JPS62165932A - Ashing device - Google Patents

Abstract

PURPOSE:To obtain a device ashing a film adhered on the surface of a wafer at a high speed by mounting an outflow section with a plate section flowing out a gas containing O3, oppositely arranged separated at a regular interval from the wafer, boring an opening to the plate section and uniformly flowing out the gas up to the outside of the wafer. CONSTITUTION:A gas outflow section 22 with a plate section, separated at a set interval from a wafer 28 is disposed oppositely facing to each other. The plate section has a local plane in which a tubular material is turned horizontally, a plurality of openings are shaped or the plate section is constituted of a porous substance, and a gas flowing out of the openings is made to reach up to the side outer than the external shape of the wafer by 5mm or more on the outside by utilizing the holes. A cooler is attached to the outflow section 22. O2 is supplied and O3 is generated and a flow rate is controlled, O3+O2 are cooled at 15-50 deg.C and fed onto the wafer temperature-regulated 6 at 150-500 deg.C, and a reaction product gas is discharged. The wafer or the outflow section can be moved vertically. According to the device, a film applied onto the wafer is exposed efficiently to O radicals having a strong oxidative effect, thus allowing ashing treatment at a high speed.

Description

[Detailed Description of the Invention] [Field of Application of Product L1-] The present invention relates to an ashing device (ashing device) for removing a film deposited on a wafer, etc., and in particular, the present invention relates to an ashing device (ashing device) for removing a film deposited on a wafer, etc. Photoresist film (resist used for condolence)
The present invention relates to an apparatus suitable for single wafer processing in which wafers are removed by oxidation.

[Prior art] Formation of fine patterns in conductor Toshiba circuits is generally carried out by using a resist film formed by exposure and development as a mask on a wafer 1. This is done by etching the top film.

Therefore, the resist film used as a mask needs to be removed from the surface of the wafer after the etching process. Ashing processing is performed to remove the resist in such a case.

This ashing process is called registry limping.

Ink IJ, including silicon wafer and mask l destinations
It is also used to remove lubricants, solvent residues, etc., and is suitable for dry cleaning in conductor processes.

Oxygen plasma is commonly used as an ashing process for resist removal.

In resist ashing using oxygen plasma, a wafer with a resist film is placed in a processing chamber, and the oxygen gas introduced into the processing chamber is turned into plasma using a high-frequency electric field. This method utilizes the effect of oxidizing and decomposing carbon dioxide into carbon dioxide, carbon oxide, and water, which are then vaporized.

However, the ashing process using oxygen plasma has the drawback that the wafer is irradiated with ions and electrons accelerated by the electric field present in the plasma, which adversely affects the electrical characteristics of semiconductor integrated circuits. be.

To avoid such drawbacks, UV light (
UV)! ! There is an apparatus that generates oxygen radicals by 6 irradiation and performs ashing processing in batch processing. This type of apparatus has the advantage of being able to perform efficient stripping and cleaning without damaging the elements, since there is almost no damage to the elements due to the electric field compared to plasma processing.

FIG. 17 shows a conventional ashing device using ultraviolet irradiation.

In the processing chamber 100, a large number of wafers 101, 101 and φ
are placed directly at predetermined intervals, and one of the processing chamber IQO
Ultraviolet rays from an ultraviolet light emitting tube 103 installed in ~1 section are irradiated through a transparent window 102 made of quartz or the like provided on the - side of the processing chamber 100 to excite oxygen filled in the processing chamber 100. and generate ozone. And oxygen + generated from this ozone atmosphere! i': An ashing process is performed by applying I' radicals to the wafer 101.

By the way, in recent years, there has been a trend towards wafers having a diameter of L1.
Along with this, the single-layer processing method in which wafers are processed one by one is becoming increasingly popular.

[Problems to be solved] There are such drawbacks.

Moreover, since the effect is in an ozone atmosphere of 111-, the resist ashing speed is 500 to 1500.
It is only about 1 person/min.

However, in the single-wafer processing of wafers suitable for one diameter, the processing speed is usually 1 μm to 2 μm/min.
A degree of ultraviolet rays is required! 1 (Conventional equipment that fires one shot cannot adequately respond to disaster treatment.

Moreover, since it uses ultraviolet rays, it has the disadvantage that it has to use a large-scale equipment, and it is expensive.

[Aspects of the Invention] This invention has been made in view of the problems of the prior art, and solves the problems of the prior art, as well as achieving a high unwinding speed ( ``Objective 1'' is to provide an ashing device that does not require the use of ultraviolet light or the like.

[P-stage for solving the problem] Means in the unwinding apparatus of the present invention for achieving the above 1-1 objective is to use an ozone-containing gas which is disposed facing the wafer at a predetermined distance. The plate part is provided with an opening for allowing the gas to flow out almost uniformly onto the wafer surface, and the gas is directed from this opening to the outside of the wafer's outer shape. The film deposited on the surface of the wafer 1 is oxidized and removed by flowing out.

[Working] By providing an ozone outlet having a flat plate part at a position opposite to the wafer at a predetermined distance, and forming a space between the wafer and the wafer in which a gas of syn+oxygen flows parallel to the wafer, will continue to supply new ozone to the This promotes the oxidation chemical reaction between the oxygen radicals and the film deposited on the wafer. Furthermore, by expanding the gas outflow region to the outside of the wafer, the carbon dioxide produced after the reaction with non-radical oxygen (02), -
Carbon oxide, water, etc. can be moved and ejected from the wafer surface in a vaporized state.

As a result, the reaction surface of the film 9, for example, an organic film, deposited on Uenoso L can be efficiently exposed to oxygen radicals, which have a very strong oxidizing action.

Therefore, it is necessary to perform high-speed ashing processing.
This makes it possible to realize an ashing device suitable for single-wafer processing.

[Example Code] An example 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 according to an embodiment to which the ashing device of the present invention is applied, and FIG.
3(a) and (b) are cross-sectional explanatory views showing the overall configuration including a wafer transport mechanism in another similar embodiment.
4 is a detailed explanatory diagram of the electrostatic chuck in the wafer transfer mechanism, in which (a) is a sectional view taken along line II in (b) of the same figure, (b) is a plan view thereof, and FIG. An enlarged explanatory diagram of the reaction part, FIG. 5(a) is a diagram illustrating the relationship between reaction and movement by oxygen atom radicals, and FIG. 5(b) and (C)
Figure 6 is a graph explaining the relationship between the diffusion amount [1] and the ashing state on the wafer, and Figure 6 is a graph explaining the relationship between the ozone decomposition half-life and the temperature of the diffusion amount. .

Furthermore, FIG. 7 is a graph explaining the relationship between the unwinding speed and the gas flow and rHH at a wafer surface temperature of 300°C, and FIG. FIG. 9 is a graph explaining the relationship between the ashing effect and FIG. 10 is an explanatory graph showing the relationship between gas temperature and resist removal rate (
a), (b), (c), and (d) are illustrations of specific examples of the space between the diffuser plates (Figure 11 (a) + (1)).
+ (c) + (d) is an explanatory diagram of a specific example of the gas cooling structure in the injection part, and FIG. 12 (a) is,
Explanatory diagram of the method of rotating the gas injection part, Fig. 12(b)
13 is an explanatory diagram of the ashing effect when the wafer side is not rotated, and FIG. 14 is an explanatory diagram of the ashing effect when the wafer side is not rotated. Figure 15 is a graph of the 4 degree change in carbon dioxide in the exhaust gas, and Figure 16 is a graph of the 4 degree change in carbon dioxide in the exhaust gas.
It is a graph explaining the relationship between ashing speed and ozone concentration.

In FIG. 1, reference numeral 1 denotes an ashing processing system, which includes an ashing device 2, an ozone + oxygen gas supply device 3 that supplies oxygen gas containing ozone to the ashing device 2, and υ1 connected to the ashing device 2. Air device 4
, a wafer mounting table 21 arranged inside the ashing device 2
The heating state of the lowering device 5 and the heating device 21a installed in the wafer mounting table 21 is adjusted to move the wafer up and down. , and a temperature regulator 6 for controlling 1 degree.

1) The ozone + oxygen gas supply device 3 in item 11 has a gas flow: j
(Regulator 3a and ozone generator 3b1 oxygen supply lh:i
3C, and the ozone concentration, gas flow rate, and gas pressure in the ashing device 2 (processing chamber) are determined based on these gas flows.
, V regulator 3 = t + ozone generator 3b, oxygen supply 'th! 3c and the relationship between the exhaust system 4 and the exhaust system 4.

1. 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 disposed inside the ashing device 2 is for holding the wafer 28 by suction.
The temperature of the held wafer 28 is maintained at a predetermined value by the temperature regulator 6.

0.5 to 20 m from the surface of the wafer 28
Cone-shaped jets 22 for injecting ozonator oxygen gas at intervals of about m are provided, and the above-mentioned intervals are 1. The wafer mounting table 21 is moved Ih' by the lowering device 5, so that it is set to a predetermined value.

In this case, is it injection? ;i<22 side is lowered by -
1- You may move it downward.

The injection part 22 is made of SUS (stainless steel) or A
λ, etc., and opposite to the wafer 28, there is a disc-shaped diffuser plate part 22 in a row of 1i with the surface of the wafer 28.
It has a. In order to carry in and take out the wafer 28, the wafer mounting table 21 is lowered by the lowering device 5, the space between the diffusion plate section 22 and the wafer 28 is expanded, and the wafer transfer mechanism is inserted into the space. This is done by the intrusion of the arm.

Now, for the up/down process, the wafer mounting table 2 l
The wafer 28 of The mixing ratio is adjusted by ozone generation JH% 3 C. And oxygen gas containing this ozone.

For example, about 3λ to 15λ/min is sent into the chamber of the ashing device 2, which is a processing chamber. The gas pressure inside the ashing device 2 at this time is, for example, 700 to 200 Torr.
Set it to a range of about r.

Next, the handling process of carrying in/out the wafer 28 into the processing chamber of the ashing device 2 will be specifically explained based on the ashing device 30 shown in FIG. Note that this ashing device 30 is similar to the ashing device 2 shown in FIG.
is 5υ, and instead of moving the wafer 1 mounting table by -1 degrees, the injection unit is moved by -1)'.

In FIG. 2, the ashing device 30 includes a processing chamber 20 and loader/unloader sections 23a and 2 disposed on both sides thereof.
3t) and these loader/unloader parts 23a, 23b.
Belt conveyance mechanisms 24a and 24 installed inside, respectively.
It is composed of b.

Here, the loader/unlower 7 section 23a, the bell 1-conveying mechanism 24a side is the side that carries in the sea urchin/%, and the loader/unloader
The unloader section 23b and the belt conveyance mechanism 24b are the side that carries out the ashed ueno\.
Both may be used as the loading side or the loading side. Furthermore, there may be only one loader/unloader section.

Although not shown, the belt conveyance mechanisms 24a, 2
At the opposite end of 4b, a car 1-liner is installed to store the wafers 1 stacked at predetermined intervals, and by moving the wafer 1-liner, the wafer 1 before being processed can be stored. Belt g feeding mechanism 2 sequentially from cart linen
4a to the loader/unloader tM<23a. And a.

/ Ueno 1 with knob processing or loader/unloader r'
J< 23 b, the sheets are sequentially stacked and stored in a cart via the belt conveyance mechanism 24b.

Now, the processing chamber 20 is made of, for example, SUS, l, or Ti.
It is equipped with a chamber 29 of A and It coated with N, etc., and a ueno 1 mounting table 205 is provided in the center of the inside thereof.
is installed. Then, the gas injection part 22a moves up and down at a predetermined interval in one part of the chamber 29.
It is supported on the ceiling side.

Here, the gas injection part 22a has a shape of a circle X (, which is made up of a disc-shaped diffusion plate 200 and a cone part 203 connected to the disc-shaped diffusion plate 200, and the cone part 203 contains ozone +
An oxygen gas introduction pipe 202 is connected at a portion thereof, and the introduction pipe 202 is hermetically surrounded by a metal bellows 201 made of SUS or the like. Oxygen/decoxygen gas, which is essential for the reaction, is introduced.

204 is a cooler for ozone + oxygen gas that spirally surrounds the outer circumference of the cone portion 203;
03 with heat conductive cement or the like. The cooler 204 is configured such that the refrigerant is introduced from the do side of the cone portion 203, exited at the cone portion 141, and guided to the outside.

~As shown in FIG. 4, the brim diffuser plate 200 has a slit (open II) 31 for blowing out the gas, and blows the cooled ozone + oxygen gas uniformly onto the surface of the wafer 28. put out.

The diffuser plate 200 is supported at three points around its periphery by pole screw mechanisms 231, 232, and 233 at intervals of approximately 120°, and moves l')''.

It is driven by pole screw mechanisms 231, 232.
The gears formed on the ball parts 234, 235, and 236 (not shown in the figure) of the motor 233 are connected to the motor 23.
This is done by meshing with a worm gear carved into the rotating shaft 236 of the 0.

In addition, injection? The lowering mechanism for J< 22 a is a combination of such a motor, ball screw, and gear (
, an air ring or the like may be used to directly move it to the "-" board.

In the position shown in the figure, the injection part 22a is -1-ν1
In the + state (standby position), the wafer 28 is loaded into or unloaded from the wafer mounting table 205. On the other hand, as shown in FIG. 4, when the injection part 22a descends, the emission of the diffuser plate 200 is at a distance (reaction position) of 0.5 to several mm or about 10 fimm from the wafer surface. The wafer mounting tables 205-. A state is reached in which gas is supplied to the surface of the wafer 28 of 1 unit.

Note that a heating device 2.degree. 6 is installed inside the wafer mounting table 205 to heat the wafer mounting table 205. In this example, in addition to the ozone-containing gas, the chamber 29 also contains N2 to cover the gas flow from the diffusion plate 200.
gas is introduced.

Now, 26a is a suction chuck part supported on the tip side of the transfer arm 25a, and loa is a suction chuck R that moves downward by 1-1 with respect to the main body of the suction chuck part 28a.
1 < 26 a. The figure shows a state in which the wafer 28 is attracted to the electrostatic chuck 1°4. In addition, the wafer adsorption in this case is
Adsorption by negative pressure may be used, or mechanical clamping or holding may be used.

The transfer arm 25a is a support located within the loader/unrotor section 23a. The other end is fixed to t27a, and the loader/
Unloader section 23a and wafer mounting table 205 in processing chamber 20
This is a frog leg transport mechanism type arm that moves back and forth between the Note that this transfer arm 25a may be constructed of a magnetic cylinder, an air cylinder, or the like.

Here, the reason why the frog leg transport mechanism is used is that the transport mechanism section can be made into a small J (1!), and, for example, ashing processing chambers are provided on both sides of the loader/unloader section.
If the support 27a of the frog leg transport mechanism is made rotatable, the frog leg transport mechanism can be directed to the desired chamber, which has the advantage of allowing wafers to be selectively transported or unloaded to both chambers.

In addition, a loader/bell 14) is installed between the feeding mechanism and the chamber.
Provide unloader section in a straight line and support it! I:27a
If the wafer is made rotatable, it is also possible to pick up the wafer from the bell 1lla transfer mechanism side, turn it over, and transfer it to the chamber side.Even in this case, the entire device can be made smaller. It can be realized as something.

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

Therefore, the wafer mounting table 205 is provided with a plurality of holes 220 for negative pressure suction. In addition, the wafer mounting table 2
Around 05, a plurality of υ holes are arranged in an annular manner at predetermined intervals in order to discharge the exhaust gas after the reaction as evenly as possible.
1-Air opening L12L9.2194141 is provided on the ring plate 222, and this ring plate 222
is fitted into the outer circumferential side of the sea urchin/1 mounting table 205 at a position slightly lower than L of the wafer/mounting table 205.

221 and 223 are exhaust pipes that respectively air the chamber 29, and are connected to the pump of the exhaust device 4. These υ1. Two or a plurality of tracheas 221 and 223 are provided so that illumination can be performed evenly, but the number of tracheas 221 and 223 may be one. Also, 224.225 are datenos (rubes).

In addition, 226 and 227 respectively indicate the belt m feeding mechanism 24.
A and 24b are conveyor belts, and 217 and 218 are chambers of the loader/unloader sections 23a and 23b.

Here, the chambers 217 and 218 of the loader/unloader sections 23a and 23b may also be evacuated to υF by a vacuum pump in accordance with the internal pressure of the chamber 29.

Next, to explain the operation of this device, the injection part 22
Assume that a is set to the 1-'n' state and held in the standby position, and the gas introduction valve [1202] is closed.

When the gate valves 224 and 225 are closed, the inside of the chamber 201 is in a reduced pressure state close to normal pressure.

In addition, in the case of lowering the wafer installation table 21 shown in FIG. 1, the h' lowering device 5 is driven to lower the urchin 11 installation 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 foa of the wafer 28 carried from the belt transport mechanism 24a to the loader/unloader section 23a, and a voltage is applied thereto to lower the wafer 28 carried into the loader/unloader section 23a. It is adsorbed by. And this static, IE chuck 10a -1-
Raise it up and pick amp Ueno 128. Next, the transfer arm 25a is extended and the adsorbed wafer 28 is transferred to the loader/
The wafer 28 is transported from the unloader section 23a to the processing chamber 20, positioned on the wafer mounting table 205, and the electrostatic chuck lOa is lowered, and the applied voltage is lowered or zeroed to drop the wafer 28 to zero. And wafer mounting table 205
The Ueno 1 is placed on the Ueno 1 mounting table 2051- by suction with negative pressure.

Next, after raising the electrostatic chuck 10a by 2", the transport arm 1.25a is reduced and the suction chuck 26a is moved to the loader/
Return to unloader m23a. After the suction 7t char 7a 26a moves to the loader/unloader section, the gate valve 22
4, 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 placed at the reaction position by raising the wafer mounting table 21 one unit by the lifting device 5.

Here, the temperature of the wafer 28 is monitored, and when the temperature reaches 1 degree, a predetermined ashing process 171 is performed.
The valve 202 is opened, and ozone and oxygen gas are evenly sprayed onto the surface of the wafer 28 placed on the wafer mounting table 205.

As a result, the resist on the wafer 28 is oxidized, and the gases generated by this chemical reaction, such as carbon oxide, carbon oxide, and water, are transferred to the υF trachea 221, 223 by the υ1 air device 4 together with the oxygen after the reaction. After that, I was rated 1 no 1.

At the time when the annotation process is completed (for example, within a few minutes), close the gas introduction valve 11202 and raise the diffusion plate 200 to the standby position (in FIG. 1, the wafer mounting table 205 is (lower it down to the standby position 1rt), open the date no.
Extend the transfer arm 251) from the unloader 23b to the processing chamber 20, move the suction chuck 26b to the wafer mounting table 205'-, and lower the electrostatic chuck 10b on the tip side. Apply voltage. Then, the wafer 28 that has been subjected to the processing is placed on the wafer 1 mounting table 205F.
- to attach the electrostatic chuck 10b to Lη1. Let's pick up the amp. After the electrostatic chuck 10a is raised by 1, the transport arm 251) is contracted and the processed sea urchin/sea urchin 28 is transported to the loader/unloader section 23b.

The sea urchin/X thus carried out to the loader/unloader section 231) is passed from the loader/unloader section 23b to the belt m feeding mechanism 24b, and is stored in a cartridge where it is placed in the a/ing process. Place the finished wafer or other wafer outside the equipment.
V is exposed.

Here, the electrode portion of the electrostatic chuck will be explained. In addition, in FIG. 1, the electrostatic chuck 10a.

10b has the same configuration, so in the following description, the electrostatic chuck 10 will be explained, and its electrode portion will be referred to as an electrostatic chuck electrode portion 17.

Now, as shown in FIGS. 3(a) and 3(b), the electrode part 17 of the electrostatic chuck 10 for wafer suction is located inside the back surface.
They are formed by first and second electrodes 11 and 12 made of a conductor such as metal in the shape of semi-circular plates, each having circular depressions 11a and 12a.

By the way, when automatically transporting a wafer, there are overwhelmingly many cases where it is required to suck the wafer from the front side and transport it. Therefore, the electrode section 17 is attached as an electrostatic chuck in a state where it is suspended from a wafer transfer device so that its suction surface side faces downward.

Here, these first. The second electrode 11.12 is the insulating film 1
3.14, and are arranged with a predetermined gap r) in between. This gap l) may be left as a void, or an insulator may be inserted depending on the structure. The selection may be determined based on the overall structure of the electrostatic chuck 10.

1st. As shown in FIG. 3(a), the second electrodes 11 and 12 have a concave interior (depth h) leaving a portion of width W on the outer periphery of a circle approximately within radius R. The portion of width W is the semiconductor wafer suction MS15.18. Adsorption f
Insulating films 15a and lea are coated on the surfaces of fl<15.16 as part of the insulating film 13.14, and these insulating films 15
The film thickness of av 16 a is determined based on the suction force of the wafer, etc. Insulating film 1 other than this part
The thickness of 3.14 is determined in consideration of the fact that this electrode part has a withstand voltage of 1 minute when it comes into contact with other metal parts.

Next, the ashing reaction will be explained in detail according to FIGS. 4, 5(a), and 6.

As shown in FIG. 4, in the ashing process, the ozone supplied from the ozone + oxygen gas supply device 3 is heated in the following thermal parallel inside the injection part 22a (or the same as the injection part 22 and later). It is in a state.

03ヰ02+0 In this case, the life of the oxygen atom radical O obtained by decomposing ozone depends on the temperature, and as shown in Figure 6, the lifespan of the oxygen atom radical O obtained by decomposing ozone is 25℃.
Nearby, it is very long.

However, when the temperature rises to some extent, its lifespan rapidly shortens.

On the other hand, the ashing process by oxygen atom radicals is an oxidation chemical reaction, and the higher the temperature, the faster it occurs. Moreover, a certain amount of time is required for the zymogen r radicals to act on the wafer surface. Therefore, a serious problem is how to efficiently continue to supply oxygen atom radicals to the surface of the wafer 28.

The ashing process proposed in this invention efficiently supplies zymogen r radicals to the surface of the wafer 28 and quickly removes reaction products from the wafer surface by 1'.
υl-division of such products and oxygen 1! : In synergistic processing with the supply of trough/cal, the processing speed of ashing processing can be increased to a level suitable for single wafer processing.

Therefore, it is important to create an appropriate gas flow space that supplies oxygen atomic radicals and excludes reaction products.

In this embodiment, as shown in FIG.
00.

The distance between the wafer mounting table 205 and the diffusion plate 200 is relatively narrow, and the heating temperature of the wafer 28 is set to be high (about 0.5 to several m111 relative to the wafer surface). In addition, the injected gas should be placed at the outermost position 11 (see Fig.
) has been determined.

By blowing the gas outward from the outer shape of the Nizueva 28 in this way, a negative pressure area is formed by the gas flow outside the wafer's outer circumference, and the generated gas from the center side is transported outward from the wafer's outer circumference more quickly. , is something that is discharged.

As a result, it is possible to facilitate the supply of ozone and the contact of oxygen atom radicals to the wafer surface, thereby promoting the oxidation reaction.

Now, the ozone + oxygen cooled by the cooler 204 is
For example, it is cooled to about 25 to 50°C.

Therefore, the oxygen source r/radical is transferred to the cone part 2 of the injection part 22a.
03 The rate held inside becomes higher.

Then, as soon as ozone (OJ, 02 +0) and oxygen 02 are injected from the opening of the diffusion plate 200, they are exposed to a high temperature atmosphere, but before their lifespan ends, they reach the wafer surface together with the oxygen and damage the wafer. Ashing (ashing) of the film adhered to the surface.

that is, oxidized and removed from the wafer surface).

As shown in FIG. 5(a), carbon dioxide, -carbon oxide, and vaporized water generated by ashing rise at the same time, and oxygen (02) and non-radical ozone (03) blow out from the diffusion plate 200. Riding on the flow, it is removed from the surface, carried through the exhaust opening 219 of the ring plate 222 to υ1: trachea 221, 223, and sequentially exhausted by the exhaust device 4.

Therefore, an environment can be created in which the surface of the wafer 28 is constantly exposed to oxygen radicals.

In addition, in FIG. 5(a), 28a is Ueno\28
, 28b is the part of the resist deposited on Ueno
It shows the flow of ozone + oxygen gas from 0.

Here, the wafer temperature is set to 300°C, and the condition of the target at the opening of the diffusion plate 200 is set using the distance (gap) between the surface of the wafer mounting table 205 and the diffusion plate 200 (on the injection [l side)] as a parameter. Gas flow M (under normal temperature and pressure conditions)
When we measured the ashing speed for
0, particularly high ashing speeds are possible, with 40
It gradually becomes saturated from about sλ/min.

In order to make this flow rate correspond to a general wafer diameter, it is converted to a flow rate per 1 m area of wafer, which is 0°0 f
~0. 25s J! /min e c Tr? becomes.

Furthermore, when the relationship between the ashing speed and the gap between the diffuser plate and the wafer surface is measured using the gas flow rate as a parameter at a wafer surface temperature of 300°C, as shown in Figure 8, when the gap is 20 mm or more, the gas jet flow;
It shows a characteristic that converges toward a constant value, regardless of the past.

Furthermore, regarding the relationship between the temperature of the gas ejected from the diffusion plate 200 and the resist removal rate, the gap to the wafer (the distance from the surface of the wafer 28 placed on the wafer mounting table 205 to the surface of the diffusion plate 200) 2 mm and the reaction time is l min, the characteristics are measured using the gas flow jil: as a parameter, as shown in Figure 9.
It can be seen that if the temperature is raised to about 200°C, it is difficult to remove.

Therefore, when performing a reaction by heating the wafer side to 200°C or higher, the injected gas (ozone + oxygen)
is preferably cooled. As a particularly preferable range, the temperature of the outflow gas of the diffuser plate 200 is 15 to 5.
It is at 0°C.

This is also consistent with the characteristics of ozone decomposition 1': sentence reduction, which we saw in Figure 6.

Furthermore, as shown in Fig. 16, when we investigated the relationship between the ashing speed and the ozone IQ degree, we found that as the ozone lr level was increased by 5 degrees, the ashing speed increased by t h'-
There is a relationship where However, at 10 weight i11% or more, it shifts toward saturation. Note that this characteristic is for a 6H wafer at a temperature of 250°C, a gas flow rate of 5 s JI/min, and a chamber pressure of 700°C.
The value was measured on a resist that had been transformed by plasma irradiation in an etching process, assuming a Torr level.

As can be understood from each of the characteristic graphs, by forming a flowing gas space in the wafer 11 portion and injecting or flowing ozone-containing gas onto the wafer,
This makes it possible to carry out an ashing process E11 (with a rate of several μm/min per copy), which is suitable for single-wafer processing and also suitable for human processing of 1-diameter wafers.

FIGS. 10(a) to 10(d) are explanatory diagrams of an example of a 5S structure of a diffusion plate 200 that uniformly injects ozone+oxygen gas onto the surface of a wafer.

FIG. 10(a) shows four arcuate slits 311 formed circularly and concentrically.
The holes may be perpendicular to the wafer, or may be oblique slots so that the gas flows outward to form a flow of gas 3 on the outside.

In FIG. 10(b), a hole 312 is provided in the center of a circle, and slits 313 are arranged radially with respect to the hole 312. In FIG. 10(C), holes 314 are provided radially, and the holes 314 become slightly larger toward the outside. 1st
FIG. 0(d) shows a case where a sintered alloy 200a is used as a diffusion plate 200, and porous holes 315 are formed over the entire surface of the plate.
are uniformly irradiated.

In FIG. 10(e), the injection port 31B is formed in a spiral shape, and in FIG. 1O(f), the small hole 31B is formed in a circular shape.
17 is worn.

Here, in order to examine the effect of uniformly discharging gas from the diffusion plate 200, we will examine two cases: a case in which holes are sparsely opened as shown in FIG. 10(f), and a case in which holes are opened sparsely as shown in FIG. In the former case, as shown in Figure 5(b), when comparing the case where the porous pores are uniformly distributed, as shown in Fig. 5(b),
The resist portion 28b is ashed in response to the gas flow 32 (arrow), and the ashing becomes uneven with gentle waves. On the other hand, in the case of the latter sintered alloy in which porous pores are uniformly distributed, uniform ashing is performed as shown in FIG. 5(C).

Therefore, it is recommended to provide gas injection to make the gas more uniform (by doing so, the processing time until complete ashing can be shortened, and even if ozone is applied to the wafer surface, it will not damage the wafer. There are advantages.

In addition, in FIGS. 5(b) and 5(C), the portion indicated by the dotted line is the surface position (thickness) of the resist of ashing 1]11.

Now, as seen in the characteristic graphs in Figure 6, etc., gas (
It is best to inject ozone + oxygen from a diffuser plate in a state that is as cool as possible.

By the way, the distance between the wafer mounting table 205 and the diffusion plate 200 is relatively short. On the other hand, the wafer mounting table 205 and the wafer 28 are heated by the heating device 206 to the reaction temperature. Therefore, the diffusion plate 200 is heated by radiant heat emitted from the wafer mounting table 205 and the wafer 28 side, and the temperature of the surface of the diffusion plate 200 tends to increase.

As a result, the temperature of the gas near the injection port rises by 1-1, and the oxygen atomic radicals supplied to the wafer surface increase! II will decrease. In particular, when the gap is large, the influence of heat is somewhat reduced, but the movement time of oxygen atom radicals becomes longer, so l! ,,Including the influence of 1 degree 1 'i+', the number of oxygen atomic radicals whose lifespan expires before reaching the surface of the wafer 28 increases. Moreover, if the gigang is too small, it will be directly affected by the temperature on the wafer machine stand 205 side, and the temperature 1-511 on the surface of the diffusion plate 200 will be more than +', 8I.
There is a tendency to In addition, the temperature value also varies depending on the flow of gas blown from the diffuser plate 200.

For this reason, there are more optimal conditions for ashing processing. In the reaction pattern shown in Figure 4,
When the wafer temperature is around 200°C to 350°C,
A more optimal gap is about 1 to 3 mm, and the gas flow rate is 5.5 mm for a 6# wafer under conditions of room temperature and pressure.
The culm degree is 5 to 17 s R/ml. Therefore, when converting this to the flow rate per li surface area of Ueno 1, it is 0.03 to 0°1sλ/mln*cn? becomes.

In addition, carbon dioxide reacted by oxygen atom radicals, -
・Reaction products such as carbon oxide and water add oxygen to JE (02)
There are weight percentages of ozone and oxygen that are more effective considering that they are carried away from the wafer surface by the oxygen.

That is, if the amount of ozone (03) is low, the ashing rate (rate of decrease in unit time with respect to film thickness) will be low, the uniformity will be poor, and the efficiency will be poor. - On the other hand, if the amount of ozone (03) is large and the amount of oxygen (02) is small, the rate will increase, but stagnation of the window product on the Ueno 1 surface will occur and the reaction rate will decrease.

Taking these points into consideration, the optimal ozone weight percentage
A suitable amount is about 3% by weight to 5% by weight.

Now, taking these matters into consideration, a specific example of a cooling structure for the injection part that injects gas at a temperature as low as possible in addition to uniformly injecting gas will be described next.

The injection part 22b shown in FIG. 11(a) has a cooling pipe 204a made of a coiled pipe also arranged on the inner surface of the diffusion plate 200, and communicates with the cooler 204. This is followed in a meandering manner while avoiding the slit 318 for this purpose.

In addition, the injection part 22b shown in FIG.
A cooling pipe 2 made of a coiled pipe is installed on the outer surface of the 00 (wafer 28 side).
04b is disposed and communicated with the cooler 204, and similarly, this is made to snake in a meandering manner while avoiding the slit 318. In this case, the 11th
In the figure (aL (b)), the cooler 204 disposed 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 diffuser plate 200 can be suppressed to a low state, and the lQ degree of the injected gas can be suppressed, thereby creating a more self-sharpening condition. This makes it possible to perform efficient ashing processing.

The injection part 22c shown in FIGS. 11(c) and 11(d) has a cylindrical shape rather than a conical shape, and has a dome 22d for gas diffusion at lfl<. After the gas is diffused in advance with a slit, it is sent to the diffusion plate 311 having slits or the diffusion plate of the sintered alloy 200a.

In particular, in FIG. 11(C), a serpentine tube-shaped cooler 204c is built inside the cylindrical portion, and in FIG. It's full inside. In addition, these have one cooler on the outside.
Although it has not sunk, as in Figure 11 (aL (b)),
Of course, a cooling pipe may be placed outside the cylindrical portion.

Next, a description will be given of an example in which the wafer and the diffusion plate are rotated relative to each other in a Ll manner to blow gas more uniformly onto the wafer surface and further promote the oxidation reaction.

The injection part 33 shown in FIG. 12(a) consists of a diffusion tube 34 and a gas introduction tube 35 communicating at the center thereof, and the gas introduction tube 36 is rotatably connected to the ceiling side of the chamber 29. It is pivotally supported.

Here, both ends of the diffusion tube 34 are closed, and on the side facing the wafer 28, jets n36, 38. A plurality of numbers are arranged at predetermined intervals. Furthermore, spray 1-13 at the position on the opposite side, facing away from the phase σ on the end side surface (the side perpendicular to the wafer surface).
7.38 is provided, and when gas is injected from there, the diffusion tube 34 rotates by itself due to the reaction. Moreover, the gas injected from both ends is located outside the outer periphery of the wafer 28 and also serves to transport the ashing products to the outside. Note that instead of the injection material 136, a porous material may be used on the surface of the diffusion tube 34.

In the example shown in FIG. 12(b), the wafer mounting table 205 is supported by a shaft, this shaft is pivotally supported on the floor side of the chamber 29, and the wafer mounting table 205 is rotated by a motor. It is. In addition, the injection part 22a is shown in FIG.
) may be tubular or rod-shaped.

Comparing the effects of using and not using such a rotation operation, we found that when using the rotation method,
The processing time during which the resist on the wafer is removed is reduced. In other words, when comparing the rotation method and the case of no rotation for the same processing time, as shown in FIG. 13, in the case of no rotation, the resist is divided by tJt at the center of the wafer, but as shown in FIG. In the peripheral area, a phenomenon is observed in which the residual portion 40 of the lens remains as a striated pattern without being removed. Note that this was performed on a 6″ wafer.

For this reason, it can be said that the rotation process is effective in shortening the ashing process time, and is also effective in ashing processes in the periphery (excluding the central part of the wafer). It is particularly effective for 11 diameter wafers such as 6# to 10''.
In this case, since the gas injection ffl< is automatically rotated, there is an advantage that the device is simple, but a large amount of gas must be injected. On the other hand, in the case of FIG. 12(b), since the wafer mounting table 205 side is rotated, the apparatus becomes somewhat complicated, but there is an advantage that the amount of gas injection: i can be reduced.

Next, detection of the end of ashing processing, which is related to overall control when single wafer processing is performed, will be described.

As shown in Figure 14, RJ' of the ashing process is υ
A gas analyzer 7 is installed in front of the F gas device 4.

Then, carbon dioxide (CO2) obtained from the gas analyzer 7 is
) A detection signal corresponding to 10 degrees is input to the end point determination/control device 8 to monitor the concentration of carbon dioxide, and when this concentration becomes zero or below a predetermined value, it is assumed that the Anno/Fugu treatment has ended. judge.

Here, the end point determination/control device 8 internally includes a comparator and a controller composed of a microprocessor, and receives an ashing process end point detection signal from the comparator which receives the output of the gas analysis 1-7. , ashing device 2. It controls the gas valve of the gas introduction pipe (see gas introduction pipe 202 (4) in Fig. 2) and the S' lowering device 5 (motor 230 in Fig. 2).

That is, when the end point is detected, a signal is generated to close the valve of the gas introduction pipe, and control is performed to stop the gas injection. At the same time, the system sends a lowering signal for the wafer mounting table 21 to the lowering device 5, controls this, increases the gap between the diffuser plate and the wafer mounting table, and lowers the wafer mounting table ( In the embodiment of FIG. 2, the injection section) is moved to the standby position.

C;1 When receiving the standby position setting signal from the descending device 5,
The end point determination/control device 8 releases a gate valve (gate valve 225 in FIG. 2) that communicates with the loader/unloader section on the wafer unloading side (see loader/unloader section 23b in FIG. 2). A control signal is sent to the ashing device 2. Upon receiving this signal, the ashing device 2 opens its gate valve and communicates the chamber (see chamber 29 in FIG. 2) with the loader/unloader section on the wafer unloading side. let

Next, the end point determination/control device 8 operates the wafer handling mechanism on the unloading side (transfer arm 25b in FIG. 2)
<7J is sent to the ashing device 2.

Upon receiving this signal, the ashing device 2 releases the suction and holding of the wafer 28, operates the wafer handling mechanism, and picks up the wafer 28 on the wafer mounting table 21 (see wafer mounting table 205 in FIG. 2) l-. Pink up and remove from the chamber. The receiver then transfers the wafer to a belt conveyance mechanism (see side 241 of the belt conveyor in FIG. 2).

On the other hand, when the wafer handling mechanism on the unloading side has completely unloaded the wafer from the chamber, the ashing device 2
sends the completion signal to the end point determination/control device 8.

Upon receiving this completion signal, the end point determination/control device 8 sends a control signal to the ashing device 2 to close the gate valve (gate valve 225) communicating with the loader/unloader section on the wafer unloading side. Then, close the valve and disconnect the loader/unloader section on the wafer unloading side. Next, a valve (
A control signal is sent to the ashing device 2 to open the valve 224 (FIG. 2).

The ashing device 2 opens its valve and communicates the chamber with the loader/unloader section.

Next, the end point determination/control device 8 sends a signal to the ashing device 2 to operate the wafer handling mechanism on the carry-in side (transfer arm 25a in FIG. 2).

The ashing device 2 operates the carry-in side wafer handling mechanism, picks up the wafer 28 from the belt conveyance mechanism (see belt conveyance mechanism 24a in FIG. 2), carries it into the chamber, and carries it to the wafer mounting table 21 (see belt conveyance mechanism 24a in FIG. 2). The wafer is placed on a wafer mounting table 205).

Then, the wafer mounting table 21 attracts and holds this.

When the wafer loading destination r of the wafer handling mechanism on the loading side is completed 1' and the arm etc. returns to the loader/unloader, the ashing device 2 sends a loading completion signal No. 2 to the end point determination/control device 8. .

Upon receiving this signal>3, the end point determination/control device 8 sends a control signal to the ashing device 2 to close the valve communicating with the loader/unloader section on the wafer loading side, and also loads the wafer on the lifting device 5. 1 unit on stand 21? Shingo (
In FIG. 2, the ejector 22 sends out a signal.

The ashing device 2, which has received the control signal to close the valve, closes the valve and separates the chamber from the loader/unloader section on the carry-in side. On the other hand, the wafer mounting table 21'-
Upon receiving the lift signal, the lifting device 5 controls the wafer mounting table 21 to set the gap between the diffusion plate and the wafer mounting table to the gap required for reaction (set to the reaction position).

At the time when the reaction position setting signal 3 is received from the lifting device 5,
The end point determination/control device 8 generates a signal to open the valve of the gas introduction pipe and controls the start of gas injection. Then, it monitors the υt gas and enters the end point determination process.

FIG. 15 is a graph showing changes in the moisture content of carbon dioxide in the exhaust gas in this case.

As shown in the figure, the concentration of carbon dioxide gradually increases as the processing time progresses and becomes a constant value. Under conditions where the gap in the oxidation reaction space, the wafer temperature, and the gas flow rate are in the optimal range, the concentration of carbon dioxide gradually increases and reaches a constant value. The ashing process is completed within 1 minute for the wafer, or from 1 to several minutes depending on the gap, wafer temperature, and gas flow rate, and the concentration rapidly approaches zero at this point. go.

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

By the way, the detected gas for the final determination is not limited to carbon dioxide, but water and carbon oxide have almost similar characteristics. Therefore, the end point of the ashing process may be determined by measuring one volume of the gas.

On the other hand, as seen in this graph, the slope tendency in which gas generation starts to decrease from a constant value and then reaches zero is almost the same characteristic for υl gas. therefore,
Point A where this characteristic changes or point B where it decreases below a certain value t''
By detecting this, the end point -r can be predicted.

The point B that has decreased can be detected by changing the reference value of the comparator described in +lii, and the predicted end point can be determined by adding a fixed time to this detection point.

Further, the detection of the change point A can be easily performed by combining a differential circuit or a peak detection circuit with a comparator.
can be realized.

By the way, when detecting that rJl "1j of gas" is less than a predetermined value, gas analysis 1. shown in FIG.
17 and the end point determination/determination unit of the control device 8 determine the specific gas i4. A detector (gas sensor) that detects l in a specific a1+'f or a specific range, and a terminal r from that detection signal.
End point r11 constant circuit that determines the point in time (judgment processing using a comparator, logic circuit, or microprocessor)
That's enough. On the other hand, when detecting a change point in D1 gas, a 111 measuring instrument or sensor that generates a signal corresponding to the clearness of a specific gas as a detection signal, or a sensor that detects only the change state is required.

As explained above, in the embodiments, the diffusion plate is disposed on one part of the wafer, or this means that the wafer is
In this case, the diffuser plate side may blow gas from C to -L in a suspended form. It may also be placed in the same position.

In short, the arrangement relationship between these is not limited to "nid", but it is sufficient that they face each other at a certain distance.

In addition, the loading of the wafer to the ashing equipment and the loading j11 are as follows:
It goes without saying that any handling mechanism may be used and is not limited to the embodiments.

In the embodiment, in order to carry in the wafer, either the wafer mounting table or the diffusion plate is relatively moved to secure insertion space for the hunt ring arm 11.

However, they may also move with each other at the same time.

Furthermore, if a configuration is adopted in which the wafer is sent to the wafer mounting table using a belt transfer mechanism and a pusher, etc., the gap between the diffusion plate and the wafer mounting table can be narrow, and 1) the enlarged space into which the handling arm etc. described in 7j enters can be reduced. Since this is unnecessary, the mechanism for moving the wafer mounting table or the diffusion plate is not essential.

The example describes the case of injecting gas, but is this true? In step 11-, it is also sufficient that ozone+oxygen gas simply flows out into the reaction space. Therefore, as much as flows inside is sufficient.

In addition, in the embodiment, the structure of the injection part is a conical one.
Although cylindrical and tubular types are listed, for example, a disk-shaped type or a nozzle-like type may be used to inject or flow out the ozone outlet, and various shapes can be used. is applicable.

Therefore, in this specification, the term ``1i'' includes a rod-shaped member whose locus forms a gas flow equal to that of the ``Y plate'' by rotating it.

A cooler may be employed depending on the reaction conditions and is not necessarily required. In addition, the structure is based on the case where the refrigerant flows through the pipe, but it is also possible to immerse a double-structured space where the refrigerant flows directly into the injection part, and various liquids such as water and cooling air can be used. It may be cooled by gas or further by a cooling metal using the Peltier effect or the like.

The diffusion plate uses a sintered alloy as having uniform porous pores, but porous materials are not limited to metals, and various materials such as ceramics can be used. Of course.

Furthermore, the temperature of the wafer during the ashing process is
The higher the value, the faster the oxidation reaction rate will be, but this is also related to the speed of wafer loading/unloading, and does not necessarily have to be set to a high value. Furthermore, considering the life time of ozone, the reaction can be carried out at about room temperature or higher. Also, iI′t′ of ozone
If the amount % can be set to a high value, i'iJ performance can be achieved even at a value lower than room temperature. However, with the current equipment, it is thought that the ozone generation ij ji 1% is not limited to around 10 to 13%.

In the examples, the explanation focuses on resist as the unsong target, but as mentioned in the prior art section, this unsong process can be applied to various things such as removing ink and solvents, and can be used to remove oxidation. Any material may be used as long as it can be removed.

In addition, the case where ozone is contained in oxygen gas is mentioned, but ozone is not limited to oxygen, but also gases that do not react with ozone, especially various inert gases such as N2 + Ar + Ne, etc. It can be used by containing.

[Effects of the Invention] As can be understood from the explanation in Part I-, in this invention, an ozone outflow portion having a β plate portion is provided at a position facing the wafer at a predetermined distance, and the wafer and Between wafer and 14? By creating a gas flow space of +'+ oxygen, new ozone is continuously supplied to the wafer, promoting the oxidation chemical reaction between oxygen atomic radicals and the film deposited on the wafer, and By expanding the gas outflow area to the outside of the wafer, carbon dioxide, carbon oxide, water, etc. generated after the reaction with non-radical oxygen (02) are transferred from the wafer surface in a vaporized state.
[You can make it come out.]

As a result, the reaction surface of the film 9, for example, an organic film deposited on the wafer 1-, can be efficiently exposed to oxygen atomic radicals, which have a very strong oxidizing action.

Therefore, it is possible to perform high-speed ashing processing (ij)
This makes it possible to realize an ashing device suitable for single-wafer processing.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an ashing processing system according to an embodiment to which the anosong apparatus of the present invention is applied, and FIG. 2 is a block diagram of another similar embodiment, showing the overall configuration including a wafer transport mechanism. 3 (a) and (b)
) is a specific explanatory diagram of the electrostatic chuck in the wafer transfer mechanism, in which (a) is a sectional view taken along line II in (b) of the same figure, (b) is a plan view thereof, and FIG. An enlarged explanatory diagram of the reaction part, FIG. 5(a), is a diagram explaining the relationship between reaction and movement by oxygen atom radicals, FIG. 5(b) and (C
) are diagrams illustrating the relationship between the diffusion amount [1 and the ashing state in the wafer, respectively, and FIG. 6 is a graph illustrating the relationship between the decomposition half-life of ozone and the temperature of the diffusion opening. Furthermore, Fig. 7 is a graph explaining the relationship between the ashing rate and the gas flow rate at a wafer surface temperature of 300°C, and Fig. 8 shows the ashing rate for the gap between the diffuser plate and the wafer surface at a wafer surface temperature of 300°C. A graph illustrating the relationship between speed, FIG. 9, and an explanatory diagram illustrating the relationship between gas temperature and resist removal rate, FIG. 10(a), (
b), (c) + (dL (eL) (f) is an explanatory diagram of a specific example of "J old" of the diffuser plate, respectively, Fig. 11 (
a), (b), (c), and (d) are explanatory diagrams of specific examples of the gas cooling structure in the injection part, respectively, and FIG. 12 (a)
is an explanatory diagram of the force type that rotates the gas injection part, Fig. 12 (
b) is an explanatory diagram of rotating the wafer side; FIG. 13 is an explanatory diagram of the song effect when the wafer side is not rotated; and FIG. 14 is a block diagram of an embodiment of an ashing processing system that determines the end of the ashing process. , Figure 15 is a graph of changes in the concentration of carbon dioxide in the υ1 gas, Figure 16.
The figure is a graph explaining the relationship between the ashing speed and the ozone concentration, and FIG. 17 is an explanatory diagram of a conventional ashing device using ultraviolet rays. l... Ashing system 1. ．． 2.20... Ashing device, 3... Oxygen gas supply device, 3a... Gas flow jit regulator, 31)... Ozone generator, 3c... Oxygen supply source, 4... υ1 Air device, 5
...! /i1 Descending device, 6...l Visibility adjuster, 7...
- Gas analyzer, 8... End point determination/control device, 10a,
10b... Electrostatic chuck, 21... Wafer mounting table, 21211 20 B... Heating device, 22.22a,
22b-gas injection section, 23a, 23b...loader/unloader section, 24a,
24b... Belt conveyance mechanism section, 25a, 25b-...
Transfer arm, 28a, 26b... suction chuck, 28... wafer, 31... slitting. 1, 'I Applicant Tokyo Electron Ltd. Figure 3 ((1) 211a 12a Figure 4 Figure 5. ÷ Tomo Rinryo (
Si! /min) Fig. 8 Fig. 9 Itori Itana D1hiko (9C) No. 11 (C) (d) Section 12 (a) (b) Fig. 17 Fig. 13

Claims (8)

[Claims] (1) An outflow section is provided, the outflow section having a flat plate section that is disposed opposite to the wafer at a predetermined distance from which the ozone-containing gas flows out; An ashing apparatus characterized in that an ashing apparatus is provided with an opening, and the gas is allowed to flow out from the opening to the outside of the wafer to oxidize and remove a film deposited on the wafer surface. (2) The ashing device according to claim 1, wherein the flat plate portion is formed as a locus of a tubular member horizontally rotated. (3) The flat plate portion is provided with a plurality of openings, and the gas flowing out from the outer openings flows out to the outside of the outer shape of the wafer.
The ashing device described in section. (4) The ashing device according to claim 3, wherein the gas is discharged over a range of 5 mm or more outside the outer shape of the wafer. (5) The ashing apparatus according to any one of claims 1 to 4, wherein the wafer is heated. (6) The facing arrangement is characterized in that the outflow portion is on top, the temperature of the gas to be cooled is in the range of 15 to 50°C, and the heating temperature of the wafer is in the range of 150 to 500°C. The ashing device according to scope 5. (7) Claims 1 to 6, characterized in that the flat plate portion is made of a porous material and placed above the wafer, and the openings are pores of the porous material. The ashing device according to any one of the above. (8) The ashing device according to claim 7, wherein at least one of the wafer and the outflow portion moves up and down.