JP2002075955A - Substrate surface processing method and substrate surface processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the stoppage of processing of removing a film on a substrate by steam containing acid, and to prevent the pollution of a processing chamber where such processing is performed. SOLUTION: A film removal process of removing an oxide film on the surface of a wafer W is removed by gas-phase etching processing by heating the wafer W on a hot plate 45 to a specified temperature, and leading fluoric acid vapour to the surface of the wafer W in that condition. The fluoric acid vapour is generated in a fluoric acid vapour generating container 43, and the is supplied to the surface of the wafer W from a punching plate 44, passing through a fluoric acid vapour supply path 36 by carrier gas. At stoppage of the film removal process, the supply of the fluoric acid vapour is stopped, an also nitrogen gas heated by heater 65 is supplied to the surface of the wafer W and into a processing chamber 85 from a nitrogen gas supply pipe 64.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vapor-phase etching process in which a vapor containing an acid such as hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid (including HF and anhydrous HF), acetic acid and the like is introduced to the surface of a substrate. The present invention relates to a substrate surface treatment method and a substrate surface treatment device for removing a film on the surface of a substrate.
Substrates to be processed include various substrates such as semiconductor wafers, glass substrates for liquid crystal displays and plasma displays, and substrates for optical, magnetic and magneto-optical disks. The material of the substrate is silicon, glass,
Materials such as resin and ceramic are included. The removal of the film on the substrate surface may be for the purpose of selectively removing a part or all of the predetermined film, or may be for the purpose of cleaning the substrate surface.

[0002]

2. Description of the Related Art In a semiconductor memory manufacturing process, when a memory capacitor film is formed on a semiconductor wafer (hereinafter, referred to as a "wafer"), BSG (Boron-Silicate Glacier) is used.
ss), PSG (Phospho-Silicate Glass), BPSG
(Boron-doped Phospho-SilicateGlass) or another oxide film containing a large amount of impurities is used as a sacrificial oxide film. These sacrificial oxide films can have a high selectivity with respect to a thermal oxide film or a CVD (chemical vapor deposition) oxide film in etching using hydrofluoric acid vapor, and the thermal oxide film or the CVD oxide film is used as an etching stopper film. And can be selectively removed.

The etching selectivity in the etching process using hydrofluoric acid vapor depends on the temperature. For example, the etching rate of a thermal oxide film sharply decreases with a rise in temperature, whereas the BPSG film maintains a relatively high etching rate regardless of a temperature change. Therefore, when the BPSG film on the thermal oxide film formed on the surface of the wafer is selectively removed, a gas phase etching process using hydrofluoric acid vapor is performed while maintaining the temperature of the wafer at 50 ° C. to 80 ° C.

[0004]

The process of etching an oxide film (silicon oxide film) using hydrofluoric acid vapor is represented by the following reaction formula. 6F ⁺ + 6H ₃ O ⁺ + SiO ₂ → H ₂ SiF ₆ + 8H ₂ O H ₂ SiF ₆ → 2HF + SiF ₄ That is, the hydrofluoric acid vapor and water vapor are adsorbed on the wafer surface (on the oxide film) and ionized, and this becomes silicon oxide and The reaction produces the reaction product H ₂ SiF ₆ , which is further hydrofluoric acid (HF) and silicon fluoride (SiF ₄ )
And evaporates out of the wafer. Thereby, the SiO ₂ in the oxide film is lost, and the etching process proceeds. Therefore, in this reaction process, hydrofluoric acid as an etching medium and a large amount of water are generated as a result of the etching reaction.

Therefore, even if the supply of the hydrofluoric acid vapor into the chamber is stopped at the end of the etching, the temperature of the wafer becomes 5
As long as the temperature is maintained at 0 ° C. to 80 ° C., the etching process cannot be stopped immediately. That is, there is a time lag between the stop of the supply of the hydrofluoric acid vapor and the actual stop of the etching. Therefore, it is difficult to stop the etching process at a desired time. Moreover, there is no guarantee that the above-mentioned time lag is equal in each part in the wafer plane.
There is also a problem in terms of uniformity of the etching process in the wafer plane.

Further, a BSG film, a PSG film or a BPSG film
During the etching of the film, a product (for example, PH ₃ OH) containing boron (B) or phosphorus (P) is generated. These products have low saturated steam pressure (low volatility)
Therefore, while being volatilized in the heated atmosphere near the wafer W, once adsorbed on the inner wall of the processing chamber having a lower temperature than the atmosphere near the wafer W, it does not evaporate easily and causes dew condensation. As a result, the processing chamber is contaminated, and if the condensed droplets fall on the surface of the wafer W, the wafer W is contaminated.

Accordingly, a first object of the present invention is to provide a substrate surface treatment method and a substrate surface treatment apparatus which can surely stop the process of removing a film on a substrate by a vapor containing an acid. is there. A second object of the present invention is to prevent contamination of a processing chamber in which a process for removing a film on a substrate by vapor containing an acid is performed, thereby preventing contamination of the substrate. An object of the present invention is to provide a substrate surface treatment method and a substrate surface treatment device.

[0008]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, a substrate (W) is heated at a predetermined temperature (for example, 40 ° C. to 80 ° C.).
Supplying a vapor containing an acid to the surface of the substrate while heating the substrate, thereby removing a film on the substrate surface (3).
4, 36, 43, 45, 54) and after the film removing step, an inert gas supplying step (63, 64, 65) for supplying an inert gas at a temperature higher than room temperature to the surface of the substrate. A substrate surface treatment method. Note that the alphanumeric characters in parentheses represent the reference numerals of the corresponding components in the embodiment described later or the components that execute the process. Hereinafter, the same applies in this section.

[0009] The film removing step may be a vapor phase etching step in which water and an acid are generated by a reaction between the vapor and water vapor containing the acid and a constituent material of the film to be removed. According to the present invention, after (preferably immediately after) a film removing step of removing a film on the substrate surface with a vapor containing an acid.
Then, an inert gas having a temperature higher than room temperature is supplied to the surface of the substrate. Thereby, the vapor of the reaction product (for example, water and acid) existing near the surface of the substrate can be immediately removed from the vicinity of the substrate surface, and the progress of the film removing step can be stopped. Therefore, the film removing step can be reliably stopped at a desired timing. Since the stop of the film removing step can be caused almost simultaneously in each portion in the substrate surface, there is no variation in the film removing process in the substrate surface. In addition, variation in processing for a plurality of substrates can be reduced.

In order to effectively remove the reaction products existing near the substrate surface, an exhaust step of supplying an inert gas to the substrate surface and exhausting the atmosphere in the processing chamber where the film removal processing is performed. (49, 55) is preferably performed. The invention according to claim 2 is the substrate surface treatment method according to claim 1, wherein the film removal step and the inert gas supply step are performed in one processing chamber (85).

According to the present invention, since the film removing step and the inert gas supplying step are performed in one processing chamber, the inert gas is introduced to the substrate surface immediately after the film removing step is completed, so that the film removing step can be performed quickly. Can be stopped. Note that the inert gas supply step is a step of introducing an inert gas to the substrate surface from an inert gas supply path (64) independent of an acid vapor supply path (36) for introducing a vapor containing an acid to the substrate surface. Is preferred. As a result, a rise in the temperature of the acid vapor supply path can be prevented, so that there is no adverse effect (for example, a change in the etching rate) on the film removal processing by the vapor containing the acid.

For the same reason, it is preferable that the inert gas discharge port (64a) of the inert gas supply path is arranged as far as possible from the acid vapor discharge port (36a) of the acid vapor supply path. . For example, the discharge port for the inert gas and the discharge port for the acid vapor may be arranged at positions substantially point-symmetric with respect to the center (center of gravity) of the substrate. According to a third aspect of the present invention, a substrate is disposed in a processing chamber (85), and while the substrate is heated at a predetermined temperature, a vapor containing an acid is supplied to the surface of the substrate to form a film on the substrate surface. Removal step (3)
4, 36, 43, 45, 54) and an inert gas supply step (63, 64, 65) for supplying an inert gas at a temperature higher than room temperature into the processing chamber. Processing method.

According to the present invention, an inert gas having a temperature higher than room temperature is supplied to the processing chamber in which the film removing step is performed (preferably, supplied when the film removing step is not performed). The reaction product generated in the film removing step can be prevented from being condensed on the inner wall of the processing chamber. That is, the reaction product generated in the film removing step is carried away from the inner wall of the processing chamber in a vapor state. Thereby, contamination of the processing chamber can be prevented, and thus, contamination of the substrate can be prevented. Thereby, good substrate surface treatment can be performed.

In order to effectively remove the reaction products generated in the film removing step to the outside of the processing chamber, an evacuation step (49,
55) is preferably performed. For example, claim 4
As described above, the inert gas supply step may be performed every time one lot of substrates is processed. Further, the inert gas supply step may be performed every time one substrate is processed.

For example, when the film removing step and the inert gas supply step in the first aspect of the present invention are performed in the same processing chamber, a common inert gas supply mechanism (63) is used. , 64, 65) can be used in combination with the invention of claim 1 or 2 and any of the inventions of claims 3 to 5. Specifically, when a high-temperature inert gas is supplied to the surface of the substrate after the film removing step, the high-temperature inert gas reaches the inner wall of the processing chamber. Can be taken simultaneously.

According to a sixth aspect of the present invention, in the inert gas supplying step, an inert gas having a temperature higher than the predetermined temperature in the film removing step is supplied. The substrate surface treatment method according to any one of the above. Thereby, it is possible to effectively stop the film removing step or prevent dew condensation of the reaction product on the inner wall of the processing chamber.
More specifically, as described in claim 7, it is preferable that in the inert gas supply step, an inert gas of 100 ° C. or higher is supplied.

Further, the temperature of the inert gas is 100.degree.
The temperature is preferably in the range of 300 ° C., and 100 ° C. to 20 ° C.
More preferably, it is in the range of 0 ° C, most preferably about 160 ° C. The invention according to claim 8 is a substrate heating means (45) for heating the substrate (W) at a predetermined temperature.
And acid vapor supply means (34, 3) for supplying a vapor containing an acid to the surface of the substrate for a film removal process for removing a film on the surface of the substrate heated by the substrate heating means.
6, 43, 54) and inert gas supply means (63, 64, 65) for supplying an inert gas at a temperature higher than room temperature to the surface of the substrate after the film removal processing. Is a substrate surface treatment apparatus.

With this configuration, the same effect as that of the first aspect can be achieved. According to the ninth aspect of the present invention, the processing chamber (8
5), a substrate heating means (45) disposed in the processing chamber and heating the substrate (W) at a predetermined temperature, and a film removing process for removing a film on the surface of the substrate heated by the substrate heating means Vapor supply means (34, 36, 43, 54) for supplying vapor containing acid to the surface of the substrate
And an inert gas supply means (63, 64, 65) for supplying an inert gas at a temperature higher than room temperature into the processing chamber.

With this configuration, the same effect as the third aspect of the invention can be achieved. It should be noted that modifications similar to those described above with respect to the invention of the substrate surface treatment method can be made also in the invention of the substrate surface treatment apparatus.

[0020]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an illustrative plan view for explaining the configuration of the substrate surface treatment apparatus according to the first embodiment of the present invention. This apparatus is an apparatus for removing an oxide film formed on the surface of a semiconductor wafer (hereinafter, simply referred to as “wafer”) W. More specifically, for example, when a sacrificial oxide film (BPSG film or the like) used for forming a memory capacitor is formed on a thermal oxide film formed on wafer W, this sacrificial oxide film is It is a device for selective removal. For this treatment, in this substrate surface treatment apparatus, a film removing step is performed by gas phase etching of hydrofluoric acid by supplying a vapor of hydrofluoric acid to the surface of the wafer W.

The configuration of the apparatus will be described. This apparatus performs a gas phase etching process using hydrofluoric acid vapor on the surface of a wafer W and a loader unit 10 on which a cassette CL containing a wafer W before processing is placed. A vapor-phase etching processing unit 40 and a water-washing / drying processing unit 50 for rinsing the wafer W after the vapor-phase etching processing, and thereafter performing draining and drying
And an unloader unit 60 on which a cassette CU for storing the wafer W processed by the water washing / drying processing unit 50 is placed.

The loader unit 10 and the unloader unit 60
The substrate is disposed behind a front panel 77 of the substrate surface treatment apparatus. Loader unit 10, gas phase etching processing unit 40,
The washing / drying processing section 50 and the unloader section 60 are arranged in this order along a substantially U-shaped wafer transfer path 78 in plan view. Between the loader unit 10 and the vapor-phase etching processing unit 40, a loader transfer robot that takes out the unprocessed wafers W one by one from the cassette CL placed in the loader unit 10 and carries the wafers W into the vapor-phase etching processing unit 40. 71 are arranged. Further, between the vapor-phase etching processing section 40 and the washing / drying processing section 50, an intermediate transfer for taking out the wafer W after the vapor-phase etching processing from the vapor-phase etching processing section 40 and carrying it into the washing / drying processing section 50. A robot 81 is provided. An unloader is provided between the rinsing / drying unit 50 and the unloader unit 60 to take out the wafer W after the rinsing / drying unit from the rinsing / drying unit 50 and store the wafer W in the cassette CU placed in the unloader unit 60. A transfer robot 72 is provided.

Each of the loader transfer robot 71, the intermediate transfer robot 81, and the unloader transfer robot 72 has a form of a bending and stretching robot having a lower arm LA and an upper arm UA. The lower arm LA is rotated along a horizontal plane by a rotation drive mechanism (not shown). At the tip of the lower arm LA, an upper arm U
A is provided so as to be freely rotatable along a horizontal plane. When the lower arm LA rotates, the upper arm UA rotates in a direction opposite to the rotation direction of the lower arm LA by an angle twice the rotation angle of the lower arm LA. As a result, the lower arm LA and the upper arm UA can assume a contracted state in which both arms are vertically overlapped, and an extended state in which both arms are deployed toward one side or the other side along the path 78. it can.

In this manner, the loader transfer robot 7
1. The intermediate transfer robot 81 and the unloader transfer robot 72 can transfer the wafer W along the path 78 between the processing units or between the cassette and the processing unit. The rinsing / drying processing unit 50 for rinsing and drying the wafer W after the vapor-phase etching processing includes, for example, a spin chuck that horizontally holds and rotates the wafer W, and a pure chuck for the wafer W held by the spin chuck. A pure water supply nozzle for supplying water is provided. With this configuration, the wafer W
Pure water is supplied to the front and / or back surface of the wafer W to wash the front surface of the wafer W with water. After washing, stop supplying pure water,
By rotating the spin chuck at high speed, the water on the surface of the wafer W is shaken off and dried.

FIG. 2 is a schematic cross-sectional view for explaining the configuration of the vapor phase etching processing section 40. The gas phase etching processing section 40 includes a hydrofluoric acid vapor generation container 43 in a housing 41 for storing a hydrofluoric acid aqueous solution 42 as an example of an aqueous solution containing an acid in a sealed state. Below this hydrofluoric acid vapor generation container 43, a punching plate 44 having a large number of through holes for discharging hydrofluoric acid vapor downward is provided.

Below the punching plate 44, a hot plate 45 for horizontally holding the wafer W to be processed in a state of facing the punching plate 44 is arranged. The hot plate 45 is fixed to an upper end of a rotary shaft 47 that is rotated around a vertical axis by a rotary drive mechanism 46 including a motor and the like. On the outer side of the hot plate 45 in plan view, the bottom surface 41a of the housing 41 is provided.
A bellows 48 that contracts up and down is provided. The bellows 48 has an upper end edge in contact with the periphery of the punching plate 44 to seal a space around the hot plate 45 to form a processing chamber 85 (a position indicated by a solid line in the drawing). A drive mechanism (not shown) extends / contracts the edge of the hot plate 45 between a retracted position (a position indicated by a broken line in FIG. 2) and a retracted position below the upper surface 45a of the hot plate 45.

The internal space of the bellows 48 is
The air is exhausted by an exhaust unit 55 through an exhaust pipe 49 connected to the bottom surface 41a of the first unit. The exhaust means 55 may be a forced exhaust mechanism such as an exhaust blower or an ejector, or may be an exhaust facility provided in a clean room where the substrate surface treatment apparatus is installed. On the side of the hot plate 45, a loading opening 21 for loading the wafer W and a loading opening 22 for discharging the wafer W are formed in the side wall of the housing 41. Shutters 38 and 39 are arranged in these openings 21 and 22, respectively. When the wafer W is loaded, the bellows 48 is in the retracted position (the position indicated by the broken line in FIG. 2).
And the shutter 38 is opened,
The wafer W is transferred to the hot plate 45 by the loader transfer robot 71 (see FIG. 1). When the wafer W is carried out, the bellows 48 is set to the retracted position, the shutter 39 is opened, and the hot plate 45 is opened.
The upper wafer W is transferred to the intermediate transfer robot 81 and carried out. Note that the arrangement relationship between the opening 21 and the shutter 38 and the opening 22 and the shutter 39 is actually such that two line segments connecting these and the center of the wafer W are orthogonal to each other in plan view. 2 and FIG. 3 to be described later.
In FIG. 5, for simplicity of illustration, these arrangement relations are such that two line segments connecting these and the center of the wafer W in a plan view overlap on a straight line (substantially pointwise with respect to the center of the wafer W). Symmetrical positional relationship).

The hydrofluoric acid vapor generating vessel 43 is connected to a nitrogen gas supply pipe 54 for supplying nitrogen gas as a carrier gas to the space 35 above the liquid surface of the hydrofluoric acid aqueous solution 42. This space 35 is formed via a valve 37,
It can be connected to a hydrofluoric acid vapor supply passage 36 for guiding hydrofluoric acid vapor to the punching plate 44. The hydrofluoric acid vapor supply passage 36 has a nitrogen gas supply source 3
Nitrogen gas from 1 is flow controller (MFC) 3
2. It is supplied through a valve 33 and a nitrogen gas supply pipe 34.

The nitrogen gas from the nitrogen gas supply source 31 is supplied through a flow controller 52 and a valve 53 to
The gas is supplied to a nitrogen gas supply pipe 54.
Hydrofluoric acid aqueous solution 4 stored in hydrofluoric acid vapor generation container 43
2 is a concentration that results in a so-called pseudo-co-fluorine composition (for example, 1
It is adjusted to about 39.6% under atmospheric pressure and room temperature (20 ° C.). This hydrofluoric acid aqueous solution 42 having a pseudo-cofluoric composition is
Since the evaporation rates of water and hydrogen fluoride are equal, hydrofluoric acid vapor is guided from the valve 37 to the punching plate 44 through the hydrofluoric acid vapor supply passage 36, so that the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor generation vessel 43 is formed. Is reduced, the concentration of the hydrofluoric acid vapor guided to the hydrofluoric acid vapor supply passage 36 is kept unchanged.

On the other hand, a nitrogen gas (inert gas) from the nitrogen gas supply source 31 is supplied to the punching plate 44 via a flow rate controller 62 and a valve 63 in a nitrogen gas supply system separate from the nitrogen gas supply pipe 34. It is supplied from a pipe 64. A heater 65 as a heating mechanism is disposed in the middle of the nitrogen gas supply pipe 64. The heater 65 changes the nitrogen gas flowing through the nitrogen gas supply pipe 64 to a temperature higher than room temperature (preferably, the temperature of the wafer W heated by the hot plate 45 (40
C. to 80 C.). For example, about 160 ° C)
Heat to The heated nitrogen gas is guided to the wafer W via the punching plate 44. The flow rate of the nitrogen gas supplied through the nitrogen gas supply pipe 64 is preferably in a range of 10 L / min to 50 L / min, and most preferably about 20 L / min.

The valves 33, 53 and 63 for switching the supply / stop of the nitrogen gas are controlled by the controller 80. FIG. 3 is an illustrative sectional view showing an enlarged configuration near the punching plate 44. Above the punching plate 44, a space 91 into which the hydrofluoric acid vapor from the hydrofluoric acid vapor supply passage 36 and the nitrogen gas as the carrier gas, and the nitrogen gas from the nitrogen gas supply pipe 64 are introduced.
Are formed. The discharge port 36 a of the hydrofluoric acid vapor supply path 36 and the nitrogen gas supply pipe 64 are
Are opened.

The discharge ports 36a and 64a are arranged in a plan view looking down on the wafer W placed on the hot plate 45,
It is arranged at a position substantially symmetrical with respect to the center of the wafer W. In other words, the discharge ports 36a and 64a are arranged as far apart as possible, so that the hydrofluoric acid vapor supply path 36 is heated by the high-temperature nitrogen gas supplied from the nitrogen gas supply pipe 64. Preventing. In FIG. 3, reference numeral 90 denotes a pipe through which temperature-regulated water for maintaining the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor generation container 43 at a constant temperature.

When performing a film removing step of removing the film on the surface of the wafer W, the bellows 48
Is raised to the close contact position (the position indicated by the solid line in FIG. 2) close to the peripheral edge of the hot plate 45 to form a closed processing chamber 85 surrounding the hot plate 45. In this state, the controller 8
A value of 0 opens the valves 33, 37 and 53, and keeps the valve 63 closed. Thereby, the hydrofluoric acid vapor generation container 4
The hydrofluoric acid vapor generated in the space 35 inside the valve 3 is supplied to the valve 37 by the nitrogen gas from the nitrogen gas supply pipe 54.
Through the hydrofluoric acid vapor supply path 36. The hydrofluoric acid vapor is further conveyed to the punching plate 44 by the nitrogen gas from the nitrogen gas supply pipe 34. Then, the wafer W is supplied to the surface of the wafer W through a through hole formed in the punching plate 44.

On the surface of the wafer W, the hydrofluoric acid vapor reacts with the oxide film (silicon oxide) on the surface of the wafer W under the participation of water molecules near the wafer W, thereby removing the oxide film. Achieved. As described above, the etching rate of the BPSG film and the thermal oxide film at a certain temperature (for example, a predetermined temperature in the range of 40 ° C. to 80 ° C.) is greatly different from that of the hydrofluoric acid vapor. BPSG on the surface of the wafer W can be selectively removed. Therefore, the hot plate 45 is energized to an internal heater so as to maintain the wafer W at the constant temperature.

The hot plate 45 is rotated around the vertical axis at a constant speed by a rotation driving mechanism 46 via a rotation shaft 47 in order to uniformly perform the processing in the plane of the wafer W. After performing the film removing step for a predetermined period of time in this manner, the controller 80
3, 37 and 53 are closed to stop the film removing step. At the same time, the controller 80 opens the valve 63,
The high-temperature nitrogen gas heated by the heater 65 is supplied to the surface of the wafer W through the through hole of the punching plate 44. As a result, water molecules and hydrofluoric acid molecules existing near the surface of the wafer W are removed, and the exhaust pipe 4
Due to the exhaust of the processing chamber 85 through 9, the processing chamber 85 is carried out of the processing chamber 85.

Immediately after the film removing step, the surface of the wafer W is supplied with nitrogen gas as a high-temperature inert gas, whereby water and hydrofluoric acid molecules near the surface of the wafer W are promptly removed. Therefore, the vapor phase etching process stops immediately. Since the stop of the vapor phase etching process occurs almost simultaneously over the entire surface of the wafer W,
A uniform film removal process can be performed on each part of the surface of the wafer W. In addition, it is possible to reduce a variation in processing for a plurality of wafers W.

The supply of the high-temperature nitrogen gas after the film removing step is continued for a predetermined time (for example, 10 seconds or more, preferably about 20 seconds). As a result, the high-temperature nitrogen gas reaches the inner wall of the processing chamber 85 (the inner surface of the bellows 48, etc.). And the vapor of the reaction product can be removed to the outside of the processing chamber 85 by exhaustion through the exhaust pipe 49. After the elapse of the predetermined time, the controller 80 closes the valve 63 to stop supplying the nitrogen gas.

Although the embodiment of the present invention has been described above, the present invention can be embodied in other forms. For example, in the above-described embodiment, the nitrogen gas supply pipe 64 of a different system from the hydrofluoric acid vapor supply path 36 is provided, but the hydrofluoric acid vapor supply path 36 may also be used for supplying high-temperature nitrogen gas. Good. That is, the nitrogen gas supply pipe 3
A heater is provided in connection with 4, and after the film removing step, the valve 33 is kept open and the heater is operated to heat the nitrogen gas flowing through the nitrogen gas supply pipe 34 to a required temperature. . As a result, high-temperature nitrogen gas is supplied from the punching plate 44 to the surface of the wafer W and the inside of the processing chamber 85 immediately after the film removing step.
However, if the temperature rise of the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor supply passage 36 or the hydrofluoric acid vapor generating vessel 43 adjacent thereto is large, the etching rate may fluctuate. The configuration shown in FIG. 3 is more preferable.

In the above-described embodiment, the nitrogen gas supply pipe 64 for supplying high-temperature nitrogen gas to the surface of the wafer W immediately after the film removing step is also used to prevent dew condensation on the inner wall of the processing chamber 85. However, an inert gas (nitrogen gas or the like) supply pipe for preventing dew condensation on the inner wall of the processing chamber 85 may be separately provided. For example, the gas supply port of the inert gas supply pipe for preventing dew condensation is located near a relatively low temperature place where dew condensation easily occurs (the inner surface of the bellows 48 or the lower part of the space surrounded by the bellows 48). As described above, an inert gas supply pipe for preventing condensation may be separately provided. In this case, the supply of the high-temperature inert gas from the inert gas supply pipe for preventing condensation may be performed every time the processing of each individual wafer W is completed, or a plurality of sheets of one lot may be supplied. It may be performed every time the processing on the wafer W is completed. In this case, the supply of the high-temperature inert gas is preferably performed, for example, at a flow rate of 50 L / min for about 10 minutes.

In the above embodiment, hydrofluoric acid vapor is used as vapor for etching the substrate surface. However, hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid (HF and anhydrous H
F) and any vapor containing an acid such as acetic acid. For example, it may be a vapor of an aqueous solution containing the acid, or a mixture of the gas containing the acid (in a gaseous state) in water vapor. Further, in the above-described embodiment, an example in which nitrogen gas is used as the inert gas has been described, but another inert gas such as argon may be used.

In addition, various design changes can be made within the scope of the matters described in the claims.

[Brief description of the drawings]

FIG. 1 is an illustrative plan view for describing a configuration of a substrate surface treatment apparatus according to an embodiment of the present invention.

FIG. 2 is an illustrative cross-sectional view for describing a configuration of a vapor phase etching processing unit.

FIG. 3 is an illustrative sectional view showing an enlarged configuration near a punching plate.

[Explanation of symbols]

 Reference Signs List 40 Gas phase etching processing part 50 Rinse / dry processing part 31 Nitrogen gas supply source 33 Valve 34 Nitrogen gas supply pipe 36 Hydrofluoric acid vapor supply path 36a Discharge port 37 Valve 42 Hydrofluoric acid aqueous solution 43 Hydrofluoric acid vapor generation container 44 Punching plate 45 Hot Plate 46 Rotating drive mechanism 47 Rotating shaft 48 Bellows 49 Exhaust pipe 52 Flow controller 53 Valve 54 Nitrogen gas supply pipe 55 Exhaust unit 60 Unloader unit 62 Flow controller 63 Valve 64 Nitrogen gas supply pipe 64a Discharge port 65 Heater 80 Controller 85 Processing chamber W Wafer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Go Okumura 4-chome, Horikawa-dori Teranouchi, Kamigyo-ku, Kyoto-shi, Kyoto 1 Fukuda-term (reference) at Dainippon Screen Mfg. Co., Ltd. 4K057 WA01 WB06 WB20 WE02 WE03 WE07 WE08 WE12 WK01 WM11 WM17 WN01 5F004 AA15 AA16 BA19 BB18 BB24 BB26 BC03 BC06 DA00 DA20 DA23 DA25 DA29 DB03 DB06 5F043 AA02 AA36 AA37 BB24 BB25 DD10 EE10 EE10 EE10

Claims (9)

[Claims] 1. A film removing step of removing a film on a surface of a substrate by supplying a vapor containing an acid to the surface of the substrate while heating the substrate at a predetermined temperature. An inert gas supply step of supplying an inert gas at a temperature higher than room temperature to the surface. 2. The substrate surface treatment method according to claim 1, wherein said film removing step and said inert gas supplying step are performed in one processing chamber. 3. A film removing step of disposing a substrate in a processing chamber, heating the substrate at a predetermined temperature, and supplying a vapor containing an acid to the surface of the substrate to remove a film on the substrate surface. An inert gas supply step of supplying an inert gas having a temperature higher than room temperature into the processing chamber. 4. The method according to claim 3, wherein the inert gas supply step is performed every time one lot of substrates is processed.
The substrate surface treatment method according to the above. 5. The substrate surface treatment method according to claim 3, wherein the inert gas supply step is performed every time one substrate is processed. 6. The method according to claim 1, wherein in the inert gas supplying step, an inert gas having a temperature higher than the predetermined temperature in the film removing step is supplied. Substrate surface treatment method. 7. An inert gas supply step of supplying an inert gas of 100 ° C. or higher in said inert gas supply step.
7. The substrate surface treatment method according to any one of items 1 to 6. 8. A substrate heating means for heating a substrate at a predetermined temperature, and an acid on the surface of the substrate for removing a film on the surface of the substrate heated by the substrate heating means. Substrate surface treatment comprising: acid vapor supply means for supplying vapor; and inert gas supply means for supplying an inert gas at a temperature higher than room temperature to the surface of the substrate after the film removal treatment. apparatus. 9. A processing chamber, a substrate heating means disposed in the processing chamber for heating a substrate at a predetermined temperature, and a film removing process for removing a film on the surface of the substrate heated by the substrate heating means. For this purpose, an acid vapor supply means for supplying a vapor containing an acid to the surface of the substrate, and an inert gas supply means for supplying an inert gas having a temperature higher than room temperature into the processing chamber are provided. Substrate surface treatment equipment.