JP2000277509A - Substrate treating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a plurality of kinds of treatment gases jet from the same height without making the gases mix with each other on the way to the jet. SOLUTION: In a substrate treating system provided with a gas feeding means for independently feeding a plurality of treatment gases from the periphery of a substrate 10 to be treated horizontally arranged within a reaction chamber 2 toward the center of the substrate 10, a gas ring 30 with a plurality of gas-blow off nozzles 37 and 38 provided in the same height on its inner periphery is provided on the gas feeding means. The plurality of the gas blow- off nozzles 37 and 38 are divided into a plurality of groups to correspond to the plurality of the treatment gases and a plurality of systems of gas passageways (buffer chambers 34 and 35), which respectively lead independently the plurality of the treatment gases introduced from the outside of the ring 30 to the gas blow-off nozzles 37 and 38 of each group, are formed in the ring 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thin film on a surface of a substrate to be processed such as a silicon wafer or a glass substrate placed in a reaction chamber, etching a thin film,
Alternatively, the present invention relates to a substrate processing apparatus that performs ashing.

[0002]

2. Description of the Related Art In recent years, the development of semiconductor manufacturing apparatuses utilizing plasma such as plasma CVD, plasma etching, and plasma ashing has been actively pursued. As a plasma source of these devices, there are a capacitive coupling type in which a plasma portion and an electrode are capacitively coupled, and an inductive coupling type in which a plasma portion and an antenna are mainly inductively coupled. In the capacitive coupling type, since the plasma generation space is close to the reaction chamber where the wafer is placed, a large number of openings provided in the upper part blow out a gas toward the substrate in the form of a shower. Nature can be secured.

On the other hand, in the inductive coupling type, a high frequency is supplied from an antenna such as a coil wound around a discharge chamber to generate high-density plasma, which is placed in a reaction chamber away from the discharge chamber which is a plasma generation space. Since plasma must be transported to the substrate, uniformity of the film cannot be ensured by ejecting gas from above. Therefore, a gas is ejected from the periphery of a horizontally arranged substrate in parallel with the substrate.

[0004] The above-mentioned inductive coupling type has attracted attention as a method for generating high-density plasma, and the pressure in the reaction chamber is 1 mTorr to 10 mTorr.
Since it can be three orders of magnitude lower than Torr to 10 Torr), it is suitable for an apparatus for forming a fine pattern, particularly for forming a film inside a groove or etching the inside of a groove.

An example of the above-described inductive coupling type substrate processing apparatus will be described with reference to FIG. This apparatus is called a high-density plasma CVD apparatus for applying a bias to the substrate 10 to be processed. In the figure, a reaction chamber 2 is formed in an airtight structure by a conductive reaction vessel 1 and a dielectric cylindrical window 3 having a lid 9, and a sample table 12 is provided at the bottom of the reaction chamber 2 via an insulating block 13. Installed. An induction coil 4 is wound around the outer periphery of the cylindrical window 3.
In addition, the high-frequency power output from the high-frequency power supply 6 is supplied via the matching unit 7.

On the sample stage 12 provided at the bottom of the reaction chamber 2, a bias is applied to the substrate 10, and charged particles in the plasma generated in the discharge chamber 5 are drawn toward the substrate 10. The high frequency power output from the high frequency power supply 15 is supplied via the matching unit 14.

The processing in this device is performed as follows. After evacuating the reaction chamber 2 with an exhaust pump (not shown),
The substrate 10 to be processed is transported to the sample table 12 in the reaction chamber 2.
Next, a reactive gas (processing gas) is supplied from a gas blowing nozzle 20 provided around the sample table 12 and a gas blowing nozzle 21a provided on the inner periphery of the gas ring 21, and a pressure control device (shown in FIG. In a state where the pressure is maintained at a predetermined pressure (omitted), the high-frequency power output from the high-frequency power supply 6 is supplied to the induction coil 4 via the matching unit 7.

Then, a plasma 11 is generated in the reaction chamber 2 by the alternating electromagnetic field formed by the induction coil 4,
The plasma 11 forms a thin film on the substrate 10 to be processed on the sample stage 12. At this time, a high-frequency power output from the high-frequency power supply 15 is supplied to the sample stage 12 through the matching unit 14 to form a thin film while applying a bias voltage to the substrate 10 to be processed.

In the above apparatus, two systems of gas supply means (gas nozzle 20 and gas ring 21) are arranged in the reaction chamber 2, and two kinds of processing gases G1, G2 are simultaneously and independently supplied into the reaction chamber 2. I can do it. This is because, in the case of gases having high reactivity with each other (for example, processing gases such as monosilane SiH ₄ and oxygen O ₂ ), if they are mixed before being supplied to the reaction chamber 2, they cause a chemical reaction with each other and cause a gas reaction. This is because a passage or the like may be blocked.
Therefore, in the prior art, two gas supply means (the gas nozzle 20 and the gas ring 21) are installed in the reaction chamber 2 in two stages vertically.

[0010]

By the way, as described above, when two systems of gas supply means (gas nozzle 20 and gas ring 21) are installed in the reaction chamber 2 in two upper and lower stages, Since the heights of the gas blowing nozzles (the gas blowing nozzles 21a of the gas nozzle 20 and the gas ring 21) are different from each other, there has been a problem that mixing of gases in the reaction chamber 2 is not performed well. Further, since components having complicated shapes (gas supply means) are installed in the reaction chamber 2 in two stages, there is a problem that the cleaning effect when cleaning the inside of the reaction chamber 2 is hindered. Further, there is a situation that increasing the number of components exposed to plasma, gas, and active species of gas is not preferable in view of pollution and the cost of pollution control.

According to the present invention, in consideration of the above circumstances, a plurality of types of processing gases can be ejected from the same height without mixing on the way, and the mixing of gases in a reaction chamber can be promoted. In addition, it is an object of the present invention to provide a substrate processing apparatus capable of simplifying a component arrangement structure in a reaction chamber.

[0012]

According to a first aspect of the present invention, there is provided a gas supply for independently supplying a plurality of processing gases from a periphery of a substrate to be processed disposed horizontally in a reaction chamber toward a center of the substrate to be processed. In the substrate processing apparatus provided with means, a plurality of gas blowing nozzles having the same height are provided around the reaction chamber as the gas supply means, and the plurality of gas blowing nozzles are provided in a plurality of groups corresponding to the plurality of processing gases. Divided into
A plurality of gas passages are formed to independently guide the plurality of processing gases to the gas blowing nozzles of each group.

In the substrate processing apparatus of the present invention, a plurality of gas passages are independently formed, and the tip of each system gas passage is
Since the processing gas is led to the grouped gas blowing nozzles, a plurality of processing gases can be blown into the reaction chamber without being mixed on the way. In addition, since all the gas blowing nozzles are provided at the same height, mixing of the gas after blowing can be promoted.

According to a second aspect of the present invention, a gas ring provided with the plurality of gas blowing nozzles is provided, and the plurality of gas passages are formed in the gas ring.

In the substrate processing apparatus of the present invention, a plurality of gas passages are independently formed in the gas ring, and the tips of the gas passages of the respective systems are led to the gas blowing nozzles which are grouped respectively. The ring allows a plurality of processing gases to be blown into the reaction chamber without mixing on the way. Moreover, since all the gas blowing nozzles on the inner periphery of the gas ring are provided at the same height, the mixing of the gas after blowing can be promoted.

According to a third aspect of the present invention, a buffer chamber is formed for uniformly discharging the processing gas introduced from the inlet of the gas passage from the plurality of gas blowing nozzles. In this case, the buffer chamber may be formed in a gas ring.

In the substrate processing apparatus of the present invention, since the buffer chamber is formed, the processing gas can be uniformly blown out of the plurality of gas blowing nozzles into the reaction chamber. In particular, when the buffer chamber is formed in a gas ring, the processing gas can be uniformly blown into the reaction chamber from a plurality of gas blowing nozzles arranged in the circumferential direction of the gas ring.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a half-sectional view of a high-density plasma CVD apparatus shown as a substrate processing apparatus according to an embodiment.
The reaction chamber 2 is made airtight by a reaction vessel 1. A sample stage (substrate stage) 12 is provided at the bottom of the reaction chamber 2, and a substrate 10 to be processed can be horizontally mounted on the upper surface thereof.

Around the space above the sample table 12, a gas ring 30 as a gas supply means is horizontally disposed coaxially with the central axis of the substrate 10 to be processed. Gas ring 30
Consists of a gas ring main body 31 and lids 32 and 33 connected to upper and lower surfaces thereof. On the inner periphery of the gas ring main body 30, a plurality of gas blowing nozzles 37 and 38 are provided at the same height and arranged in a line in the circumferential direction. These gas blowing nozzles 37 and 38 are alternately divided into two groups, with every other nozzle as one group. The first group of gas blowing nozzles 37 blows a first type of gas G1 into the reaction chamber 2, and the second group of gas blowing nozzles 38 blows a second type of gas G2 into the reaction chamber 2. It is for blowing out. Here, when the first gas G1 and the second gas G2 are mixed before being supplied into the reaction chamber 2, they immediately cause a chemical reaction. For example, monosilane (SiH ₄ ) and oxygen (O ₂ ) It is a gas like a combination of In addition, according to various conditions, a pipe-shaped nozzle having an appropriate length and an appropriate diameter is usually screwed and attached to the opening of the gas blowing nozzles 37 and 38.

An annular groove is formed on the upper and lower surfaces of the gas ring main body 31, and the lids 32 and 33 are put on the annular groove to constitute the gas ring 30, so that the first and the second in the upper and lower parts in the gas ring 30 are formed. Two buffer chambers 34 and 35 are formed. Each of these buffer chambers 34 and 35 has a first gas G1
Is connected to the supply pipe 44 of the second gas G2. On the bottom surface of the groove forming the first buffer chamber 34, a small hole 34 a communicating with the gas blowing nozzle 37 classified into the above-described first group is formed, and the small hole 34 a of the groove forming the second buffer chamber 35 is formed. On the bottom, the second
Small holes 35a communicating with the gas blowing nozzles 38 classified into the group are formed.

As a result, the first gas G1 introduced from the supply pipe 44 is supplied into the gas ring 30 via the first buffer chamber 34, and the gas blow nozzles 3 of the first group are supplied.
The second gas G2 introduced from the supply pipe 45 and the second gas G2 introduced from the supply pipe 45 through the second buffer chamber 35 from the second group of gas blowing nozzles 38 through the first gas passage 38 for blowing out into the reaction chamber 2 from A second gas passage for blowing out into the reaction chamber 2 is provided. These two gas flow paths do not intersect each other in the gas ring 30. Therefore, the first gas G1 and the second gas G2 are independent without being mixed in the gas flow path. And is blown into the reaction chamber 2. When the gas is blown out, the buffer chambers 34 and 35 transfer the gas introduced from the inlet of the gas passage,
A plurality of gas blowing nozzles 37, 38 arranged in a circumferential direction
Performs the function of blowing out evenly.

FIG. 2 is a schematic view showing only the hollow portion constituting the gas passage. Upper and lower buffer rooms 3
The gas blowing nozzles 37 and 38 are positioned between the nozzles 4 and 35.
Are formed, and every other of these holes is communicated with the upper or lower buffer chambers 34, 35 via small holes 34a, 35a.

As described above, the gas ring 30 having the function of independently blowing two systems of gas is provided at the upper end of each support rod 80 inserted vertically from the bottom of the reaction vessel 1 into the reaction chamber 2. Supported. The part of the support rod 80 that is outside is covered with a bellows 81, and the airtightness in the reaction chamber 2 is ensured. The support rod 80 is raised and lowered by a lifting mechanism (not shown) so that the height of the gas ring 30 can be adjusted.

Next, the processing flow will be described. Substrate to be processed 1
In the case of performing the process 0, first, the inside of the reaction chamber 2 is evacuated by an exhaust pump (not shown), and then the substrate 10 to be processed is transported onto the sample stage 12, and two types of processing gases are separately supplied. The gas is supplied to the gas ring 30 through the pipes 44 and 45.
Then, the gas blowing nozzles 37, 38 at the same height
Therefore, two kinds of gases are independently blown out toward the center of the space above the substrate 10 in parallel with the substrate 10, and a thin film is formed on the surface of the substrate 10 or is already formed. The thin film is etched.

At this time, since the gas blowing nozzles 37 and 38 on the inner periphery of the gas ring 30 are all arranged at the same height, mixing of the blown gas is promoted. Further, since one gas ring 30 can blow out two types of processing gases into the reaction chamber 2 without mixing them on the way, the number of components in the reaction chamber 2 can be reduced.

Further, the height of the gas ring 30 can be adjusted to make the film forming rate or the etching rate uniform. The thin film forming speed on the substrate to be processed 10 is distributed substantially concentrically. When the nozzle position is low, the thickness distribution is convex downward, and when the nozzle position is high, the thickness distribution is convex upward. In the middle of this, the distribution of the film forming rate becomes M-shaped (two-bulged). That is, the nozzle position is a parameter for controlling the uniformity of the film forming speed. Therefore, the pressure,
Even if the film formation rate becomes non-uniform due to changes in the substrate processing conditions such as the gas amount and high-frequency applied power, the gas ring 30
By moving the height to an optimum position in accordance with the processing conditions of the substrate 10 to be processed, the uniformity of the processing speed within the substrate surface can be easily maintained within a certain range.

Next, a gas ring in a substrate processing apparatus according to another embodiment of the present invention will be described. This gas ring makes the buffer chamber more complicated. Here, it is assumed that the flowing gas is monosilane and oxygen. Oxygen is not high in viscosity, so a single buffer chamber is sufficient, but monosilane has a higher viscosity than oxygen, so a three-stage buffer chamber is provided in the middle of the gas flow path.
The processing gas is blown out uniformly.

FIG. 3 shows an expanded configuration of the buffer chamber on the monosilane side. From the gas introduction side to the outlet side (gas blowing nozzle side), the first-stage buffer chambers 55, 2
The buffer chamber 56 at the third stage and the buffer chamber 57 at the third stage are arranged in this order. The first-stage buffer chamber 55 has one entrance 54, the second-stage buffer chamber 56 and two slits 58.
Connected. The second-stage buffer chamber 56 is connected to the third-stage buffer chamber 57 by four slits 59. The third-stage buffer chamber 57 has 24 small holes 5.
Each gas outlet nozzle (not shown here) is connected by 7a.

Thus, one introduction port (entrance)
Is introduced into the flow path (first
The two slits 58 pass through the buffer chamber 55)
From the buffer chamber 56 of the second stage. Then, it is further divided into two parts left and right in the second-stage buffer chamber 56 and enters the third-stage buffer chamber 57 through a total of four slits. 3
Twenty-four gas blowing nozzles (not shown in the figure) communicate with the buffer chamber 57 of the tier through small holes 57a.
The gas that has entered the third-stage buffer chamber 57 is blown into the reaction chamber 2 from these 24 gas blowing nozzles.

FIGS. 4 to 6 show the structure of the main body 51 of the gas ring having the three-stage buffer chamber shown in FIG. 3 on one side. The gas ring main body 51 forms a gas ring by connecting aluminum material lids to upper and lower surfaces with screws or the like. FIG. 4 shows a front-side configuration in which three-stage buffer chambers (only grooves are shown) for monosilane are formed, and FIG. 5 shows a buffer chamber for oxygen (only grooves are shown).
2 shows the configuration on the back surface side on which is formed. FIG.
(A) shows a cross section taken along the line VIa-VIa in FIG. 4, and (b) and (c) are partially enlarged views thereof.

As shown in FIG. 4, three annular grooves are formed concentrically on the surface of the gas ring main body 51, and a first-stage buffer chamber 55 is formed by the outermost annular grooves. , A second-stage buffer chamber 56 is constituted by the intermediate annular groove, and a third-stage buffer chamber 57 is constituted by the innermost annular groove. The first-stage buffer chamber 55 and the second-stage buffer chamber 56 communicate with each other through two slits 58 formed on the boundary wall at equal intervals in the circumferential direction. The second-stage buffer chamber 56 and the third-stage buffer chamber 57 communicate with each other through four slits 59 formed in the boundary wall at equal intervals in the circumferential direction. Ideally, the inner peripheral side slit 59 and the outer peripheral side slit 58 are located as far apart as possible, so that the outer peripheral side slit 5 is positioned at an intermediate angle between the two inner peripheral side slits 59, 59.
8 is located. As a result, the first-stage buffer chamber 55 to the third-stage buffer chamber 57
Is set to be as long as possible.

The inner circumferential surface of the annular groove forming the third-stage buffer chamber 57 on the innermost peripheral side is equally spaced in the circumferential direction.
Four small holes 57a are formed. These small holes 57a
As shown in FIG. 6, among the 48 fine holes penetrated in the radial direction at the middle in the thickness direction of the gas ring main body 51, each of the fine holes communicates with 24 fine holes constituting the gas blowing nozzle 37. I have. Forty-eight such pores are formed at the same position in the thickness direction of the gas ring main body 51 and are equally arranged in the circumferential direction, and the outer peripheral side open end is closed with a plug member, and the inner peripheral side open end is formed. The gas blowing nozzles 37 and 38 are configured by screwing a pipe-shaped nozzle (not shown) prepared separately. Here, out of the 48 gas blowing nozzles in the entire circumference, every other 24 gas blowing nozzles 37 are for monosilane gas blowing nozzles, and the other 24 gas blowing nozzles for every other 24 are oxygen blowing nozzles 38. It is classified as a gas blowing nozzle.

As shown in FIG. 5, on the back surface of the gas ring main body 51, one buffer chamber 35 forming an oxygen gas passage by an annular groove is formed. On the bottom surface of the annular groove constituting the buffer chamber 35, 24 small holes 35a are equally spaced in the circumferential direction, and these small holes 35a are
As shown in FIG.
It communicates with each of the pores.

As described above, by cutting out one member, two gas passages which do not cross each other are formed on the front side and the back side of the gas ring main body 51. Therefore, the two types of gases can be introduced into the reaction chamber without being mixed on the way to the reaction chamber.

The number and arrangement of the gas blowing nozzles 37 and 38 can be appropriately selected according to the processing conditions and the like. For example, the ratio of system division (group division) is not necessarily one, such as 12 for one gas system, one for another gas system, and a total of 18 lines.
It is not necessary to classify every other book.

In the above example, when the number of nozzles is not required to be 24 per system, instead of screwing a pipe-shaped nozzle, a screwed plug material is screwed in and sealed, and the necessary number of nozzles is sealed. It is also possible to use only the number.

Further, in the above embodiment, the case where two systems of gas are introduced into one gas ring has been described, but the present invention can be applied to the case where three or more systems of gas are introduced.

FIG. 7 is a perspective view schematically showing an example of the structure of the gas ring 60 when introducing three types of gas. In this case, by forming three annular grooves concentrically in the gas ring main body 61, the buffer chambers 64, 65, 66 of each gas passage are formed.
And gas blowing nozzles 67 and 6 drilled in the radial direction.
8 and 69, each buffer chamber 64, 65, 66
a, 65a, 66a. Thereby, a plurality of gas blowing nozzles 67 and 6 arranged at the same height are provided.
8 and 69, three types of gases can be blown out independently.

[0039]

As described above, according to the first aspect of the present invention, a plurality of systems of gas passages are independently formed in a gas ring, and the ends of the gas passages of each system are grouped into gas blowouts. Since the gas is guided to the nozzle, a plurality of processing gases can be blown into the reaction chamber by one gas ring without being mixed on the way. Therefore, the number of components in the reaction chamber can be reduced, the cost of contamination and contamination countermeasures can be reduced, and the effect of cleaning the reaction chamber can be enhanced. Moreover, since all the gas blowing nozzles on the inner periphery of the gas ring are provided at the same height, the mixing of the gas after blowing can be promoted.

According to the second aspect of the present invention, since the buffer chamber is formed in the gas ring, the processing gas is uniformly introduced into the reaction chamber from a plurality of gas blowing nozzles arranged in the circumferential direction of the gas ring. Can be blown out.

[Brief description of the drawings]

FIG. 1 is a half cross-sectional perspective view illustrating a main configuration of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a gas passage inside a gas ring in the substrate processing apparatus.

FIG. 3 is a schematic view showing a gas path inside a gas ring in a substrate processing apparatus according to another embodiment of the present invention, which is developed in a plane.

FIG. 4 is a plan view showing one surface of a gas ring main body constituting the gas ring of FIG. 3;

FIG. 5 is a plan view showing a back surface of the gas ring main body of FIG. 4;

6A is a sectional view taken along the line VIa-VIa in FIG. 3;
(B) is an enlarged view of the VIb part in (a), (c) is (a)
It is an enlarged view of the VIc part of the figure.

FIG. 7 is a perspective view schematically showing a gas passage inside a gas ring in a substrate processing apparatus according to still another embodiment of the present invention.

FIG. 8 is a sectional view of a conventional substrate processing apparatus.

[Explanation of symbols]

 2 Reaction chamber 10 Substrate to be processed 30, 60 Gas ring 34, 35, 64, 65, 66 Buffer chamber 37, 38, 67, 68, 69 Gas blowing nozzle 55 First-stage buffer chamber 56 Second-stage buffer Room 57 Third-stage buffer room

Continuation of the front page F term (reference) 4K030 AA06 AA14 CA04 CA06 DA04 DA08 EA01 EA05 EA06 FA01 FA04 GA02 LA15 5F004 AA01 BA20 BB13 BB28 BC03 BD01 CA06 5F045 AC01 AC11 BB01 DP02 DP04 EB02 EB05 EE04 EE12 EE20 E04 EF12 EF20 E04

Claims (3)

[Claims] 1. A substrate processing apparatus comprising gas supply means for independently supplying a plurality of processing gases from a periphery of a substrate to be processed horizontally disposed in a reaction chamber toward a center of the substrate to be processed. As supply means, a plurality of gas blowing nozzles having the same height are provided around the reaction chamber, and the plurality of gas blowing nozzles are divided into a plurality of groups corresponding to the plurality of processing gases. A substrate processing apparatus, wherein a plurality of gas passages are independently guided to gas blowing nozzles of a group. 2. The substrate processing apparatus according to claim 1, wherein a gas ring having the plurality of gas blowing nozzles is provided, and the plurality of gas passages are formed in the gas ring. 3. The substrate processing apparatus according to claim 1, wherein a buffer chamber for uniformly blowing the processing gas introduced from an inlet of the gas passage from the plurality of gas blowing nozzles is formed. apparatus.