JP2562578B2 - Ashing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ashing device.

[Prior Art] For example, ashing processing in semiconductor processing will be described as an example. Generally, in forming a fine pattern of a semiconductor integrated circuit, an organic polymer resist film formed by exposure and development is used as a mask, This is performed by etching the base film formed on the wafer, but the resist film used as the mask needs to be removed from the surface of the wafer after the etching process. The ashing process is performed as a process for removing the resist.

This ashing process is also used for resist stripping, cleaning of silicon wafers, masks, removal of ink, removal of solvent residues, and the like, and is suitable for performing dry cleaning processes in semiconductor processes.

FIG. 17 shows a conventional ashing device by ultraviolet irradiation, and the processing chamber 100 has a large number of wafers 101, 101.
.. are vertically arranged at predetermined intervals, and the processing chamber 10
Ultraviolet rays from the ultraviolet ray emitting tube 103 installed at the upper part of 0 are transparent windows 102 such as quartz provided on the upper surface of the processing chamber 100.
When it is irradiated with oxygen, the oxygen filled in the processing chamber 100 is excited to generate ozone.

Then, the ashing process is performed by causing the oxygen atom radicals generated from the ozone atmosphere to act on the wafer 101.

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional technique, there is a drawback that it takes time because of batch processing, and since it is merely an action in an ozone atmosphere, its resist ashing rate is 500 Å Only ~ 1500Å / min. However, in single-wafer processing of wafers suitable for large diameters, a processing speed of about 1 μm to 2 μm / min is usually required,
A conventional apparatus that irradiates with ultraviolet rays cannot sufficiently deal with single-wafer processing.

[Means for Solving the Problem] The present invention has been made in view of the above description, and includes a processing chamber that can be closed in an airtight manner, and a mounting table that is provided in the processing chamber to mount a wafer, And an outflow portion which is disposed at a predetermined distance from the wafer and outflows a reaction gas that generates oxygen radicals to the wafer,
In the ashing device having an opening for allowing the gas to flow out substantially uniformly to the wafer, the outflow section has a cooler for making the temperature of the gas flowing out of the outflow section 15 ° C to 50 ° C, and the mounting table. Is equipped with a heating device for heating the temperature of the mounted wafer to 200 ° C. to 350 ° C., and either the mounting table or the outflow section is movable up and down, and the mounting table during the ashing process. Alternatively, one of the outflow portions moves, the two approach each other, and the predetermined interval becomes 1 to 3 mm, and after the ashing process ends, either the mounting table or the outflow portion moves and both are separated from each other. A control device for controlling the movement of the mounting table or the outflow portion so as to be in a standby state is provided.

According to the ashing treatment of such a configuration, the temperature of the gas flowing out from the outflow portion is first cooled to 15 ° C. to 50 ° C., so that the reaction gas is, for example, an ozone-containing gas, as described in Examples below. In this case, a gas conforming to the decomposition half-life of ozone can be discharged to the wafer, and can be efficiently discharged to the wafer in a state where the oxygen radicals for ashing have a long life. On the other hand, the wafer temperature is
Since it is heated to 200 ° C to 350 ° C, the ashing process by the enzyme radical becomes faster.

Furthermore, under the control of the control device, either the mounting table or the outflow section moves during the ashing process, and both approach each other so that the distance between the wafer and the mounting table is 1 to 1.
Since the thickness is 3 mm, the balance between the influence of heat from the wafer and the moving time of oxygen radicals is good, as described later. Then, under the control of the control device, after the ashing process is completed, either the mounting table or the outflow unit moves,
Since the two are separated from each other and are in the standby state, the heat that the outflow portion receives from the mounting table can be relaxed. Therefore, even when the next wafer is immediately processed, the temperature of the gas does not unduly rise when the gas starts to flow from the outflow.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of an ashing processing system of one embodiment in which the present invention is applied to an ashing device, and FIG. 2 is another similar embodiment, showing an overall configuration including a wafer transfer mechanism. 3A and 3B are specific explanatory views of the electrostatic chuck in the wafer transfer mechanism, and FIG. 3A is a sectional view taken along the line II of FIG.
FIG. 5B is a cross-sectional view, FIG. 5B is a plan view thereof, FIG. 5A is a view for explaining the relationship between reaction and transfer by oxygen atom radicals, and FIGS. 5B and 5C are diffusion openings, respectively. FIG. 6 is a graph for explaining the relationship with the ashing state on the wafer surface, and FIG. 6 is a graph for explaining the relationship between the decomposition half-life of ozone and the temperature of the diffusion opening.

FIG. 7 is a graph for explaining the relationship between the gas flow rate and the ashing rate at a wafer surface temperature of 300 ° C., and FIG. 8 is a ashing rate for the gap between the diffusion plate and the wafer surface at a wafer surface temperature of 300 ° C. 9 is a graph for explaining the relationship between FIG. 10 and FIG. 10 is an explanatory view showing the relationship between the gas temperature and the resist removal rate, FIG. 10 (a), (b),
(C) and (d) are explanatory views of a specific example of the opening of the diffusion plate, and FIGS. 11 (a), (b), (c), and (d) are respectively views of the cooling structure of the gas in the injection part. Illustration of a specific example,
FIG. 12 (a) is an explanatory diagram of a method of rotating the gas injection unit, and FIG. 12 (b) is an explanatory diagram of rotating the wafer side.
13 is an illustration of the ashing effect when not rotating,
FIG. 14 is a block diagram of an embodiment of an ashing processing system for determining the end of ashing processing, and FIG. 15 is a graph of the concentration change of carbon dioxide in the exhaust gas,
FIG. 16 is a graph explaining the relationship between the ashing rate and the ozone concentration.

In FIG. 1, reference numeral 1 denotes an ashing processing system, which is an ashing device 2, an ozone + oxygen gas supply device 3 for supplying oxygen gas containing ozone to the ashing device 2, and an exhaust gas connected to the ashing device 2. Device 4,
A temperature controller 6 for controlling the temperature of the wafer by adjusting the heat generation state of the heating device 21a provided inside the wafer mounting table 21 arranged inside the ashing device 2 is provided.

The ozone + oxygen gas distribution device 3 is a gas flow controller.
3a, an ozone generator 3b, an enzyme supply source 3c,
The ozone concentration, the gas flow rate, and the gas pressure in the ashing device 2 (processing chamber) are controlled by the gas flow rate controller 3a and the ozone generator.
3b, the oxygen supply source 3c, and the exhaust device 4 are adjusted. In particular, the ozone concentration supplied to the ashing device 2 is adjusted by the ozone generator 3b and set to a predetermined value.

Further, the wafer mounting table 21 installed inside the ashing device 2 holds the wafer 28 by suction, and the temperature of the held wafer 28 is maintained at a predetermined value by the temperature controller 6.

On the upper part of the wafer 28, there is provided a cone-shaped injection part 22 for injecting ozone + oxygen gas from the surface thereof at an interval of about 0.5 to 20 mm, and the interval is raised and lowered. A predetermined value is set by raising the wafer mounting table 21 by the device 5. In this case, the injection unit 22 side may be moved up and down by a lifting device.

The injection unit 22 is made of SUS (stainless steel), Al, or the like, and has a disc-shaped diffusion plate 22a on the surface facing the wafer 28, which is parallel to the surface of the wafer 28. The loading and unloading of the wafer 28 is performed on the wafer mounting table 21.
Is lowered by the elevating device 5, the space between the diffusion plate portion 22 and the wafer 28 is enlarged, and the arm of the wafer transfer mechanism enters the space.

Now, as the ashing process, the wafer 28 on the wafer mounting table 21 is in the range of about 150 ° C. to 500 ° C., particularly 200 ° C. to 350 ° C.
It is performed by heating the wafer to a specific value of ° C, and the mixing ratio of ozone and oxygen by the generated ozone is adjusted by the ozone generator 3c. Then, oxygen gas containing ozone, for example, about 3 l to 15 l / min is fed into the chamber of the ashing device 2 which is the processing chamber. Ashing device 2 at this time
The gas pressure inside is set in the range of, for example, about 700 to 200 Torr.

Next, a process of loading / unloading the wafer 28 into / from the processing chamber of the ashing device 2 will be specifically described with reference to the ashing device 30 shown in FIG. The ashing device 30 is the ashing device 2 shown in FIG.
Unlike the above, it employs a configuration in which the ejection unit is moved up and down instead of moving the wafer mounting table up and down.

2, the ashing device 30 includes a processing chamber 20 and loader / unloader units 23a and 23b disposed on both sides thereof.
The loader / unloader units 23a and 23b are provided with belt transport mechanisms 24a and 24b, respectively, provided inside the loader / unloader units 23a and 23b.

Here, the loader / unloader section 23a and the belt transfer mechanism 24a side is the side for loading the wafer, and the loader / unloader section 23b and the belt transfer mechanism 24b are the side for loading the ashed wafers. It may be the side or the unloading side. Furthermore, only one of the loader / unloader unit may be provided.

Although not shown, the belt transport mechanisms 24a and 24b
Cartridges for accommodating and stacking wafers at predetermined intervals are installed at the opposite ends of the cartridges. By moving the cartridges up and down, the wafers before processing are sequentially transferred from the cartridges by the belt transfer mechanism 24a. It is sent to the loader / unloader unit 23a. Then, the ashed wafers are sequentially stacked and stored in the cartridge from the loader / unloader 23b through the belt transfer mechanism 24b.

The processing chamber 20 includes an Al chamber 29 coated with, for example, SUS, Al, or TiN, and a wafer mounting table 205 is installed in the center of the inside thereof. A gas injection unit 22a is supported on the upper side of the chamber 29 at a predetermined interval on the ceiling side of the chamber 29 so as to be vertically movable.

Here, the gas injection unit 22a has a conical shape including a disc-shaped diffusion plate 200 and a cone portion 203 connected thereto, and the cone portion 203 has an ozone + oxygen gas introduction pipe 2
02 is connected in the upper part, and the introduction pipe 202 is made of SUS.
It is enclosed and enclosed by a metal bellows 201 composed of, for example, so as to be movable up and down, and ozone and oxygen gas necessary for a reaction for ashing are introduced from this introduction pipe 202.

Reference numeral 204 denotes a cooler for ozone + oxygen gas that spirally covers the outer periphery of the cone 203, and is fixed to the cone 203 by heat conductive cement or the like. And the cooler 204, the refrigerant is introduced from below the cone section 203,
It is configured to be discharged at the apex and guided to the outside.

On the other hand, as shown in FIG. 4, the diffusion plate 200 has a slit (opening) 31 for blowing gas, and blows cooled ozone + oxygen gas uniformly to the surface of the wafer 28.

The diffusion plate 200 is supported by ball screw mechanisms 231, 232, 233 at three points at its peripheral portion at approximately 120 ° intervals and moves up and down. The driving is performed by the gears formed in the ball portions 234, 235, 236 (not shown in the figure) of the ball screw mechanisms 231, 232, 233 meshing with the worm gear engraved on the rotary shaft 236 of the motor 230.

The elevating mechanism of the ejection unit 22a may be configured to move straight up and down by using an air cylinder or the like instead of the combination of the motor, the ball screw, and the gear.

At the position shown in FIG. 2, the injection unit 22a is in the raised state (standby position), and the wafer 28 is loaded into or unloaded from the wafer mounting table 25. on the other hand,
As shown in FIG. 4, when the injection part 22a descends,
The blowout surface of the diffusion plate 200 is positioned at an interval (reaction position) of about 1 to 3 mm from the wafer surface, is positioned above the wafer mounting table 205, and supplies gas to the surface of the wafer 28 on the wafer mounting table 205. Become.

Inside the wafer mounting table 205, as shown in FIG. 2, a heating device 2 for heating the wafer mounting table 205 is provided.
06 is installed. In addition, in this example, in addition to the gas containing ozone, the flow of the gas from the diffusion plate 200 does not affect the chamber 29, and an N ₂ gas is introduced into the chamber 29 so as to cover the gas. I have.

Now, 26a is an adsorption chunk portion supported on the tip side of the transfer arm 25a, and 10a is an electrostatic chuck supported on the adsorption chuck portion 26a that moves up and down with respect to the main body of the adsorption chuck portion 26a. Is. The figure shows a state in which the wafer 28 is attracted to the electrostatic chuck 10a.

The transfer arm 25a has the other end fixed to a support member 27a arranged in the loader / unloader unit 23a, and moves back and forth between the loader / unloader unit 23a and the wafer mounting table 205 of the processing chamber 20. Is the arm of. The transfer arm 25a may be composed of a magnetic cylinder, an air cylinder, or the like.

Here, the reason for using the frog leg transport mechanism is
The transport mechanism can be miniaturized and, for example, a loader /
If an ashing processing chamber is provided on both sides of the unloader section and the support member 27a of the frog leg transport mechanism is rotatable,
Since the frog-leg transfer mechanism can be directed to the desired chamber side, there is an advantage that the wafer can be selectively transferred or unloaded to the chambers on both sides.

In addition, a belt transport mechanism is installed in the middle of the chamber to loader /
If the unloader section is provided linearly and the supporting member 27a is made rotatable, it is also possible to pick up a wafer from the belt transfer mechanism side, reverse it, and transfer it to the chamber side. Even in such a case, the whole apparatus can be realized as a small one.

Now, also in the loader / unloader section 23b, a transfer arm 25b of a similar frog leg transfer mechanism type in a symmetrical relationship, a suction chuck 26b, its electrostatic chuck 10b, and a support 27b.
Are provided respectively. In FIG. 2, the processed wafer 28 is attracted to the electrostatic chuck 10b.

Therefore, the wafer mounting table 205 has a hole 220 for negative pressure suction.
Are provided in plural. Further, in order to exhaust the exhaust gas after the reaction as evenly as possible around the wafer mounting table 205, a plurality of exhaust openings 21 annularly provided at predetermined intervals are provided.
Are provided on the ring plate 222, and the ring plate 222 is fitted on the outer peripheral side of the wafer mounting table 205 at a position slightly lower than the upper surface of the wafer mounting table 205.

Reference numerals 221 and 223 denote exhaust pipes for exhausting the chamber 29, respectively, which are connected to the pump of the exhaust device 4. Although two or more of these exhaust pipes 221 and 223 are provided so as to perform uniform exhaust, one may be provided. 224 and 225 are gate pulps, respectively.

Further, 226 and 227 are conveyor belts of the belt conveyor mechanisms 24a and 26b, respectively, and 217 and 218 are loader / unloader section 23.
These are chambers a and 23b. The chambers 217 and 218 of the loader / unloader sections 23a and 23b here can also be exhausted by a vacuum pump in accordance with the internal pressure of the chamber 29.

Next, the operation of this device will be described.
It is assumed that a is set to the ascending state, held at the standby position, and the valve of the gas inlet 202 is closed.

When gate valves 224 and 225 are closed, chamber 2
Inside 01 is in a reduced pressure state close to normal pressure.

In the case of raising and lowering the wafer setting table 21 in FIG. 1, the elevating device 5 is driven to lower the wafer apparatus table 21 and set it to the standby position. However, the relationship between the loader / unloader section is the same as that shown in FIG.

Now, in this state, the gate valve 224 is opened to lower the electrostatic chuck 10a of the wafer 28 loaded into the loader / unloader unit 23a from the belt transfer mechanism 24a, and a voltage is applied to the wafer 28 to move the suction chuck 10a. Raise the wafer 2
Pick up 8. Next, extend the transfer arm 25a,
The attracted wafer 28 is transferred from the loader / unloader unit 23a to the processing chamber 20, positioned on the wafer mounting table 205 to lower the electrostatic chuck 10a, and the applied voltage is lowered or reduced to zero to drop the wafer 28 by its own weight. Let Then, the wafer is mounted on the wafer mounting table 205 by attracting the wafer to the wafer mounting table 205 under a negative pressure.

Next, after raising the electrostatic chuck 10a, the transfer arm 2
5a is reduced and the suction 26a is returned to the loader / unloader unit 23a. After the suction chuck 26a moves to the loader / unloader section, the gate valve 224 is closed, the injection section 22a is lowered to the reaction position, and the diffusion plate 200 is set at the reaction position shown in FIG.

In the case of the ashing device 2 shown in FIG. 1, the wafer 28 is set at the reaction position by raising the wafer mounting table 21 by the raising device 5.

Here, the temperature of the wafer 28 is monitored, and when the temperature reaches a predetermined ashing processing temperature, the valve of the gas inlet 202 is opened immediately, and ozone + oxygen gas is applied to the surface of the wafer 28 installed on the wafer mounting table 205. Spray evenly.

As a result, the resist of the wafer 28 is oxidized, and gases such as carbon dioxide, carbon monoxide, and water generated by this chemical reaction are exhausted by the exhaust device 4 through the exhaust pipes 221 and 223 together with oxygen after the reaction. .

When the ashing process is completed (for example, 1 min to several mi
In (n), the valve of the gas inlet 202 is closed, and the diffusion plate 200 is raised to the standby position (in FIG.
5 down to the standby position) and gate valve 2
25, the transfer arm 25b is extended from the loader / unloader section 23b to the processing chamber 20, the suction chuck 26b is moved onto the wafer mounting table 205, and the electrostatic chuck 10b on the tip side thereof is lowered to Voltage. Then, the ashed wafer 28 is adsorbed on the wafer mounting table 205 and the electrostatic chuck 10a is lifted and picked up. After raising the electrostatic chuck 10a, the transfer arm 25b is reduced and the processed wafer 28 is carried out to the loader / unloader unit 23b.

The wafer thus unloaded to the loader / unloader section 23b is transferred from the loader / unloader section 23b to the belt transfer mechanism 24b and stored in the cartridge, and the ashed wafer is taken out of the apparatus.

Here, the electrode portion of the electrostatic chuck will be described. Since the electrostatic chucks 10a and 10b have the same configuration in FIG. 1, the electrostatic chuck 10a and 10b will be described below.
The electrode section is referred to as an electrostatic chuck electrode section 17.

As shown in FIGS. 3 (a) and 3 (b), the electrode part 17 of the electrostatic chuck 10 for sucking the wafer has a semi-circular metal shape or the like in which semi-circular depressions 11a and 12a are provided inside the back surface. Is formed by the first and second electrodes 11 and 12 made of the conductor.

By the way, in the case of automatically carrying a wafer, it is often overwhelmingly required to suck the wafer from the front surface side and carry it. Therefore, the electrode portion 17 is attached as the electrostatic adsorption chuck so that the adsorption surface is on the lower side in a state of being suspended from the wafer transfer device.

By adopting the above-mentioned configuration, the processing surface of the wafer 28 is always directed upward in the transportation and placement of the wafer 28. Therefore, while satisfying the above requirements, each of these operations can be performed at high speed. It can be executed, and high-speed movement into the processing chamber 20 is possible.

Moreover, since the wafer 28 is adsorbed and held by the electrostatic chuck, the holding force is strong and even if the wafer 28 is transferred at high speed, the positional deviation does not occur and the wafer 28 can be accurately held and transferred.

The first and second electrodes 11 and 12 are thinly coated with the insulating films 13 and 14 and are arranged with a predetermined gap D therebetween. The gap D may be a void, or an insulator may be inserted depending on the structure. The selection may be determined from the overall structure of the electrostatic chuck 10.

As shown in FIG. 3 (a), the first and second electrodes 11 and 12 are recessed in the inside (depth h ), The portions of this width w are the suction portions 15 and 16 of the semiconductor wafer. On the respective surfaces of the adsorption parts 15 and 16, insulating films 15a and 16a are provided as layers coated as a part of the insulating films 13 and 14, and the film thickness of these insulating films 15a and 16a is the wafer. It is determined by the suction power of the. The thicknesses of the insulating films 13 and 14 other than this portion are determined in consideration of the fact that this electrode portion has a sufficient breakdown voltage when it contacts another metal portion or the like.

Then, as described above, the electrodes of the electrostatic chuck 10 are configured as the first electrode 11 and the second electrode 12, and each of these electrodes is the third electrode.
As shown in the figure, since the two facing surfaces contacting the wafer 28 are arranged side by side, the wafer 28 is firmly held,
Even if it is conveyed at high speed, the positional deviation does not occur.

Next, the ashing reaction will be described in detail with reference to FIG. 4, FIG. 5 (a) and FIG.

As shown in FIG. 4, in the ashing process, the ozone supplied from the ozone + oxygen gas supply device 3 is in the following thermal equilibrium state inside the injection part 22a (or the same for the injection part 22 and below). ing.

O ₃ O ₂ + O In this case, the lifetime of the oxygen atom radical O obtained by the decomposition of ozone depends on the temperature, and as shown in FIG.
In the vicinity, it is very long. However, when the temperature rises, its life is rapidly shortened.

On the other hand, the ashing process using oxygen atom radicals is an oxygen chemical reaction, which becomes faster as the temperature rises.
Moreover, it takes some time for the oxygen atom radicals to act on the wafer surface. Therefore, how to efficiently supply oxygen atom radicals to the surface of the wafer 28 is an important problem.

The ashing process proposed in this embodiment efficiently supplies oxygen atom radicals to the surface of the wafer 28 and quickly removes reaction products from the wafer surface. In the processing having a synergistic effect with the supply of atomic radicals, the ashing speed can be increased to a processing speed suitable for single-wafer processing.

Therefore, while supplying oxygen atom radicals,
It is important to create a suitable gas flow space to eliminate reaction products.

In this embodiment, this gas flow space is formed between the wafer mounting table 205 and the diffusion plate 200 of the injection table 22a as shown in FIG.

The distance between the wafer mounting table 205 and the diffusion plate 200 is relatively small, and if the heating temperature of the wafer 28 is set high, it is necessary to be about 0.5 to several mm with respect to the wafer surface. Is. Further, the outermost opening position (position of the slit 31a in FIG. 4) of the injected gas is determined so as to blow out by 5 mm or more due to the outer shape of the wafer 28.

By blowing gas to the outside by the outer shape of the wafer 28 in this way, a negative pressure region due to the gas flow is formed outside the outer peripheral portion of the wafer to transport the generated gas from the outer side of the central portion to the outer side of the outer peripheral portion of the wafer faster, It is what is discharged.

As a result, there is an effect that the supply of ozone and the contact of oxygen atom radicals to the wafer surface are facilitated, and the oxidation reaction can be promoted.

Now, the ozone + oxygen cooled by the cooler 204 is
For example, it is cooled to 25 to 50 ° C. Therefore, the rate at which oxygen atom radicals are retained inside the cone 203 of the injection unit 22a increases.

Then, ozone (O ₃ , O ₂ + O) and oxygen O ₂ are diffused in the diffusion plate 200.
Although it is exposed to a high temperature atmosphere as soon as it is ejected from the opening of the wafer, it reaches the wafer surface together with oxygen before its life expires, and the film deposited on the wafer surface is ashed (ashed, that is, oxidized). And removed from the wafer surface).

As shown in FIG. 5 (a), carbon dioxide, carbon monoxide, and vaporized water generated by ashing rise simultaneously and are ejected from the diffusion plate 200 as oxygen (O ₂ ) and ozone (O ₃ ) that is not a radical. ), Is removed from its surface, and is discharged from the exhaust opening 219 of the ring plate 222 to the exhaust pipe 221,
It is carried to 223 and is sequentially exhausted by 4 to the exhaust device.

Therefore, the surface of the wafer 28 can create an environment that is always exposed to oxygen atom radicals. In FIG. 5A, 28a is a surface portion of the wafer 28, 28b is a resist portion deposited on the wafer 28, and an arrow 32 is ozone + oxygen from the diffusion plate 200. The flow of gas is shown.

Here, the wafer temperature is set to 300 ° C. and the wafer mounting table 205
The ashing speed with respect to the gas flow rate in the standard state (normal temperature and normal pressure conditions) at the opening of the diffusion plate 200 is measured using the gap (gap) between the surface of the diffusion plate 200 and the diffusion plate 200 (on the injection port side) as a parameter. And as you can see in Figure 7,
For a 6 ″ wafer, particularly high-speed ashing treatment is possible in the range of about 2 sl to 40 sl (sl: normal temperature, flow rate converted to normal pressure), and the gradual saturation starts from about 40 sl / min.

In order to correspond this flow rate to a general wafer diameter, when converted to a flow rate per unit area of the wafer, 0.01 to 0.25 sl
/ min · cm ² .

Also, when the relationship between the ashing speed and the gap between the diffusion plate and the wafer surface was measured with the gas flow rate as a parameter at a wafer surface temperature of 300 ° C., as shown in FIG. Irrespective of the above, a characteristic is shown in which the value converges toward a constant value.

In other words, the gap length between the diffuser and the wafer surface is 20
By setting it to less than mm, the ashing speed can be controlled by the gas injection flow rate. Moreover, the ashing speed in that case is faster than in the past. Therefore, it is possible to perform the assig processing more appropriately and faster than in the conventional case.

Further, regarding the relationship between the temperature of the gas ejected from the diffusion plate 200 and the resist removal rate, a gap between the wafer and the wafer (from the surface of the wafer 28 mounted on the wafer mounting table 205 to the diffusion plate 2
If the reaction time is set to 2 min and the reaction time is set to 1 min, and the characteristics are measured with the gas flow rate as a parameter, as shown in FIG. Understand that it is difficult to remove.

Therefore, when the wafer side is heated to 200 ° C or higher to carry out the reaction, the injected gas (ozone + oxygen) is
Cooling is preferred. And as a particularly preferable range, the outflow gas temperature of the diffusion plate 200 is 15 to 50 ° C.

This is in agreement with the characteristic of ozone decomposition half-life, which was seen in FIG.

Further, as shown in FIG. 16, when the relationship between the ashing rate and the ozone concentration is investigated, it is found that the ashing rate increases as the ozone concentration increases.
However, at about 10% by weight or more, it shifts to the saturation direction. Note that this characteristic is for a 6 "wafer and its temperature is 25
0 ° C, gas flow rate 5 sl / min, chamber pressure 70
It is measured for a resist cured by plasma irradiation in the etching process as about 0 Torr.

As can be understood from the respective characteristic graphs, a flowing gas space is formed above the wafer, and a gas containing ozone is jetted or discharged from the wafer, thereby forming a fluid gas space.
Ashing processing of several μm / min is possible.

In this regard, in the conventional ashing method by UV irradiation shown in FIG. 17 described above, it takes time because of batch processing, and since it is an action in a simple ozone atmosphere, its resist ashing rate Is 500Å ~ 1
It is only about 500Å / min.

Therefore, in the above-described embodiment, the processing speed of the ashing process itself is remarkably improved, so that ashing suitable for single-wafer processing and large-diameter wafer processing is realized.

Further, unlike the above-mentioned conventional technique, since the ashing process does not use ultraviolet rays, the device can be downsized and the manufacturing cost can be kept low.

FIGS. 10A to 10D are explanatory views of a specific example of the diffusion plate 200 that uniformly ejects ozone and oxygen onto the surface of the wafer.

FIG. 10 (a) shows four arc-shaped slits 311 formed in a circular shape and a concentric shape. The grooves may be perpendicular to the wafer, but the gas flow to the outer side. In order to form the gas, the slots are formed obliquely so that the gas flows out toward the outside.

In FIG. 10 (b), holes 312 are provided at the center of the circle, and slits 313 are arranged radially to the holes.
In FIG. 10 (c), holes 314 are provided radially, and each hole 314 is slightly larger outward. FIG. 10 (d)
A sintered alloy 200a is used as the diffusion plate 200,
The entire surface of the plate is tiled and has porous holes 315 uniformly.

In FIG. 10 (e), the injection port 316 is formed in a spiral shape, and in FIG. 10 (f), the small hole 317 is simply formed in a circular shape.

Here, in order to study the effect of evenly outflowing the gas from the diffusion plate 200, the holes are sparsely formed as shown in FIG. 10 (f) and the sintered alloy 200a of FIG. 10 (d) is used. Compared with the case where the porous pores are evenly distributed,
In the former case, as shown in FIG. 5 (b), the resist portion 28b is ashed corresponding to the gas flow 32 (arrow), and the ashing can be wavy and uneven. On the other hand, when the porous pores are uniformly distributed as in the latter sintered alloy, uniform ashing is performed as shown in FIG. 5 (c).

Therefore, it is preferable to provide a gas injection port so that the gas becomes more uniform. This has the advantage that the processing time until complete ashing can be shortened, and the wafer is hardly damaged even if ozone is applied to the wafer surface. . In FIGS. 5 (b) and 5 (c), the portion shown by the dotted line is the surface position (thickness) of the resist before ashing.

As shown in the characteristic graphs of FIG. 6 and the like, it is preferable that the gas (ozone + oxygen) be injected from the diffusion plate while being cooled as much as possible.

By the way, the distance between the wafer mounting table 205 and the diffusion plate 200 is
Relatively close. On the other hand, the wafer mounting table 205 and the wafer 28
It is heated to the reaction temperature by the heating device 20. Therefore, the diffusion plate 200 is heated by the radiant heat or the like emitted from the wafer device table 205 and the wafer 28 side, and the temperature of the surface of the diffusion plate 200 tends to rise.

As a result, the temperature of the gas rises near the injection port and the amount of oxygen atom radicals supplied to the wafer surface decreases. In particular, if the gap is large, the effect of heat will be somewhat reduced, but since the oxygen atom radicals will take longer to move, the oxygen atom radicals that will reach the end of their life by the time they reach the surface of the wafer 28, including the effect of temperature rise. Also increases. Also,
If the gap is too small, the temperature of the surface of the diffusion plate 200 tends to be higher due to the direct influence of the temperature on the wafer mounting table 205 side. In addition, the temperature rise value differs depending on the flow rate of the gas blown from the diffusion plate 200.

For this reason, there are more optimal conditions in the ashing process. In the reaction mode shown in FIG. 4, when the wafer temperature is about 200 ° C. to 350 ° C., the optimum gap is about 1 to 3 mm, and the gas flow rate is room temperature and atmospheric pressure. For 6 ″ wafer, 5.5-17 sl /
It is about min. Therefore, when converted into a flow rate per unit surface area of the wafer, it becomes 0.03 to 0.1 sl / min.

In addition, carbon dioxide reacted by oxygen atom radicals,
Considering that reaction products such as carbon monoxide and water are carried out from the wafer surface mainly by oxygen (O ₂ ),
There is a more efficient weight percent of ozone and oxygen.

That is, if the amount of ozone (O ₃ ) is small, the rate of ashing (the rate of decrease of the unit time with respect to the film thickness) becomes low, resulting in poor uniformity and poor efficiency. On the other hand, when the amount of ozone (O ₃ ) is large and the amount of oxygen (O ₂ ) is small, the rate is high, but stagnation of reaction products occurs on the wafer surface and the reaction rate decreases.

Taking these points into consideration, the optimum weight% of ozone is about 3 to 5% by weight.

Now, a specific example of the cooling structure of the injection unit that injects the gas with the lowest possible temperature, together with the uniform gas injection in consideration of the above, will be described below.

The injection section 22b shown in FIG. 11 (a) is provided with a cooling pipe 204a made of a coiled pipe also on the inner side of the diffusion plate 200,
It communicates with 4, which is a meandering crawler that avoids the slit 318 for gas injection.

The injection unit 22b shown in FIG. 11 (b) has a cooler 204b, which is a flexible tube, provided on the outer surface (wafer 28 side) of the diffusion plate 200 and communicates with the cooler 204. Similarly, it is meandering and crawling in a state where the slit 318 is avoided. In this case, in FIGS. 11A and 11B, the cooler 204 arranged around the cone portion 203 may not be provided.

By doing so, even if there is heat radiation from the wafer mounting table 205 side, the surface of the diffusion plate 200 can be controlled to a low state, the temperature of the gas to be jetted can be suppressed, and under more free conditions. It is possible to perform efficient ashing processing.

The injection portion 22c shown in FIGS. 11 (c) and (d) is not a conical shape but a cylindrical shape, and has a dome 22d for gas diffusion at an upper portion. Diffusion plate with slit after gas is diffused in advance
311 or sintered alloy 200a is sent to the diffusion plate.

In particular, in FIG. 11 (c), a snake-shaped cooler 204c is built in the inside of the cylindrical portion, and in FIG. 11 (d), a ball 200b having a relatively large diameter is provided in order to make the injection uniform. It is filled inside. It should be noted that these do not have a cooler provided outside, but it goes without saying that a cooling pipe may be provided outside the cylindrical portion, as in FIGS. 11 (a) and 11 (b).

Next, an example will be described in which the gas is blown more uniformly onto the wafer surface, and the wafer and the diffusion plate are relatively rotated for the purpose of promoting the oxidation reaction.

The injection unit 33 shown in FIG. 12 (a) is composed of a diffusion tube 34 and a gas introduction tube 35 communicating with the central portion thereof. The gas introduction tube 36 is rotatable on the ceiling side of the chamber 29 so as to be rotatable. It is pivoted.

Here, both ends of the diffusion tube 34 are closed, and a plurality of injection ports 36, 36, ... For diffusing and blowing the gas are arranged at predetermined intervals on the opposing surface side of the wafer 28. . In addition, injection ports 37 and 38 are provided at positions opposite to each other on the end side surfaces (the side perpendicular to the wafer surface), and when the gas is injected from these, the diffusion pipe 34 is formed.
Rotates on its own by the reaction. In addition, the gas injected from both ends is located outside the outer periphery of the wafer 28 and also serves to transport the ashing product to the outside. Instead of the injection port 36, a porous material may be used on the lower surface of the diffusion tube 34.

In the example shown in FIG. 12 (b), the wafer mounting table 205 is axially supported, and this shaft is pivotally supported on the floor surface side of the chamber 29.
In this example, a motor is used to rotate the wafer mounting table 205. The jetting part 22a may be tubular or rod-shaped as shown in FIG. 12 (a).

Comparing the effects of such a rotation operation and those not, a rotation method is used.
The processing time for removing the resist from the wafer is shortened. That is, comparing this with the case of not rotating in the same processing time as the rotating method, as shown in FIG. 13, when not rotating, the resist is eliminated in the central portion of the wafer, In the peripheral portion, there is a phenomenon that the resist remaining portion 40 is not removed and remains as a linear pattern. Note that this was performed on a 6 ″ wafer.

From this, it can be said that the rotation processing is effective in shortening the ashing processing time, and is also effective for the ashing processing in the peripheral part except the central part of the wafer. In particular, it is effective for a large-diameter wafer such as 6 ″ to 10 ″. In the case of FIG. 12 (a), since the gas injection unit is automatically rotated, there is an advantage that the apparatus is simple, but the gas must be injected more. On the other hand, in the case of FIG. 12 (b), since the wafer mounting table 205 side is rotated, the apparatus is somewhat complicated, but there is an advantage that the gas injection amount is small.

Next, detection of the end of the ashing process related to the overall control when performing the single-wafer process will be described.

As shown in FIG. 14, the gas analyzer 7 is interposed before the exhaust device 4 when the ashing process is completed. Then, the detection symbol corresponding to the carbon dioxide (CO ₂ ) concentration obtained from the gas analyzer 7 is input to the end point determination / control device 8 to monitor the carbon dioxide concentration, and the concentration becomes zero or less than a predetermined value. When it becomes, it is determined that the ashing process is completed.

Here, the end point determination / control device 8 has a comparator and a controller constituted by a microprocessor inside, and receives an ashing processing end point detection signal from a comparator that receives an output of the gas analyzer 7, and performs ashing. Device 2, gas introduction pipe (gas introduction pipe 202 in FIG. 2)
Gas pulp and lifting device 5 (see FIG. 2 motor).
230) Control.

That is, when the end point is detected, a signal for closing the valve of the gas introduction pipe is generated, and control for stopping gas injection is performed. Simultaneously with this, a descending signal of the wafer mounting table 21 is sent to the elevating device 5 and controlled to increase the gap between the diffusion plate and the wafer apparatus table so that the wafer apparatus table (see FIG. 2). In the example, the injection unit) is moved to the standby position.

At the time of receiving the standby position setting signal from the lifting device 5, the end point determination / control device 8 causes the gate valve (see FIG. 2) communicating with the rotor / unloader unit on the wafer transfer side (see the loader / unloader unit 23b in FIG. 2). The control signal for opening the gate valve 225) is sent to the ashing device 2. Upon receiving this signal, the ashing apparatus 2 releases its gate valve to make the chamber (see the chamber 29 in FIG. 2) communicate with the loader / unloader unit on the wafer unloading side.

Next, the end point determination / control device 8 sends a signal to the ashing device 2 to operate the unloading side wafer handling mechanism (transport arm 25b in FIG. 2). The ashing device 2 is
In response to this signal, the suction and holding of the wafer 28 is released and the wafer handling mechanism is operated to pick up the wafer 28 on the wafer mounting table 21 (see the wafer mounting table 205 in FIG. 2) and carry it out of the chamber. To do. Then, the belt unloading mechanism for the wafer (see the belt transport mechanism 24b in FIG. 2)
Hand over to

On the other hand, when the unloading-side wafer handling mechanism completes the unloading of the wafer from the chamber, the ashing device 2
Sends its completion signal to the end point determination / control device 8.
At the time of receiving this completion signal, the end point determination / control device 8 sends to the ashing device 2 a control signal for closing the gate valve (gate valve 225) communicating with the loader / unloader unit on the wafer unloading side. , The valve is closed to disconnect the loader / unloader unit on the wafer unloading side. Next, a valve (second valve) communicating with the loader / unloader section (see loader / unloader section 23a in FIG. 2) on the wafer loading side.
A control signal for releasing the valve 224) shown in the figure is sent to the ashing device 2. The ashing device 2 releases its valve to make the chamber communicate with the loader / unloader unit.

Next, the end point determination / control device 8 sends a signal to the ashing device 2 for operating the loading-side wafer handling mechanism (transport arm 25a in FIG. 2). The ashing device 2 is
The wafer handling mechanism on the loading side is operated to pick up the wafer 28 from the belt transport mechanism (see the belt transport mechanism 24a in FIG. 2), which is loaded into the chamber and placed on the wafer mounting table 21 (wafer mounting table 205). To install. Then, the wafer mounting table 21 holds the wafer by suction. When the completion of wafer loading by the wafer handling mechanism on the loading side is completed and the arm or the like returns to the loader / unload mode, the ashing device 2 sends a loading completion signal to the end point determination / control device 8.

Upon receiving this signal, the end point determination / control device 8 sends a control signal for closing the valve communicating with the loader / unloader unit on the wafer loading side to the ashing device 2 and also sends the wafer mounting table 21 to the elevating device 5. (A descending signal of the injection unit 22 in FIG. 2).

Ashing device 2 receiving control signal to close valve
Block the valve, load the chamber and loader / loader
Separate from the unloader section. On the other hand, the elevating device 5 that has received the lift signal of the wafer mounting table 21 controls the wafer mounting table 21 to set the gap between the diffusion plate and the wafer mounting table to a gap necessary for the reaction (set to the reaction position). ).

At the time of receiving the reaction position setting signal from the lifting device 5, the end point determination / control device 8 generates a signal for opening the valve of the gas introduction pipe, and controls to start the gas injection. Then, the exhaust gas is monitored to start an end point determination process.

FIG. 15 is a graph showing a change in the concentration of carbon dioxide in the exhaust gas in this case.

As shown in the figure, the concentration of carbon dioxide gradually increases to a constant value as the ashing time elapses, and when the temperature of the gap of the oxidation reaction space and the temperature of the wafer and the gas flow rate are in the optimum range, 6 ″ The ashing process is completed within 1 minute for the wafer and within 1 to several minutes depending on the temperature of the gap and the wafer and the gas flow rate, and the concentration thereof rapidly approaches zero at this point. go.

Therefore, the end point determination of the ashing process can be detected by comparing and detecting the carbon dioxide concentration with a comparator based on zero or a constant value close to zero.

Incidentally, the detection gas of the final determination is not limited to carbon dioxide, but water and carbon monoxide have substantially the same characteristics. Therefore, the end point of the ashing process may be determined by measuring the amount of the gas.

On the other hand, as seen in this graph, the tendency that the gas generation starts to decrease from a constant value and becomes zero becomes almost the same characteristic in the exhaust gas. Therefore,
By detecting the change point A of this characteristic or the point B reduced to a certain value or less, the end point time thereof can be predicted.

The detection of the decreased point B may be performed by changing the reference value of the comparator, and the prediction end point can be determined by adding a certain time to the detection point.

Further, the detection of the change point A can be easily realized by combining a differentiating circuit or a peak detecting circuit and a comparator.

By the way, when detecting that the amount of exhaust gas is equal to or less than the predetermined value, the gas analyzer 7 and the determination unit of the end determination / control device 8 shown in FIG. Detector (gas sensor) that detects a value or a specific range
And an end point determination circuit (a determination process by a comparator, a logic circuit, or a microprocessor) that determines the end time point from the detection signal is sufficient. On the other hand, when detecting the change point of the exhaust gas, a measuring instrument that generates a signal corresponding to the amount of the specific gas as a detection signal, a sensor, or a sensor that detects only the change state is required.

As described above, in the embodiment, the diffusion plate is arranged on the upper part of the wafer. This is because the wafer is on the upper side, and the gas can be hung from the lower side to the upper side of the diffusion plate. May be blown up, and further, these may be arranged with a gap at a predetermined interval in the lateral direction. In short, these arrangement relations are not limited to the upper and lower sides, but may be any arrangement as long as they face each other at a fixed interval.

In the embodiment, in order to load the wafer, either the wafer mounting table or the diffusion plate is relatively moved to secure the insertion space for the handling arm. However, even if both are vertically moved at the same time. Good.

Further, in the embodiment, the case of injecting the gas is described, but this may be performed by simply flowing out the gas of ozone and oxygen into the reaction space. Therefore, it is enough that it simply flows out.

Further, in the embodiment, the structure of the injection portion is a conical shape,
Cylindrical ones and tubular ones are fried, but for example, a disc-shaped one or a nozzle-like one may be used to inject or flow out ozone + gas, and various shapes may be used. Things are applicable.

Therefore, the flat plate portion in this specification includes a flat portion formed by rotating a rod-shaped object so that its trajectory forms an even gas flow with the flat plate.

The cooler may be adopted depending on the reaction conditions and is not always necessary. In addition, the structure cites a case in which a refrigerant flows through a pipe. In this case, a double structure space in which a refrigerant flows directly may be provided in an injection unit, and various liquids and gases including water and cooling air may be provided. Further, cooling may be performed by a cooling metal or the like utilizing the Peltier effect or the like.

As the diffusion plate, an example using a sintered alloy is given as one having uniform porous holes, but the porous material is not limited to metal, and various materials such as ceramics can be used. Of course.

Furthermore, the higher the temperature of the wafer during the ashing process, the faster the oxidation reaction speed, but this is related to the speed of loading / unloading the wafer, and is not necessarily set to a high value. Is also good. Furthermore, the reaction can be carried out at about room temperature or lower, even in view of the lifetime of ozone. Further, if the weight% of ozone can be set to a high value, a value lower than room temperature is possible. However, in the current apparatus, it is considered that the limit of the ozone generation weight% is around 10 to 13%.

In the examples, the resist is mainly described as the ashing target, but such an ashing treatment can be applied to various things such as ink removal and solvent removal, and what is possible if it can be removed by oxidation? It may be anything.

Although the case where ozone gas contains oxygen gas is mentioned, the gas is not limited to oxygen, and various inert gases such as N ₂ , Ar, Ne, etc. may be contained with ozone. Can be used.

As can be understood from the above description of the embodiment, in the above embodiment, a rotating ozone outflow portion is provided at a position facing the wafer at a predetermined interval, and the wafer is provided between the wafer and the rotating ozone outflow portion. Form a gas flow space of ozone + oxygen parallel to the surface and uniform. As a result, new ozone is continuously supplied to the wafer surface to promote the oxidation chemical reaction between the oxygen atom radicals and the film deposited on the wafer, as well as carbon dioxide generated after the reaction due to non-radical oxygen (O ₂ ). Carbon monoxide, water, etc. can be moved and discharged from the wafer surface in the vaporized state.

As a result, it is possible to efficiently expose the reaction surface of the film deposited on the wafer, for example, the film of an organic substance, to the oxygen atom radicals that perform an extremely strong oxidizing action.

Therefore, high-speed ashing processing can be performed, and an ashing apparatus suitable for single-wafer processing can be realized.

Therefore, in the above embodiment, the loader / unloader chamber capable of vacuuming is provided adjacent to the gate valve of the processing chamber, and further, the gate valve is opened while the loader / unloader chamber is evacuated. The wafer is transported, and the transportation at this time is performed such that the processing surface of the semiconductor wafer always faces upward. Therefore, from these points as well, the time required for the ashing processing can be shortened.

Moreover, unlike the conventional mechanical sandwiching means, since the semiconductor wafer is attracted by the electrostatic chuck, the holding force is strong, and the transfer is performed in the vacuum exhausted state. It enables high-speed transportation without any problems.

Further, since the electrostatic chuck has two electrodes and two electrodes are arranged on the opposing surface in contact with the semiconductor wafer, the semiconductor wafer is more firmly held. Therefore, even if the sheet is conveyed at a high speed, the positional deviation does not occur during the conveyance.

EFFECTS OF THE INVENTION According to the present invention, during the ashing process, the distance between the outflow portion for outflowing the gas generating oxygen radicals and the wafer is set to 1 to 3 mm by the control of the controller, and Since the ashing process can be performed with the outflowing gas temperature set to 15 ° C to 50 ° C and the wafer temperature set to 200 ° C to 350 ° C, the ashing process can be performed efficiently before the life of oxygen radicals reaches the wafer. Can be made to flow out, and the oxidation chemical reaction by oxygen radicals can be promoted. Therefore, faster ashing processing than before is possible. It is also possible to control the ashing speed by adjusting the gas injection amount.
After the ashing process is completed, the control unit separates the outflow unit from the mounting table and puts them in a standby state, so that the heat received by the outflow unit from the mounting table can be relaxed. Therefore, even when the next wafer is immediately processed, the temperature of the gas which has started to flow out from the outflow portion does not unduly rise. Therefore, since the desired ashing process can be performed from the beginning of the process with the gas at a low temperature, the ashing process can be performed at a high speed also from this point.

[Brief description of drawings]

FIG. 1 is a block diagram of an ashing processing system of an embodiment to which the present invention is applied, and FIG. 2 is another similar embodiment, which is a sectional view showing the overall structure including a wafer transfer mechanism. FIGS. 3A and 3B are specific explanatory views of the electrostatic chuck in the wafer transfer mechanism. FIG. 3A is a sectional view taken along line II of FIG. 3B, and FIG. A plan view thereof, FIG. 4 is an enlarged explanatory view of the reaction portion thereof, FIG. 5 (a) is a view explaining a relationship between a reaction by oxygen atom radicals and migration, and FIGS. 5 (b) and (c) are FIG. 6 is a graph for explaining the relationship between the diffusion opening and the ashing state on the wafer surface, and FIG. 6 is a graph for explaining the relationship between the decomposition half-life of ozone and the temperature of the diffusion opening. FIG. 7 is a graph for explaining the relationship between the gas flow rate and the ashing rate at a wafer surface temperature of 300 ° C. FIG. 8 is an ashing rate for the gap between the diffusion plate and the wafer surface at a wafer surface temperature of 300 ° C. FIG. 9 is an explanatory diagram showing the relationship between the gas temperature and the resist removal rate, and FIGS. 10 (a), (b),
(C), (d), (e) and (f) are explanatory diagrams of specific examples of the opening of the diffusion plate, respectively, and FIGS. 11 (a), (b) and
(C) and (d) are explanatory views of a specific example of the gas cooling structure in the injection part, FIG. 12 (a) is an explanatory view of a method of rotating the gas injection part, and FIG. 112 (b) is , An explanatory view of rotating the wafer side, FIG. 13 is an explanatory view of the ashing effect when not rotating, FIG. 14 is a block diagram of an embodiment of an ashing processing system for determining the end of the ashing processing, and FIG. FIG. 16 is a graph showing a change in the concentration of carbon dioxide in the exhaust gas, FIG. 16 is a graph explaining the relationship of the ashing speed with respect to ozone concentration, and FIG. 17 is an explanatory view of a conventional ultraviolet ashing device. 1 ... Ashing system, 2,20 ... Ashing device,
3 ... Oxygen gas supply device, 3a ... Gas flow rate controller, 3b ...
… Ozone generator, 3c …… Oxygen source, 4 …… Exhaust device,
5 ... Lifting device, 6 ... Temperature controller, 7 ... Gas analyzer, 8 ... End point determination / control device 10a, 10b ... Electrostatic chuck 21 ... Wafer mounting table 21a, 206 ... Heating device 22 , 22a, 22b ...... Gas injection part 23a, 23b …… Loader / unloader part, 24a, 24b …… Belt transfer mechanism part, 25a, 25b …… Transfer arm 26a, 26b …… Suction chuck, 28 …… Wafer, 31 ……slit.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroyuki Sakai 1-26-2, Nishishinjuku, Shinjuku-ku, Tokyo Within Tokyo Electron Limited (56) Reference JP-A-52-20766 (JP, A) JP 58-168230 (JP, A) JP 59-28354 (JP, A)

Claims (1)

(57) [Claims] 1. A processing chamber which can be closed in an airtight manner, a mounting table which is provided in the processing chamber and on which a wafer is mounted, and which is arranged at a predetermined distance from the wafer and has oxygen radicals on the wafer. In an ashing device having an opening through which the reaction gas for generating the gas flows out substantially uniformly to the wafer, wherein the temperature of the gas flowing out from the outflow portion is 15 While having a cooler to ℃ ~ 50 ℃, the mounting table includes a heating device for heating the temperature of the mounted wafer to 200 ℃ ~ 350 ℃, further any of the mounting table or the outflow section up and down When the ashing process is performed, either the mounting table or the outflow section moves, and both approach each other so that the predetermined interval is 1 to
3mm, after the ashing process is completed, either the mounting table or the outflow section moves, so that the two stand apart from each other, and a control device that controls the movement of the mounting table or the outflow section. An ashing device comprising: