KR20140018059A - Hybrid bell jar type electrode and plasma generator using it - Google Patents

Abstract

The present invention relates to a hybrid bell jar type electrode and a plasma generator using the same, and more specifically, to a hybrid bell jar type electrode which is a hybrid between a CCP type and an ICP type and a plasma generator which generates plasma by passing reactive gas through the hybrid bell jar type electrode. The plasma generator of the present invention comprises: a chamber which includes a reactive gas supplying unit; a hybrid bell jar type electrode which has a barrel-shaped body with multiple reactive gas supplying holes, and which is installed at a region of the chamber where the reactive gas supplying unit is formed; an RF coil which supplies electromagnetic field energy to the hybrid bell jar type electrode; a power distribution circuit and a source matching network which are connected to the RF coil; an electrostatic chuck which is positioned in the chamber, and on which a substrate is mounted; a bias matching network which is connected to the electrostatic chuck; and a frequency synthesizer which is connected to the source matching network and the bias matching network, and which generates a high frequency to make a frequency having a voltage level and a phase required for external oscillation. [Reference numerals] (100) Power distribution circuit; (60) TURBO pump; (90) Rf filter; (AA) reactive gas; (BB) Inert gas; (CC) Valve

Description

Hybrid bell-shaped electrode and plasma generator using same {HYBRID BELL JAR TYPE ELECTRODE AND PLASMA GENERATOR USING IT}

The present invention relates to a hybrid bell-shaped electrode and a plasma generating device using the same, and more particularly, a hybrid bell-type electrode and a reactive gas applied to the hybrid bell-shaped electrode in the form of a mixture of CCP type and ICP type. It relates to an apparatus for generating a plasma by passing through.

Plasma generators are widely used in not only deposition and etching of thin films, but also ion implantation into the substrate, polymer or surface modification, etc. in the manufacturing process of various electric, electronic and optical devices including semiconductor wafers. Applications are increasing in the fabrication of microelectronic devices such as implantation, etching and lamination.

In other words, with the development of the related semiconductor industry, semiconductor manufacturing apparatuses are pursuing high capacity and high functionality. Accordingly, more devices are required to be integrated in a limited area, and semiconductor manufacturing technology is extremely fine and highly integrated in pattern. It is currently being researched and developed.

In the semiconductor device manufacturing process for realizing such an ultra-fine and highly integrated semiconductor device, the reaction gas is activated and transformed into a plasma state, whereby cations or radicals of the reaction gas in the plasma state affect a predetermined region of the semiconductor substrate. The technique using the plasma is widely used.

The plasma generator can be classified into a capacitively coupled plasma (CCP) generator and an inductively coupled plasma (ICP) generator according to the method of forming the plasma. RF power is applied to generate a plasma using an RF electric field formed vertically between both electrodes, and the latter is a method of converting a raw material into a plasma by using an induction electromagnetic field induced by a coil antenna.

In other words, ICP generates plasma using a current flowing in an RF coil when generating a plasma, and CCP generates a plasma using a gas supplied to a chamber electrode (Cathode and Anode) when a plasma is generated and supplied to the chamber. Make.

On the other hand, the conventional plasma generation method is a method for generating a plasma by supplying a separate electromagnetic field to the plasma generation source (ICP & CCP), and by using a high power to generate the plasma and lower the power to proceed the process The method is applied.

That is, the conventional plasma generation method has a problem in that the additional device and process costs increase.

In more detail, the conventionally proposed methods for generating high density plasma require high RF power energy because the amount of energy supplied from the outside is closely related to the generation of high density plasma.

However, it is not possible to increase the RF field energy required to obtain high density plasma indefinitely because it is related to the problem of chamber structure, process components such as chamber component damage and polymer formation.

Patent Registration 10-1007822 (January 06, 2011) Patent Publication 10-2010-0030806 (March 19, 2010)

The present invention has been made to solve the above problems, it is possible to easily form a plasma with a low external energy supply, to pass the reactive gas through the hybrid bell-shaped electrode to make the reactive gas excited state to produce a low power It is an object of the present invention to provide a hybrid bell-shaped electrode and a plasma generator using the same, which are suitable for energy saving, long life of chamber components, and micro processes.

Hybrid bell-shaped electrode according to the present invention for achieving the above object is a plurality of reactive gas supply holes are formed in the cylindrical body, a state in which the reactive gas passing through the reactive gas supply hole excited by external electromagnetic energy Characterized in that can be supplied by making.

In addition, the plasma generating apparatus according to the present invention, the chamber including a reactive gas supply;

A hybrid bell-shaped electrode formed in a tubular body, wherein a plurality of reactive gas supply holes are formed and installed in a chamber portion where the reactive gas supply unit is formed;

An RF coil for supplying electromagnetic energy to the hybrid bell-shaped electrode;

A power distribution circuit and a source matching network connected to the RF coil;

An electrostatic chuck positioned inside the chamber and having a substrate seated thereon;

A bias matching network coupled to the electrostatic chuck; And

A frequency synthesizer connected to the source matching network and the bias matching network to generate a high frequency to generate a frequency having a magnitude and phase of a voltage required for oscillation from the outside; And a control unit.

According to the above-mentioned means for solving the problem, it is possible to easily form a plasma with a low external energy supply, and pass the reactive gas through the hybrid bell-shaped electrode to excite the reactive gas to make the plasma to save energy by using low power and It can extend the life of chamber components and is suitable for micro processes.

1A and 1B are front and cross-sectional views of a hybrid bell-shaped electrode according to an embodiment of the present invention.
2A and 2B are front and cross-sectional views of a hybrid bell-shaped electrode according to another embodiment of the present invention.
3A and 3B are perspective and front views of the hybrid bell-shaped electrode and the RF coil.
4 is a configuration diagram of a plasma generator according to a first embodiment of the present invention.
5 is a configuration diagram of a plasma generator according to a second embodiment of the present invention.
6 is a configuration diagram of a plasma generator according to a third embodiment of the present invention.
7 is a configuration diagram of a plasma generator according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

It is to be noted that the same components of the drawings are denoted by the same reference numerals and symbols as possible even if they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

1A and 1B are front and cross-sectional views of a hybrid bell-shaped electrode according to an embodiment of the present invention.

As shown, the hybrid bell-shaped electrode 10 is formed by forming a plurality of reactive gas supply holes 12 up and down in a cylindrical body consisting of up and down.

In this case, the hybrid bell-shaped electrode 10 is made of an insulating material such as sapphire, ceramic, quartz, silicon (Si), silicon carbide (SiC), etc., and the size of the reactive gas supply hole 12 is 0.1 to 11 mm. desirable.

The hybrid bell-shaped electrode 10 is installed in the upper portion of the chamber so that the upper portion of the reactive gas supply hole 12 is connected to the reactive gas pipe and the lower portion is in communication with the inside of the chamber.

2A and 2B are front and cross-sectional views of a hybrid bell-shaped electrode according to another embodiment of the present invention.

As shown, the hybrid bell-shaped electrode 10 is formed by forming a plurality of reactive gas supply holes 12 up and down in a hexagonal cylindrical body consisting of up and down.

In this case, the hybrid bell-shaped electrode 10 is made of an insulating material such as sapphire, ceramic, quartz, silicon (Si), silicon carbide (SiC), etc., and the size of the reactive gas supply hole 12 is 0.1 to 11 mm. desirable.

The hybrid bell-shaped electrode 10 is installed in the upper portion of the chamber so that the upper portion of the reactive gas supply hole is connected to the reactive gas pipe and the lower portion is in communication with the inside of the chamber.

Hereinafter, the hybrid bell-shaped electrode 10 according to the present invention may be used for the lower electrode and the side electrode as well as the upper electrode of the plasma generator.

3A and 3B are a perspective view and a front view of the hybrid bell-shaped electrode and the RF coil, and show the configuration of the hybrid bell-shaped electrode 10 and the RF coil 30 at the same time.

As shown, the RF coil 30 is half surrounded and surrounded by the outer side of the hybrid bell-shaped electrode 10 in which the plurality of reactive gas supply holes 12 are formed, and each half of the RF coil 30 has an upper side and a lower side, respectively. The semi-circular shape is connected to each other to surround the half of the hybrid bell-shaped electrode 10, but the lower half circle is formed larger than the upper half circle.

The RF coil 30 is a load through which applied high frequency energy (current and voltage) is transmitted, and a length of RF current flows and RF energy delivered to the RF coil 30 is induced to introduce a new electromagnetic field into the chamber. It plays a role in creating the induced electromagnetic field formed in the.

4 is a configuration diagram of a plasma generator according to a first embodiment of the present invention.

As shown, the plasma generator 1 includes a hybrid bell-shaped electrode 10, a chamber 20, an RF coil 30 and 40, an electrostatic chuck 50, a turbo pump 60, a frequency synthesizer 70, It includes a matching network (80a, 80b), the RF filter 90 and the power distribution circuit (100).

The hybrid bell-shaped electrode 10 is installed above the chamber 20 so that a reactive gas is supplied into the chamber 20 through the hybrid bell-shaped electrode 10, and RF coils 20 and 30 to which source power is applied. Acts to create an induced electromagnetic field.

The shape of the RF coils 30 and 40 shown in the enlarged view shows that the current is designed to flow in the same direction according to the shape of the coil, and the maximum electromagnetic field may be induced only when the current flows in the same direction to create a high density plasma.

Although not shown, an inductively coupled plasma (ICP) coil used for plasma generation is located outside the chamber 20.

The chamber 20 includes a reactive gas supply unit 22, an inert gas supply unit 24, and an outlet 26.

The reactive gas supply unit 22 communicates with the reactive gas supply hole 12 of the hybrid bell-shaped electrode 10 installed above the chamber 20 to supply the reactive gas (CF4, C4F6, CHF6, SF4, BC13, etc.) to the chamber. (20) Supply inside.

Inert gas supply unit 24 is installed on both sides of the chamber 20 to supply inert gas (oxygen, nitrogen, arcon, helium, H2, etc.) into the chamber 20, the inert gas to increase the plasma density or the chamber (20) Transfer energy to the reaction inside.

The outlet 26 discharges the reactive gas and the inert gas to the outside.

The power distribution circuit 100, the source matching network 80b, and the frequency synthesizer 70 are connected to the RF coils 30 and 40.

The power distribution circuit 100 divides the RF power (current and power) to be supplied to the RF coils 30 and 40 by a predetermined rule.

The source matching network 80b reduces the efficiency of power supplied because the output impedance of RF power (ie, source power) and the impedance of the RF coils 30 and 40 which are loads are different from each other. To prevent this, adjust the load impedance to the output impedance of the source supply.

The frequency synthesizer 70 generates a high frequency to generate a frequency having a magnitude and phase of a voltage required for oscillation from the outside.

Here, the third frequency oscillator F3 connected to the frequency synthesizer 70 oscillates a frequency of 13.56 to 60 MHz or 1 to 60 MHz band.

An electrostatic chuck 50 is provided below the chamber 20 to fix the substrate W and to which a bias power is applied.

A bias matching network 80a and the frequency synthesizer 70 are connected to the electrostatic chuck 50.

When the output impedance of the bias power supply and the load impedance of the bias power supply are different from each other, the bias matching circuit 80a reduces the efficiency of the supplied power. The bias matching circuit 80a adjusts the load impedance to the output impedance of the source power supply.

In this case, the duty ratio of the bias power source is preferably 5: 5 because the unbalanced duty ratio is most suitable for combination with the process gases.

In addition, a source power source applied to the RF coils 30 and 40 for generating plasma, and a bias power source applied to the lower electrode of the chamber 20 for the purpose of utilizing the ions, electrons, and radicals of the plasma generated from the source power source. It is preferable that phase difference between is 0-45 degree and 315-360 degree.

If the phase is out of the above range, a problem occurs in impedance matching and processing, where 0-45 degrees puts the phase difference in the positive direction and 0-45 (315-360) the phase difference in the negative direction.

The frequency synthesizer 70 generates a high frequency to generate a frequency having a magnitude and phase of a voltage required for oscillation from the outside.

Here, the first frequency oscillator (F1) connected to the frequency synthesizer 70 to apply a bias power source oscillates a frequency of 60 ~ 100MHz band, the second frequency oscillator (F2) oscillates a frequency of 9KHz ~ 27MHz band .

The range of the three frequencies (13.56 ~ 60MHz or 1 ~ 60MHz, 60 ~ 100MHz, 9KHz ~ 27MHz) is a frequency that can be used to generate a plasma, in the plasma generation method of the plasma generating apparatus 1 according to the present invention Indicates available frequency range.

For example, it is difficult to control the plasma in the ICP using the RF coils 30 and 40 in the frequency range of 9 KHz to 27 MHz. As the frequency increases, the length of the wavelength becomes shorter and a problem occurs when generating the plasma.

That is, it is difficult to match and a voltage standing wave is formed in the chamber 20 to cause sputtering and the like and damage the equipment inside the chamber 20.

In addition, an RF filter 90 is branched and connected between the electrostatic chuck 50 and the bias matching circuit 80a.

When a high frequency is applied to the electrostatic chuck 50 as a bias power source, the RF energy is radiated in all directions due to the characteristics of the high frequency to affect other electronic devices in the vicinity, and the RF filter 90 blocks the RF energy to prevent this. do.

The outlet port 26 of the chamber 20 is provided with a turbo pump (60).

The turbo pump 60 makes the inside of the chamber 20 high vacuum, and the valve controls the pressure between the chamber 20 and the turbo pump 60.

Referring to the operation of the plasma generating apparatus 1 according to the above-described configuration, first placing the substrate (W) in the electrostatic chuck 50 and then applying power to the electrostatic chuck 50, the substrate (W) is electrostatic power It is mounted and fixed to the electrostatic chuck 50 by applying a bias power supply to the electrostatic chuck 50, and a source power supply to the RF coils 30 and 40, respectively.

At this time, the bias power supplies the bias energy at the duty ratio of on-state 0-99% or off-state 1-99% except the duty ratio of 5: 5, and the corresponding frequency range is 9KHz-27MHz, and the bias power and source Phase difference control is used for process optimization of power supply.

The phase difference control method refers to forcibly shifting the frequency synthesis or the frequency difference so as to transmit a constant incident wave to in-phase, reverse phase, or process variables.

In addition, the phase of the source power supply and the bias power supply phase are coordinated with the process progress step so that the phase difference is 0 to 45 degrees and 315 to 360 degrees.

On the other hand, while the reactive gas (CF4, C4F6, CHF6, SF4, BC13, etc.) passes through the reactive gas supply hole 12 of the hybrid bell-shaped electrode 10, the energy of the electromagnetic field supplied by the external RF coil 30 is It is delivered to the reactive gas passing through this hybrid bell-shaped electrode 10.

The transferred energy is absorbed by the reactive gas passing through the hybrid bell-shaped electrode to be excited.

The excited gas absorbed by the energy is excellent in activity and easily ionized to weak electromagnetic energy as it enters the chamber 20, and the high-density plasma also becomes easy.

In more detail, when a high frequency current flows by applying a source power to the RF coil 20 located above the hybrid bell-shaped electrode 10, the reactive gas passing through the hybrid bell-shaped electrode 10 obtains energy. do.

However, it does not become a plasma state.

As the reactive gas moves to the center portion of the hybrid bell-shaped electrode 10, the electric field energy formed by the surrounding magnetic field is further obtained.

The reactive gas having passed through the hybrid bell-shaped electrode 10 is introduced into the chamber 20 while maintaining the basic properties of the reactive gas in the state of bearing energy.

Then, the plasma is generated while ionizing the RF coil 40 and the RF energy of the ICP coil located outside the chamber 20.

At this time, there is an advantage that the plasma can be easily formed even with low RF energy in the RF coil 40 and the ICP coil.

In addition, it is possible to save energy by using low power and to easily dissolve the process gas, thereby minimizing gas consumption.

In addition, the lifespan of the consumable parts forming the chamber 20 is also extended, thereby reducing the equipment maintenance cost.

In addition, when the bias energy ratio timing method is applied, CD (critical dimension) control, uniformity control and Rox (Remain Oxide) can be controlled.

FIG. 5 is a configuration diagram of a plasma generator according to a second embodiment of the present invention. The difference from FIG. 4 is that one RF coil 30 to which source power is applied for plasma generation is not two.

Since the rest of the configuration and the action according to the configuration is the same as in FIG.

FIG. 6 is a configuration diagram of a plasma generating apparatus according to a third embodiment of the present invention. The difference from FIG. 4 is that a plurality of hybrid bell-shaped electrodes 10 are provided on the chamber 20, and accordingly, the RF coil 30 is provided. 40 is also composed of a plurality.

Since the rest of the configuration and the action according to the configuration is the same as in FIG.

7 is a configuration diagram of a plasma generating apparatus according to a fourth embodiment of the present invention, which is different from FIG. 5, in which a plurality of hybrid bell-shaped electrodes 10 are provided on the chamber 20, and accordingly, an RF coil 30 is provided. ) Is also made up of a plurality.

Since the rest of the configuration and the action according to the configuration is the same as in FIG.

Capacitive plasma and inductive plasma can be generated through the plasma generator 10. By using the hybrid bell electrode 10 and distributing the amount of source power supplied to the RF coils 30 and 40 through the power distribution circuit 100 to generate an inductive plasma, the hybrid bell-shaped electrode Only reactive gas may be supplied to (10) independently to generate capacitive plasma.

1: plasma generator
10: hybrid bell-shaped electrode 20: chamber
30,40: RF coil 50: electrostatic chuck
60: turbopump 70: frequency synthesizer
80a, 80b: Matching network 90: RF filter
100: power distribution circuit

Claims (14)

And a plurality of reactive gas supply holes are formed in the cylindrical body, and the reactive gas passing through the reactive gas supply holes can be excited by external electromagnetic energy and supplied. The method of claim 1,
The hybrid bell-shaped electrode is made of an insulating material, the size of the reactive gas supply hole is a hybrid bell-shaped electrode, characterized in that 0.1 ~ 11mm. The method of claim 1,
A hybrid bell-shaped electrode, wherein the hybrid bell-shaped electrode is used as at least one of an upper electrode, a lower electrode, and a side electrode in a chamber of a plasma generator; The method of claim 1,
The hybrid bell-shaped electrode, characterized in that configured to be surrounded by half the RF coil for supplying electromagnetic energy to the outside of the hybrid bell-shaped electrode. 5. The method of claim 4,
The half-divided RF coil is a hybrid bell-shaped electrode, characterized in that the upper side and the lower side is surrounded by a half of the hybrid bell-shaped electrode by being connected to each other in a semicircular shape, the lower half-circle is formed larger than the upper half-circle. A chamber comprising a reactive gas supply;
A hybrid bell-shaped electrode formed in a tubular body, wherein a plurality of reactive gas supply holes are formed and installed in a chamber portion where the reactive gas supply unit is formed;
An RF coil for supplying electromagnetic energy to the hybrid bell-shaped electrode;
A power distribution circuit and a source matching network connected to the RF coil;
An electrostatic chuck positioned inside the chamber and having a substrate seated thereon;
A bias matching network coupled to the electrostatic chuck; And
A frequency synthesizer connected to the source matching network and the bias matching network to generate a high frequency to generate a frequency having a magnitude and phase of a voltage required for oscillation from the outside; Plasma generator comprising a. The method according to claim 6,
The RF coil is a plasma generating apparatus, characterized in that the first RF coil located on the hybrid bell-shaped electrode to make the reactive gas passing through the reactive gas supply hole excited. The method according to claim 6,
The RF coil is located on top of the hybrid bell-shaped electrode and the first RF coil to make the reactive gas passing through the reactive gas supply hole excited;
And a second RF coil positioned above the chamber to ionize a reactive gas in an excited state together with the ICP coil outside the chamber. 9. The method according to claim 7 or 8,
The hybrid bell-shaped electrode is installed in a plurality of chambers and accordingly a plurality of first RF coil and a second RF coil is provided, characterized in that provided. The method according to claim 6,
And generating an inductive plasma by using the hybrid bell-shaped electrode and distributing the amount of source power supplied to the RF coil through a power distribution circuit. The method according to claim 6,
Plasma generator, characterized in that to generate a capacitive plasma by supplying only the reactive gas to the hybrid bell-shaped electrode independently. The method according to claim 6,
The bias power applied to the electrostatic chuck has a duty ratio of on-state 0-99% or off-state 1-99% except for a duty ratio of 5: 5, and the frequency domain is 9KHz-27MHz. The method of claim 12,
And a source power applied to the bias power and the RF coil using a phase difference control method. 14. The method of claim 13,
The phase difference between the source power source and the bias power source is a plasma generator, characterized in that 0 ~ 45 degrees or 315-360 degrees.

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