JP2004214283A - Semiconductor device manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To economically manufacture a semiconductor device manufacturing apparatus and also to improve heat treatment efficiency within a reaction pipe, while improving heat insulation efficiency and reducing heat capacity of the heat shielding structure itself through introduction of a vacuum heat shielding structure. <P>SOLUTION: The semiconductor device manufacturing apparatus 1 is provided with a cylindrical reaction pipe 20 which integrally forms an upper surface and a side surface with the lower surface opened, a boat which is loaded with wafers and is accommodated within the reaction pipe 20, a heater 2 for heating the internal side of the reaction pipe, and a vacuum heat insulating layer 70 which is formed to cover the periphery of the reaction pipe 20. The vacuum heat shielding layer 70 is formed by combining, through close sealing at the lower ends and then setting the internal space thereof into the vacuum condition, a cylindrical vessel 73 which is formed by integrating the upper surface and side surface with the lower surface opened, and a cylindrical external vacuum vessel 74 which is formed by integrating the upper surface and side surface with the lower surface opened. The heater 2 is arranged between the vacuum heat shielding layer 70 and the reaction pipe 20. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor manufacturing apparatus, and particularly to a semiconductor manufacturing apparatus having a vacuum heat insulating layer for performing a heat treatment process such as oxidation, diffusion, and CVD (Chemical Vapor Deposition) of a silicon wafer.
[0002]
[Prior art]
As a conventional semiconductor manufacturing apparatus of this type, there is a vertical heating apparatus disclosed in Patent Document 1. This vertical heating device has a cylindrical inner tube erected so as to surround a space in which a heated object to be heated is stored, and an erect space surrounding the inner tube, and has an airtight space inside. And a heater for heating the inside of the outer tube and the inner tube. The vertical heating device has a double-walled vacuum tube that is arranged so as to surround the outer tube and hermetically seals the outer tube side against the outside air. A vacuum space is formed inside the vacuum tube and hermetically sealed to the outside and can be decompressed. A heater is housed in the vacuum space. The double-walled vacuum tube is formed by integrally forming an inner vacuum tube and an outer vacuum tube, the inner vacuum tube is opened at a lower surface, and the outer vacuum tube is formed at an upper surface.
[0003]
[Patent Document 1]
JP 2001-102314 A
[Problems to be solved by the invention]
However, in the above prior art, the double-walled vacuum tube is formed integrally with the inner vacuum tube and the outer vacuum tube, the inner vacuum tube is opened on the lower surface, and the outer vacuum tube is opened on the upper surface, Therefore, there is a problem that manufacturing is difficult and cost is increased. In addition, since the heater is housed in the vacuum space, the inside of the outer tube and the inner tube is heated through the inner vacuum tube, and the heating efficiency has to be reduced. there were. Moreover, the inner vacuum tube needs to be made of a material suitable for transmitting the heat of the heater to the outer tube side, and has a problem that it must be made of a material excellent in both vacuum maintenance and heat transfer. .
[0005]
An object of the present invention is to provide a semiconductor manufacturing apparatus that can be manufactured at low cost and improve the heating efficiency in a reaction tube while improving the heat insulating efficiency and reducing the heat capacity of the heat insulating structure itself by using a vacuum heat insulating structure. Is to do.
[0006]
Other objects and advantages of the present invention will be apparent from the following description.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a tubular reaction tube having an upper surface and a side surface formed integrally and opening a lower surface, a boat loaded with a wafer and housed in the reaction tube, A heater for heating the inside of the reaction tube, and a vacuum heat insulating layer formed so as to cover the periphery of the upper surface and the side surface of the reaction tube, wherein the vacuum heat insulating layer integrally formed the upper surface and the side surface and the lower surface was opened. A cylindrical inner vacuum container and a cylindrical outer vacuum container having an upper surface and a side surface formed integrally and an open lower surface are tightly sealed at the lower end and combined to form a vacuum in the internal space. The heater is arranged between the vacuum heat insulating layer and the reaction tube.
[0008]
The other means of the present invention will be apparent from the following description.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or corresponding components.
[0010]
First, a vertical semiconductor manufacturing apparatus according to a first embodiment of the present invention will be described with reference to FIGS.
[0011]
The vertical semiconductor manufacturing apparatus includes a tubular reaction tube 20 having an upper surface and a side surface formed integrally and an opening at a lower surface, a boat 40 loaded with a wafer 41 and housed in the reaction tube 20, It comprises a heater 2 for heating the inside and a vacuum heat insulating layer 70 formed so as to cover the periphery of the upper surface and side surfaces of the reaction tube 20.
[0012]
As one of the semiconductor manufacturing processes, there is a heat treatment step for performing oxidation, diffusion, CVD, and the like of a silicon wafer, and this step is performed using the vertical semiconductor manufacturing apparatus 1.
[0013]
In the vertical semiconductor manufacturing apparatus 1, a soaking tube 3 is provided in a heater 2, and a reaction tube 20 is provided in the soaking tube 3. The soaking tube 3 is made of a material having a high thermal conductivity (for example, a SiC material), and is used to maintain temperature uniformity in the reaction tube 20. The heat equalizing tube 3 has an upper surface and a side surface formed integrally and is formed in a cylindrical shape with an open lower surface, and a lower end portion is formed with an outwardly extending flange.
[0014]
The periphery of the heater 2 is covered with a vacuum heat insulating layer 70. The heater 2 is formed and arranged between the vacuum heat insulating layer 70 and the heat equalizing tube 3 in a cylindrical shape, and is vertically divided into a plurality. Further, the heater 2 is attached to the inner side surface of the inner vacuum vessel 73.
[0015]
The reaction tube 20 is provided with one gas introduction pipe (gas introduction passage) 5 and one exhaust pipe (gas exhaust passage) 6 at the lower part, and each is communicated with the internal space. The gas introduction pipe 5 is connected to a reaction gas supply source (not shown), and the exhaust pipe 6 is connected to an exhaust device (not shown).
[0016]
The lower end of the reaction tube 20 is open and serves as an entrance, from which a plurality of wafers 41 loaded in a boat 40 in a horizontal posture are introduced and led out. That is, the boat 40 is introduced into the reaction tube 20 from below by being raised by an elevating mechanism (not shown), and is taken out of the reaction tube 20 by being lowered.
[0017]
A flange 62 is provided around the lower end of the reaction tube 20, and a space between the flange 62 and the furnace head cover 61 is sealed by an airtight seal (for example, an O-ring) 63 when the furnace cover 61 is closed. It has become.
[0018]
The heat equalizing tube 3 and the reaction tube 20 have a structure that can be removed for assembling and maintenance (such as cleaning). The soaking tube 3 is sealed with a vacuum heat insulating layer 70 and a hermetic seal (for example, an O-ring) 65, and the reaction tube 20 is sealed with a soaking tube 3 and a hermetic seal (for example, an O-ring 66).
[0019]
When the CVD process is performed on the wafer 41, the wafer 41 is heated and maintained at the processing temperature by the heater 2, and in this state, the source gas is supplied from the gas introduction pipe 5 to the reaction pipe 20. Then, the source gas reacts to form a CVD film on the surface of the wafer 41. The gas after the reaction is exhausted through the exhaust pipe 6.
[0020]
Further, a rotation mechanism 64 for rotating the boat 40 is provided in order to make the in-plane temperature distribution of the wafer 41 uniform. Further, a plurality of heat insulating plates 60 (for example, quartz plates) are loaded in the lower part of the boat 40. The heat insulating plate 60 is provided to prevent the temperature distribution between the upper and lower portions of the wafer 41 disposed above from becoming uneven.
[0021]
The vacuum heat insulating layer 70 includes a cylindrical inner vacuum container 74 having an upper surface and a side surface formed integrally and having a lower surface opened, and a cylindrical outer vacuum container 75 having an upper surface and a side surface formed integrally and having a lower surface opened. It is formed by tightly sealing at the lower end and assembling, and making the internal space a vacuum state. That is, the side surface and the upper surface of the vertical semiconductor manufacturing apparatus 1 are covered with the vacuum heat insulating layer 70 having a double structure with the inner vacuum vessel 73 and the outer vacuum vessel 74.
[0022]
The vacuum heat insulating layer 70 is connected to a vacuum pump 71 via a valve 81, and has a vacuum heat insulating function by opening the valve 81 and evacuating by the vacuum pump 71.
[0023]
A plurality of radiation shields 72 are provided on the side surface of the vacuum heat-insulating layer 70 with a gap in the heat-insulating direction, and are fastened and supported by the support 75 to the vacuum vessels 73 and 74. A plurality of radiation shields 72 are also provided on the upper surface of the vacuum heat insulating layer 70 with a gap in the heat insulating direction, and are fastened and supported by the support 100 to the vacuum vessel 74. The radiation shield 72 has several holes 10 for exhaust.
[0024]
The supports 75 and 100 are made of a material having low heat conductivity and strength. For example, the supports 75 and 100 are configured using a support receiver or a screw made of glass fiber fiber or carbon fiber fiber.
[0025]
The inner vacuum vessel 73 is formed with a flange 76 whose lower end extends outward, and the outer vacuum vessel 74 is formed with a flange 77 that extends outward at its lower end. The inner vacuum vessel 73 and the outer vacuum vessel 74 have a double structure by inserting the inner vacuum vessel 73 from below the outer vacuum vessel 74, and hermetically seal (for example, an O-ring 78) between the flanges 76 and 77 provided respectively. And is detachable.
[0026]
The soaking tube 3 and the reaction tube 20 have a structure that can be removed for assembling and maintenance (cleaning and the like). The soaking tube 3 and the vacuum container 73 are separated by a flange 77 and an O-ring 67 of the vacuum container 73. The reaction tube 20 and the soaking tube 3 are sealed with an O-ring 66, respectively.
[0027]
The structure of the support 75 will be described in detail with reference to FIG. The radiation shield 72 is fitted in a groove of the support receiver 101 made of, for example, a glass fiber material. The support receiver 101 is fastened and supported to the vacuum vessel 74 by screws 102 made of, for example, a glass fiber material. The structure of the support 75 is applied in the same manner above and below the radiation shield 72. As a result, the radiation shield 72 is insulated and supported by the outer vacuum vessel 74. The support receiver 101 and the screw 102 have a heat insulating effect due to their low thermal conductivity. However, as shown in FIG. By contact, the thermal resistance can be increased.
[0028]
The structure of the support 100 will be described in detail with reference to FIG. The support 100 includes a support portion 103 and screws 102 and 104. The support portion 103 is made of, for example, a glass fiber material, the screw 102 is made of, for example, a glass fiber material, and the support portion 103 is fastened and supported to the vacuum container 74 by the screw 102. Then, the support portion 103 is passed through the perforated portion of the radiation shield 72, and receives the outer vacuum container 74 with the screw 104 made of, for example, the glass fiber material described above. By doing so, the support 100 having a high heat insulating effect can be obtained.
[0029]
According to the present embodiment, the cylindrical reaction tube 20 formed integrally with the upper surface and the side surface and having the lower surface opened, and the vacuum heat insulating layer 70 formed so as to cover the periphery of the upper surface and the side surface of the reaction tube 20. The vacuum heat insulating layer 70 includes a cylindrical inner vacuum container 73 integrally formed with an upper surface and a side surface and having an open lower surface, and a cylindrical outer vacuum container 74 integrally formed with an upper surface and a side surface and having an opened lower surface. Are combined by tightly sealing at the lower end, and the interior space is formed in a vacuum state, so that the reaction tube 20, the inner vacuum vessel 73, and the outer vacuum vessel 74 can be easily and inexpensively formed with an extremely simple structure. Can be manufactured. Further, since the heater 2 is disposed between the vacuum heat insulating layer 70 and the reaction tube 20, the vacuum heat insulating layer 70 is not directly related to heating the inside of the reaction tube 20 by the heater 2, and the vacuum heat insulating layer 70 The restriction on the material of the inner vacuum vessel 73 constituting the above can be eliminated. Thus, the inner vacuum container 73 can easily adopt a material suitable for the vacuum heat insulating function.
[0030]
Further, since the inner vacuum vessel 73 and the reaction tube 20 are detachably attached to the outer vacuum vessel 74 in order from below, they can be manufactured very easily. In particular, the inner vacuum vessel 73 having a flange 77 extending outward at the lower end is inserted into the outer vacuum vessel 76 from below, and the flange 77 is detachably attached to the lower end of the outer vacuum vessel 74 via a hermetic seal 78. The heat equalizing tube 3 having a flange 3a extending outward at the lower end is inserted into the inner vacuum vessel 73 from below, and the flange 3a is detachably attached to the flange 77 of the inner vacuum vessel 73 via an airtight seal 67. Since the reaction tube 20 is inserted into the heat tube 3 from below and is detachably attached via the airtight seal 66, these can be manufactured very easily.
[0031]
Further, since a plurality of radiation shields 72 are provided in the space formed by the inner vacuum vessel 73 and the outer vacuum vessel 74 with a gap in the heat insulating direction, the heat insulating performance of the vacuum heat insulating layer 70 is greatly improved. can do.
[0032]
Next, a second embodiment of the present invention will be described with reference to FIG. In the description of the second embodiment, the overlapping description of the parts common to the first embodiment will be omitted. In the second embodiment, the same effects as those of the first embodiment are obtained in the same configuration.
[0033]
The second embodiment is an embodiment in which a rapid temperature raising / lowering mechanism is added to the configuration of the first embodiment, and a device for supplying a cooling gas to the vacuum heat insulating layer 70 is provided. The cooling gas supply device includes a cooling air flow path 80 and valves 82 and 83. At the time of raising and lowering the temperature, the following procedure is performed.
[0034]
First, at the time of temperature rise, the valves 82 and 83 are closed, the vacuum pump 71 is operated, and the air 110 in the vacuum heat insulating layer 70 is exhausted by opening the valve 81 to evacuate the vacuum heat insulating layer 70. When the temperature is lowered after the film forming process of the wafer 41 is completed, the valve 81 is closed, the valves 82 and 83 are opened, and the cooling gas (for example, cooling air) 111 is caused to flow through the vacuum heat insulating layer 70 and the cooling air flow path 80 to quickly Then, the inside of the reaction tube 20 is cooled. When the temperature is to be increased again, the above-described procedure is repeated. By doing so, rapid temperature rise and fall can be efficiently performed.
[0035]
Note that a plurality of valves 82 provided in the outer vacuum container 74 may be provided in the circumferential direction in order to achieve uniform cooling. The holes 10 formed in the radiation shield 72 are formed so that the cooling air 111 flows evenly in the vacuum heat insulating layer 70 during cooling, so that the pressure loss at the lower portion of the radiation shield 72 is reduced as compared with the pressure loss at the upper portion. (For example, the diameter of the hole 10 provided in the lower part of the radiation shield 72 is made larger than that of the upper part, or the number of holes is increased).
[0036]
Next, a third embodiment of the present invention will be described with reference to FIG. In the description of the third embodiment, the overlapping description of the parts common to the first and second embodiments will be omitted. In the third embodiment, the same effects as those of the first and second embodiments can be obtained.
[0037]
The third embodiment is different from the second embodiment in that a ceiling and a cap heater are provided in a furnace in order to further increase the temperature rapidly and to make the temperature distribution of the wafer rows uniform. That is, a ceiling heater 90 is provided in a portion surrounded by the heat equalizing tube 3 and the vacuum vessel 73, and a cap heater 91 is provided below the row of wafers 41 and the heat insulating plate 60. By doing so, the temperature of the wafer 41 can be raised efficiently and the temperature distribution of the wafer row becomes uniform, so that a semiconductor device excellent in uniformity of film thickness can be obtained with high efficiency.
[0038]
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the description of the fourth embodiment, the overlapping description of the parts common to the first to third embodiments will be omitted. In the fourth embodiment, the same effects as those of the first to third embodiments can be obtained.
[0039]
The fourth embodiment is different from the third embodiment in that a vacuum heat insulating layer cap 79 is provided instead of the heat insulating plate 60 in order to further improve the heat insulating performance. The vacuum insulating layer cap 79 is formed by, for example, vacuum-sealing the inside of double quartz glass. By doing so, the heat radiation below the row of wafers 41 is suppressed, so that the temperature of the wafer 41 can be raised efficiently and the temperature distribution of the row of wafers becomes uniform, so that a semiconductor device having excellent uniformity in film thickness can be obtained with high efficiency. Is obtained.
[0040]
【The invention's effect】
As described above, according to the present invention, a semiconductor that can be manufactured at low cost and improve the heating efficiency in a reaction tube while improving the heat insulation efficiency and reducing the heat capacity of the heat insulation structure itself by using a vacuum heat insulation structure. A manufacturing apparatus can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a semiconductor manufacturing apparatus illustrating a first embodiment of the present invention.
FIG. 2 is a detailed sectional view showing a radiation shield support member located on a side surface of the semiconductor manufacturing apparatus of FIG. 1;
FIG. 3 is a detailed sectional view showing a radiation shield supporter located on the upper surface of the semiconductor manufacturing apparatus of FIG. 1;
FIG. 4 is a longitudinal sectional view of a semiconductor manufacturing apparatus according to a second embodiment of the present invention.
FIG. 5 is a vertical sectional view of a semiconductor manufacturing apparatus according to a third embodiment of the present invention.
FIG. 6 is a longitudinal sectional view of a semiconductor manufacturing apparatus according to a third embodiment of the present invention.
FIG. 7 is a sectional view showing a conventional semiconductor manufacturing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vertical semiconductor manufacturing apparatus, 2 ... Heater, 3 ... Heat equalizing pipe, 4 ... Heat insulation material, 5 ... Gas introduction pipe, 6 ... Exhaust pipe, 7 ... Exhaust pipe, 10 ... Hole, 20 ... Reaction pipe, 40 ... Boat 41, wafer, 60, heat insulating plate, 61, furnace lid, 62, flange, 63, O-ring, 64, rotating mechanism, 65, O-ring, 66, O-ring, 67, O-ring, 70, vacuum heat insulating layer, 71 vacuum pump, 72 radiation shield, 73 inner vacuum vessel, 74 outer vacuum vessel, 75 support, 76 flange, 77 flange, 78 O-ring, 79 vacuum insulation cap, 80 cooling Wind channel, 81: valve, 82: valve, 83: valve, 90: ceiling heater, 91: cap heater, 100: support, 101: support receiver, 102: screw, 103: support, 104: screw, 110 ... Air, 111 ... cooling air .

Claims (7)

A tubular reaction tube formed integrally with the upper surface and the side surfaces and opening the lower surface,
A boat loaded with wafers and housed in the reaction tube;
A heater for heating the inside of the reaction tube;
A vacuum heat insulating layer formed so as to cover the periphery of the upper surface and side surfaces of the reaction tube,
The vacuum heat-insulating layer has a lower end formed by a cylindrical inner vacuum container having an upper surface and side surfaces formed integrally and having a lower surface opened, and a cylindrical outer vacuum container formed integrally with upper surface and side surfaces and having a lower surface opened. It is formed by bringing the internal space into a vacuum state,
The semiconductor manufacturing apparatus, wherein the heater is disposed between the vacuum heat insulating layer and the reaction tube. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the inner vacuum vessel and the reaction tube are detachably attached to the outer vacuum vessel in order from below. The inner vacuum container having a flange extending outward at a lower end portion is inserted into the outer vacuum container from below, and the flange is detachably attached to a lower end portion of the outer vacuum container via a hermetic seal. A heat equalizing pipe having a flange extending to the inner vacuum vessel is inserted from below into the inner vacuum vessel, and the flange is detachably attached to a flange of the inner vacuum vessel via an airtight seal, and the reaction tube is inserted into the heat equalizing pipe from below. 3. The semiconductor manufacturing apparatus according to claim 2, wherein the semiconductor device is detachably attached via a hermetic seal. 4. The apparatus according to claim 1, wherein a device is provided in a space formed by the inner vacuum vessel and the outer vacuum vessel, in which the vacuum state is released and a cooling gas flows when the wafer is carried out. A semiconductor manufacturing apparatus according to any one of the above. The semiconductor manufacturing device according to any one of claims 1 to 4, wherein a plurality of radiation shields are provided in the space formed by the inner vacuum vessel and the outer vacuum vessel with a gap in the adiabatic direction. apparatus. 6. The semiconductor manufacturing apparatus according to claim 5, wherein exhaust holes 10 are formed in the plurality of radiation shields. 7. The semiconductor manufacturing apparatus according to claim 1, wherein a heater is provided in a lower portion of the reaction tube, and a vacuum heat insulating layer is provided below the heater.

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