KR20240129826A - A apparatus for supplying the radiofrequency power by multi-channel - Google Patents

Abstract

The present invention relates to a phase correction RF power supply device which checks whether a plurality of RF signals output from a phase control unit, when a process is performed on a plurality of electrodes in a single chamber, are signals of a desired phase when viewed at a matching box output terminal through each RF signal generator, and automatically corrects the phase difference if a difference occurs. The phase correction RF power supply device according to the present invention comprises: a plurality of electrodes installed in a single chamber; a plurality of RF signal generators which are installed in the same number as the plurality of electrodes and generate RF (Radio Frequency) signals having a predetermined frequency and phase; a plurality of RF signal application units which connect the plurality of RF signal generation units and the plurality of electrodes one-to-one and apply the RF signals to the plurality of electrodes respectively; a plurality of matching boxes which are respectively installed in the plurality of RF signal application units and sense a reflected wave transmitted from the electrodes and automatically perform an impedance matching function so that the reflected wave becomes "0"; a plurality of phase detection units which are installed in each of the plurality of matching boxes and detect the phase of the RF signal applied from the RF signal generation units; It includes a phase correction unit that is installed to be respectively connected to the plurality of RF signal generation units and corrects the RF signal generated for the plurality of RF signal generation units by reflecting the phase difference of the RF signal detected by the plurality of phase detection units.

Description

{A APPARATUS FOR SUPPLYING THE RADIOFREQUENCY POWER BY MULTI-CHANNEL}

The present invention relates to a phase correction RF power supply, and more specifically, to a phase correction RF power supply which, when a process is performed on a plurality of electrodes in a single chamber, checks whether a plurality of RF signals sent from a phase control unit are signals of a desired phase when viewed at a matching box output terminal through each RF signal generation unit, and automatically corrects the phase difference if a difference occurs.

Plasma is a highly ionized gas containing an equal number of positive ions and electrons. Plasma discharge is used here to generate an activated gas containing ions, free radicals, atoms, and molecules. Active gases are widely used in various fields and are used in various semiconductor manufacturing processes such as etching, deposition, cleaning, and ashing to manufacture devices such as integrated circuit devices, liquid crystal displays, and solar cells.

There are several plasma sources for generating plasma, representative examples of which are capacitive coupled plasma and inductive coupled plasma using radio frequency.

In general, such a plasma processing device (1) places an upper electrode (5) and a lower electrode (7) in parallel within a plasma chamber (3) configured as a vacuum chamber, as shown in Fig. 1, and mounts a substrate (2) to be processed (semiconductor wafer, glass substrate, etc.) on the lower electrode (7).

The upper electrode (5) is connected to a power supply source (10) and an impedance matcher (12), and a high frequency is applied from the power supply source (10). Then, electrons accelerated by the high frequency electric field between the two electrodes, secondary electrons emitted from the electrode, or heated electrons cause ionizing collisions with molecules of the processing gas, thereby generating plasma of the processing gas, and desired microprocessing, such as etching processing, is performed on the substrate surface by radicals or ions in the plasma.

However, with the miniaturization and high integration of devices in semiconductor process technology, a plasma process with higher efficiency, higher density, and lower bias is required in capacitively coupled plasma processing devices, and to this end, the current trend is to increase the frequency of the high frequency used for plasma generation as much as possible. On the other hand, with the enlargement of the size of the substrate to be processed and the enlargement of the substrate diameter, a plasma with a larger diameter is required, and the chamber (processing container) is becoming larger and larger.

The problem here is that it is very difficult to make the plasma density uniform within the chamber processing space. That is, when the RF frequency for discharge increases, the center becomes the maximum on the substrate and the edge becomes the lowest due to the wave effect that forms standing waves within the chamber or the skin effect that concentrates high frequencies at the center on the electrode surface, so the plasma density becomes uneven.

In order to solve these problems, a technology is disclosed to make the plasma density uniform by dividing the upper electrode (5) into multiple parts. In addition, since the construction of a clean room requires a huge cost, there is a growing need to reduce costs by quickly processing a large number of substrates to be processed (semiconductor wafers, glass substrates, etc.) in a small area and thereby increase productivity. Therefore, a technology is required to install multiple reactors in one chamber so that a large number of substrates to be processed can be processed simultaneously.

When multiple electrodes are used in a single chamber, even if multiple RF signals of the same phase are output, a slight phase difference occurs in each RF signal due to the delay that occurs as they pass through each RF power generator and matching box, and depending on the phase difference, they affect each other, resulting in a serious problem that affects the plasma process.

The technical problem to be solved by the present invention is to provide a phase correction RF power supply device that checks whether a plurality of RF signals sent from a phase control unit are signals of a desired phase when viewed at the output terminal of a matching box through each RF signal generation unit when a process is performed using a plurality of electrodes in one chamber, and automatically corrects the phase difference if a difference occurs.

In order to solve the above-described technical problem, the phase correction RF power supply device according to the present invention comprises: a plurality of electrodes installed in one chamber; a plurality of RF signal generators installed in the same number as the plurality of electrodes and generating an RF (Radio Frequency) signal having a predetermined frequency and phase; a plurality of RF signal application units connecting the plurality of RF signal generators and the plurality of electrodes one-to-one and applying the RF signal to each of the plurality of electrodes; a plurality of matching boxes installed respectively in the plurality of RF signal application units and sensing a reflected wave transmitted from the electrodes and automatically performing an impedance matching function so that the reflected wave becomes "0"; a plurality of phase detection units installed in each of the plurality of matching boxes and detecting a phase of an RF signal applied from the RF signal generation units; and a phase correction unit installed so as to be respectively connected to the plurality of RF signal generation units and correcting an RF signal generated for the plurality of RF signal generation units by reflecting a phase difference of an RF signal detected by the plurality of phase detection units.

And in the present invention, it is preferable that the phase correction unit corrects the phase difference when a difference occurs in the phase information detected by the plurality of phase detection units so that an RF signal of the same phase is applied from the plurality of RF signal generation units.

In addition, in the present invention, it is preferable that the phase correction unit controls the RF signal generation unit so that a minute phase difference occurs in each RF signal generation unit according to the phase information detected by the plurality of phase detection units.

According to the phase correction RF power supply of the present invention, the phase of each RF signal supplied to a plurality of electrodes installed in one chamber can be maintained identically, so that a uniform plasma process can be implemented by a plurality of electrodes installed in one chamber.

Figure 1 is a drawing schematically illustrating the configuration of a typical plasma processing device.
FIG. 2 is a diagram schematically illustrating the configuration of a phase-compensated RF power supply according to one embodiment of the present invention.

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

The phase correction RF power supply (100) according to the present embodiment may be configured to include a plurality of electrodes (110), a plurality of RF signal generators (120), a plurality of matching boxes (140), a plurality of phase detection units (150), and a phase correction unit (160), as shown in FIG. 2.

First, as shown in Fig. 2, the electrodes (110) are components that are installed side by side in a spaced manner within one chamber (101) and to which the same RF power is applied.

Next, the above-described multiple RF signal generating units (120) are installed in the same number as the above-described multiple electrodes (110), as shown in FIG. 2, and are components that generate RF (Radio Frequency) signals having a predetermined frequency and phase. The RF signal generating units (120) can employ a generally known RF generator, and a detailed description thereof is omitted.

Next, as shown in Fig. 2, the RF signal application unit (130) is a component that connects the plurality of RF signal generation units (120) and the plurality of electrodes (110) one-to-one and applies the same RF signal to each of the plurality of electrodes (110). It is preferable that the plurality of RF signal application units (130) be installed so that the connection conditions with the RF signal generation unit (120), such as the length of the connecting wire, are all the same, as this is suitable for applying the same RF signal.

Next, the matching box (140) is installed in each of the plurality of RF signal application units (130), as shown in FIG. 2, and is a component that senses the reflected wave transmitted from the electrode (110) and automatically performs an impedance matching function so that the reflected wave becomes “0”.

The above matching boxes (140) are also installed in the same number as the electrodes (110), and can have various structures capable of sensing the reflected wave reflected and transmitted from the electrodes (110) in response to the output of the RF signal generating unit (120) and automatically performing an impedance matching function using a variable network so that the reflected wave becomes “0”.

Next, the phase detection unit (150) is installed at each output terminal of the plurality of matching boxes (140), as illustrated in FIG. 2, and is a component that detects the phase of the RF signal applied from the RF signal generation unit (120) in real time. That is, the plurality of phase detection units (150) confirm whether the RF signal is of a desired phase when viewed from the output terminal of the plurality of matching boxes (140) and provides the detection information to the phase correction unit (160).

In this embodiment, the phase detection unit (150) may be configured as a general phase detection sensor.

Next, the phase correction unit (160) is installed so as to be connected to each of the plurality of RF signal generation units (120), as illustrated in FIG. 2, and is a component that corrects RF signals generated for the plurality of RF signal generation units (120) by reflecting the phase difference of RF signals detected by the plurality of phase detection units (150).

That is, when the phase correction unit (160) detects that there is a difference in phase information in each RF signal detected by the plurality of phase detection units (150), it calculates the phase difference between each output and corrects the output by that difference so that RF signals of the same phase are applied from the plurality of RF signal generation units (120).

In this way, the phase of each RF signal supplied to a plurality of electrodes (110) within the chamber (101) can be maintained identically, so there is an advantage in that a uniform plasma process can be implemented by a plurality of electrodes (110) installed within one chamber (10).

Meanwhile, the phase correction unit (160) according to the present embodiment may not adjust the phase so that RF signals of the same phase are applied to all output terminals, but may control the RF signal generation unit (120) so that a slight phase difference occurs in each RF signal generation unit (120) according to phase information detected by the plurality of phase detection units (150).

In a plasma process performed on a plurality of electrodes (110), if there is a process-related need to control RF signals so that a phase difference occurs for each electrode, the phase correction unit (160) finely controls the phase of each RF signal so that a difference equal to the required phase difference occurs.

100: Phase-compensated RF power supply according to one embodiment of the present invention
110: Multiple electrodes 120: Multiple RF signal generators
130: Multiple RF signal input section 140: Multiple matching boxes
150: Multiple phase detection units 160: Phase correction unit

Claims (3)

Multiple electrodes installed within one chamber;
A plurality of RF signal generators installed in the same number as the above plurality of electrodes and generating RF (Radio Frequency) signals having a predetermined frequency and phase;
A plurality of RF signal applying units that connect the plurality of RF signal generating units and the plurality of electrodes one-to-one and apply the RF signals to the plurality of electrodes respectively; A plurality of matching boxes that are respectively installed in the plurality of RF signal applying units and sense the reflected waves transmitted from the electrodes and automatically perform an impedance matching function so that the reflected waves become "0";
A plurality of phase detection units installed in each of the above plurality of matching boxes and detecting the phase of an RF signal applied from the RF signal generation unit;
A phase correction RF power supply device including a phase correction unit that is installed to be respectively connected to the plurality of RF signal generation units and corrects RF signals generated for the plurality of RF signal generation units by reflecting the phase difference of RF signals detected by the plurality of phase detection units. In the first paragraph, the phase correction unit,
A phase correction RF power supply device characterized in that, when a difference occurs in the phase information detected by the plurality of phase detection units, the phase difference is corrected so that an RF signal of the same phase is applied from the plurality of RF signal generation units. In the second paragraph, the phase correction unit,
A multi-channel pulse RF power supply device characterized in that the RF signal generation unit is controlled so that a minute phase difference is generated in each RF signal generation unit according to the phase information detected by the plurality of phase detection units.

Images