A laser light introduction window 41 provided in the chamber 40 and capable of passing laser light incident from the outside of the chamber and irradiating the semiconductor wafer with laser light, A high frequency supply source 43 provided for applying a high frequency bias to the electrode is provided in the chamber 40 and is provided in the chamber 40. The high frequency supply source 43 is provided in the chamber 40, And a gas inlet (44) for introducing a gas of a predetermined temperature into the chamber. And a laser light introducing window 41 which is provided in the chamber 40 and through which laser light incident from the outside of the chamber 40 can pass to irradiate the semiconductor wafer with laser light, An electrode 42a provided on the outer surface side of the laser light introduction window 41 so as to be freely attached and detached, a high frequency supply source 43 provided for applying a high frequency bias to the electrode, And a gas inlet (44) for introducing a predetermined gas into the chamber (40) from the outside of the chamber (40). 5. The semiconductor manufacturing apparatus according to claim 4, wherein the electrode (42a) is set in a state of being separated from the outer surface side of the laser light introduction window (41) during a period of irradiating the semiconductor wafer with laser light, Is installed on the outer surface side of the laser light introduction window (41) during an arbitrary period of time during which no laser light is irradiated to the laser light introduction window (41). When a semiconductor wafer is accommodated in a chamber 40 having a laser light introducing window 41 and laser light incident from the outside of the chamber is irradiated onto the semiconductor wafer through the laser light introducing window 41, The gas is introduced into the chamber 40 and high-frequency power is applied to the ring-shaped electrode over the outer circumferential side of the outer side of the laser light introduction window 41, And the inside of the laser light introducing window (41) is removed by removing the deposit inside the laser light introducing window (41).