Patent ID: 12205799

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.

Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals, and the redundant description thereof may be omitted.

In the present specification, directions such as parallel, perpendicular, orthogonal, horizontal, vertical, up/down, left/right, and the like are allowed to deviate to the extent that the effects of the embodiments are not impaired. The shape of corners is not limited to a right angle, and may be arcuately rounded. Parallel, perpendicular, orthogonal, horizontal, vertical, circular, and coincident may include substantially parallel, substantially perpendicular, substantially orthogonal, substantially horizontal, substantially vertical, substantially circular, and substantially coincident.

[Plasma Processing Apparatus]

An example of a plasma processing apparatus according to an embodiment will be described.FIG.1is a schematic cross-sectional view showing an example of a plasma processing apparatus100according to the embodiment. The plasma processing apparatus100includes a processing container101, a mounting table102, a gas supplier103, an exhauster104, a microwave radiation source140, and a controller106.

The processing container101is made of a metal material such as aluminum coated with yttria (Y2O3) or the like, and has a bottom-closed cylindrical container body112and a ceiling wall111. The ceiling wall111is provided on the top of the container body112. The ceiling wall111constitutes a part of the processing container101. A plasma processing space U is formed by the container body112and the ceiling wall111. The ceiling wall111has an upper surface111band a lower surface111a. The lower surface111ais exposed to the plasma processing space U. The ceiling wall111has openings. Microwave radiation sources140are arranged on the upper surface111bside so as to close the openings.

The mounting table102is arranged at the bottom of the processing container101. The mounting table102has a disc shape and is made of a metal material such as aluminum whose surface is anodized, or a ceramic material such as aluminum nitride (AlN). The mounting table102mounts a substrate W such as a semiconductor wafer. The mounting table102is supported by a metal support member120extending upward from the bottom of the container body112via an insulating member121.

Further, inside the mounting table102, lift pins (not shown) for lifting the substrate W are provided so as to be protrude and retract with respect to the upper surface of the mounting table102. Moreover, a heater107as a heating means is provided inside the mounting table102. The heater107is powered by a heater power source127to generate heat. By controlling the output of the heater107according to a temperature signal from a sensor (e.g., a thermocouple) provided near the upper surface of the mounting table102, the substrate W is controlled to have a predetermined temperature.

A high-frequency power source122is electrically connected to the mounting table102. In a case where the mounting table102is made of ceramics, an electrode is provided on the mounting table102, and the high-frequency power source122is electrically connected to the electrode. The high-frequency power source122applies high-frequency power as bias power to the mounting table102. The frequency of the high frequency power applied by the high-frequency power source122is preferably in the range of 0.4 to 27.12 MHz.

An exhaust pipe116is provided at the bottom of the container body112, and the exhauster104is connected to the exhaust pipe116. The exhauster104includes a vacuum pump, a pressure control valve, and the like. The inside of the processing container101is evacuated by the vacuum pump through the exhaust pipe116and is controlled to a desired vacuum state. The pressure inside the processing container101is controlled by a pressure control valve based on the value of a pressure gauge (not shown). The side wall of the container body112is provided with a loading/unloading port114for loading and unloading the substrate W into and from a transfer chamber (not shown) adjacent to the processing container101. When the substrate W is loaded and unloaded, the loading/unloading port114is opened by a gate valve115provided along the side wall of the container body112.

The microwave radiation sources140are arranged at six openings (only two of which are shown inFIG.1) in the outer peripheral region of the ceiling wall111and one opening in the central region of the ceiling wall111. In this embodiment, the transmission windows145at the lower ends of the seven microwave radiation sources140are configured to close the openings of the ceiling wall111, so that all the microwave radiation sources140are installed on the upper surface111bof the ceiling wall111. However, the number and arrangement of the microwave radiation sources140are not limited thereto. For example, only one microwave radiation source140may be arranged in the central region of the ceiling wall111, or multiple microwave radiation sources140may be arranged only in the outer peripheral region of the ceiling wall111.

The microwave radiation sources140are connected to the microwave output part130via an amplifier142. The microwave output part130generates microwaves, distributes the microwaves, and outputs the microwaves to the respective amplifier142. Each amplifier142mainly amplifies the distributed microwaves and outputs the microwaves it to each microwave radiation source140.

The microwave radiation source140includes an antenna module143, a slot antenna144, and a transmission window145. The antenna module143is a coaxial waveguide having an inner conductor143aand an outer conductor143barranged concentrically around the inner conductor143a. Microwaves propagate in the space between the inner conductor143aand the outer conductor143b. Annular dielectric members M1and M2are provided in the space between the inner conductor143aand the outer conductor143b. The dielectric member M1is disposed above the dielectric member M2. The dielectric members M1and M2are vertically movable to adjust the impedance.

A tip of the outer conductor143b(a tip of the antenna module143) is enlarged in diameter. A disk-shaped slot antenna144is fitted into the enlarged portion of the outer conductor143b. The antenna module143and the slot antenna144are provided above (outside) the ceiling wall111. The inner conductor143aabuts on the center of the upper surface of the slot antenna144. The slot antenna144has an arcuate or annular slot S around the center of the slot antenna144. The slot antenna144has a function of an antenna that radiates microwaves from the slot S.

Below the slot antenna144, there is provided the transmission window145through which the microwaves radiated from the slot S are radiated into the processing container10. The transmission window145is made of a dielectric material such as alumina (Al2O3) and is configured to transmit microwaves. The transmission window145closes the opening provided in the ceiling wall111at a position above the opening. As a result, the opening below the transmission window145is formed as a recess portion V. The recess portion V functions as a supply port for supplying microwaves, which are an example of electromagnetic waves, to the plasma processing space U. The microwaves transmitted through the transmission window145are radiated from the supply port of the recess portion V to the plasma processing space U inside the processing container101.

The gas supplier103includes gas introduction pipes124to126, a gas supply pipe128, and a gas supply source129. The gas introduction pipes124to126are connected to the gas supply source129via the gas supply pipe128. The gas introduction pipes124to126supply a gas from around the microwave radiation source140in the central region of the ceiling wall111.

The gas introduction pipes124and125are connected respectively to first gas supply paths R1and R2configured to vertically penetrate the ceiling wall111. The first gas supply path R1has a first gas supply hole124aopened on the lower surface111a, and the first gas supply path R2has a first gas supply hole125aopened on the lower surface111a(seeFIG.3A).

The gas introduction pipes126are connected to a second gas supply path R3including a path126b(seeFIG.3A) extending upward from the ceiling wall111and a path126cbending laterally within the ceiling wall111and extending to the inner surface111cof the recess portion V. The second gas supply path R3has a second gas supply hole126aopened on the inner surface111c.

The gas supply source129supplies a processing gas. As an example, when forming a silicon nitride film (SiN) on the substrate W, an N2gas and/or NH3gas is supplied from the first gas supply holes124a, and a SiH4(silane) gas is supplied from first gas supply holes125a. In addition, an N2gas and/or NH3gas is supplied from the plurality of second gas supply holes126a.

However, the supply of the processing gas is not limited thereto. The first gas supply hole125amay supply a gas that is relatively easy to decompose, and the second gas supply hole126amay supply a gas that is relatively difficult to decompose. The first gas supply hole124amay supply the gas that is relatively easy to decompose or the gas that is relatively difficult to decompose.

The gas supply pipe128is provided with a valve for controlling the supply and stop of the processing gas and a flow rate controller for adjusting the flow rate of the processing gas.

The controller106is, for example, a computer including a controller106aand a memory106b. The controller106may include an input device, a display device, and the like. The controller106acontrols each part of the plasma processing apparatus100. In the controller106a, an operator can use an input device to input commands to manage the plasma processing apparatus100. In addition, the controller106acan visualize and display the operating status of the plasma processing apparatus100and the like using the display device. Further, the memory106bstores control programs and recipe data for controlling various processes executed in the plasma processing apparatus100by the controller106a. The controller106aexecutes a control program to control each part of the plasma processing apparatus100according to recipe data, thereby executing substrate processing such as film formation or the like using the plasma processing apparatus100.

[Gas Supply Mechanism]

Next, details of the gas supply structure near the supply port for supplying microwaves will be described with reference toFIGS.2A,2B,3A, and3B.FIG.2Ais a diagram showing an example of a gas supply structure according to a reference example.FIG.3Ais a diagram showing an example of a gas supply structure according to an embodiment.

In the reference example ofFIG.2A, a recess portion V is formed under a transmission window145′. The recess portion V′ serves as a supply port for supplying microwaves radiated from a transmission window145′ into the processing container101. The depth of the recess portion V is indicated by H4. In other words, the length of the inner side surface111cof the recess portion V is H4. When gases A and B are supplied, the gas B, which is relatively easy to decompose, is supplied from the gas introduction pipes123to the gas supply holes123a, and the gas A, which is relatively difficult to decompose, is supplied from the gas introduction pipes124to the first gas supply holes124a. As an example, the processing gas B is a SiH4gas, and the processing gas A is an N2gas and/or NH3gas. In the reference example, the SiH4gas (gas B), which is relatively easy to decompose, is supplied into the processing container101from gas nozzles111dprojecting from the lower surface111aof the ceiling wall111. The length of the gas nozzles111dfrom the lower surface111aof the ceiling wall111is indicated by H3.

The transmission window145′ has a disk shape and closes the opening of the ceiling wall111from the upper surface111bside of the opening. An O-ring146is provided at a boundary between the transmission window145′ and the ceiling wall111. The O-ring146seals the inside of the processing container101from the atmosphere outside the processing container101and keeps the inside of the processing container101airtight.

The first gas supply holes124asupply an N2gas and/or NH3gas into the processing container101from the lower surface111aof the ceiling wall111. The gas supply holes123asupply the SiH4gas from a tip of the gas nozzle111d.

FIG.2Bis a diagram showing the vicinity of the recess portion V under the transmission window145′ as viewed from the lower surface111aside of the ceiling wall111. As shown inFIG.2B, the first gas supply holes124aand the gas supply holes123aprovided in the gas nozzle111dare arranged on the same circumference. The gas supply holes123aand the first gas supply holes124aare provided alternately. In addition, inFIG.2A, for the sake of convenience, the positions of the first gas supply holes124aand the gas supply holes123aare shown as if they are shifted in the radial direction.

The N2gas and/or NH3gas is activated by the plasma generated in the processing container101including the vicinity of the recess portion V′, so that the gas can be easily reacted. A high-density plasma region is formed by the activated N2gas and/or NH3gas near the recess portion V. Therefore, if the SiH4gas supply position is close to the region of the recess portion V′, the highly reactive SiH4gas may be polymerized in the gas phase and may fly onto the substrate W to become particles. In addition, abnormal discharge may occur in the gas supply holes123afor supplying the SiH4gas.

Therefore, in the reference example, the SiH4gas is supplied from the supply holes123aprovided at the positions lower than the height of the first gas supply holes124afor the N2gas and the NH3gas by the length H3and located away from the high-density plasma region. Thus, a silicon nitride film is formed on the substrate W by causing the SiH4gas to react with the activated N2gas and/or NH3gas and nitriding Si derived from the SiH4gas. This suppresses generation of particles and suppresses abnormal discharge at the gas supply holes123afor the SiH4gas.

However, in the reference example, by protruding the gas nozzles111ddownward from the lower surface111aof the ceiling wall111, the shape of the ceiling wall111becomes complicated, which leads to an increase in the difficulty of processing and thus the cost. In addition, since the ceiling wall111is made of aluminum, the ceiling wall111is thermally sprayed with a thermal spray film of yttria or the like in order to increase plasma resistance. However, during the spraying, the degree of difficulty of the thermal spraying process increases due to the protrusions of the gas nozzles111d, which leads to an increase in the processing cost or the equipment cost.

Further, when the silicon nitride film adhering to the inner wall of the processing container101or the like is removed during cleaning, an NF3gas is supplied from the gas nozzle111d. At that time, by-products such as aluminum fluoride (AlF) and yttrium fluoride (YF) adhere to the gas nozzles111dand generate particles. In addition, due to the protrusions of the gas nozzles111d, the arrangement of the gas supply holes may be limited, thereby hindering free design.

Therefore, in the gas supply structure according to the embodiment, as shown inFIG.3A, the structure of the gas nozzles111dis eliminated, and the lower surface111aof the ceiling wall111is positioned downward by, for example, the length H3. That is, the ceiling wall111of the embodiment is formed thicker by H3than the ceiling wall111of the reference example, and the high-density plasma region is shifted upward by H3. Thus, the first gas supply holes124afor supplying the N2gas and/or NH3gas and the first gas supply holes125afor supplying the SiH4gas are formed on the same surface (lower surface111a) and on the same circumference. That is, the lower surface111aof the ceiling wall111can be made flat, and the first gas supply holes124aand125aare provided at the same height. As a result, by simplifying the shape of the ceiling wall111, it is possible to simplify the gas supply structure in the vicinity of the microwave supply port and reduce the degree of difficulty in processing.

In the embodiment ofFIG.3A, the recess portion V is formed below the transmission window145. The recess portion V serves as a supply port for supplying microwaves radiated from the transmission window145into the processing container101. The depth of the recess portion V is increased by the thickness of the ceiling wall111(i.e., H3), and the length of the inner side surface111cof the recess portion V is H4+H3. The first gas supply holes125aare configured to supply a SiH4gas (gas B) that is relatively easy to decompose, and the first gas supply holes124aare configured to supply a N2gas and/or NH3gas (gas A) that is relatively difficult to decompose. However, the supply of the N2gas and/or NH3gas (gas A) that is relatively difficult to decompose from the first gas supply holes124ais not essential due to the provided second gas supply holes126a, which will be described later.

FIG.3Bis a diagram showing the vicinity of the recess portion V under the transmission window145as viewed from the lower surface111aside of the ceiling wall111. As shown inFIG.3B, the first gas supply holes125afor supplying the SiH4gas (gas B) and the first gas supply holes124afor supplying the N2gas and/or NH3gas (gas A) are provided alternately on the same circumference. The first gas supply holes125aand the first gas supply holes124aare provided at regular intervals. In addition, inFIG.3A, for the sake of convenience, the first gas supply holes124aand the first gas supply holes125aare shown as if they are shifted in the radial direction.

The depth of the recess portion V is larger than that of the reference example by the length of H3at which the ceiling wall111is thickened. Therefore, the second gas supply holes126afor supplying the N2gas and/or NH3gas are arranged on the inner side surface111cof the recess portion V at regular intervals. Thus, the second gas supply holes126acan be arranged apart from the first gas supply holes124aand125a. As a result, it is possible to prevent or suppress the occurrence of abnormal discharge in the first gas supply holes125aand the occurrence of polymerization of the highly reactive SiH4gas in the gas phase, which may otherwise generate particles.

The N2gas and/or NH3gas is directly supplied to the high-density plasma region under the transmission window145from the second gas supply holes126a. This can promote the activation of the N2gas and/or NH3gas.

The transmission window145has a downwardly recessed shape and has an annular thickness on the outer peripheral side. The O-ring146is provided at the boundary between the transmission window145and the ceiling wall111. The O-ring146seals the inside of the processing container101from the atmosphere outside the processing container101and keeps the inside of the processing container101airtight.

Also in the embodiment, the ceiling wall111is coated with a thermally sprayed film of yttria or the like, and the inner wall of the recess portion V is also coated with a thermally sprayed film. On the other hand, the lower surface of the transmission window145is recessed, and the position of the O-ring146of the embodiment is lower than that of the reference example by the thickness of the outer periphery of the transmission window145. As a result, the O-ring146can be arranged at a position where the plasma density and temperature are lower than those of the reference example, the consumption of the thermally sprayed film around the O-ring146can be reduced, and the time required until the maintenance and replacement of the ceiling wall111can be lengthened.

In view of the above, it is preferred that the second gas supply holes126aare arranged at or below a position where the wear of the thermally sprayed film around the O-ring146can be reduced and at a position as close as possible to the high-density plasma region under the transmission window145. As a result, the consumption of the thermally sprayed film in the recess portion V can be alleviated, and the activation of the N2gas and/or NH3gas can be promoted.

The N2gas and/or NH3gas supplied from the first gas supply holes124adilutes the SiH4gas supplied from the first gas supply holes125a, and has the effect of suppressing the reactivity (decomposition) of the SiH4gas. Therefore, it is preferred that the first gas supply holes124aand the first gas supply holes125aare arranged alternately on the same circumference. However, the first gas supply holes124aand the first gas supply holes125ado not need to be arranged in pairs (e.g., alternately) as long as particles and abnormal discharge can be suppressed to the extent that they do not cause a problem. For example, the first gas supply holes124amay be arranged on the inner peripheral side or the outer peripheral side of the first gas supply holes125a. The first gas supply holes124amay be omitted if the problem of particles and abnormal discharge can be resolved. According to the gas supply structure of the embodiment, by eliminating the protrusions from the lower surface111aof the ceiling wall111and making the lower surface111aflat, it is possible to increase a degree of freedom in designing the gas supply holes.

[Arrangement of Second Gas Supply Holes]

FIGS.4A and4Bare diagrams showing an arrangement example of gas supply holes according to the embodiment.FIGS.4A and4Bare diagrams showing the lower surface111aof the ceiling wall111. InFIGS.4A and4B, the inside and outside of the boundary line Ar indicated by a circle are divided into a central region and an outer peripheral region. InFIGS.4A and4B, the ceiling wall111has a total of seven openings, one in the central region and six in the outer peripheral region. The seven openings are closed by seven transmission windows145. InFIG.4A, the second gas supply holes126aare provided on the inner side surface111cof the recess portion V below the transmission window145that closes the opening in the central region among the seven openings. Around the second gas supply holes126a, the first gas supply holes124aand the first gas supply holes125aare arranged alternately on the same circumference.

InFIG.4B, the second gas supply holes126aare provided for each of the inner side surfaces111cof the seven recess portions V formed under the seven transmission windows145that close the seven openings. Around each of the second gas supply holes126a, the first gas supply holes124aand the first gas supply holes125aare arranged alternately on the same circumference.

However, the arrangement of the gas supply holes inFIGS.4A and4Bis merely an example, and the number and arrangement of the gas supply holes are not limited thereto. For example, the number of openings provided in the ceiling wall111may be zero or may be one or more in the central region. The number of openings provided in the ceiling wall111may be zero or may be a plurality other than six in the outer peripheral region.

[Orientation of Second Gas Supply Holes]

The height direction of the recess portion V is defined as a Z direction, and the plane perpendicular to the Z direction is defined as an XY plane. The Z axis is an axis perpendicular to the lower surface111aof the ceiling wall111, and the XY plane is horizontal to the lower surface111a. As shown inFIGS.3B and6A, the axis passing through the center of the transmission window145(the center of the recess portion V) is particularly defined as a Z1 axis.

FIGS.5A and5Bare diagrams showing an example of an angle of the second gas supply holes126ain the XZ plane.FIGS.6A and6Bare diagrams showing an example of an angle of the second gas supply holes126ain the XY plane.

ComparingFIG.5AwithFIG.3A, the second gas supply holes126ashown inFIG.3Aare formed on the XY plane and are perpendicular to the Z direction. Further, as shown inFIG.3B, all of the second gas supply holes126aface the Z1 axis on the XY plane. That is, the second gas supply holes126ashown inFIGS.3A and3Bare opened perpendicularly to the inner surface of the recess portion V.

On the other hand, the second gas supply holes126ashown inFIG.5Aare formed to be upturned from the XY plane and have an angle in the Z direction. As shown inFIG.5B, an angle in the Z direction with respect to the X direction in the XZ plane is defined as θzx. In the second gas supply holes126ashown inFIG.5A, the angle θzx is greater than 0°, and may be, for example, 30° or more and 45° or less, or may be 45° or more. The angle θzx of the second gas supply holes126ais not limited thereto. The second gas supply holes126amay be formed to be upturned from the XY plane, and preferably upturned toward the transmission window145.

Further, the second gas supply holes126ashown inFIG.5Aface the Z1 axis in the XY plane just like the orientation indicated by an arrow inFIG.3B. That is, the second gas supply holes126ashown inFIG.5Aare opened straight without any inclination in the XY direction with respect to the inner surface of the recess portion V, and are opened to be upturned in the Z direction at an angle θzx larger than 0°. The angle θzx does not take a value smaller than 0°. That is, the second gas supply holes126aare not opened at an angle downward with respect to the XY plane.

Plasma with a higher density is generated immediately below and in the vicinity of the transmission window145in the recess portion V. When the second gas supply holes126aare opened so that the angle θzx in the Z direction becomes 0° as shown inFIG.3A, the N2gases and/or NH3gases supplied in the horizontal direction from the second gas supply holes126aarranged on the inner surface111ctend to collide with each other in the recess portion V. On the other hand, if the second gas supply holes126aare opened to be upturned so that the angle θzx becomes greater than 0° as shown inFIG.5A, it is difficult for the N2gases and/or NH3gases to collide head-on with each other, and the gases flow smoothly to the vicinity directly below the transmission window145. As a result, it is possible to promote activation of the N2gas and/or NH3gas in the high-density plasma region below the transmission window145.

Further, assuming that an angle θxy in the X direction in which the second gas supply holes126aface the Z1 axis in the XY plane is 0°, the second gas supply holes126ashown inFIGS.6A and6Bare opened laterally while having an inclination angle in the Y direction of Oxy. The angle θxy may be positive or negative. When the angle θxy is positive as shown inFIG.6B, all of the second gas supply holes126aare opened at the same angle to the right with respect to the direction facing the Z1 axis. When the angle θxy is negative, all of the second gas supply holes126aare opened at the same angle to the left with respect to the direction facing the Z1 axis.

Further, the angle θzx in the Z direction of the second gas supply holes126ashown inFIGS.6A and6Bmay be 0° or may be greater than 0°. However, it is more preferable that the angle θzx in the Z direction of the second gas supply holes126ashown inFIGS.6A and6Bis greater than 0° and the second gas supply holes126aare opened obliquely upward so as to generate a swirling flow.

Moreover, although it is preferable that all the angles θzx of the second gas supply holes126aare set to the same angle, the second gas supply holes126amay have slightly different orientations (angles). Similarly, although it is preferable that all the angles θxy of the second gas supply holes126aare set to the same angle, the second gas supply holes126amay have slightly different orientations (angles).

As described above, the second gas supply holes126aare formed obliquely in the XY plane direction with respect to the direction facing the Z1 axis, which is the center axis of the recess portion V, and may be configured so that a swirling flow is generated in the recess portion V. As a result, the N2gas and/or NH3gas activated in the high-density plasma region forms a swirling flow and smoothly flows into the high-density plasma region, whereby a flow of active species can be formed so as to be pushed out from the recess portion V toward the first gas supply holes124aand125a.

By forming the swirling flow of the N2gas and/or NH3gas in the recess portion V in this way, the N2gas and/or NH3gas can be evenly supplied to the high-density plasma region, and the efficiency in activation of the N2gas and/or NH3gas can be increased. In addition, it is possible to avoid generation of a turbulent flow due to the collision of gases in the recess portion V, and it is possible to increase the efficiency in transporting the activated N2gas and/or NH3gas to the first gas supply holes124aand125a.

In order to improve the activation efficiency and transport efficiency of the N2gas and/or NH3gas, the angle θzx of the second gas supply holes126ais preferably greater than 0 and the angle θxy preferably has a positive or negative value other than 0. In other words, the second gas supply holes126aare preferably opened rightward, leftward, upward, obliquely upward and rightward, or obliquely upward and leftward when the horizontal direction facing the Z1 axis is defined as the X direction.

As described above, according to the plasma processing apparatus100of the present embodiment, the lower surface111ais provided with the first gas supply holes125a, and the inner surface111cof the recess portion V is provided with the second gas supply holes126a. As a result, the lower surface111ahas no protrusion, which makes it possible to simplify the gas supply structure in the vicinity of the electromagnetic wave supply port and to prevent or suppress the generation of particles and the occurrence of abnormal discharge.

[Others]

The number of first gas supply holes124aand125aand the number of second gas supply holes126amay be the same or different.

It is preferable to independently control the N2gas and/or NH3gas supplied from the first gas supply holes124aand the N2gas and/or NH3gas supplied from the second gas supply holes126a. The N2gas and/or NH3gas supplied from the second gas supply holes126ahas a function of efficiently generating N radicals and/or NH radicals mainly by high-density plasma. On the other hand, the N2gas and NH3gas supplied from the first gas supply holes124ahas a function of diluting the SiH4gas supplied from the first gas supply holes125a. It is preferred that the controller106separately performs the control operations necessary for causing the N2gas and/or NH3gas to exhibit different functions as described above, and optimizes the dissociation degrees and flow rates of the gas supplied from the first gas supply holes124aand the gas supplied from the second gas supply holes126a. This makes it possible to more effectively prevent or suppress the generation of particles and the occurrence of abnormal discharge. Further, it is possible to more accurately control the dissociation state of the SiH4gas and to form a SiN film having a good quality.

Therefore, the gas type and/or gas flow rate may be changed for the gas supplied from the first gas supply holes124aand the gas supplied from the second gas supply holes126a. For example, an NH3gas may be introduced from the second gas supply holes126aand may be activated (dissociated). An N2gas may be introduced from the first gas supply holes124a, and a silane gas may be diluted with the N2gas. Conversely, an N2gas may be introduced from the second gas supply holes126a, and an NH3gas may be introduced from the first gas supply holes124a. The gas supplied from the first gas supply holes124aand/or the second gas supply holes126amay be a gas other than the N2gas and the NH3gas and may be gases suitable for each process. For example, it may be conceivable to use an H2gas, an N2O gas, an NO gas, an O2gas, an H2O gas, and mixed gases thereof.

In order to individually control the flow rates of the gases supplied from three locations, i.e., the first gas supply holes124aand125aand the second gas supply holes126a, it is preferable to provide flow rate controllers, one in the central region and one in the outer peripheral region for each of the three types of gas supply holes. In other words, it is preferable to arrange at least three flow rate controllers in the central region and at least three flow rate controllers in the outer peripheral region, six in total.

More preferably, three flow controllers are provided for each of the six gas supply structures for the six transmission windows145in the outer peripheral region, and one flow controller is provided for each gas supply structure for one transmission window145in the central region. In this case, a total of 21 flow rate controllers, 3 in the central region and 18 (=3×6) in the outer peripheral region, are arranged. Depending on the number and arrangement of the flow rate controllers, it is possible to more effectively control the flow rates of the various gases supplied from the three types of gas supply holes. Therefore, the generation of particles and the occurrence of abnormal discharge can be more effectively prevented or suppressed by controlling the degree of activation, transportation, and dilution of various gases with higher accuracy. Further, it is possible to control the dissociation state of the SiH4gas more accurately and to form a SiN film having a good quality.

The plasma processing apparatuses according to the embodiments disclosed this time should be considered to be exemplary and not limitative in all respects. The embodiments may be modified and improved in various ways without departing from the scope and spirit of the appended claims. The items described in the above-described embodiments may take other configurations within a consistent range and may be combined with each other within a consistent range.

According to the present disclosure in some embodiments, it is possible to efficiently activate a gas by plasma near a supply port of electromagnetic waves.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.