KR20230137122A - Substrate processing apparatus and method of processing substrate - Google Patents

Abstract

A substrate processing apparatus according to an aspect of the present invention includes a process chamber having a plurality of reaction spaces formed therein, a plurality of substrate supports installed in the process chamber to respectively support a plurality of substrates within the plurality of reaction spaces, and , a plurality of gas injection units installed in the process chamber to face each of the plurality of substrate supports to inject process gas into the plurality of reaction spaces, and RF for forming a plasma atmosphere in the plurality of reaction spaces. A plurality of plasma power supplies respectively connected to the plurality of gas injection units to supply power, a plurality of RF phase meters for respectively measuring RF phases of the RF powers, and RF obtained from the plurality of RF phase meters and a control unit that controls the generation of RF powers of the plurality of plasma power units to synchronize phases.

Description

Substrate processing apparatus and method of processing substrate}

The present invention relates to the manufacturing of semiconductor devices, and more specifically, to a substrate processing apparatus and substrate processing method for manufacturing semiconductor devices.

In order to manufacture semiconductor devices, various substrate processing processes are performed in a substrate processing apparatus in a vacuum atmosphere. For example, processes such as loading a substrate into a process chamber and depositing a thin film on the substrate or etching the thin film may be performed. The substrate is supported on a substrate supporter installed in the process chamber, and process gas may be injected into the substrate through a gas injection unit installed on top of the substrate supporter. Furthermore, this substrate processing device can use RF power to create a plasma atmosphere in the process chamber.

Recently, in order to increase the productivity of substrate processing, a substrate processing device that simultaneously processes a plurality of substrates by forming a plurality of reaction spaces in a process chamber has been used. However, due to complex factors such as structural factors between reaction spaces within the process chamber and deviations of hardware modules coupled thereto, an imbalance of RF powers, such as RF phase difference, may occur between reaction spaces. Accordingly, RF power imbalance or interference occurs between reaction spaces, and the thickness variation of thin films formed on substrates in reaction spaces increases, reducing process reliability.

The present invention is intended to solve the above-mentioned problems, and its purpose is to provide a substrate processing apparatus and a substrate processing method that can increase process reliability by equalizing RF powers transmitted to a plurality of reaction spaces in a process chamber. However, these tasks are illustrative and do not limit the scope of the present invention.

A substrate processing apparatus according to one aspect of the present invention for solving the above problem includes a process chamber having a plurality of reaction spaces formed therein, and a plurality of substrates installed in the process chamber to support each of the plurality of substrates within the plurality of reaction spaces. A plurality of substrate supports, a plurality of gas injection units installed in the process chamber opposite each of the plurality of substrate supports to inject process gas into the plurality of reaction spaces, and a plasma in the plurality of reaction spaces. A plurality of plasma power supplies respectively connected to the plurality of gas injection units to supply RF powers for forming an atmosphere, a plurality of RF phase meters for each measuring RF phases of the RF powers, and the plurality of RF and a control unit that controls the generation of RF powers of the plurality of plasma power sources to synchronize RF phases obtained from phase meters.

According to the substrate processing apparatus, a plurality of impedance matching units are respectively connected between the plurality of plasma power sources and the plurality of gas injection units, and the plurality of RF phase measurement units are connected to the plurality of impedance matching units and the plurality of gas injection units. They can each be coupled to RF lines connecting the injection units.

According to the substrate processing apparatus, the plurality of RF phase measurers may be respectively coupled to connection portions of the plurality of gas injection units of the RF lines.

According to the substrate processing apparatus, the control unit sets the RF phase measured from the RF power supplied through one gas injection unit among the plurality of gas injection units as the master phase, and sets the RF power supplied through the remaining gas injection units as the master phase. The RF phases measured in can be set as slave phases, and the generation of RF powers of the plurality of plasma power units can be controlled to synchronize the slave phases with the master phase.

According to the substrate processing apparatus, it includes a common exhaust part connected to the process chamber so as to be commonly connected to the plurality of reaction spaces, and process gas in the plurality of reaction spaces may be exhausted through the common exhaust part.

According to the substrate processing apparatus, a gas supply line for commonly supplying a process gas to the plurality of gas injection units may be included.

According to the substrate processing apparatus, each of the plurality of RF phase measuring devices includes a VI sensor, and each of the plurality of RF phase measuring devices can measure the phase of voltage or current measured through the VI sensor.

According to another aspect of the present invention for solving the above problem, according to the substrate processing method, each of the substrates is placed on the plurality of substrate supports, and from the plurality of plasma power sources to the plurality of gas injection units. supplying RF powers, measuring RF phases of the RF powers using the plurality of RF phase meters, and using the control unit to synchronize the RF phases obtained from the plurality of RF phase meters. and controlling the generation of RF powers of the plurality of plasma power sources.

According to the substrate processing apparatus and substrate processing method according to an embodiment of the present invention as described above, the RF power applied to a plurality of reaction spaces in the process chamber is uniformly applied to reduce the process deviation between the reaction spaces to improve the process. Reliability can be improved. Of course, the scope of the present invention is not limited by this effect.

1 is a schematic diagram showing a substrate processing apparatus according to an embodiment of the present invention.
Figure 2 is a schematic partial cross-sectional view of the substrate processing apparatus of Figure 1;
FIG. 3A is a graph showing RF phases before RF phase synchronization according to a comparative example, and FIG. 3B is a graph showing RF phases after RF phase synchronization according to an embodiment of the present invention.
Figure 4 is a graph showing the thin film stress distribution between reaction spaces before RF phase synchronization according to a comparative example and the thin film stress distribution between reaction spaces after RF phase synchronization according to an embodiment of the present invention.

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

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified into various other forms, and the scope of the present invention is as follows. It is not limited to the examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete and to fully convey the spirit of the present invention to those skilled in the art. Additionally, the thickness and size of each layer in the drawings are exaggerated for convenience and clarity of explanation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will now be described with reference to drawings that schematically show ideal embodiments of the present invention. In the drawings, variations of the depicted shape may be expected, for example, depending on manufacturing technology and/or tolerances. Accordingly, embodiments of the present invention should not be construed as being limited to the specific shape of the area shown in this specification, but should include, for example, changes in shape resulting from manufacturing.

FIG. 1 is a schematic diagram showing a substrate processing apparatus 100 according to an embodiment of the present invention, and FIG. 2 is a schematic partial cross-sectional view of the substrate processing apparatus 100 of FIG. 1 .

Referring to FIGS. 1 and 2 , the substrate processing apparatus 100 includes a process chamber 110, a plurality of gas injection units 120, a plurality of substrate supports 130, and a plurality of plasma power sources 140. can do.

The process chamber 110 may have a plurality of reaction spaces 112 formed therein. For example, the reaction spaces 112 may be spaced apart within the process chamber 110 and may be formed to have substantially the same or similar structure. The reaction spaces 112 may define a space for processing the substrates S. In some embodiments, reaction spaces 112 may be arranged within the process chamber 110 to communicate with each other.

The reaction spaces 112 may be arranged within the process chamber 110 to share at least some of the external utilities, for example, arranged in a matrix or arranged in a row. The number of reaction spaces 112 may be appropriately selected considering productivity and process uniformity.

More specifically, the process chamber 110 is configured to maintain airtightness as a whole, and has an entrance for loading or unloading the substrates 50 into or from the reaction spaces 112 and an opening and closing thereof. It may include a gate structure (not shown) to do this. The process chamber 110 may be provided in various shapes, and may include, for example, a side wall portion and a cover portion located on top of the side wall portion, for example, a top lead.

Additionally, a common exhaust 152 may be connected to the process chamber 110 such that it is commonly connected to the reaction spaces 112 . For example, the common exhaust portion 152 may be commonly connected to the exhaust port at the bottom of the reaction spaces 112. Accordingly, the process gas in the reaction spaces 112 can be exhausted through the common exhaust part 152, and further, the common exhaust part 152 is a vacuum pump (not shown) to adjust the degree of vacuum in the reaction spaces 112. ) can be connected to.

Gas injection units 120 may be installed in the process chamber 110 to inject process gas into the reaction spaces 112 . For example, the gas injection units 120 may be installed in the process chamber 110 to face the substrate supports 130 . Each gas injection unit 120 may be installed on the upper part of the process chamber 110 constituting the reaction space 112 to spray process gas on the substrate S seated on the substrate support 130. .

For example, each gas injection unit 120 includes an inlet through which the process gas is introduced, a blocker plate for dispersing the process gas passing through the inlet, and an inlet for injecting the process gas into the reaction space 112. It may include a distribution plate for. The structure of the gas injection units 120 may be modified in various ways and is not limited to this structure.

In some embodiments, each gas injection unit 120 may have various shapes, such as a shower head shape or a nozzle shape. When the gas injection units 120 are in the form of a shower head, the gas injection units 120 may each be coupled to the process chamber 110 in a form that partially covers the upper part of the process chamber 110. For example, the gas injection units 120 may be arranged to be spaced apart from the cover or side wall of the process chamber 110 .

Additionally, a gas supply line 122 may be provided to commonly supply process gas to the gas injection units 120. For example, the gas supply line 122 may be branched and commonly connected to the gas injection units 120. Valves (not shown) that can open and close the supply of process gas may be inserted in the gas supply line 122. A plurality of gas supply lines 122 may be installed depending on the type of process gas. In this case, each gas supply line 122 may be branched and connected to the gas injection units 120. In some embodiments, each gas supply line 122 may be separately connected to the gas injection units 120.

Substrate supports 130 may be installed in the process chamber 110 to support each of the substrates S within the reaction spaces 112 . For example, the substrate supports 130 may be installed in the process chamber 110 to face the gas injection units 120, respectively. Furthermore, each substrate supporter 130 may include a heater 182 therein for heating the substrate S. For example, the heater power supply unit 180 is connected to the heater 182 to apply power to the heater 182, and additionally, an RF filter 185 may be interposed between the heater 182 and the heater power supply unit 180. You can.

The shape of the top plate of each substrate support unit 130 generally corresponds to the shape of the substrate S, but is not limited to this and may be provided in a variety of shapes larger than that of the substrate S so that the substrate S can be stably seated. In one example, the shaft of each substrate support unit 130 may be connected to an external motor (not shown) to enable raising and lowering, and in this case, a bellows pipe (not shown) may be connected to maintain airtightness. Furthermore, since each substrate support portion 130 is configured to place the substrate S thereon, it may also be called a substrate seating portion, a susceptor, etc.

The plasma power sources 140 may be respectively connected to the gas injection units 120 to supply RF powers for forming a plasma atmosphere in the reaction spaces 112 within the process chamber 110 . For example, each plasma power source 140 may include at least one RF power source to apply at least one radio frequency (RF) power to the corresponding reaction space 112 . For example, each plasma power source 140 may be connected to apply RF power to the corresponding gas injection unit 120, and in this case, each gas injection unit 120 may be called a power supply electrode or an upper electrode.

In some embodiments, each plasma power source 140 may include a high frequency (HF) power source and/or a low frequency (LF) power source. For example, the high frequency (HF) power source may be an RF power source with a frequency range from 5 MHz to 60 MHz, optionally from 13.56 MHz to 27.12 MHz. The low frequency (LF) power source may be an RF power source with a frequency range of 100 kHz to 5 MHz, optionally 300 kHz to 600 kHz.

Additionally, a plurality of impedance matching units 146 may be connected between the plasma power sources 140 and the gas injection units 120, respectively. The RF power supplied from each plasma power source 140 can be appropriately impedance matched between each plasma power source 140 and each gas injection unit 120 through the corresponding impedance matching unit 146. In this case, the process chamber It can be effectively transmitted to the process chamber 110 without being reflected at 110 and returning.

For example, each impedance matching unit 146 may be composed of a series or parallel combination of two or more selected from the group of resistors, inductors, and capacitors. Furthermore, each impedance matching unit 146 may adopt at least one variable capacitor or capacitor array switching structure so that its impedance value can be varied according to the frequency of RF power and process conditions.

A plurality of RF phase meters 148 may be provided to respectively measure RF phases of RF powers. The RF phase meters 148 are for measuring the deviation of the plasma atmosphere within the reaction spaces 112, and are used to measure the deviation of the plasma atmosphere from the plasma power sources 140 through the gas injection units 112 and/or the substrate supports 130. RF phases of RF power can be measured. For example, each of the RF phase meters 148 may include a VI sensor. Each RF phase meter 148 can measure the phase of voltage or current measured through the VI sensor.

For example, the RF phase meters 148 may be respectively coupled to the RF lines 142 connecting the impedance matching units 146 and the gas injection units 120. In this case, the RF phase measurers 148 can measure the RF phases supplied to each gas injection unit 120 by performing impedance matching. Furthermore, the RF phase meters 148 may be respectively coupled to the connection portions of the gas injection units 120 of the RF lines 142, in which case the RF phase meters 148 are substantially connected to the gas injection units 120. ), it has the advantage of being able to directly measure the RF phase of the RF powers supplied to the gas injection units 120.

In some embodiments, the RF phase measurers 148 may be installed in front of the impedance matching units 147 to measure the RF phases of RF powers input to the impedance matching units 147. In this case, RF phases that change as they are supplied to the gas injection units 120 through the impedance matching units 147 may not be measured. In some other embodiments, the RF phase meters 148 may be installed at the rear end of the substrate supports 130. In this case, the RF phase meters 148 may be considered a somewhat indirect monitoring method in that they measure the RF phase of the RF power flowing to the ground through the substrates S.

The RF phase meters 148 can measure in real time the RF phase differences of RF powers between the reaction spaces 112 within the process chamber 110, and thus the reaction spaces ( 112) The RF phase differences between RF powers can be monitored in real time. The RF phase measurers 148 may transmit measured information to the control unit 190.

The control unit 190 may control the generation of RF power of the plasma power sources 140 to synchronize the RF phases obtained from the RF phase meters 148. For example, the control unit 190 controls the plasma power supplies 140 so that the RF phases of the output power of the power generators in the plasma power supplies 140 are synchronized based on the RF phases obtained from the RF phase meters 148. can do. The control unit 190 may be a main control unit responsible for overall control of the substrate processing apparatus 100 or may refer to an RF phase synchronization unit for synchronizing the above-described RF phases.

In some embodiments, the control unit 190 sets the RF phase measured from the RF power supplied through one of the gas injection units 112 as the master phase, and sets the remaining gas injection units 112 to the master phase. RF phases measured from RF powers supplied through units 112 can be set as slave phases. Subsequently, the control unit 190 may control the generation of RF power of the plasma power sources 140 to synchronize the slave phases to the master phase in order to synchronize the RF phases.

In some embodiments, the controller 190 may calculate the average value of the RF phases obtained from the RF phase measurement devices 148 and then control the generation of RF power of the plasma power sources 140 so that the RF phases become the average value.

Accordingly, the control unit 190 checks the RF phase difference between the reaction spaces 112 in real time based on the RF phases obtained from the RF phase meters 148 and synchronizes the RF phases so that the RF phases are substantially the same. You can. Accordingly, RF power of substantially the same phase may be applied to the reaction spaces 112 within the process chamber 110, and thus RF interference or plasma deviation between the reaction spaces 112 may be reduced or eliminated.

For example, the above-described substrate processing apparatus 100 may be used as a plasma enhanced chemical vapor deposition (PECVD) device to form a thin film on the substrate S.

Below, a substrate processing method using the substrate processing apparatus 100 will be described. In some embodiments, the substrate processing method includes placing each of the substrates S on the substrate supports 130 and supplying RF powers from the plasma power sources 140 to the gas injection units 20. and measuring RF phases of the RF powers using RF phase meters 148, and using the control unit 190 to synchronize the RF phases obtained from the RF phase meters 148 to the plasma power supplies 140. ) may include controlling the generation of RF powers.

Furthermore, a step of performing processing on the substrates S under a plasma atmosphere in which RF phases are synchronized may be followed by a step of unloading the substrates S out of the process chamber 110 . RF phase synchronization may be performed in real time before the actual process for the substrates S, for example, a deposition process, or during the deposition process.

According to the above-described substrate processing apparatus 100 and the substrate processing method using the same, the deviation of RF phases caused by structural factors between the reaction spaces 112 or deviation of hardware modules can be measured and monitored in real time. And, furthermore, these RF phases can be controlled to synchronize. Accordingly, the plasma atmosphere can be maintained substantially the same between the reaction spaces 112 in the process chamber 110, thereby reducing or eliminating process variation between the reaction spaces 112, thereby improving process reliability.

FIG. 3A is a graph showing RF phases before RF phase synchronization according to a comparative example, and FIG. 3B is a graph showing RF phases after RF phase synchronization according to an embodiment of the present invention.

Referring to FIG. 3A, it can be seen that there is a deviation in the RF phases obtained through the RF phase measuring devices 148 before RF phase synchronization. Any one of these RF phases can be set as the master phase, and the other phases can be set as slave phases. For example, the master phase and slave phases may be determined in conjunction with the master and slave settings for the reaction spaces 112.

Referring to FIG. 3B, it can be confirmed that the RF phases obtained through the RF phase measurement devices 148 after RF phase synchronization are substantially the same. Accordingly, it can be seen that RF powers with substantially no phase difference can be supplied to the reaction spaces 112.

Figure 4 is a graph showing the thin film stress distribution between reaction spaces before RF phase synchronization according to a comparative example and the thin film stress distribution between reaction spaces after RF phase synchronization according to an embodiment of the present invention. In Figure 4, the thin film exemplarily shows a silicon nitride (SiN) film.

Referring to FIG. 4, according to the comparative example on the left, when RF phase synchronization is not performed, the stress values of thin films grown in the reaction spaces (STG1, STG2, STG3, STG3, STG4) have a maximum deviation of about 37Mpa. On the other hand, according to the example on the right, when RF phase synchronization is performed, it can be seen that the stress value of the thin films has a maximum deviation of about 26 MPa. Therefore, it can be seen that when the thin film is grown by performing RF phase synchronization according to the present invention, the stress difference between the thin films between the reaction spaces (STG1, STG2, STG3, STG3, and STG4) is reduced, which is due to the thickness deviation of the thin films. Alternatively, it may mean that membrane quality variation is reduced.

Therefore, if RF phase synchronization is performed before or during the process according to an embodiment of the present invention, the difference in the plasma atmosphere within the reaction spaces (STG1, STG2, STG3, STG3, STG4) is reduced, and the thin films grown therein are reduced. It can be seen that thickness deviation or film quality deviation can be reduced.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

100: substrate processing device
110: Process chamber
120: gas injection unit
130: substrate support
140: Plasma power unit
148: RF phase meter
190: Control unit

Claims (8)

A process chamber with a plurality of reaction spaces formed therein;
a plurality of substrate supports installed in the process chamber to respectively support a plurality of substrates within the plurality of reaction spaces;
a plurality of gas injection units installed in the process chamber to face each of the plurality of substrate supports to spray process gas into the plurality of reaction spaces;
a plurality of plasma power sources respectively connected to the plurality of gas injection units to supply RF powers for forming a plasma atmosphere in the plurality of reaction spaces;
a plurality of RF phase meters for each measuring RF phases of the RF powers; and
Comprising a control unit that controls the generation of RF powers of the plurality of plasma power sources to synchronize the RF phases obtained from the plurality of RF phase meters,
Substrate processing equipment. According to claim 1,
A plurality of impedance matching units are respectively connected between the plurality of plasma power sources and the plurality of gas injection units,
The plurality of RF phase meters are each coupled to RF lines connecting the plurality of impedance matching units and the plurality of gas injection units,
Substrate processing equipment. The method of claim 2, wherein the plurality of RF phase meters are each coupled to connection portions of the plurality of gas injection units of the RF lines.
Substrate processing equipment. According to claim 1,
The control unit sets the RF phase measured from the RF power supplied through one of the plurality of gas injection units as the master phase, and sets the RF phases measured from the RF power supplied through the remaining gas injection units as the slave phase. Set the phases,
Controlling the generation of RF powers of the plurality of plasma power supplies to synchronize the slave phases to the master phase,
Substrate processing equipment. According to claim 1,
Comprising a common exhaust connected to the process chamber to be commonly connected to the plurality of reaction spaces,
Process gas in the plurality of reaction spaces is exhausted through the common exhaust part,
Substrate processing equipment. The method of claim 1, comprising a gas supply line for commonly supplying process gas to the plurality of gas injection units.
Substrate processing equipment. According to claim 1,
Each of the plurality of RF phase meters includes a VI sensor,
Each of the plurality of RF phase meters measures the phase of the voltage or current measured through the VI sensor,
Substrate processing equipment. A substrate processing method using the substrate processing device of claim 1, comprising:
Placing each substrate on the plurality of substrate supports;
supplying RF powers from the plurality of plasma power sources to the plurality of gas injection units;
measuring RF phases of the RF powers using the plurality of RF phase meters; and
Comprising the step of controlling, using the control unit, the generation of RF powers of the plurality of plasma power units to synchronize the RF phases obtained from the plurality of RF phase meters,
Substrate processing method.