JPH0479324A - Method and equipment for surface treatment of substrate - Google Patents

Abstract

PURPOSE:To speed up ashing process with safety to make it possible for removing metallic impurity from photoresist well by mixing acid contained vapor generated by evaporating acid contained water solution in at least either one of ozone and oxygen prior to activation. CONSTITUTION:In an acid contained vapor generating means 15, a nozzle 5 is supplied with acid containing vapor generated by evaporating acid contained vapor and ozone generated by an ozone generator 23. Acid contained vapor and ozone activated by radiating ultraviolet ray from an ultraviolet lamp 4 are supplied evenly to the surface of a substrate held by spin chuck 3 through a diffusing hole 5a to resolve organic substance adherent to the surface of the substrate W to remove and to convert metallic impurities into metallic salt. After the completion of this processing, using the second conveyor 7b to move the substrate W onto a substrate holding table 27 in a pure water rinsing and cleaning treatment chamber 8. Next, the substrate W placed on the substrate holding table 27 is supplied with pure water from a pure water supply nozzle 28 to clean the substrate to remove metallic salt from the substrate.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention is applicable to the surface of a substrate when manufacturing semiconductors that require miniaturization and high integration, such as ultra-large scale integrated circuits (VLSI). The present invention relates to a substrate surface treatment method and apparatus for ashing a photoresist using active oxygen generated by activating at least one of ozone and oxygen.

<Prior Art> Conventionally, there have been the following methods for surface treatment of this type of substrate.

A. First Conventional Example As disclosed in Japanese Unexamined Patent Publication No. 64-48421, a mixed gas of oxygen gas and water is turned into plasma in a vacuum, and active species generated in the plasma are used as reactive species to manufacture semiconductors. The photoresist, which is considered the biggest organic contamination during the process, is removed.

B. Second Conventional Example As disclosed in Japanese Unexamined Patent Publication No. 1189122, the photoresist is removed using an active oxidizing gas generated by a reactive gas containing ultraviolet light and ozone, ultraviolet light energy, and radiant heat from a radiant heat source.

C1 Third Conventional Example As disclosed in Japanese Unexamined Patent Publication No. 1-233728, nitrous oxide (N, O) is generated by thermal decomposition by irradiating ultraviolet rays on an oxygen/ozone mixed gas containing moisture and ammonium nitrate. Produce an excited reaction between the gas and the oxygen/ozone mixed gas, and promote the excited reaction using moisture as a catalyst,
To obtain a high concentration of active oxygen and improve the ashing speed.

D. Fourth Conventional Example As disclosed in Japanese Patent Application Laid-Open No. 57-210632,
The substrate is immersed in a strongly oxidizing treatment solution containing nitric acid and hydrogen peroxide to wet-oxidize the deteriorated layer of the photosensitive resin film, which weakens the resistance of the deteriorated layer of the photosensitive resin film to oxygen plasma. The film-altered layer is etched together with the photosensitive resin film using oxygen plasma.

<Problems to be Solved by the Invention> The first and second conventional examples described above have the following drawbacks.

■Photoresist ashing speed is slow and processing capacity is limited.

■Metal impurities in photoresist are difficult to remove.

■ Phosphorus (P) It is difficult to remove the resist after ion implantation (so-called P implant resist).

Further, although the third conventional example can improve the ashing speed, it has the following drawbacks.

(2) Depending on the temperature of the hot plate on which the substrate is placed, ammonium nitrate (NH, NO) undergoes a chemical change and there is a risk of explosion.

■Metal impurities in the photoresist are not removed.

(2) Control of the peeling process requires a complicated means for detecting the end point of the peeling process.

Further, in the fourth conventional example, since it is a wet oxidation treatment, waste liquid treatment is required after the washing and cleaning treatments, and the treatment efficiency is low.

The present invention has been made in view of the above circumstances, and aims to improve the ashing speed while being safe, and to effectively remove metal impurities in photoresist. shall be.

Means for Solving the Problem> In order to achieve such an object, the invention of claim No. ( ) supplies active oxygen generated by activating at least one of ozone and oxygen to the surface of a substrate. A surface treatment method for a substrate in which organic matter on the surface of the substrate is decomposed and removed, characterized in that, prior to activation, at least one of ozone and oxygen is mixed with an acid-containing vapor generated by boiling an aqueous solution containing an acid. It is said that

In addition, the invention of claim (2) provides a substrate surface treatment method in which active oxygen generated by activating at least one of ozone and oxygen is supplied to the substrate surface to decompose and remove organic matter on the substrate surface. The method is characterized in that, prior to activation, at least one of ozone and oxygen is mixed with at least one of nitrogen monoxide gas and nitrogen dioxide gas.

In addition, the invention of claim (3) provides a substrate surface treatment method according to the invention of claim (1) or (2), after decomposing and removing organic substances on the substrate surface, the substrate is purified. It is characterized by supplying water to clean the surface.

The invention of claim (4) also provides a gas supply means for supplying at least one of ozone and oxygen; and a substrate surface treatment chamber which holds a substrate therein and supplies active oxygen activated by a gas activation means to the surface of the substrate to decompose and remove organic matter adhering to the surface of the substrate. In the surface treatment apparatus, an acid-containing steam generating means stores an acid-containing aqueous solution therein and evaporates the aqueous solution, and an acid-containing steam generating means supplies the acid-containing steam generated by the acid-containing steam generating means to the gas activation means. A deionized water cleaning treatment chamber is provided adjacent to the containing vapor supply means and the substrate surface treatment chamber, and is equipped with a deionized water supply means for supplying substrate surface deionized water.

As the aqueous solution containing acid, hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, acetic acid, and a mixture thereof with hydrogen peroxide can be used.

<Function> According to the configuration of the substrate surface treatment method according to the invention of claim (1), the following effects are achieved.

The acid-containing vapor generated by evaporation of the acid-containing aqueous solution described above undergoes the following photochemical reaction when irradiated with ultraviolet light having wavelengths of 184.9r+m and 253.7n.

In the case of hydrochloric acid vapor, hν HCI −H・+ CI・
hν H,O → H・ten OH・ 170-190 nm Chlorine radical CI hydrogen radical H・ or hydroxyl radical OH・ generated in this photochemical reaction is a chemical compound such as organic matter (c
It acts as a catalyst to promote the decomposition of v o z ) into carbon dioxide gas (Cot) and water (H20), and chlorine radical CI
・acts on metal impurities and converts them into metal salts that can be easily removed by heating or washing with water.

In the case of nitric acid vapor hν HNO3-OH・+ N02 200 ~ 300 nm hν 28 nm hν 2NOx −+2NO−+ 01
, > 436 nm or NO, + No ・hν Ht O→ H・+OH・ 170 ~ 190 nm Oxygen radicals 0・, nitrogen monoxide radicals NO・, and nitrogen dioxide NO! generated in this photochemical reaction. has a strong oxidizing effect and decomposes and removes organic substances such as resist. In addition, hydroxyl radicals OH・, nitrogen monoxide radicals No・, and hydrogen radicals H・ are carbon dioxide gas (
Cot) and water (H, O), and acts as a catalyst to promote the decomposition into hydroxyl radical ○H・ and nitrogen monoxide radical No.
Active acid groups such as .not only decompose @ substances but also act on metal impurities, converting them into metal salts that can be easily removed by sublimation due to heating, sputtering during etching, washing with water, etc.

The nitric oxide radical No. can decompose and remove potassium, magnesium, and phosphorus through its strong oxidizing action, and can also promote the decomposition of the P implant resist. Also, Al′! It is highly possible that the sidewall polymer after dry etching of the IT electrode wiring can also be removed at the same time.

Hydrogen radicals H・ and hydroxyl radicals OH・ obtained by activating acid-containing steam in this way act as catalysts that promote the decomposition of organic substances by ozone radicals O1・, oxygen radicals 0・, or ultraviolet rays. In addition, acid radicals (
For example, No. for nitric acid vapor, 0 for hydrochloric acid vapor.
1, etc.) not only acts to promote the decomposition of organic matter, but also acts as a reactive species that reacts with metal impurities in the photoresist to generate metal salts.

Note that among metal salts, metal chlorides are highly volatile and are easily vaporized, and since metal salts remaining on the substrate surface are easily dissolved in water, they can also be removed by a cleaning process.

Further, according to the configuration of the substrate surface treatment method according to the invention as claimed in claim (2), the following effects can be obtained.

When nitric oxide and nitrogen dioxide are irradiated with ultraviolet light, they produce nitric oxide radicals NO・ and nitrogen dioxide radicals NO□ ・ through photochemical reactions, and these nitric oxide radicals No. and nitrogen dioxide radicals NO □ The strong oxidizing action of ・promotes the decomposition of organic matter by oxygen radicals and ozone radicals, and also acts on metal impurities, converting them into metal salts that can be easily removed by sublimation by heating, sputtering during etching, washing with water, etc.

Nitric oxide radicals NO・ and nitrogen dioxide radicals NO□・ decompose and remove potassium, magnesium, and phosphorus with their strong oxidizing action, and also
) It can react with phosphorus (P) attached to the resist after injection and promote the decomposition of the resist. Furthermore, there is a high possibility that the sidewall polymer after the A1 electrode wiring tri-etching can also be removed at the same time.

Further, according to the configuration of the substrate surface treatment method according to the invention as claimed in claim (3), the following effects can be obtained.

The metal impurity residues in the photoresist that have been converted into metal salts as described above are washed away with pure water.

That is, the solubility of nitrate is N a N 0391.
8g/100g (25°C), 175.5g/10
0g (100″C), KNO, 31,59g /
10h (20°C), 240g/100g (10
0°C), CaN 0.129.9g/100g
(20°C), Fe (NO3) *87.3g
/100g (25°c), Nt (NOs)
z 94.2g/100g (25℃), Cu (
NOS)! 60g/100g (25℃). Similarly, chloride is NaCl35°8g/100g
(20°C), N i Cl, 67.8g/1
00g (26”C) and dissolves well in pure water.

Further, according to the configuration of the substrate surface treatment apparatus according to the invention as claimed in claim (4), the following effects can be obtained.

In the substrate surface treatment chamber, organic matter is removed and metal impurities are converted into metal salts, and the surface-treated substrate is transferred to a pure water cleaning treatment chamber, where the converted metal salts are washed away with pure water.

<Example> Next, an example of the present invention will be described in detail based on the drawings.

1. Figure 1 is a schematic vertical cross-sectional view showing a first embodiment of the substrate surface treatment apparatus, in which a spin chuck 3 with a built-in heater 2 for heating the substrate 2 is installed in the substrate surface treatment chamber 1. is provided, and a wavelength of 184.9n+ is provided as a gas activation means.
A nozzle 5 made of quartz is provided with a built-in ultraviolet lamp 4 that irradiates ultraviolet light with a wavelength of 253.7r+m.

Note that the ultraviolet lamp 4 may be suspended below the nozzle 5.

The spin chuck 3 is configured to be driven and rotated around a vertical axis by a motor M.

A large number of diffusion holes 5a are formed in the bottom plate of the nozzle 5 and are uniformly distributed at predetermined intervals.

In order to increase the decomposition and removal efficiency of WJ, materials, and conversion efficiency of inorganic materials, it is preferable to shorten the distance between the base 1w on the spin chuck 3 and the ultraviolet lamp 4 as much as possible.

A loading inlet 1a and an unloading outlet 1b for the substrate W are formed to face the peripheral wall of the substrate surface treatment chamber 1 in the diametrical direction. Shanks 6a' and 6b are provided that can be opened and closed by sliding.

Outside the substrate surface processing chamber 1, there is a first substrate transport mechanism 7a that carries the substrate W into the substrate surface processing chamber 1 through the loading port 1a, and a first substrate transport mechanism 7a that carries the substrate W into the substrate surface processing chamber 1 through the loading port 1b. In addition, a second substrate transport mechanism 7b that carries the substrate into the pure water cleaning processing chamber 8, and a third substrate transport mechanism 70 that carries out the substrate from the pure water cleaning processing chamber 8 are provided.

These first, second and third substrate transport mechanisms 7a, 7
b and 7c each have the same structure, and as shown in the perspective view of FIG. 2, they include an electric motor 10, a first arm 11 attached to the rotating shaft of the electric motor 10,
A second arm 12 rotatably attached to the free end of the first arm 11; a transmission mechanism 13 that transmits the rotational motion of the first arm 11 to rotate the second arm 12; It is formed at the end and is composed of a vacuum chaff 14 and the like that sucks and holds the mounted substrate W by vacuum suction.

An acid-containing steam generating means 15 for evaporating an aqueous solution containing an acid such as hydrochloric acid or nitric acid is connected to the introduction pipe 5b of the nozzle 5 via a steam supply pipe 17 having an on-off valve 16 interposed therein.

The acid-containing steam generating means 15 is composed of a storage tank 18 for storing an aqueous solution containing an acid, and a temperature control means 19 such as a heater provided on the outer periphery of the storage tank 18. The aqueous solution containing acid is heated and evaporated by the temperature control means 19, and the acid-containing vapor generated by the evaporation is passed through the steam supply pipe 17.
It is designed to be supplied to the nozzle 5 through. Although not shown, the steam supply pipe 17 is coated with a heat insulating material so that the steam does not reach a temperature below the dew point and liquefy while flowing inside.

Connected to the storage tank 18 are an aqueous solution supply pipe 20 that replenishes an aqueous solution containing an acid, and a carrier gas supply pipe 21 that supplies nitrogen N2 gas as a carrier gas. Valves 20a and 21a are interposed.

The steam supply pipe 17 with the opening/closing valve 16 interposed therein and the carrier gas supply pipe 21 constitute acid-containing steam supply means.

Further, a gas supply means consisting of an oxygen pump 22 and a gas supply pipe 24 in which an ozone generator 23 is interposed is connected to a midway point of the steam supply pipe 17, and both sides of the ozone generator 23 of the gas supply pipe 24 are connected. On-off valves 24a and 24b are interposed in each of them.

An exhaust chamber 25 for gases such as CO2 and H2O generated during the decomposition and removal of existing materials is formed on the bottom plate of the substrate surface processing chamber 1, and an exhaust pipe 26 communicating with the chamber 25 is connected to a vacuum pump (not shown) for suction and exhaust. It is connected.

A substrate mounting table 27 is installed inside the deionized water cleaning chamber 8 so that it can be raised freely, and on the top plate of the deionized water cleaning chamber 8,
For example, a pure water supply nozzle 28 is provided as a pure water supply means for supplying high temperature pure water of 80°C.

The substrate mounting table 27 is configured to be driven and rotated around a vertical axis by a motor M2. Further, on the substrate mounting table 27, a bin 2 is placed at a position opposite to the substrate mounting table 27 in the diametrical direction.
7a are erected, and a protrusion 27 for holding the substrate is provided inside them.
b is attached.

A loading inlet 8a and an unloading outlet 8b for the substrate W are formed to face the peripheral wall of the pure water cleaning processing chamber 8 in the diametrical direction. Shutters 29a29,b are provided which can be opened and closed by sliding.

A drain and exhaust pipe 30 is connected to the bottom plate of the pure water cleaning chamber 8.

By using the substrate surface treatment apparatus with the above configuration,
The method for surface treatment of a substrate according to claim (1) is carried out.

That is, acid-containing steam generated by evaporation of an acid-containing aqueous solution in the acid-containing steam generating means 15 and ozone generated in the ozone generator 23 are supplied to the nozzle 5, and the acid-containing steam and ozone are heated with an ultraviolet lamp. 4, and acid-containing vapor and ozone activated by the UV irradiation are uniformly supplied to the surface of the substrate W held on the spin chuck 3 through the diffusion holes 5a... It decomposes and removes organic substances and converts metal impurities into metal salts.

After the processing, the substrate W is transferred onto the substrate mounting table 27 in the pure water cleaning processing chamber 8 by the second transport mechanism 7b, and the substrate W placed on the substrate mounting table 27 is purified. Pure water is supplied from the water supply nozzle 28 to wash and remove the metal salts mentioned above.

As the pure water supplied from the pure water supply nozzle 28, it is better to use high-temperature pure water to accelerate the removal of metal salts.
k) Ultrasonic waves with a frequency higher than EZ may be added to pure water to increase the cleaning efficiency, or pure water at room temperature may be supplied.

Figure 3 is a schematic vertical sectional view showing a second embodiment of the substrate surface treatment apparatus, and the differences from the first embodiment are as follows.

That is, in place of the ultraviolet lamp 4 as the gas activation means in the first embodiment, a plasma generation means 32 equipped with a microwave generation means 31 is provided, and the plasma generation means 32 is operated via an on-off valve 33a. installed steam supply pipe 3
3, the storage tank 18 is connected to the oxygen cylinder 22 via the oxygen supply pipe 34 which has an on-off valve 34a, and the plasma generation means 32 and the nozzle 5 are connected to each other through the on-off valve 35a. It is connected via a pipe 35.

The other configurations are the same as those in the first embodiment, are given the same drawing numbers, and the explanation thereof will be omitted.

According to the configuration of this second embodiment, both the acid-containing air and the oxygen gas are activated in the plasma generating means 32 and then supplied to the nozzle 5.

No.1! Figure 4 is a schematic vertical sectional view showing a third embodiment of a substrate surface treatment apparatus used to carry out the substrate surface treatment method of claim (2), and is different from the first embodiment. The differences are as follows.

That is, in place of the acid-containing atrophy generating means 15 of the first embodiment, a nitrogen dioxide bomb 36 is provided, and the nitrogen dioxide bomb 36 and the nozzle 5 are connected to a nitrogen gas supply pipe 37 with an on-off valve 31a interposed. connected via.

Since the other configurations are the same as those of the first embodiment, illustration of the pure water treatment chamber 8 is omitted, and the same parts are given the same figure numbers and their explanations are omitted.

According to the configuration of the third embodiment, both nitrogen dioxide gas and ozone are supplied to the nozzle 5 and activated by the ultraviolet lamp 4, and the activated ozone radicals and nitrogen dioxide radicals are transferred to the surface of the substrate W. supplied to

In this third embodiment, nitrogen monoxide may be supplied instead of nitrogen dioxide. Also, in the third embodiment, as in the second embodiment shown in FIG. 3, instead of the ultraviolet lamp 4, the gas may be activated by plasma generation means equipped with microwave generation means.゛Next, the experimental results will be explained.

In the experiment, a substrate surface treatment chamber 1 having the same configuration as the substrate surface treatment chamber 1 in the first embodiment described above was used to perform the surface treatment of the substrate, and the substrate W was placed in the same substrate surface treatment chamber 1.
After the surface treatment, a pure water supply nozzle was introduced and a cleaning process using pure water was performed.

In addition, a 5-inch N (100) type silicon wafer was used as the sample substrate, and the silicon wafer was heated at a temperature of 23°C.
Dehydration shake for 1 minute at 0℃, 5000r
While rotating at p-, apply a positive photoresist [rOFPR-800 manufactured by Tokyo Ohka ■ to a film thickness of 1 to 2 μm.
J (product name)] at a temperature of 135°C.
The one that had been shaken for a minute was used.

Then, the film thickness on the surface was measured at 108 points.

First, hydrochloric acid vapor obtained by evaporating hydrochloric acid having an azeotropic composition concentration of about 20% and ozone are irradiated with ultraviolet rays and supplied to a substrate for treatment, and this is designated as the first example product AI.

Next, ultraviolet rays were irradiated to nitric acid gas obtained by evaporating nitric acid having an azeotropic composition concentration of 69% and ozone, and the substrate was supplied and treated, thereby obtaining a second example product A2.

In addition, a stripping solution made by adding nitrogen dioxide to nitric acid at a concentration of 98% [RA-Stripper (trade name) manufactured by Kanto Kagaku Co., Ltd.] is evaporated and ozone is irradiated with ultraviolet rays and then supplied to the substrate for treatment. , this is referred to as the third example product A3.

On the other hand, ozone was irradiated with ultraviolet rays and supplied to the substrate for treatment, and this was designated as a first comparative example product B1.

Further, a mixture of ozone and nitrogen gas was irradiated with ultraviolet rays and supplied to the substrate for treatment, and this was designated as a first comparative example product B2.

In the actual height measurement, the ozone supply amount was 10 liters per minute, and the carrier gas supply amount was 21 liters per minute.On the other hand, the ozone supply amount in the first comparative example product B1 was 12 A per minute. 2 In Comparative Example Product B2, the ozone supply amount was 10ff per minute, and the nitrogen gas supply amount was 21 ff per minute.
In any case, the temperature of the hot plate in the spin chuck 3 during the processing is 2
The temperature was 50°C and 300°C, and the asong time was 3 minutes in both cases.

After the above treatment, the first to third embodiment products Al.

A2. A3, first and second comparative example products B1. The film thickness of each B2 substrate was measured at 108 points.

The ashing speeds (r+m/3m1n) of the first and second example products Al, A2 and the first and second comparative example products Bl, B2 when processed at a hot plate temperature of 250"C are shown below. As a result, the results shown in the graph of FIG. 5 were obtained.

Also, set the temperature of the hot plate to 250°C and 300°C.
2nd and 3rd example products A2. when processed at °C. When the ashing speed (nm/3+pin) of each of A3 and the second comparative example B2 was determined, the results shown in the graph of FIG. 6 were obtained.

Next, experimental results obtained by 51M5 analysis will be explained.

In this experiment, 51M5
By analysis, 283 it −”Na” 27A1+
39 to 1 4eCa+ S6F e'l 5t
Measure the ion strength of Cr+ and calculate the average value, 23N a'' 27AI -39 to -411
Ca.

56) The ratio of the ionic strength of "e" % Z Cr + each to the ionic strength of zs31' was determined.

The results are shown in the table below.

(Hereinafter, blank spaces) In the above table, columns I to ■ indicate the results of the following treatments, respectively.

Column I: The substrate without photoresist was simply exposed to ozone radicals for 45 minutes.

The photoresist was treated with niosine radicals for 455 minutes.

Hydrochloric acid vapor was mixed with m41jl ozone using nitrogen gas as a carrier gas, and the mixture was activated to treat the photoresist for 455 minutes.

rVlt! nitric acid vapor [the above-mentioned stripping solution (RA-stripper)] was applied to fl niosine using nitrogen gas as a carrier gas.
(the same applies hereinafter)] and activated them to perform a 50% overashing process on the photoresist.

■8 Niosine is mixed with nitric acid vapor using nitrogen gas as a carrier gas, and after activating them and overashing the photoresist by 50%, pure water is poured onto the horizontally rotating substrate for 60 seconds (flow rate 1.572 /Ta1n
) and then shaken off and dried by high-speed rotation.

■ Column After 50% overashing of the photoresist with niosine radicals, pure water was applied to the horizontally rotating substrate for 6 minutes.
The solution was supplied for 0 seconds (flow rate: 1.51/win), and then spun off and dried by high-speed rotation.

Next, the above experimental results will be discussed.

First, let us consider the ashing speed. From the results shown in FIG. 5, the addition of hydrochloric acid vapor or nitric acid vapor has the effect of increasing the ashing rate, and this effect is noticeable when nitric acid vapor is added. This suggests that the effect of nitrogen monoxide radicals and nitrogen dioxide radicals, which participate as reactive species, is greater than that of chlorine radicals, which participate in reactions as catalysts, but activation by ultraviolet light energy must be performed sufficiently. It is thought that the effect can be improved even in the case of hydrochloric acid vapor. The results shown in FIG. 6 show that the higher the nitric acid concentration in the vapor source, the higher the ashing rate.

Since nitrogen oxide radicals and nitrogen dioxide radicals participate in the decomposition of photoresist as reactive species, the higher the concentration, the higher the reaction rate.This effect of adding nitric acid vapor is due to (microwave) plasma. Asher
It is considered that this is also acceptable. Note that when an azeotropic acid aqueous solution is used, the concentration of acid-containing vapor generated by evaporation can be kept constant, so the photoresist decomposition process can be controlled using a simple method such as time control. becomes possible.

Next, the cleaning effect will be considered.

A comparison between column II and column (■) shows that a considerable amount of sodium f 3 N al remains on the silicon wafer surface after photoresist ashing.

Z7Al- does not appear to be present in the photoresist. 40CaI is also not present in the photoresist 56
Fe# is 5bSi, - and it seems that ``5ICrt'' is slightly included in 39.

Therefore, we decided to evaluate various types of cleaning by narrowing down the elements to "Na", "9", and 5tCr-. Comparing column ■ and column ■, the strength ratio of :CoNa"CoqK""Cr" has slightly decreased due to the addition of hydrochloric acid vapor, but 1
ZN a″” on the silicon wafer surface compared to m.
It can be seen that a considerable amount of K'''' remains. The expected cleaning effect was not observed. Chlorides such as NaCl and KCl generated by hydrochloric acid vapor are exposed to ultraviolet irradiation at 250°C.
It can be seen that the particles could not be removed even under conditions of .degree. C. to 300.degree. C., and remained transferred and adsorbed onto the wafer surface. When comparing column ■ and column ■, Z″Na− is slightly lower when ashing is performed by adding nitric acid vapor, and 39+
52Cr" has the opposite result. Even without adding nitric acid vapor, the cleaning effect with pure water is large, and the cleanliness has increased to the reference level of NM.

It was found that the cleaning effect of pure water is extremely large.

As described above, from the results shown in FIGS. 5 and 6, it is clear that the ashing speed of positive photoresist can be improved by adding hydrochloric acid vapor or nitric acid vapor. It was clear from columns and Vllll+ that the cleaning effect could be extremely improved by cleaning with pure water.

In addition, from the decomposition performance when nitric acid vapor is added, phosphorus (
P) It can be inferred that it also has the effect of removing the resist after ion implantation treatment and the sidewall polymer removal effect after active ion etching of the aluminum (A1) wiring board.

The gas activation means described above is not limited to the ultraviolet lamp 4 as in the first embodiment and the plasma generation means equipped with microwave generation means as in the second embodiment, but also those activated by heating. But it's okay.

In the above embodiment, ozone or oxygen gas is activated and supplied to the substrate, but both ozone and oxygen gas may be supplied to the substrate.

In the first or second embodiment, ozone and acid-containing vapor or nitrogen dioxide are activated by irradiation with ultraviolet rays and then supplied to the surface of the substrate W. For example, ozone and acid-containing vapor or nitrogen dioxide Nitrogen may be supplied to the substrate surface and ultraviolet rays may be irradiated there. In short, any material that can treat the surface of the substrate W with ozone and oxygen activated by ultraviolet irradiation or with nitrogen dioxide may be used.

In the substrate surface treatment apparatus of the above embodiment, the surface treatment with ozone and acid-containing vapor or nitrogen dioxide and the cleaning treatment with pure water are performed in separate rooms, but the substrate surface treatment method of the present invention As explained in the experiment, image processing may be performed in the same room.

In the above embodiments, a single-wafer type surface treatment apparatus is shown, but the present invention is directed to a so-called hatch-2 surface treatment apparatus that uses a substrate boat to surface-treat a large number of substrates at once. can also be applied.

In addition to the above-mentioned examples, hydrofluoric acid (HF10H) is also used.

It is also possible to use aqueous solutions containing other acids, such as 0), sulfuric acid (H2S04 + H20), etc.

<Effects of the Invention> According to the substrate surface treatment method according to the invention of claim (1), the active acid group promotes the decomposition of oxygen radicals and ozone radicals, so that the ashing rate can be improved. Became.

Moreover, since active acid groups act on metal impurities in the resist and convert them into metal salts, metal impurities can be removed safely without the risk of explosion that occurs when using conventional ammonium nitrate. Ta.

Furthermore, since the decomposition and removal of the mobile and the conversion of metal impurities into metal salts are performed using acid-containing steam generated by ignition of the acid-containing aqueous solution, impurities are not mixed into the acid-containing aqueous solution. Even if the impurities are not supplied to the substrate surface, it has become possible to decompose and remove organic substances and convert metal impurities into metal salts extremely well.

Further, according to the substrate surface treatment method according to the invention of claim (2), the decomposition of organic matter by oxygen radicals and ozone radicals is promoted by the strong oxidizing action of nitric oxide radicals and nitrogen oxide radicals. Ashing speed can now be improved.

Moreover, since nitrogen monoxide radicals and nitrogen dioxide radicals act on metal impurities in the resist and convert them into metal salts, metal impurities can be removed safely without the risk of explosion that occurs when using conventional ammonium nitrate. It can now be removed.

Furthermore, phosphorus can also be decomposed by nitric oxide radicals and nitrogen dioxide radicals, which promotes the decomposition of resist after phosphorus (P) ion implantation, which is the most difficult process to remove.
It is highly possible to remove the sidewall polymer after dry etching the surface of the substrate on which the electrodes are wired, and it is useful because it can improve versatility.

Further, according to the method for surface treatment of a substrate according to the invention of claim (3), since metal salts are removed by washing with pure water, it is possible to reliably avoid residual metal salts and remove metal impurities without using a chemical solution. The cleaning process can be simplified and the treatment efficiency can be improved.

Further, according to the substrate surface treatment apparatus according to the invention of claim (4), the removal of the movable material, the conversion of metal impurities into metal salts, and the cleaning with pure water are performed in separate processing chambers. This prevents water droplets from adhering to the peripheral walls of the processing chamber due to scattering and being mixed into the acid-containing steam when the next acid-containing steam is supplied, and particles and impurities in the atmosphere are removed from the substrate. It is now possible to reliably prevent the product from adhering to the surface.

[Brief explanation of drawings]

The drawings show an embodiment of the substrate surface treatment method and apparatus according to the present invention. The first drawing is a schematic vertical sectional view showing the first embodiment of the substrate surface processing apparatus, and the second drawing shows a schematic longitudinal sectional view of the substrate surface processing apparatus according to the first embodiment. 3 is a schematic longitudinal sectional view showing a second embodiment of the substrate surface treatment apparatus; FIG. 4 is a schematic longitudinal sectional view showing the third embodiment of the substrate surface treatment apparatus; FIG. 5 and FIG. 6 are graphs showing experimental results of ashing speed. 1... Substrate surface treatment chamber 4... Ultraviolet lamp 8 as ultraviolet irradiation means...
Pure water cleaning processing chamber 15... Acid-containing steam generation means 28... Pure water supply nozzle 31 as a pure water supply means.
...Microwave generating means 32...Plasma generating means W...Substrate

Claims (4)

[Claims] (1) In a substrate surface treatment method in which active oxygen generated by activating at least one of ozone and oxygen is supplied to the substrate surface to decompose and remove organic matter on the substrate surface, prior to activation, ozone and oxygen are A method for surface treatment of a substrate, comprising mixing at least one side with acid-containing vapor generated by evaporation of an aqueous solution containing an acid. (2) In a substrate surface treatment method in which active oxygen generated by activating at least one of ozone and oxygen is supplied to the substrate surface to decompose and remove organic matter on the substrate surface, prior to activation, ozone and oxygen are At least on one side
A method for surface treatment of a substrate, comprising mixing at least one of nitrogen monoxide gas and nitrogen dioxide gas. (3) In the substrate surface treatment method according to claim (1) or (2), the substrate surface is cleaned by supplying pure water to the substrate after decomposing and removing organic substances on the substrate surface. surface treatment method. (4) a gas supply means for supplying at least one of ozone and oxygen; a gas activation means for activating at least one of the ozone and oxygen supplied by the gas supply means; In a substrate surface treatment apparatus equipped with a substrate surface treatment chamber that decomposes and removes organic matter adhering to the substrate surface by supplying active oxygen activated by a gas activation means to the surface of the substrate, an acid-containing vapor generating means for storing the aqueous solution in the gas activating means; an acid-containing vapor supplying means for supplying the acid-containing vapor generated by the acid-containing vapor generating means to the gas activation means; A substrate surface treatment apparatus characterized in that a deionized water cleaning treatment chamber is provided adjacent to the deionized water cleaning chamber equipped with deionized water supply means for supplying deionized water to the surface of the substrate.