JP2010283270A - Heat processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out preliminary heating at a required gas temperature immediately after gas is introduced even if a heat capacity taken by the gas is large. <P>SOLUTION: A heat processing device includes a processing chamber 21a for processing a wafer 1, and a preliminary heating device 29 for supplying a gas 28 preliminarily heated in a heating chamber 41 to the processing chamber 21a. In the heat processing device, a heating plate 43 for accelerating the heating of the gas 28 is disposed in the heating chamber 41 so that the thickness T of the heating plate 43 is formed thicker than the thickness t of a wall of the heating chamber 41. A plurality of venting holes 44 are formed on the heating plate 43. Since the heating plate 43 is thick, heating at the required gas temperature can be achieved immediately after the gas is introduced even if the heat capacity taken by the gas 28 is large. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a heat treatment apparatus, and more particularly to a preheating apparatus for preheating gas.
For example, in a method of manufacturing a semiconductor integrated circuit device (hereinafter referred to as an IC), annealing for activating carriers after ion implantation into a semiconductor wafer (hereinafter referred to as a wafer) on which an IC is formed, and planarization of a multilayer wiring process Heat treatment such as low-temperature annealing, oxidation, diffusion and film-forming thermal treatment for reflow, metal oxide removal of metal wiring in the wiring process and termination of unbonded species (interface defects) of silicon oxide The present invention relates to a technique effective for use in a process and a heat treatment apparatus (furnace).

A batch-type vertical hot wall heat treatment apparatus (hereinafter referred to as a heat treatment apparatus) is widely used for performing a heat treatment process in a so-called pre-process of an IC manufacturing method.
A conventional heat treatment apparatus of this type includes a preheating apparatus for preheating gas, and the preheating apparatus is a gas diffusion plate in which a plurality of openings are provided in a heating chamber formed by a container such as quartz. There are some that are installed and configured. For example, see Patent Document 1.

Japanese Patent Laid-Open No. 10-173025

In a preheating device in which a plurality of gas diffusion plates are installed in the heating chamber, if the heat capacity taken up by the gas is small, such as a reduced pressure field or a gas flow rate of 1 liter per minute or less, the temperature is brought to the desired temperature from the beginning of gas introduction. It is possible to heat.
However, if the heat capacity taken by the gas such as the atmospheric field or 5 liters per minute increases, the temperature of the heating chamber decreases temporarily immediately after the introduction of the gas, making it difficult to heat to the desired gas temperature.

  An object of the present invention is to provide a heat treatment apparatus capable of heating to a desired gas temperature immediately after gas introduction even when the heat capacity taken away by the gas is large.

Typical inventions disclosed in the present application are as follows.
(1) In a heat treatment apparatus including a processing chamber for processing a substrate and a preheating device for supplying a gas preheated in the heating chamber to the processing chamber,
A heat treatment apparatus, wherein a heating plate for promoting gas heating is provided in the heating chamber, and the thickness of the heating plate is thicker than the side wall of the heating chamber.
(2) The heat treatment apparatus according to (1), wherein the heating plate has a plurality of ventilation holes, and the ventilation holes are opened in an oblique direction so that the gas is directed toward a side wall of the heating chamber. .
(3) A plurality of the heating plates are installed in the heating chamber, and a plurality of ventilation holes are respectively formed in the plurality of heating plates, and the plurality of ventilation holes of the plurality of heating plates are respectively staggered. The heat treatment apparatus according to (1), wherein the heat treatment apparatus is arranged.

  According to the present invention, even when the heat capacity taken away by the gas is large, the gas can be heated to a desired gas temperature immediately after the introduction of the gas.

It is side surface sectional drawing which shows before boat loading of the heat processing apparatus which is 1st embodiment of this invention. FIG. It is back sectional drawing which similarly shows boat loading. It is a longitudinal section showing the preheating device concerning a first embodiment of the present invention. It is a longitudinal cross-sectional view which shows the preheating apparatus which concerns on 2nd embodiment of this invention. It is a longitudinal cross-sectional view which shows the preheating apparatus which concerns on 3rd embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 to 4 show a first embodiment of the present invention.
In this embodiment, as shown in FIG. 1 and FIG. 2, the heat treatment apparatus according to the present invention removes a natural oxide film from a metal wiring and an unbonded species (interface defect) of silicon oxide in an IC manufacturing method. It is configured as a batch type vertical hot wall annealing apparatus (hereinafter referred to as an annealing apparatus) 10 that performs termination processing and the like.
An annealing apparatus 10 shown in FIGS. 1 and 2 is a load lock type (a gate chamber or the like is used to isolate a processing chamber and a spare chamber to prevent the inflow of air into the processing chamber, and the temperature, pressure, etc. The heat treatment apparatus is a system that stabilizes the treatment by reducing the disturbance.
That is, the annealing apparatus 10 includes a housing 11 constructed in a substantially rectangular parallelepiped box shape, and the housing 11 forms an airtight chamber capable of maintaining airtightness at atmospheric pressure and less than atmospheric pressure (reduced pressure). The hermetic chamber of the housing 11 is a load lock type spare chamber, and constitutes a standby chamber 12 in which the boat waits for loading / unloading into the processing chamber. A wafer loading / unloading port 13 is opened on the front wall of the standby chamber 12, and the wafer loading / unloading port 13 is opened and closed by a gate valve 14.

A boat loading / unloading port 15 is opened on the ceiling wall of the waiting room 12, and a heater unit 16 is vertically installed on the ceiling wall so as to cover the boat loading / unloading port 15.
The heater unit 16 includes a case 17 formed of a stainless steel plate, a heat insulating tank 18 formed in a cylindrical shape by a heat insulating material and installed in the case 17, an electric resistance heating element, and the like. And a heater 19 laid on the peripheral surface. The heater 19 is subjected to sequence control and feedback control by a temperature controller.

  A heat equalizing tube 20 is arranged concentrically with the heater 19 inside the heater 19 and vertically stands on the casing 11. A process tube 21 is connected to the heat equalizing tube 20 inside the heat equalizing tube 20. They are arranged concentrically. The soaking tube 20 is made of silicon carbide (SiC) or quartz (SiO2), and has an outer diameter smaller than the inner diameter of the heater 19 and is formed in a cylindrical shape with the upper end closed and the lower end opened. It is covered concentrically so as to surround the outside. The soaking tube 20 is disposed concentrically at the boat loading / unloading port 15 and is supported by the ceiling wall of the standby chamber 12 of the housing 11.

The process tube 21 is made of quartz and is formed in a cylindrical shape whose outer diameter is smaller than the inner diameter of the soaking tube 20 and whose upper end is closed and whose lower end is opened. The process tube 21 is arranged concentrically with the boat loading / unloading port 15 so as to penetrate the boat loading / unloading port 15, and is supported by a support 22 fixed to the ceiling wall of the housing 11.
The cylindrical hollow portion of the process tube 21 forms a processing chamber 21a, and the processing chamber 21a is configured to accommodate a plurality of wafers held in a state of being aligned in a vertical direction in a substantially horizontal posture by a boat. Has been.
The lower end opening of the process tube 21 constitutes a furnace port 21b for taking in and out the wafer, and the inner diameter of the process tube 21 is set to be larger than the maximum outer diameter (for example, 300 mm) of the wafer to be handled. . When the boat 40 is being carried out of the processing chamber 21a, the furnace port 21b is closed by a shutter 23 that is a furnace port gate valve.

  As shown in FIG. 1, a transfer chamber 30 is formed adjacent to the wafer loading / unloading port 13 side of the standby chamber 12, and a wafer transfer device 31 is installed in the transfer chamber 30. Yes. The wafer transfer device 31 is configured to hold a plurality of wafers 1 or one wafer 1 with a tweezer 32, carry them in from the wafer loading / unloading port 13, and transfer them to the boat 40.

  As shown in FIG. 2, a boat elevator 33 constituted by a feed screw shaft device is installed in the standby chamber 12. That is, the boat elevator 33 is vertically supported on the inside of the standby chamber 12 and is rotatably supported, a motor 35 that is installed outside the standby chamber 12 and rotationally drives the feed screw shaft 34, A lifting platform 36 that meshes with the feed screw shaft 34 and moves up and down as the feed screw shaft 34 rotates, and a support arm 37 that projects horizontally from the lifting platform 36 are provided.

A seal cap 39 that closes the furnace port 21 b is horizontally supported at the tip of the support arm 37 via a base 38. The seal cap 39 is constructed in a disk shape substantially equal to the outer diameter of the process tube 21.
On the center line of the seal cap 39, a boat 40 formed in a substantially cylindrical shape is vertically erected and supported via a heat insulating cap 40A formed in a cylindrical shape. The heat insulating cap 40A lifts the boat 40 from the seal cap 39, thereby separating the boat 40 from the vicinity of the furnace port 21b where the temperature control is unstable.
The boat 40 is configured to hold a plurality of wafers 1 in a state where the centers are aligned and horizontally aligned.

  An exhaust pipe 24 for exhausting the inside of the processing chamber 21a is connected to the lower end portion of the process tube 21, and the exhaust pipe 24 is connected to an exhaust device 25 constituted by a vacuum pump, a control valve, and the like. The exhaust pipe 24 constitutes a main exhaust line as a decompression exhaust line. A slow exhaust line is connected to the main exhaust line, and an atmospheric pressure exhaust line is connected upstream of the connection point of the slow exhaust line.

  One end of a gas supply pipe 26 that supplies gas to the processing chamber 21 a is inserted into the lower end of the process tube 21, and a gas supply device 27 is connected to the other end of the gas supply pipe 26. The gas supply unit 27 is configured to supply a processing gas such as hydrogen gas or deuterium gas and a gas 28 such as an inert gas such as nitrogen gas. The gas supply pipe 26 is provided with a preheating device 29 for preheating the gas 28.

As shown in FIG. 4, the preheating device 29 includes a container 42 that forms a heating chamber 41. The container 42 is formed in a cylindrical shape in which both ends are closed using quartz (SiO 2), and the hollow portion of the container 42 constitutes the heating chamber 41. The thickness t of the wall of the container 42 forming the heating chamber 41 is set to 2 mm to 3 mm, which is sufficient even when the heating chamber 41 is heated and the pressure in the heating chamber 41 is reduced. Gas supply pipes 26 are respectively connected to both end walls of the container 42 so as to communicate with the heating chamber 41.
A heating plate 43 is provided in the heating chamber 41 to promote gas heating. The thickness T of the heating plate 43 is formed to be thicker than the thickness t of the wall of the heating chamber 41. That is, the thickness T of the heating plate 43 is set to 30 mm to 50 mm.
A plurality of vent holes 44 are formed in the heating plate 43. The gas 28 supplied to the upstream chamber of the heating chamber 41 flows through the vent hole 44 to the downstream chamber of the heating chamber 41, and flows to the processing chamber 21 a through the gas supply pipe 26.
A heater unit 45 is installed on the outer periphery of the container 42. The heater unit 45 includes a case 46 formed of a stainless steel plate or the like, a heat insulating tank 47 formed in a cylindrical shape by a heat insulating material and installed in the case 46, an electric resistance heating element, and the like. And a heater 48 laid on the peripheral surface. The heater 48 is sequence-controlled by a controller 50 (see FIGS. 2 and 3), and is feedback-controlled based on a measurement value of a temperature sensor 49 inserted in the heating chamber 41.
The controller 50 is configured to comprehensively control the exhaust device 25, the gas supply device 27, and the like.

A method of annealing the H2 on the wafer 1 using the annealing apparatus 10 having the above configuration will be described.
In the following description, the operation of each part constituting the annealing apparatus 10 is controlled by the controller 50.

  In the wafer charging step, a plurality of wafers 1 to be processed are picked up by a tweezer 32 of a wafer transfer device 31 and are shown in FIG. 1 and FIG. Reprinted as if At this time, the furnace port 21 b of the process tube 21 is closed by the shutter 23.

When a predetermined number of wafers 1 are loaded into the boat 40, in the boat loading step, the boat 40 is lifted by the boat elevator 33 and loaded into the processing chamber 21a from the furnace port 21b of the process tube 21 (boat loading). .
As shown in FIG. 3, when the boat 40 is completely carried into the processing chamber 21 a, the furnace port 21 b is hermetically sealed by the seal cap 39.
In this state, the boat 40 is placed in the processing chamber 21a.

After the boat loading step, the exhaust device 25 and the gas supply device 27 are controlled by the controller 50, whereby the N2 gas is supplied to the processing chamber 21a through the gas supply pipe 26, while the inside of the processing chamber 21a is the slow exhaust of the exhaust pipe 24. Slow vacuumed by line.
Next, the supply of N2 gas through the gas supply pipe 26 is stopped, and main vacuum is performed by the main exhaust line as the decompression exhaust line of the exhaust pipe 24.
After a predetermined time has passed, a leak check is performed.

Until the temperature raising step starts, the temperature in the processing chamber 21a is maintained at a preset standby temperature of 50 to 500 ° C.
With the start of main vacuum, the temperature raising step is started. The main vacuum and leak check are performed in parallel with the temperature raising step.
When the temperature in the processing chamber 21a reaches a predetermined processing temperature of 100 to 900 ° C., the temperature is kept constant.

  After the leak check, the gas supply device 27 is controlled by the controller 50, whereby N2 gas is supplied into the processing chamber 21a via the gas supply pipe 26, and the processing chamber 21a is purged with N2 gas.

When the inside of the processing chamber 21a is purged with N2 gas and the temperature is stabilized, the exhaust device 25 and the gas supply device 27 are controlled by the controller 50, whereby the supply of N2 gas in the processing chamber 21a is stopped and the H2 gas is discharged. The gas is supplied into the processing chamber 21 a via the gas supply pipe 26.
The H2 gas supplied from the gas supply pipe 26 into the processing chamber 21a flows down in the processing chamber 21a and is exhausted through the exhaust pipe 24.

When the processing time of the heat treatment step set in advance elapses, the temperature in the processing chamber 21a is lowered with the temperature sequence of the temperature lowering step set in advance. The boat unloading step is started at the same time as the temperature lowering step is started.
When the temperature of the processing chamber 21a reaches 50 to 500 ° C., which is a preset standby temperature, the temperature is maintained constant.

  While the supply of H2 gas is stopped, N2 gas is supplied into the processing chamber 21a via the gas supply pipe 26, and the processing chamber 21a is purged with N2 gas. At this time, the exhaust pipe 24 continues to exhaust the processing chamber 21a.

  Thereafter, in the wafer discharging step, the processed wafer 1 is removed (discharged) from the boat 40 by the wafer transfer device 31.

By the way, when the heating capacity of the preheating device 29 is low, a phenomenon occurs in which the gas 28 flowing into the processing chamber 21a from the gas supply pipe 26 rapidly decreases the temperature in the processing chamber 21a.
However, in the present embodiment, the preheating device 29 has a large heating capacity by installing the heating plate 43 having a large thickness T in the heating chamber 41, and therefore circulates through the gas supply pipe 26. The gas 28 is sufficiently preheated by the preheating device 29. As a result, when the gas 28 flows into the processing chamber 21a, the temperature in the processing chamber 21a is not rapidly decreased.

For example, the wafer heating step, the boat loading step, and the temperature raising time are calculated backward, and the temperature of the preheating device 29 is started so as to be in time for the introduction time of the gas 28. When the temperature of the processing chamber 21a and the temperature of the preheating device 29 reach preset temperatures, the introduction of the gas 28 is started. The gas 28 is preheated to a preset temperature by the preheating device 29 and is introduced into the processing chamber 21a.
At this time, since the thickness T of the heating plate 43 for promoting the heating of the gas 28 in the heating chamber 41 of the preheating device 29 is formed to be thicker than the thickness t of the wall of the heating chamber 41, the pressure reduction Not only when the heat capacity taken away by the gas 28 is small, such as when the field or gas flow rate is less than 1 liter per minute, but also when the heat capacity taken away by the gas 28 is large, such as when the atmosphere 28 or more than 5 liters per minute It can be heated to the set temperature from the beginning of the introduction of 28.

  According to the present embodiment, the following effects can be obtained.

1) By making the thickness of the heating plate in the heating chamber thicker than the wall thickness of the heating chamber, not only when the heat capacity taken away by the gas is small, but also when the heat capacity taken away by the gas is large, To the set temperature.

2) Since the gas can be heated to the set temperature from the beginning of the introduction of the gas, it is possible to prevent a phenomenon in which the gas flowing into the processing chamber from the gas supply pipe rapidly decreases the temperature in the processing chamber.

FIG. 5 shows a preheating device according to the second embodiment of the present invention.
The present embodiment is different from the first embodiment in that a plurality of vent holes 44 </ b> A are formed in diagonal directions toward the periphery of the heating chamber 41 with respect to the heating plate 43.
According to this embodiment, since the heating efficiency of the heating plate 43 can be increased, the preheating ability of the preheating device 29 can be further increased.

FIG. 6 shows a preheating device according to the third embodiment of the present invention.
This embodiment is different from the first embodiment in that a plurality of heating plates 43B are installed in the heating chamber 41 at intervals, and a plurality of vent holes 44B are staggered in each stage of the heating plates 43B. It is the point each arrange | positioned so that it may become a shape.
According to the present embodiment, the gas 28 supplied to the heating chamber 41 passes through the vent holes 44B of the heating plate 43B of each stage before being discharged from the heating chamber 41, and then the heating plate 43B and the heating of the next stage Since the heating efficiency of the heating plate 43B can be increased by colliding with the wall of the chamber 41, the preheating ability of the preheating device 29 can be further increased.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, the gas supply pipe is not limited to be shared by the processing gas and the inert gas, but may be configured to be used separately.

  The heater unit for heating the heating chamber is not limited to the structure described above, and may be configured, for example, to a structure using a lamp heater.

  The heat treatment apparatus according to the present invention is not limited to use in a batch type vertical hot wall type annealing apparatus, but can be used in general heat treatment apparatuses such as a single wafer type heat treatment apparatus.

  The heat treatment apparatus according to the present invention can be applied not only to a method for manufacturing an IC but also to a method for manufacturing a photomask, a printed wiring board, a liquid crystal panel, an SOG (system on glass), an optical disk, a magnetic disk, and the like.

1 ... wafer (substrate),
DESCRIPTION OF SYMBOLS 10 ... Hot-wall type annealing apparatus (heat processing apparatus), 11 ... Housing, 12 ... Standby room (preliminary room), 13 ... Wafer loading / unloading port, 14 ... Gate valve, 15 ... Boat loading / unloading port, 16 ... Heater unit, DESCRIPTION OF SYMBOLS 17 ... Case, 18 ... Heat insulation tank, 19 ... Heater, 20 ... Soaking tube, 21 ... Process tube, 21a ... Processing chamber, 21b ... Furnace port, 22 ... Supporting tool, 23 ... Shutter (furnace port gate valve), 24 ... exhaust pipe, 25 ... exhaust device,
26 ... gas supply pipe, 27 ... gas supply device, 28 ... gas, 29 ... preheating device,
DESCRIPTION OF SYMBOLS 30 ... Transfer chamber, 31 ... Wafer transfer apparatus, 32 ... Tweezer, 33 ... Boat elevator, 34 ... Feed screw shaft, 35 ... Motor, 36 ... Lifting stand, 37 ... Support arm, 38 ... Base, 39 ... Seal cap (Furnace gate valve), 40 ... boat, 40A ... heat insulation cap,
DESCRIPTION OF SYMBOLS 41 ... Heating chamber, 42 ... Container, 43, 43B ... Heating plate, 44, 44A, 44B ... Vent hole, 45 ... Heater unit, 46 ... Case, 47 ... Heat insulation tank, 48 ... Heater, 49 ... Temperature sensor, 50 ... controller.

Claims (1)

In a heat treatment apparatus comprising a processing chamber for processing a substrate and a preheating device for supplying a gas preheated in the heating chamber to the processing chamber,
A heat treatment apparatus, wherein a heating plate for promoting gas heating is provided in the heating chamber, and the thickness of the heating plate is thicker than the side wall of the heating chamber.

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