JPH0936107A - Method and device for forming plasma film forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contamination such as the metal contamination of an insulating film by a method wherein the effect of the sputter etching, which is apt to increase on the corner part of a recessed part, is suppressed as much as possible while an excellent embedding of circuit pattern is being performed on the recessed part by impinging the ions in plasma against the board to be treated. SOLUTION: When a collimater 4 is composed of metal material and negative potential is given to the collimater 4 by connecting a DC electrode 42 to the collimater 4, the ions, which are made incident obliquely to a grain passage, is absorved by the collimater 4, and as a result, the ions which passed through the collimater 4 have high verticality. Then, the composition, for oblique incidence of ions in plasma against the wafer to be treated, is mentioned below. Rectangular electrodes 5A and 5C, to be used for dispersion of four rectangular ion incident direction are arranged on the circumference of the receptacle stand 3 in a film-forming chamber 22 at regular intervals. One end of AC power source parts V5A and V5C is connected to each of electrodes 5A and 5C respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a plasma film forming method and an apparatus thereof.

[0002]

2. Description of the Related Art Aluminum wiring is mainly used as a wiring pattern of an integrated circuit, and a film quality is good as a method of forming an interlayer insulating film, for example, an SiO ₂ film (silicon oxide film) for insulating the wiring. ECR (Electron Cyclo) combining microwave and magnetic field
Tron Resonance) plasma treatment tends to be adopted.

FIG. 17 shows an example of a conventional plasma processing apparatus for performing this ECR plasma processing. When a microwave of 2.45 GHz, for example, is supplied into the plasma generation chamber 1A via a waveguide not shown, at the same time, a predetermined value is given. size,
For example, a magnetic field of 875 Gauss is applied by the electromagnetic coil 10 to generate a high density plasma generating gas such as Ar gas and O ₂ gas by the interaction (resonance) between the microwave and the magnetic field, and the plasma is used to form the film forming chamber 1B. The reactive gas introduced therein, for example, SiH ₄ gas is activated to form ionic species, and the surface of the semiconductor wafer W on the mounting table 11 is simultaneously subjected to sputter etching and deposition. The contradictory sputter etching operation and the deposition operation are controlled so that the deposition operation is dominant in a macroscopic view, and the deposition is performed as a whole.

When performing such ECR plasma processing, 13.56 MHz is generally applied to a mounting table 11 (susceptor) on which a wafer is mounted by, for example, a high frequency power supply unit 12.
By applying a negative high frequency bias voltage of z, plasma ions are attracted to the wafer side as much as possible to maximize the sputtering effect.

When the deposition is performed while performing the sputter etching in this way, as shown in FIG. 19, the deposit on the edge portion 14 of the concave portion of the aluminum wiring 13 is mainly affected by the sputter etching, and the film is formed on this portion. As a result, the gap between the aluminum wirings is widened, and the aluminum wiring is sufficiently deposited to a deep portion to enable filling with a small number of voids, the film becomes dense, and the adhesion to the base becomes good. The film 15 on the surface of the aluminum wiring 13 is a very thin TiN film.

[0006]

By the way, in order to obtain the effect of sputter etching, it is necessary to lower the scattering probability of argon ions, and to sufficiently attract the sheath ions on the mounting table 11 side to secure the verticality of the argon ions. Therefore, it is essentially necessary to apply a bias voltage much higher than about 0.1 V, which is equivalent to thermal energy. However, the sputter etching effect is not limited to widening the opening of the concave portion (pattern shape), but also scrapes the edge portion 14 too much to scrape even the underlying aluminum, and this is taken into the SiO film, and especially the circuit pattern is miniaturized. However, there is a problem that the insulation becomes worse. The method of increasing the pressure in the film forming chamber to increase the probability of argon ion scattering and weakening the sputter etching effect deteriorates the generation efficiency of active species, and therefore cannot increase the pressure in the film forming chamber. Further, simply lowering the bias voltage causes a problem in film quality.

The present invention has been made under such circumstances, and an object of the present invention is to increase the corners of a concave portion which tends to increase while satisfactorily filling the concave portion of a circuit pattern on a wafer. Another object of the present invention is to provide a plasma film forming method and an apparatus therefor capable of suppressing the effect of the sputter etching as much as possible and preventing contamination in the film, for example, metal contamination in the insulating film.

[0008]

According to a first aspect of the present invention, a processing gas is supplied into a vacuum container provided with a substrate to be processed,
In the plasma film forming method of forming a thin film on the substrate to be processed by plasmatization using electron cyclotron resonance, ions in the plasma are obliquely incident on the substrate to be processed. .

According to a second aspect of the present invention, a plasma deposition method is provided in which a processing gas is supplied into a vacuum container in which a substrate to be processed is provided and plasma is formed by using electron cyclotron resonance to form a thin film on the substrate to be processed. In the above method, the ions in the plasma are obliquely incident on the substrate to be processed while being obliquely incident on the substrate.

According to the third aspect of the present invention, a processing film is supplied into a vacuum container provided with a substrate to be processed, plasma is formed by using electron cyclotron resonance, and a thin film is formed on the substrate to be processed. In the above, the film is formed by providing a period in which the ions in the plasma are obliquely incident and a period in which the ions are vertically incident on the substrate to be processed.

According to a fourth aspect of the present invention, the processing gas is supplied into the vacuum container in which the substrate to be processed is provided, and plasma is generated.
In the plasma film forming method of forming a thin film on the substrate to be processed, the film is formed by alternately providing a period in which ions in the plasma are obliquely incident and a period in which ions are vertically incident on the substrate to be processed. Characterize.

In a fifth aspect of the present invention, a magnetic field is formed in a vacuum container in which a mounting table for a substrate to be processed is provided, a high frequency for plasma generation is supplied, and plasma gas is plasma-generated by using electron cyclotron resonance. In the plasma film forming method of forming a thin film on the substrate to be processed while activating the reactive gas by the plasma and supplying a bias for drawing plasma to the mounting table, the central axis of the substrate to be processed is crossed. It is characterized in that an electric field in the direction of the flow is formed in the passage of the plasma flow and the plasma flow is forced to be obliquely incident on the substrate to be processed.

In a sixth aspect of the present invention, a magnetic field is formed in a vacuum container in which a mounting table for a substrate to be processed is provided, a high frequency for plasma generation is supplied, and plasma gas is plasma-generated by using electron cyclotron resonance. In the plasma film forming method of forming a thin film on the substrate to be processed while activating the reactive gas by the plasma and supplying a bias for drawing plasma to the table, the peripheral edge of the substrate to be processed on the table. An electrode for dispersing the ion incident direction is provided on the outer side of the substrate, and by using this electrode, an alternating electric field in a direction intersecting with the central axis of the substrate to be processed is formed in the passage of the plasma flow and the magnitude of the alternating electric field is increased. And the plasma flow is obliquely incident on the substrate to be processed by the alternating electric field.

According to a seventh aspect of the present invention, a plasma film forming apparatus for forming a thin film on the substrate to be processed by supplying a processing gas into a vacuum container in which the substrate to be processed is provided and converting it into plasma using electron cyclotron resonance. In the above method, ions in the plasma are obliquely incident on the substrate to be processed.

According to an eighth aspect of the present invention, a processing gas is supplied into a vacuum container provided with a substrate to be processed, and plasma is formed by using electron cyclotron resonance to form a thin film on the substrate to be processed. , N provided at equal intervals in the circumferential direction on the outer side of the peripheral edge of the substrate to be processed.
(N is an integer of 2 or more) The phase of the potential of each of the plurality of electrodes and the electrode for dispersion in the ion incident direction is n / 2 in order.
and a power supply unit for applying an alternating voltage between the electrodes so as to shift by π.

According to a ninth aspect of the present invention, a plasma film forming apparatus for supplying a processing gas into a vacuum container provided with a substrate to be processed and converting it into plasma using electron cyclotron resonance to form a thin film on the substrate to be processed. In, in order to form an electric field in the direction intersecting the central axis of the substrate to be processed on the mounting table in the vicinity of the surface to be processed of the substrate to be processed, on the outer side of the periphery of the substrate to be processed. A plurality of electrodes for dispersion of the ion incident direction provided in the circumferential direction, a power supply unit for applying an AC voltage between the plurality of electrodes, and a circumferential direction provided upstream of the plasma flow from the electrodes. A plurality of auxiliary electrodes, and a power supply unit for applying an AC voltage between the auxiliary electrodes so that an alternating electric field in a direction different from the alternating electric field formed by the ion incident direction dispersion electrodes is formed between the auxiliary electrodes. Equipped with The features.

According to a tenth aspect of the present invention, a processing gas is supplied into a vacuum container in which a substrate to be processed is provided, and plasma is formed using electron cyclotron resonance to form a thin film on the substrate to be processed. In a first ion dispersion direction dispersion electrode provided so as to surround the central axis of the substrate to be processed, and the electrode located upstream of the electrode with respect to the central axis of the substrate to be processed. Of the second ion incident direction dispersion electrode, the first ion incident direction dispersion electrode, and the second ion incident direction dispersion electrode that are provided closer to each other and surround the central axis. And a power supply unit for applying an AC voltage therebetween.

In the eleventh aspect of the present invention, a magnetic field is formed in a vacuum container in which a mounting table for a substrate to be processed is provided, and a high frequency for plasma generation is supplied, and plasma gas is plasma-generated by using electron cyclotron resonance. In the plasma film forming apparatus for forming a thin film on the substrate to be processed while activating the reactive gas by the plasma and supplying a bias for drawing the plasma to the mounting table, the plasma film forming device is located outside the peripheral edge of the substrate to be processed. It is characterized in that it is provided with a plurality of electrodes for dispersing the ion incident direction, which are provided at intervals on the side in the circumferential direction, and a power supply section for applying an AC voltage between the plurality of electrodes.

According to the invention of claim 12, claims 8, 9, 1 are provided.
The invention of 0 or 11 is characterized in that the amplitude of the AC voltage between the electrodes for ion incident direction dispersion changes with time at a frequency lower than the frequency of the AC voltage.

In the thirteenth aspect of the present invention, the eighth, ninth, and first aspects are provided.
In the invention of 1 or 12, the particle direction regulating member, in which a large number of particle passages extending vertically or almost vertically to the substrate to be processed on the mounting table are bundled, is provided at a position upstream of the ion incident direction dispersion electrode. And is provided so as to face the surface to be processed of the substrate to be processed.

According to a fourteenth aspect of the present invention, there is provided a plasma generating chamber and a film forming chamber which communicates with the plasma generating chamber and is provided with a mounting table for a substrate to be processed. The plasma generating chamber forms a magnetic field and plasma. A high frequency for generation is supplied, plasma gas is made into plasma by using electron cyclotron resonance, the reactive gas is activated in the film forming chamber by the plasma, and a bias for plasma drawing is supplied to the mounting table. Meanwhile, in a plasma film forming apparatus for forming a thin film on a substrate to be processed, a plurality of the plasma generating chambers are arranged side by side so as to communicate with a common film forming chamber, and magnetic field forming means is provided for each of the plasma generating chambers. It is characterized by that.

According to a fifteenth aspect of the present invention, a magnetic field is formed in a vacuum container in which a mounting table for a substrate to be processed is provided, a high frequency for plasma generation is supplied, and plasma gas is plasma-generated by using electron cyclotron resonance. In the plasma film forming apparatus for forming a thin film on the substrate to be processed while activating the reactive gas by the plasma and supplying a bias for drawing plasma to the table, the substrate to be processed on the table is described above. The present invention is characterized in that a net-like electrode provided so as to face the processing surface and a power supply unit for applying a negative bias to the electrode are provided.

In the present invention, when a direction intersecting with the central axis of the substrate to be processed on the mounting table, for example, the central axis direction of the substrate to be processed is the vertical direction, an alternating electric field is formed in the lateral direction, whereby the plasma flow is covered. The light is incident on the surface to be processed of the processing substrate obliquely. Then, by changing the magnitude of this alternating electric field with time, for example, the plasma flow sways and the plasma ions are obliquely incident on the surface to be processed, and the plasma ions are vertically incident vertically. Alternately, the upper corners of the depressions of the semiconductor microstructure are cut with various angles according to the variation of the ion incident direction. Therefore, the upper corners are rounded. As a result, it becomes easier to suppress the ground of the corner portion from being scraped. Further, if the particle direction regulating member is used, the directionality of the neutral film-forming particles is made uniform, the perpendicularity of the neutral film-forming particles to the substrate to be processed is improved, good embedding is performed, and voids are generated. It gets harder. Then, if an auxiliary electrode is provided on the upstream side of the plasma flow with respect to the electrode for dispersing the ion incident direction and an electric field in the opposite direction, for example, the electric field between the electrodes, is formed between the auxiliary electrodes, the ions are temporarily transferred by the auxiliary electrode. For example, after being swung to the right side, it is swung to the left side by the electrode for dispersing the ion incident direction and then is incident on the substrate to be processed, so that the uniformity of the ion incidence on the substrate to be processed becomes high.

Further, according to the fourteenth aspect of the present invention, since the ions enter the film forming chamber from the plurality of plasma generating chambers, the directional distribution pattern of the ions as viewed from the substrate to be processed is complicated, and the dispersibility in the ion incident direction is improved. According to the fifteenth aspect of the invention, since the ions are attracted to this electrode when passing through the mesh electrode, the ions are shaken and the dispersibility in the incident direction of the ions is enhanced.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a plasma film forming apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view showing a plasma processing apparatus according to this embodiment. As shown in the figure, this plasma processing apparatus has a stepped vacuum container 2 formed of, for example, aluminum, and the vacuum container 2 is located above and has a plasma chamber 21 for generating plasma and below this. The interior is partitioned into a film forming chamber 22 which is communicated with and connected to. The vacuum container 2 is grounded to have zero potential.

The upper end of the vacuum container 2 is opened, and a transparent window 23 made of a material such as quartz which transmits microwaves is hermetically provided in this portion.
It is designed to maintain a vacuum inside. A waveguide 25 connected to a high-frequency power supply unit 24 as a high-frequency supply unit for generating plasma of, for example, 2.45 GHz is provided outside the transmission window 23, and microwaves generated by the high-frequency power supply unit 24 are provided. Guide M through the waveguide 25 and the transmission window 2
3 can be introduced into the plasma chamber 21 in alignment with each other.

On the side wall defining the plasma chamber 21, there is provided a supply of processing gas, for example, a plasma gas nozzle 26 which is evenly arranged along the circumferential direction thereof and the nozzle 2 is provided.
A plasma gas source (not shown), for example, an Ar gas source and an O ₂ gas source, is connected to 6, so that a plasma gas such as Ar gas or O ₂ gas can be uniformly and evenly supplied to the upper portion in the plasma chamber 21. It is like this. In the figure, the nozzle 26
In order to avoid complicating the drawing, only two are shown, but more are actually provided. Also, the plasma chamber 2
A ring-shaped electromagnetic coil 27, for example, is disposed as a magnetic field forming means close to the outer periphery of the side wall partitioning 1 and a magnetic field in this plasma chamber 21 is directed in a direction, for example, from above to below, for example, 875 gauss. The magnetic field B can be formed, and the ECR plasma condition is satisfied. A permanent magnet may be used instead of the electromagnetic coil 22.

By thus forming the frequency-controlled microwave M and the magnetic field B in the plasma chamber 21, the ECR plasma is generated by their interaction. At this time, a resonance action occurs in the introduced gas at the frequency and plasma is formed with high density.
That is, this device is an electron cyclotron resonance (EC
R) It constitutes a plasma processing apparatus.

On the other hand, in the film forming chamber 22, there is provided a mounting table 3 made of, for example, aluminum as a susceptor which is insulated from the bottom of the container and supported by an insulating material 31, for example. A semiconductor wafer W, which is an object to be processed, is suction-held on a mounting surface on the upper surface via a temporarily fixed flat plate of the object to be processed, for example, an electrostatic chuck (not shown). Further, the mounting table 3 is provided with a heater for heating the wafer W to a predetermined temperature, a pusher pin (not shown), and the like. Furthermore, for example, a DC power supply unit 32 for plasma attraction is connected to the mounting table 3 so as to apply a bias voltage for attracting ions to the wafer W.

On the side wall of the film forming chamber 22, there is provided a reactive gas introducing nozzle 33 for introducing, for example, silane (SiH ₄ ) gas as a reactive gas therein, and an exhaust port (not shown) is provided at the bottom. It is provided. A particle direction regulating member (hereinafter referred to as “collimator”) 4 is arranged in the film forming chamber 22 so as to face the wafer W on the mounting table 3. The collimator 4 is, as shown in FIG. For example, it is made of a metal material in a honeycomb shape, and a large number of particle passages 41 each having a polygonal cross section are bundled to form a cylindrical outer shape.
It is formed to have a size of about mm and a length of about 2 to 4 times the diameter, and is oriented so that its axial direction is perpendicular to the wafer W (including almost perpendicular).

The collimator 4 aligns the directionality of the neutral film-forming particles, that is, allows the film-forming particles having a high perpendicularity to the wafer W to pass therethrough, so that the recesses (pattern) of the wafer W can be filled. This is to improve the quality and suppress the generation of voids. The material of the collimator 4 is not limited to a metal material, and an insulating material may be used.
1 is made of a metal material, and a direct current power source 42 is connected to the collimator 4 as shown in FIG. 1 to make it have a negative potential, the ions obliquely incident on the particle passage 41 are adsorbed by the collimator 4. The passed ions become highly vertical. In this case, the ion transmittance can be controlled by adjusting the voltage value of the DC power supply 42.
It is possible to adjust the ratio of the amount of ions toward the film and the film-forming particles.

Next, a specific example of the structure for allowing the ions in the plasma to obliquely enter the wafer W to be processed will be described. Inside the film formation chamber 22, four rectangular plate-shaped electrodes 5A to 5D for dispersing the ion incident direction are arranged around the mounting table 3 (as shown in FIGS. 1 and 3) at equal intervals in the circumferential direction. It is arranged. In FIG. 1, the electrodes on the opposite side of the mounting table 3 are not shown. One ends of AC power supply units V5A to V5D are connected to the electrodes 5A to 5D, respectively.

Next, a specific example of the structure in which the sputtering effect by the ions is eliminated or pulsed will be described. The other ends of the AC power supply units V5A to V5D are commonly connected to a common ground, for example, and the phases of the voltages are equally divided and shifted by 90 degrees in this embodiment, that is, the potential phases of the electrodes 5A to 5D. Are shifted by 90 degrees in this order, and the amplitude of the voltage is further changed with time.

The voltages of the AC power supply units V5A and V5B are respectively set to V
When expressed by 1 (t) and V2 (t) (t is time), the voltages of the AC power supply units V5C and V5D are -V1 (t) and -V2, respectively.
It is represented by (t) and, for example, V1 (t) = sin ² ω1t · sin ω2t V2 (t) = sin ² ω1t · cos ω2t. However, ω1 = 2πf1 and ω2 = 2πf2, and the frequencies f1 and f2 are, for example, f1 of 1 MHz and 10
In case of KHz and 50Hz, 10KHz and 50Hz respectively
It can be set to a value of about 1 Hz. The distance between the ion incidence direction dispersion electrodes 5A to 5D and the wafer W is set to, for example, 20 cm. The area of the ion incidence direction dispersion electrodes 5A to 5D and the power of the AC power supply units V5A to V5D are, for example, 200 cm ² and It is set to 1-2 Kw. However, the common terminal side of the AC power supply units V5A to V5D and the ground side of the plasma drawing power supply 32 are insulated from each other. FIG. 4 shows an AC power supply unit V5A (V5B to V5D)
The solid line shows the sine wave voltage of the frequency f1, and the dotted line shows the sine wave voltage of the frequency f2.

Next, a method of forming an interlayer insulating film such as a SiO ₂ film using the apparatus of the above-mentioned embodiment will be described.
First, a gate valve (not shown) provided on the side wall of the vacuum container 2 is opened, and a wafer W having, for example, aluminum wiring formed on its surface is loaded and placed on the mounting table 3 by a transfer arm (not shown).

Subsequently, after closing the gate valve to seal the inside, the internal atmosphere is exhausted from an exhaust port (not shown) to evacuate to a predetermined vacuum degree, and the plasma gas nozzle 2
A plasma generating gas such as O ₂ gas or Ar gas is introduced into the plasma chamber 21 from 6 and a silane gas is introduced into the film forming chamber 22 from the reactive gas introducing nozzle 33 to maintain the internal pressure at a predetermined process pressure. Then, the high frequency power source 24 for plasma generation is turned on, and the film forming process of SiO ₂ on the wafer W is started.

A high frequency (microwave) of 2.45 GHz from the high frequency power source 24 for plasma generation is applied to the waveguide 25.
Is transported to the ceiling of the vacuum vessel 2, where the microwaves M are introduced into the plasma chamber 21 through the transmission window 23. In the plasma chamber 21, a magnetic field B generated by an electromagnetic coil 27 provided outside the plasma chamber 21 is applied downward from above with a strength of, for example, 875 Gauss, and the magnetic field B and the microwave M are applied. E by interaction with
Electron cyclotron resonance is induced by inducing (electric field) × B (magnetic field), and Ar gas or O ₂ gas is made into plasma and densified by this resonance. The plasma flow flowing into the reaction chamber 22 through the outlet 21a of the plasma generation chamber 21 activates the reactive gas SiH ₄ gas to form active species, and the direction of the collimator 4 changes. They are aligned and head for the wafer W. On the other hand, in this example, plasma ions are drawn into the wafer W by a bias voltage for drawing in plasma, the corners of the pattern (recess) on the surface of the wafer W are scraped off to widen the frontage, and in parallel with this sputter etching action, active species are generated. Si in the recess
O ₂ is embedded.

During the film formation, the AC power supply unit V is connected between the electrodes 5A to 5D and the common terminal (ground).
Voltage of 5A to V5D, for example, frequency 1 kHz to 100 kHz
A voltage of z and a voltage value of 100 to 500 V is applied, whereby an electric field is formed in the lateral direction and a lateral force acts on the Ar ions of the plasma flow by the electric field, and the Ar ions are obliquely incident on the wafer W. To do. And AC power supply unit V5
Since the voltages of A to V5D are 90 degrees out of phase with each other, the obliquely incident ion flow is further rotated while being oblique to the central axis of the wafer W, and the incident angle is perpendicular to the wafer W. Therefore, there is a temporal change between the large angle state and the high vertical state.

FIG. 5 shows the results of computer simulation of the relationship between the angle of incidence of ions on the wafer surface and the sputtering effect of the angle of the recess. In this simulation, the value of λ is used as a parameter. However, λ means, for example, a state in which the Maxwell distribution is doubled and expanded in the normal direction of the wafer. From these simulation results, it can be seen that the larger the angle of incidence of the ion stream with respect to the vertical axis, the smaller the sputtering effect, and the higher the perpendicularity of the ion stream, the greater the sputtering effect. It is possible to embed in the recess while moderately obtaining the sputtering effect. As a result, it is possible to suppress or prevent scraping (sputtering) of the underlying aluminum while satisfactorily embedding, and it is possible to prevent mixing of aluminum into the SiO ₂ film and ensure the original insulating property.

The number of electrodes for dispersing the ion incident direction may be two, three, or five or more. In the embodiment of FIG. 6, three electrodes 5A to 5C are arranged, and AC power supply units VA to V for supplying voltages with a phase difference of 120 degrees between these electrodes 5A to 5C and a common terminal (ground).
C is provided. Also, for example, the electrode 5A shown in FIG.
At ~ 5D, instead of changing the AC power supply unit of frequency f1 with time with frequency f2, it is changed intermittently, that is, turned on for a certain period of time and then turned off, thus repeating on / off and oblique incidence of ions and vertical incidence. It is also possible to adjust the time and the ratio of.

Next, an embodiment in which a first auxiliary electrode and a second auxiliary electrode are added to the embodiment shown in FIG. 1 will be described with reference to FIG. In this embodiment, a plurality of first auxiliary electrodes 6 are provided along the circumferential direction of the plasma flow between the collimator 4 and the electric field region of the ion AC power supply units 5A to 5D, and the collimator 4 further upstream in the plasma flow. A second auxiliary electrode 7 is provided in the vicinity along the circumferential direction of the plasma flow. Regarding the arrangement of the first auxiliary electrode 6, when four ion incident direction dispersion electrodes 5A to 5D are arranged as in the previous embodiment, as shown in FIG.
The first auxiliary electrodes 6A to 6D are arranged in the same manner, and the second auxiliary electrode 7 also has four auxiliary electrodes 7A to 6D.
A to 7D are similarly arranged.

The first auxiliary electrodes 6A to 6D are respectively connected to one end sides of AC power supply units V6A to V6D, and these AC power supply units V6A to V6D are commonly connected to the ground and the second auxiliary electrodes are also connected. Similarly, AC power supply units V7A to V7D are connected to 7A to 7D. Each AC power supply unit V
6A to V6D and V7A to V7B are configured such that the voltages are out of phase by 90 degrees as in the AC power supply units V5A to V5D, and the amplitudes similarly change at the frequency f2, for example. However, in the plan view of FIG. 7, the phase of the voltage applied to the first auxiliary electrode 6 located on the same side as the ion incident direction dispersion electrodes 5A to 5D is the ion incident direction dispersion electrodes 5A to 5D. The AC power supply units V6A to V6D are configured so as to deviate from each other by 180 degrees. For example, the voltage applied to the first auxiliary electrode 6A is 180 degrees out of phase with the voltage applied to the ion incident direction dispersion electrode 5A.

This relationship is the same between the first auxiliary electrodes 6A to 6D and the second auxiliary electrodes 7A to 7D. For example, the phase of the voltage of the AC power supply section V7C is the same as the voltage of the AC power supply section V6C. AC power supply V
7A to V7D are configured. The AC power supply (V5
A-5D), (V6A-V6D), (V7A-V7D)
The common terminals (ground) of are insulated from each other.

According to such an embodiment, as shown in FIG. 9, when the ion flow R is directed obliquely from the upper right toward the left edge by the electric field between the ion incident direction dispersion electrodes 5A to 5D, the collimator 4 The ion flow R that has passed through the first auxiliary electrodes 6A to 6D is once swung to the right side, so that the surface of the wafer W is irradiated with high uniformity. If the second auxiliary electrodes 7A to 7D are not provided, the ion current obliquely enters the collimator 4 due to the electric field of the first auxiliary electrodes 6A to 6D, and when the collimator 4 is made of metal, Although it may be scraped by the plasma ions, the use of the second auxiliary electrodes 7A to 7D causes an electric field to act so that the ion current that is obliquely incident on the collimator 4 is directed vertically, so that it is incident on the collimator 4. The incident angle of the generated ion stream becomes small, the spatter of the collimator 4 is suppressed, and the metal contamination is suppressed.

The collimator 4 may be arranged so as to be surrounded by the ion incidence direction dispersion electrodes 5A to 5D as shown in FIG. Further, in the present invention, as shown in FIG.
A divided ring-shaped grid electrode 43 is provided, and between the grid electrode 43 and the ground, for example, 100 kHz,
An AC power supply unit 44 of about 100 to 500 V may be connected, and this electrode has an effect of allowing ions to be incident on the wafer without waste.

Furthermore, the ion incident direction dispersion electrode may be provided at the bottom of the film forming chamber 22 via an insulating material 34, as shown in FIGS. In this embodiment, the three ion incident direction dispersion electrodes 5A to 5C are arranged at equal intervals in the circumferential direction. The frequency at this time is the same as that of the power supply 44, and the phase is assumed to be shifted by 180 degrees.

As for the ion incident direction dispersion electrode, as shown in FIG. 13, a ring-shaped first ion incident direction dispersion electrode 51 surrounding the mounting table 3 (enclosing the central axis of the wafer W). And a ring-shaped second electrode having a smaller diameter than the electrode 51 is provided above the electrode 51.
Of the ion incident direction dispersion electrode 52 are provided, and AC power supply units V51 and V5 are provided between the electrode 51 and the ground (common terminal), respectively.
2 may be connected. In this case, AC power supply unit V
The electric power of 51 and V52 is set to 0.5 to 1 Kw, and the phase difference between both voltages is set to 180 degrees, for example.

In such an embodiment, since an alternating electric field is formed between the electrodes 51 and 52, the plasma ion flow passing through the ring-shaped electrode 52 is a trumpet when the electrode 51 has a negative potential. Since the negative potential is changed and the magnitude of the negative potential is changed, the spread state and the squeezing state are alternately repeated, so that the sputter effect at the corner of the recess to be embedded is weakened. That is, the effect of removing the recess is reduced or eliminated by performing the sputtering effect in a pulsed manner.

In the above, according to the present invention, a plurality of plasma generating chambers may be provided as shown in FIG. 14 as a method for weakening the sputtering effect by plasma ions.
In the embodiment shown in FIGS. 14 and 15, three plasma generation chambers 8A to 8C are provided at equal intervals in the circumferential direction. A road-wave tube 81 is connected to the upper part of each, and a common film forming chamber 80 is provided in communication with the lower part thereof. A ring-shaped electromagnetic coil 82 is provided around each of the plasma generation chambers 8A to 8C to form a magnetic field inside the plasma generation chambers 8A to 8C. Reference numeral 83 is a transparent window, 84 is a plasma gas nozzle 85, and a high-frequency power source for plasma generation. In this case, an example of the dimensions of the apparatus is the wafer W
To the upper end of the film formation chamber 80, the inner diameter of the plasma generation chambers 8A to 8C is 15 cm, and the distance between the centers of the plasma generation chambers 8A to 8C is 40 cm.

According to this structure, the plasma flow introduced from each of the plasma generating chambers 8A to 8C spreads like a trumpet in the film forming chamber 80, but the directional distribution pattern of the ion flow in the vicinity of the surface of the wafer W is three. Plasma generation chambers 8A ~
Since it becomes the sum of the ion flow introduced from 8C, the directional distribution of the ion flow becomes complicated, the dispersibility in the incident direction of the ions becomes large, and the sputter etching effect at the corners of the recesses on the surface of the wafer W is suppressed.

Further, in the present invention, as shown in FIG. 16, a grid electrode 9 formed by stacking mesh bodies in, for example, double or triple layers is provided so as to face the wafer W, and the grid electrode 9 and the ground are connected to each other. Alternatively, for example, a negative DC voltage may be applied by the DC power supply 91. With such a configuration, when the ion flow passes through the grid electrode 9, the ions are attracted to the electrode 9 as shown in FIG. 17, so that the dispersibility of the passed ions is improved and the same as in the above-described embodiment. The effect of is obtained. In each of the embodiments described above, the wafer W may be rotated (rotated around the central axis in the direction normal to the center of the wafer surface).

[0052]

According to the present invention, when embedding a pattern (recess) by, for example, ECR plasma processing, the incident directions of the ions incident on the substrate to be processed are dispersed, so that the effect of removing the corners of the recess is weakened. Therefore, it is possible to reduce or prevent the ground portion from being scraped and being mixed into the thin film, which is useful, for example, in preventing metal from being mixed into the interlayer insulating film.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a plasma film forming apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a collimator.

FIG. 3 is a plan view showing an arrangement relationship between a collimator and an ion incident direction dispersion electrode in the embodiment of FIG.

FIG. 4 is a waveform diagram showing an example of a voltage applied between electrodes for ion incident direction dispersion.

FIG. 5 is an explanatory diagram showing, as a simulation result, a relationship between an incident direction of ions and a state of burying a recess.

FIG. 6 is a plan view showing another example of the arrangement of the ion incident direction dispersion electrodes.

FIG. 7 is a vertical cross-sectional view showing a plasma film forming apparatus according to another embodiment of the present invention.

8 is a plan view showing an arrangement relationship between an ion incident direction dispersion electrode, first and second auxiliary electrodes, and a collimator in the embodiment of FIG.

FIG. 9 is an explanatory view schematically showing an ion flow in the embodiment of FIG.

FIG. 10 is a vertical sectional view showing a plasma film forming apparatus according to still another embodiment of the present invention.

FIG. 11 is a vertical sectional view showing a plasma film forming apparatus according to still another embodiment of the present invention.

12 is a plan view showing an ion incident direction dispersion electrode according to the embodiment of FIG.

FIG. 13 is a vertical cross-sectional view showing a plasma film forming apparatus according to an example other than the above.

FIG. 14 is a vertical cross-sectional view showing a plasma film forming apparatus according to an example other than the above.

FIG. 15 is a plan view showing the arrangement of plasma generation chambers according to the embodiment of FIG.

16 is a plan view showing the arrangement of plasma generation chambers according to the embodiment of FIG. 14. FIG.

FIG. 17 is an explanatory diagram showing a state in which ions are attracted to a grid electrode.

FIG. 18 is a schematic sectional view showing a conventional ECR plasma processing apparatus.

FIG. 19 is an explanatory diagram showing how recesses are filled in a conventional ECR plasma processing method.

[Explanation of symbols]

 2 vacuum container 21 plasma generation chamber 22 film formation chamber 26 plasma gas nozzle 27 electromagnetic coil 3 mounting table 33 reactive gas nozzle 4 collimator 5A to 5C ion incident direction dispersion electrodes V5A to V5C AC power supply unit 6 and 6A to 6C first auxiliary Electrodes 7, 7A to 7C Second auxiliary electrodes V6A to V6C, V7A to V7C 43 Grid electrode 51 First ion incident direction dispersion electrode 52 Second ion incident direction dispersion electrode 8A to 8C Plasma generation chamber 81 Electromagnetic coil 9 Grid electrode 91 DC power supply

Claims (15)

[Claims] 1. A plasma film forming method for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container provided with the substrate to be processed, plasmatization using electron cyclotron resonance. A plasma film forming method, wherein ions in the plasma are obliquely incident on the substrate. 2. A plasma film forming method for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container in which the substrate to be processed is provided and plasmatizing using electron cyclotron resonance. A plasma film forming method, wherein ions in the plasma are obliquely incident on the substrate while being rotated while being incident. 3. A plasma film forming method for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container provided with the substrate to be processed and converting the plasma into plasma using electron cyclotron resonance. A plasma film forming method comprising forming a film by providing a period in which ions in plasma are obliquely incident on a substrate and a period in which ions are vertically incident on the substrate. 4. A plasma film forming method for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container in which the substrate to be processed is provided and converting the plasma into plasma. A plasma film forming method, characterized in that a film is formed by alternately providing a period in which the ions inside are obliquely incident and a period in which the ions are vertically incident. 5. A substrate for placing a substrate to be processed forms a magnetic field in a vacuum vessel provided inside and supplies a high frequency for plasma generation to generate plasma gas by using electron cyclotron resonance, and the plasma is generated by the plasma. In a plasma film forming method of forming a thin film on the substrate to be processed while activating a reactive gas and supplying a bias for drawing plasma to a mounting table, an electric field in a direction intersecting a central axis of the substrate to be processed is applied. A plasma film forming method, characterized in that the plasma film is formed in a passage of a plasma flow and the plasma flow is forced to be obliquely incident on a substrate to be processed. 6. A substrate for processing a substrate to be processed forms a magnetic field in a vacuum container provided inside and supplies a high frequency for plasma generation to generate plasma gas by using electron cyclotron resonance, and the plasma is generated by the plasma. In a plasma film forming method for forming a thin film on a substrate to be processed while activating a reactive gas and supplying a bias for drawing plasma to the table, the outside of the peripheral edge of the substrate to be processed on the table. An electrode for dispersing the ion incident direction is provided in the electrode, and by using this electrode, an alternating electric field in a direction intersecting with the central axis of the substrate to be processed is formed in the passage of the plasma flow and the magnitude of the alternating electric field is temporally changed. A plasma film forming method, wherein the plasma flow is changed and the plasma flow is obliquely incident on the substrate to be processed by the alternating electric field. 7. A plasma film forming apparatus for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container provided with the substrate to be processed and converting it into plasma using electron cyclotron resonance. A plasma film forming apparatus, wherein ions in the plasma are obliquely incident on the substrate. 8. A plasma film forming apparatus for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container in which the substrate to be processed is provided and plasmatizing using electron cyclotron resonance. The n (n is an integer of 2 or more) electrodes for ion incident direction dispersion, which are provided at equal intervals in the circumferential direction on the outer side of the periphery of the substrate, and the phase of the potential of each of the plurality of electrodes is A plasma film forming apparatus, comprising: a power supply unit for applying an alternating voltage between the electrodes so that they are sequentially shifted by n / 2π. 9. A plasma film forming apparatus for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container provided with the substrate to be processed and converting the plasma into plasma using electron cyclotron resonance. Provided in a circumferential direction outside the peripheral edge of the substrate to be processed so that an electric field in a direction intersecting the central axis of the substrate to be processed is formed in the vicinity of the surface to be processed of the substrate to be processed. A plurality of electrodes for ion incident direction dispersion, a power supply unit for applying an AC voltage between the plurality of electrodes, and a plurality of auxiliary electrodes provided along the circumferential direction on the upstream side of the plasma flow with respect to the electrodes. A power supply unit that applies an AC voltage between the auxiliary electrodes so that an alternating electric field in a direction different from the alternating electric field formed by the ion incident direction dispersion electrodes is formed between the auxiliary electrodes. Characterized by Zuma film-forming apparatus. 10. A plasma film forming apparatus for forming a thin film on a substrate to be processed by supplying a processing gas into a vacuum container in which the substrate to be processed is provided and plasmatizing using electron cyclotron resonance. A first ion incident direction dispersion electrode provided so as to surround the central axis of the substrate, and an electrode located upstream of the electrode and closer to the central axis of the substrate to be processed than the electrode. An alternating voltage is applied between the second ion incident direction dispersion electrode, the first ion incident direction dispersion electrode, and the second ion incident direction dispersion electrode that are provided so as to surround the central axis. A plasma film forming apparatus comprising: a power supply unit for applying a voltage. 11. A substrate for processing a substrate to be processed forms a magnetic field in a vacuum container provided therein and supplies a high frequency for plasma generation, and plasma plasma gas is generated by using electron cyclotron resonance, and the plasma is generated by the plasma. In a plasma film forming apparatus for forming a thin film on a substrate to be processed while activating a reactive gas and supplying a bias for drawing plasma to a mounting table, in a circumferential direction outside the peripheral edge of the substrate to be processed. 1. A plasma film forming apparatus comprising: a plurality of electrodes for ion incident direction dispersion, which are spaced apart from each other, and a power supply unit for applying an AC voltage between the plurality of electrodes. 12. The method according to claim 8, wherein the amplitude of the AC voltage between the electrodes for ion direction dispersion is temporally changed at a frequency lower than the frequency of the AC voltage.
The plasma film forming apparatus according to 0 or 11. 13. A particle direction regulating member comprising a bundle of a large number of particle passages extending vertically or substantially vertically to a substrate to be processed on a mounting table, the particle direction regulating member being provided at a position upstream of an electrode for ion direction dispersion. 10. The substrate is provided so as to face a surface to be processed of the substrate to be processed.
2. The plasma film forming apparatus described in 2. 14. A plasma generating chamber and a film forming chamber communicating with the plasma generating chamber and provided with a mounting table for a substrate to be processed, wherein a magnetic field is formed in the plasma generating chamber and a high frequency for plasma generation is generated. On the substrate to be processed while supplying and biasing the plasma gas into plasma by using electron cyclotron resonance, activating the reactive gas in the film forming chamber by the plasma, and supplying a bias for drawing plasma to the mounting table. In a plasma film forming apparatus for forming a thin film on a substrate, a plurality of the plasma generating chambers are arranged side by side so as to communicate with a common film forming chamber, and magnetic field forming means is provided for each of the plasma generating chambers. Plasma film forming apparatus. 15. A substrate for placing a substrate to be processed forms a magnetic field in a vacuum container provided therein and supplies a high frequency for plasma generation, and plasma gas is converted into plasma by using electron cyclotron resonance. In a plasma film forming apparatus that forms a thin film on a substrate to be processed while activating a reactive gas and supplying a bias for drawing plasma to the table, it faces the surface of the substrate to be processed on the table. And a power supply unit for applying a negative bias to the electrode.