JP5608333B2 - Heat treatment apparatus and semiconductor device manufacturing method - Google Patents

Description

The present invention relates to a heat treatment apparatus for performing heat treatment on a substrate such as a semiconductor wafer or a glass substrate.

In a semiconductor device, an oxide film laminated on the surface of a substrate is used. Oxide films are widely used in semiconductor devices including MOS transistor gate oxide films because of their good interface state, but direct tunneling current is observed as transistors become thinner due to the integration of transistors. It became so. This direct tunnel current is difficult to reduce with a single silicon oxide film, and nitrogen (
By introducing N) into the oxide film, the tunnel current is directly reduced.

Nitrogen annealing treatment for introducing nitrogen into the oxide film is performed by using nitrogen-containing gas such as NO ₂ , N ₂ O, NH _{3 and the} like to replace oxygen (O) in the oxide film with nitrogen (N). In this process, nitrogen is introduced into the film. To maintain the nitrogen concentration in the oxide film, it is necessary to heat the nitrogen-containing gas before supplying it to the processing chamber. It is necessary to sufficiently heat the nitrogen-containing gas.

Therefore, the present inventors have studied heating the nitrogen-containing gas through the nitrogen-containing gas through an external combustion apparatus provided in the gas supply system of the heat treatment apparatus, but have the following problems.

The external combustion apparatus has a heating chamber for generating a combustion reaction, a gas inlet for introducing gas into the heating chamber, a gas outlet for discharging gas from the heating chamber, and a heating chamber raised by heating. The apparatus has a heater for heating, introduces hydrogen gas and oxygen gas into a heating chamber heated to a predetermined temperature, and generates steam by a combustion reaction of hydrogen and oxygen. The temperature of the heating chamber is also a heater. Therefore, it may be suitable as an apparatus for heating the nitrogen-containing gas before introducing it into the processing chamber.
However, since the gas inlet, heating chamber, and gas outlet of the external combustion device are arranged in a straight line and gas can be easily discharged, the gas residence time (residence time) in the heating chamber is shortened, and the gas is sufficient. There is a risk of being supplied to the processing chamber before being heated.

In view of the above, an object of the present invention is to enable sufficient heating according to processing before supplying gas to the processing chamber to the processing chamber.

An aspect according to the present invention includes a processing chamber for processing a substrate, a gas supply system for supplying a gas for processing a substrate into the processing chamber, and a heating unit provided in the gas supply system, and the heating unit Is
A plurality of wall bodies provided on the inner side wall, wherein a first gap is provided between the first wall body and the side wall, and a second wall body adjacent to the first wall body; A second heat treatment apparatus is provided between the side walls, and a second heat treatment apparatus is provided at opposite side wall positions so that the first gap and the second gap do not overlap.

According to the present invention, the gas is retained in the heating unit for a long time, and heat is transmitted from the inner wall of the heating unit to sufficiently heat the gas, whereby it can be thermally decomposed, and the heated or pyrolyzed gas is supplied to the processing chamber. Can be supplied. For this reason, in the annealing process, a gas obtained by thermally decomposing the nitrogen-containing gas can be supplied to the processing chamber, and a desired nitrogen concentration can be maintained in the nitrogen annealing process. Further, a desired nitrogen concentration can be realized by adjusting the temperature, adjusting the flow rate, or the like.

It is the schematic which illustrates the heat processing apparatus as an oxidation treatment apparatus (nitriding treatment apparatus) used for the oxidation treatment process (nitriding treatment process) concerning this invention centering on a processing furnace. It is the schematic which illustrates the heat processing apparatus as an oxidation treatment apparatus (nitriding treatment apparatus) used for the oxidation treatment process (nitriding treatment process) concerning this invention centering on an external combustion apparatus. It is the schematic which illustrates mainly the shape inside the heating apparatus of the oxidation treatment apparatus (nitriding treatment apparatus) used for the oxidation treatment process (nitriding treatment process) which concerns on this invention. It is A arrow directional view of FIG.3 and FIG.6. It is a figure which shows the example of the shape of the hole provided in a resistance board. It is sectional drawing which shows the modification of the heating apparatus shown in FIG. It is sectional drawing which shows other embodiment of the heating apparatus which provided the gas supply nozzle instead of the resistance board, and was made to increase the residence time of process gas. It is sectional drawing which shows the installation position of the 2nd gas supply pipe | tube in a heating apparatus, and a 3rd gas supply pipe | tube. It is a figure which shows the result of the component analysis of the internal atmosphere of the 2nd gas supply pipe which discharges | emits gas from a heating apparatus. It is a figure which shows the result of having performed the component analysis of internal atmosphere in the exhaust-port vicinity in the case where process gas is passed through a ceiling part, and the case where process gas is not passed through a ceiling part.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1A and FIG. 1B are schematic configuration diagrams showing a configuration of a processing furnace 202 of a substrate processing apparatus suitably used as a heat processing apparatus in an embodiment of the present invention, and are shown as longitudinal sectional views. Yes. In FIG. 1B, in order to clarify the difference in configuration from FIG. 1A, the upper side is omitted, the lower side is shown, and the same components are denoted by the same reference numerals. . The configuration omitted in FIG. 1B is the same as the processing furnace shown in FIG.

As shown in FIG. 1A, the processing furnace 202 has a heater 206 as a heating device. The heater 206 has a cylindrical shape and is vertically installed by being supported by a heater base 251 as a holding plate.
Inside the heater 206, for example, a cylindrical heat equalizing tube (outer tube) 205 made of a heat resistant material such as silicon carbide (SiC), closed at the upper end and opened at the lower end is arranged concentrically with the heater 206. It is installed. Further, inside the soaking tube 205, a cylindrical reaction tube (inner tube) 204 made of a heat-resistant material such as quartz (SiO ₂ ) and having an upper end closed and a lower end opened is concentric with the soaking tube 205. It is arranged in a shape. A cylindrical hollow portion of the reaction tube 204 serves as a processing chamber 201, and is configured so that wafers 200 as substrates can be accommodated in a state of being aligned in multiple stages in a vertical posture in a horizontal posture by a boat 217 (described later).

A gas introduction unit 230 is provided at the lower end of the reaction tube 204, and the reaction tube 204 extends from the gas introduction unit 230 to the ceiling 233 of the reaction tube 204 as a gas introduction tube.
It is arranged along the outer wall of the. The gas introduced from the gas introduction part 230 reaches the ceiling part 233 through the narrow tube 234 and is introduced into the processing chamber 201 from a plurality of gas introduction ports 233 a provided in the ceiling part 233. In addition, a gas exhaust unit 231 for exhausting the atmosphere in the reaction tube 204 from the exhaust port 231a is provided at a position different from the gas introduction unit 230 at the lower end of the reaction tube 204.

A first gas supply pipe 232 is connected to the gas introduction unit 230. On the upstream side, which is the opposite side to the connection side of the first gas supply pipe 232 with the gas introduction unit 230, the first gas supply pipe 23.
2 is branched, and one branch pipe is a process gas supply source, a carrier gas supply source, and an inert gas supply source (not shown) via a mass flow controller (hereinafter abbreviated as MFC) 241 as a gas flow rate controller. The other branch pipe is also connected to the processing gas supply source, the carrier gas supply source, and the inert gas supply source via the MFC 284.
When it is necessary to supply water vapor into the processing chamber 201, an external combustion device 270 is provided downstream of the MFC 241 in the first gas supply pipe 232 as shown in FIG.
A second gas supply pipe 278 is connected between the processing chamber 201 of the first gas supply pipe 232 and the external combustion device 270, and a heating device 271 is provided upstream of the second gas supply pipe 278. Further, an MFC 284 is provided upstream of the heating device 271 of the second gas supply pipe 278.
A gas flow rate control unit 235 is electrically connected to the MFC 241 and is configured to control at a desired timing so that the flow rate of the supplied gas becomes a desired amount. Similarly, the MFC 284 is also electrically connected to a gas flow rate control unit (not shown), and is configured to control at a desired timing so that the flow rate of the supplied gas becomes a desired amount. However, when the external combustion device 270 is not provided, as shown in FIG.
The FC 241 is directly connected to the first gas supply pipe 232 without going through the external combustion device 270.

A gas exhaust pipe 229 is connected to the gas exhaust unit 231. A pressure sensor 245 as a pressure detector is provided on the downstream side of the gas exhaust pipe 229 opposite to the connection side with the gas exhaust part 231.
Further, an exhaust device 246 is connected via a pressure adjusting device 242, and the exhaust gas is exhausted so that the pressure in the processing chamber 201 becomes a predetermined pressure.
A pressure control unit 236 is electrically connected to the pressure adjustment device 242 and the pressure sensor 245, and the pressure control unit 236 uses the pressure adjustment device 242 based on the pressure detected by the pressure sensor 245 in the processing chamber 201. Control is performed at a desired timing so that the pressure becomes a desired pressure. The exhaust device 246 includes a device capable of controlling the inside of the reaction tube 204 to a high vacuum state of 100 Pa or less, for example, a vacuum pump or a turbo molecular pump.

At the lower end of the reaction tube 204, a base 257 as a holding body capable of hermetically closing the lower end opening of the reaction tube 204 and a seal cap 219 as a furnace port lid are provided.
The seal cap 219 is made of a metal such as stainless steel and has a disk shape. The base 257 is made of, for example, quartz, is formed in a disk shape, and is attached on the seal cap 219. An O-ring 220 is provided on the upper surface of the base 257 as a seal member that contacts the lower end of the reaction tube 204.
A rotation mechanism 254 that rotates the boat 217 is installed on the side of the seal cap 219 opposite to the processing chamber 201.
The housing of the rotation mechanism 254 is fixed to the lower surface portion of the seal cap 219, and the rotation shaft 255 of the rotation mechanism 254 passes through the seal cap 219 and the base 257 and is connected to a heat insulating cylinder 218 and a boat 217 described later. . In other words, the rotating mechanism 254 rotates the rotating shaft 255 with the housing as a fixed system, so that the heat insulating cylinder 218 integrated with the rotating shaft 255 is obtained.
The boat 217 is rotated, and the wafer 200 is rotated by rotating the boat 217.

The seal cap 219 is configured to be vertically lifted by a boat elevator 115 as a lifting mechanism vertically installed outside the reaction tube 204, and thereby the boat 217 is carried into and out of the processing chamber 201. Is possible.
A drive control unit 237 is electrically connected to the rotation mechanism 254 and the boat elevator 115, and is configured to control at a desired timing so as to perform a desired operation.

The boat 217 as a substrate holder is made of a heat resistant material such as quartz or silicon carbide (SiC), and is configured to hold a plurality of wafers 200 in a horizontal posture and aligned with each other in the center. Yes.
Below the boat 217, a heat insulating cylinder 218 as a cylindrical heat insulating member made of a heat resistant material such as quartz or silicon carbide is provided to support the boat 217, and heat from the heater 206 reacts. The tube 204 is configured to be difficult to be transmitted to the lower end side.

Between the soaking tube 205 and the reaction tube 204, a temperature sensor 263 as a temperature detector is installed. A temperature control unit 238 is electrically connected to the heater 206 and the temperature sensor 263, and the temperature in the processing chamber 201 is adjusted by adjusting the power supply to the heater 206 based on the temperature information detected by the temperature sensor 263. Is controlled at a desired timing so as to have a desired temperature distribution.

The gas flow rate control unit 235, the pressure control unit 236, the drive control unit 237, and the temperature control unit 238 are
An operation unit and an input / output unit are also configured, and are electrically connected to a main control unit 239 that controls the entire substrate processing apparatus. These gas flow rate control unit 235, pressure control unit 236, drive control unit 237, temperature control unit 238, and main control unit 239 are configured as a controller 240.

  Next, the external combustion device 270 and the heating device 271 will be described.

FIG. 2 is a cross-sectional view showing the configuration of the external combustion device 270.
The external combustion device 270 is provided outside the vertical processing furnace 202 as shown in FIG.
For example, it is connected to a first gas supply pipe 232 made of quartz. External combustion device 27
As shown in FIG. 2, 0 includes a combustion pipe 272 made of, for example, transparent quartz.

The outer periphery of the combustion tube 272 is surrounded by, for example, a heater 273, and the heater 27
3 is covered with a cylindrical heat insulator 274. The heater 273 is, for example, a combustion pipe 272.
Based on a temperature detection signal from a temperature sensor 280 made of a thermocouple provided in the heater 2
Temperature control is performed by controlling the energization amount to 73.

In the case where hydrogen gas or oxygen gas is supplied into the combustion pipe 272 as a processing gas, water vapor is generated by a combustion reaction of hydrogen and oxygen, and wet oxidation is performed using this water vapor, the gas supply path 2
Oxygen gas is supplied from 76A to the combustion pipe 272, and hydrogen gas is supplied into the combustion pipe 272 from the gas supply path 277B. Thereby, water vapor is generated in the combustion pipe 272 by the combustion reaction of hydrogen gas and oxygen gas.

FIG. 3 is a cross-sectional view showing an embodiment of the heating device 271.
As shown in FIGS. 1A and 1B, the heating device 271 is upstream of the second gas supply pipe 278 that branches from between the first gas supply pipe 232 of the processing furnace 202 and the external combustion apparatus 270. A heating tube 285 connected to the side and forming a cylindrical heating chamber 290 in the second gas supply tube 278
Is connected. The second gas supply pipe is made of, for example, quartz, and the heating pipe 285 is made of, for example, transparent quartz or opaque SiC.
As shown in FIG. 3, the heating chamber 290 introduces and discharges a processing gas, for example, a nitrogen-containing gas, so that a second gas supply pipe 278 is provided at one end and a third gas is provided at the other end. Gas supply pipe 27
9 is communicated. The inner diameter of the heating pipe 285 is larger than the outer shape of the third gas supply pipe 279,
Inside, there are resistance plates (also called baffle plates or partition plates) 281A as the first wall body and the second wall body.
And a resistance plate 281B.
The resistance plate 281A and the resistance plate 281B are each formed in a disk shape, and the heating tube 285 is formed.
Between the one side wall of the heating chamber 290 and the resistance plate 281A, the heating chamber 290
Hole 30 serving as a first gap and a second gap, respectively, between the other side wall and the resistance plate 281B.
It is provided to form 0. That is, the holes 300 are provided alternately in the axial direction of the heating tube 285. The heater 273 is controlled to heat the gas to a predetermined temperature based on the detection value of the temperature sensor 280 as a temperature detection device and the detection value of the temperature set value. The temperature of the heater 273 is controlled by the temperature control unit 238 so as to thermally decompose the nitrogen-containing gas during the nitrogen annealing.

When the resistance plate 281A is provided in the heating device 271, the gas introduced into the heating chamber 290 from the third gas supply pipe 279 hits the first resistance plate 281A, and then the second gap from the first gap. To the second resistance plate 281B while changing the direction of the gas, and further reaches the second gas supply pipe 278 while changing the traveling direction, and then passes through the first gas supply pipe 232 and passes through the processing chamber 20l. Introduced into This prolongs the residence time in the gas heating device 271 and sufficiently heat-treats the gas. Further, gas is supplied to each resistance plate 281.
There is also an aim of urging the gas activation by colliding with A and 281B.

In the illustrated example, the hole position of the resistor plate 281A is provided on the upper side in the drawing, and the hole 300 of the resistor plate 281B is provided on the lower side in the drawing. However, in the adjacent resistor plate 281A and resistor plate 281B, The resistor plate 281A may have a hole on the right side and the resistor plate 281B on the left side.
Further, any number of resistance plates (wall bodies) 281A and 281B may be provided. However, in the case where five resistance plates are provided rather than three, vortices are formed at higher temperatures, so that the gas is easily decomposed. I know that. Therefore, although depending on the capacity of the heating chamber 290, it can be said that the larger the number of resistance plates, the easier it is to disassemble. Further, in the present invention, the shape of the hole (gap) provided in the resistance plate (wall body) is circular, semi-circular (including crescent shape), fan-shaped, etc., where the gas stays efficiently and is easily decomposed by heating. Any shape is acceptable. However, as shown in FIG. 5, the most preferable shape is preferably a shape in which the area of the contact surface in contact with the side wall of the heating device 271 is as large as possible, such as a semicircular shape or a sector shape. A heater 273 is disposed on the outer peripheral portion of the side wall of the heating device 271.
This is because the larger the area in contact with the side wall, the easier the gas is preheated.

In the present invention, as the point of the hole 300 position provided in the resistance plates 281A, 281B,
[1] A point installed at a position in contact with the wall side of the heating chamber 290, and [2] a plurality of resistance plates 281A.
, 281B may be provided on the opposing side walls on the resistance plate so that the holes 300 do not overlap each other.

Moreover, the following effect is acquired when the hole 300 is provided in this way.
[1] When gas collides with the two surfaces of the resistance plate and the wall surface, vortices are easily formed compared to the case where a hole is formed in the central portion of the resistance plate where the gas collides with only one surface. Residence time is increased.
[2] The time of contact with the wall side is increased, and the gas is more easily heated by the heat of the heater 273 installed on the outer periphery of the heating chamber 290, thereby improving the heat transfer efficiency.
[3] By making the gas flow direction zigzag, the gas trajectory becomes longer.
[4] When the gas cannot be short-passed (turns around), the flow resistance value of the baffle plate is increased and the pressure in the heating chamber 290 is increased, so that the gas flow rate is decreased and the gas residence time is increased. In other words, heat transfer is facilitated due to an increase in pressure in the heating chamber 290, so that preheating is facilitated.

FIG. 3 shows an example in which one resistor plate 281A and one resistor plate 281B are provided, but a plurality of resistor plates 281A and resistor plates 281B may be alternately provided in the axial direction of the heating tube 285. . In the embodiment according to the present invention, it is most preferable to provide one hole in each of the resistance plates 281A and 281B. However, the temperature sensor 280 is inserted into the heating chamber 290, and the temperature of the heating tube chamber 290 is accurately set. When detecting, the temperature sensor 2 is connected to each resistance plate 281A, 281B.
You may provide the hole which lets 80 pass. In this case, the largest hole 3 of each resistance plate 281A, 281B
00 is preferably provided on the opposite inner surfaces of the heating tube 285 so as to be staggered.

Next, a modified example of the heating device 271 shown in FIG. 3 and other embodiments will be described.
In addition, about the structure same as the heating apparatus 271 demonstrated in FIG. 3, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

FIG. 6 is a modification of the heating device 271 shown in FIG.
As shown in FIG. 6, in this example, in order to increase the residence time of the gas in the heating chamber 290, a guide for changing the gas flow direction to the peripheral edge of the hole 300 of the resistance plate 281A and the resistance plate 281B. A plate (also referred to as a protrusion) 301 is provided. In this embodiment, the guide plate 301 is provided in the hole 300 so as to change the flow direction of the gas supplied from the third gas supply pipe 279 to the heating chamber 290 to the opposite side by 180 °. Thereby, the residence time of gas can be increased.

FIG. 7 shows an example in which a gas supply nozzle 282 is provided in place of the resistor plate 281A and resistor plate 281B described with reference to FIGS. 3 and 6 to increase the residence time of the processing gas.
The gas supply nozzle is disposed in the heating chamber 290 and is attached by connecting the base portion of the gas supply nozzle 282 to the end portion of the third gas supply pipe 279 on the heating chamber 290 side.
The gas supply nozzle 282 is disposed adjacent to the side wall (inner surface) of the heating tube 285, and increases the gas residence time by multiple bends. In this embodiment, the gas supply nozzle 28
2 is the second from the second gas supply pipe 279 side along the side surface (inner surface) on one side of the heating pipe 285.
After being extended to the vicinity of the connection portion with the gas supply pipe 278, the combustion pipe 272 is bent from one side wall (inner surface) side to the other side wall (inner surface) side, and further, near the other side wall side Further, it is bent toward the second gas supply pipe side.
The gas supply nozzle 282 is close to the side wall of the heating chamber 290, and is configured to be heated by radiant heat from the heating tube 285 and heat conduction through the internal atmosphere of the heating chamber 290, and is bent a plurality of times. Thus, the residence time of the gas in the heating chamber 290 is increased. A gas such as a nitrogen-containing gas is introduced from the third gas supply pipe 279 to the gas supply nozzle 282 and ejected from the gas ejection port 279A. The ejection direction is the second gas supply pipe 2
78 is the opposite direction. Further, the ejected gas reaches the wall surface of the heating chamber 290 opposite to the second gas supply pipe 278 side, and further changes the traveling direction while changing the traveling direction.
After reaching 8, the gas is introduced into the processing chamber 201 through the first gas supply pipe 232. This extends the residence time of the gas in the heating device 271 and sufficiently heat-treats the gas. Another aim is to promote gas activation by subjecting the gas to heat treatment.

FIG. 8 shows a second gas supply pipe 278, a third gas supply unit 271 for the heating device 271 described with reference to FIG.
It is sectional drawing which shows the installation position of the gas supply pipe | tube 279 of this.
As shown in FIG. 8, the third gas supply pipe 279 is attached to an eccentric position shifted outward from the axial center line of the heating chamber 290, and the second gas supply pipe 278 is connected to the heating chamber 290. The second gas supply pipe 278 is attached to a position where it matches the axial line.
In addition, a temperature sensor 280 is provided to control the temperature of the heater 273.
In this way, when the position of the third gas supply pipe 279 is eccentric, the third gas supply pipe 2
The gas introduced into the heating chamber 290 from 79 hits the heating chamber wall surface 283 and then reaches the second gas supply pipe 278 while changing the traveling direction, and then passes through the first gas supply pipe 232 and passes through the processing chamber 201. To be introduced. As a result, the residence time of the gas in the heating chamber 290 is extended and sufficient heat treatment is performed on the gas. In addition, by sufficiently performing the heat treatment of the gas,
There is also an aim to promote the activation of gas.

Next, a method of performing an N ₂ O annealing process or a process such as oxidation or diffusion on the wafer 200 as one step of the semiconductor device manufacturing process using the processing furnace 202 as the heat treatment apparatus according to the present embodiment will be described. In the following description, it is assumed that the operation of each part constituting the substrate processing apparatus is controlled by the controller 240.

When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), FIG.
2, the boat 217 holding the plurality of wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201 (boat loading).
In this state, the seal cap 219 is connected to the reaction tube 20 via the base 257 and the O-ring 220.
4 The bottom end is sealed.

The inside of the processing chamber 20l is exhausted by the exhaust device 246 so as to obtain a desired pressure. At this time, the pressure in the processing chamber 201 is detected by the pressure sensor 245, and the pressure adjusting device 242 is feedback-controlled based on the detected pressure. In addition, the inside of the processing chamber 201 is heated by the heater 206 so as to have a desired temperature.
At this time, the power supply to the heater 206 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Subsequently, the wafer 200 is rotated by rotating the heat insulating cylinder 218 and the boat 217 by the rotation mechanism 254.

Next, a N ₂ O annealing treatment method or an oxidation / diffusion treatment is performed.

In the N ₂ O annealing process, a nitrogen-containing gas is supplied from a processing gas supply source, and a carrier gas is supplied from a carrier gas supply source.
The nitrogen-containing gas (N ₂ O gas) and the carrier gas controlled to have a desired flow rate by the MFC 284 are introduced from the second gas supply pipe 278 to the first gas supply pipe 232, and the first gas From the supply pipe 232 to the ceiling part 233 through the gas introduction part 230 and the narrow pipe 234,
A plurality of gas introduction ports 233a are introduced into the processing chamber 201 in a shower shape.
At this time, since the annealing process is performed using the nitrogen-containing gas sufficiently heated with respect to the wafer 200, the nitrogen-containing gas is controlled to a desired flow rate by the MFC 284. The nitrogen-containing gas is supplied to the heating device 271 and heated to a predetermined temperature by the heater 274.
The gas decomposed by the preheating of 71 is introduced into the processing chamber 201. The cracked gas introduced into the processing chamber 201 flows down in the processing chamber 201, flows through the exhaust port 231 a, and is exhausted from the gas exhaust unit 231.
When the nitrogen-containing gas passes through the processing chamber 201, the surface of the wafer 200 and the oxide film (
Contact with SiO ₂ ). Temperature of the processing chamber 201, the pressure, the temperature suitable for the N 2 _O anneal, because it is held in the pressure, N 2 _O anneal processing is performed. In the N ₂ O annealing process, nitrogen is introduced into the oxide film by a substitution reaction of oxygen and nitrogen in the oxide film on the surface of the wafer 200.
In this manner, since nitrogen that has been thermally decomposed and activated in advance is supplied to the wafer 200, the nitrogen concentration in the oxide film is maintained at a high value.

  Subsequently, a wet oxidation treatment method will be described as an example of the treatment such as oxidation and diffusion.

In the oxidation and diffusion processes, a processing gas is supplied from a processing gas supply source, and a carrier gas is supplied from a carrier gas supply source. These gases are controlled to a predetermined flow rate by the MFC 241,
From the gas supply pipe 232 to the ceiling part 233 through the gas introduction part 230 and the narrow pipe 234,
A plurality of gas introduction ports 233a are introduced into the processing chamber 201 in a shower shape.
Note that when an oxidation process using water vapor is performed on the wafer 200, a process gas containing hydrogen and oxygen is supplied as a process gas. Process gas containing hydrogen and oxygen is MFC
It is controlled to a desired flow rate at 241 and is supplied to the external combustion device 270.
Since the inside of the external combustion apparatus 270 is heated to a predetermined temperature by the heater 274, water vapor is generated by a combustion reaction between hydrogen and oxygen, and the gas containing the generated water vapor (H ₂ O) is supplied to the processing chamber 201. be introduced.
The processing gas introduced into the processing chamber 201 flows down in the processing chamber 201 and is exhausted from the gas exhaust unit 231 through the exhaust port 231a.
When the processing gas is a gas containing water vapor, it contacts the surface of the wafer 200 when flowing down the processing chamber 201. As a result, the wafer 200 is subjected to processing such as oxidation and diffusion.
However, as shown in FIG. 1A, if the external combustion device 270 is not provided, the MFC
It is assumed that the gas is supplied directly to the reaction tube 204 by being connected directly to the first gas supply tube 232 from 241.
Note that the oxidation and diffusion treatments according to the present embodiment are not limited to wet oxidation treatments, but include CVD,
An oxidation treatment such as isotropic oxidation, reduced pressure oxidation, and high vacuum oxidation may be used.

Until one example. As processing conditions for processing the wafer 200 in the processing furnace 202 of the present embodiment, for example, in the N ₂ O-anneal (N ₂ O-annealing) processing, the processing temperature is 600 to 1000 ° C. and the processing pressure is 50. ˜110000 Pa, gas type: N ₂ O or H
Illustrated are Cl (in the case of HCl oxidation treatment) and a gas flow rate of 0.1 to 20.00 sccm. By maintaining each processing condition constant at a value within each range, the wafer 20
Processing of 0 is performed.

When a preset processing time has elapsed, an inert gas is supplied from an inert gas supply source,
The processing chamber 201 is replaced with an inert gas, and the pressure in the processing chamber 201 is returned to normal pressure.

Thereafter, the seal cap 219 is lowered by the boat elevator 115 and the reaction tube 2
The lower end of 04 is opened, and the processed wafer 200 is unloaded from the lower end of the reaction tube 204 to the outside of the reaction tube 204 while being held by the boat 217 (boat unloading). Thereafter, the processed wafer 200 is taken out from the boat 217 (wafer discharge).

  <Example>

Examples according to the present invention will be described below.
In this example, component analysis of the internal atmosphere of the second gas supply pipe 278 was performed by flowing N ₂ O gas through the heating device 271 using the heating device 271 shown in FIG.
The process temperature in the reaction tube 204 is 600 ° C., the process pressure is 960 hPa, the temperature of the heating device 271 is changed to 700 ° C., 800 ° C., and 900 ° C., and the flow rate of N ₂ O gas is 0.5 sl.
Component analysis was performed with the flow rate of m, N ₂ gas (diluted gas) set to 5.0 slm.
For comparison, a test was performed under the same conditions using a heating apparatus having a structure in which the resistance plates 281A and 281B were removed from the heating apparatus 271, and component analysis of the internal atmosphere of the second gas supply pipe 278 was performed.
When a test was performed on each of the heating device 271 according to the present embodiment and the heating device having a structure in which the resistance plates 281A and 281B were removed, the results shown in FIGS. 9A and 9B were obtained.

9A and 9B both show the temperature of the heating device 271 and the gas concentration of each detected gas type.
From these results, it was confirmed that the heating device 271 provided with the resistance plates 281A and 281B performs thermal decomposition of N ₂ O rather than the heating device 271 provided with no resistance plates 281A and 281B.

In another embodiment, the N ₂ O gas is flowed to the heating device 271 using the heating device 271 shown in FIG. 3, and the component analysis of the internal atmosphere is performed near the outlet of the reaction tube 204, that is, near the exhaust port 231a. Went.
The process temperature in the reaction tube 204 is 900 ° C., the process pressure is 960 hPa, the temperature of the heating device 271 is room temperature, the flow rate of N ₂ O gas is 2.0 slm, and the flow rate of N ₂ gas (dilution gas) is 10.0 slm. As a first form, for comparison with a case where a diluted N ₂ O gas is introduced into the processing chamber 201 from the plurality of gas inlets 233a through the ceiling 233 in the reaction tube 204, that is, the buffer chamber, As the second form, the ceiling 233 in the reaction tube 204, that is, the one in which the diluted N ₂ O gas is directly introduced into the processing chamber 201 from the thin tube 234 without providing the buffer chamber, is the same in each form. The test was performed under the conditions, and the internal atmosphere was analyzed in the vicinity of the exhaust port 231a.

The result is shown in FIG. In FIG. 10, the furnace temperature of each of the first form and the second form and the detected gas species, concentrations of NO, N ₂ O, and NO ₂ (unit: ppm) are shown.
From this result, it was confirmed that the decomposition of the N ₂ O gas was promoted when the N ₂ O gas was introduced into the processing chamber 201 from the plurality of gas inlets 233a through the buffer chamber.
That is, when decomposing more than a predetermined amount before introducing a processing gas such as N ₂ O gas into the processing chamber 201, heating is performed again in the ceiling portion 233 if the heating device 271 alone is not sufficient for decomposition. Thus, the decomposition action can be further promoted, and the process gas that has been cooled and inactivated before reaching the process chamber 201 from the heating device 271 can be activated again. In other words, decomposition of the processing gas is promoted or reactivated by heating the processing gas in two stages of the heating device and the buffer chamber, and when more components decomposed are required for processing the substrate in the processing chamber. Is particularly effective.

<Appendix>
Hereinafter, preferred embodiments of the present invention will be described.
(1) including a processing chamber for processing a substrate, a gas supply system for supplying a gas for processing the substrate into the processing chamber, and a heating unit provided in the gas supply system, A plurality of wall bodies provided on the side wall of the first wall body, wherein a first gap is provided between the first wall body and the side wall, and the second wall body adjacent to the first wall body and the side wall A heat treatment apparatus provided at opposite side wall positions so that a second gap is provided between the first and second gaps, and the first gap and the second gap do not overlap.
When the first wall and the second wall are provided on the opposing side walls so as not to overlap the first interval and the second interval, a series of paths that are folded back multiple times are formed in the heating section. The gas moves along this passage. When such a passage is formed, the moving distance of the gas in the heating chamber is extended, and the residence time of the gas is increased. Each wall is provided on the side wall and is heated by heat conduction. When gas flows through the passage, the gas moves along the side wall, then collides with the wall body and changes direction, and then moves along the wall body and then collides with the side wall to change direction. .
Thereby, after the gas is sufficiently heated, it can be supplied to the processing chamber. When nitrogen is introduced into the oxide film of the substrate, a nitrogen-containing gas is supplied to the heating unit. Nitrogen gas is thermally decomposed by heating and is introduced into the processing chamber in this state. Nitrogen is introduced into the oxide film by a substitution reaction with oxygen in the oxide film.

(2) The heat treatment apparatus according to (1), wherein the gap is semicircular.
When the gap is semicircular, the area of the contact surface in contact with the side wall of the heating unit increases, and thus preheating is easily performed.

(3) The heat treatment apparatus according to (1), wherein the gap has a fan shape.
When the gap is fan-shaped, the area of the contact surface in contact with the side wall of the heating unit increases, and therefore, preheating is easily performed.

(4) The heat treatment apparatus according to (1), wherein the heating unit heats to a temperature at which a gas necessary for processing the substrate is decomposed.

(5) The heat treatment apparatus according to (1), wherein any number of the wall bodies can be installed.

(6) The heat treatment apparatus according to (1), wherein an external combustion unit is provided in the gas supply system.
When the water vapor is formed by the combustion reaction of hydrogen gas and oxygen gas by an external combustion device and the gas containing water vapor is supplied to the treatment chamber, the substrate can be oxidized.

(7) The heat treatment apparatus according to (1), wherein a protrusion is provided on a peripheral portion of the gap.

(8) including a processing chamber for processing the substrate, a gas supply system for supplying a gas for processing the substrate, and a heating unit provided in the gas supply system, and a gas supply nozzle is provided in the heating unit. The heat processing apparatus which curves the gas supply port of a gas supply nozzle so that it may face in the reverse direction with the gas exhaust port provided in the location facing the said gas supply port in a heating part, and ejects gas.
The nozzle faces the gas introduction side opposite to the gas discharge port side of the heating unit, and the gas is introduced into the heating unit in this direction. The gas ejected from the ejection port collides with the inner surface on the side opposite to the exhaust port side due to the inertia of the fluid, and diffuses in the heating unit. Thereby, the residence time of the gas in the heating unit can be increased, and a sufficiently heated gas can be supplied into the processing chamber.
Therefore, even in such a form, the nitrogen-containing gas can be heated to a predetermined temperature and supplied to the processing chamber.

(9) A gas supply port that includes a processing chamber for processing the substrate, a gas supply system that supplies a gas for processing the substrate, and a heating unit provided in the gas supply system, and supplies gas into the heating unit; A heat treatment apparatus in which gas exhaust ports for exhausting gas from the heating unit are not on the same horizontal line.
Disposing the gas supply port, heating unit, and gas discharge port on the same horizontal line facilitates gas discharge and reduces the residence time of the gas in the heating unit. When the shaft center is shifted, gas blow-off is prevented, and the residence time of the gas in the heating chamber increases. Thereby, the heated gas can be supplied to the processing chamber.
(10) A step of carrying the substrate into the processing chamber, a step of heating the gas by a heating unit provided in a gas supply system that supplies the gas into the processing chamber, and introducing the gas into the processing chamber to process the substrate And a step of unloading the substrate from the processing chamber, wherein the heating unit has a plurality of wall bodies provided on the side wall inside the heating unit, and the gap is between the first wall body and the side wall. A first gap is provided, a second gap is provided between the second wall adjacent to the first wall and the side wall, and the first gap and the second gap overlap. A method for manufacturing a semiconductor device provided on opposite sidewalls.

As described above, the present invention can be variously modified, and the present invention naturally extends to the invention thus modified.

20 l Processing chamber 200 Wafer (substrate)
202 processing furnace 233a gas inlet 270 external combustion device 271 ripening device 278 second gas supply pipe (gas supply system)
279 Third gas supply pipe (gas supply system)
279A Gas outlet 281A Resistance plate (side wall)
281B Resistance plate (side wall)
282 Gas supply nozzle 283 Heating chamber wall surface (side wall)
285 Heating tube (heating unit)
290 Heating chamber (heating unit)
A276 Gas supply path B277 Gas supply path

Claims (4)

A processing chamber for processing the substrate;
A gas supply system for supplying a gas for processing the substrate into the processing chamber;
A heating unit provided in the gas supply system,
A second wall having a plurality of wall bodies provided on an inner side wall, wherein a first gap is provided at least between the first wall body and the side wall, and is adjacent to the downstream side of the first wall body. A heating chamber provided at opposite side wall positions so that the second gap is provided between the wall body and the side wall, and the first gap and the second gap do not overlap, and A heating unit having a heater for heating the heating chamber;
Wherein is from the upstream side outside of the heating chamber is inserted into the heating chamber, passes through a hole provided in the first wall of the heating chamber, said first wall, said second wall, said A temperature detection device provided apart from the side wall ;
And a control unit that controls an energization amount to the heater based on a temperature detection signal from the temperature detection device. A processing chamber for processing the substrate;
A gas supply system for supplying a gas for processing the substrate into the processing chamber, and a heating unit provided in the gas supply system of the heat treatment apparatus,
A second wall having a plurality of wall bodies provided on an inner side wall, wherein a first gap is provided at least between the first wall body and the side wall, and is adjacent to the downstream side of the first wall body. A second gap is provided between the wall and the side wall,
A heating chamber provided in a side wall position facing each other so that the first gap and the second gap do not overlap, and a heater for heating the heating chamber,
The heater, the are from the upstream side outside of the heating chamber is inserted into the heating chamber, passes through a hole provided in the first wall of the heating chamber, said first wall, said second A heating unit whose energization amount is controlled based on a temperature detection signal from a temperature detection device provided apart from the wall body and the side wall . A step of carrying the substrate into the processing chamber; a step of heating the gas by a heating unit provided in a gas supply system for supplying a gas into the processing chamber; and introducing the heated gas into the processing chamber; A step of processing, and a step of unloading the substrate from the processing chamber,
In the heating step, the gas reaches the first wall body among the plurality of wall bodies provided on the side wall of the heating chamber inside the heating section, and is provided between the first wall body and the side wall. The gas flows through the first gap, the gas reaches the second wall body adjacent to the downstream side of the first wall body, changes direction, and the second wall body and the side wall are changed. Gas flows in a second gap provided between the
Wherein is from the upstream side outside of the heating chamber is inserted into the heating chamber, passes through a hole provided in the first wall of the heating chamber, said first wall, said second wall, said A step of controlling an energization amount to a heater that heats the gas in the heating chamber based on a temperature detection signal from a temperature detection device provided apart from the side wall ;
A heat treatment method comprising at least A step of carrying the substrate into the processing chamber; a step of heating the gas by a heating unit provided in a gas supply system for supplying a gas into the processing chamber; and introducing the heated gas into the processing chamber; A step of processing, and a step of unloading the substrate from the processing chamber,
In the heating step, the gas reaches the first wall body among the plurality of wall bodies provided on the side wall of the heating chamber inside the heating section, and is provided between the first wall body and the side wall. The gas flows through the first gap, the gas reaches the second wall body adjacent to the downstream side of the first wall body, changes direction, and the second wall body and the side wall are changed. with gas flows in the second gap provided between the, inserted from the upstream side outside of the heating chamber into the heating chamber, it passes through a hole provided in the first wall of the heating chamber Based on a temperature detection signal from a temperature detection device provided apart from the first wall body, the second wall body, and the side wall , an energization amount to a heater that heats the gas in the heating chamber is determined. A controlling step;
A method for manufacturing a semiconductor device including at least