JP4993965B2 - Semiconductor manufacturing apparatus, substrate processing method, substrate manufacturing method, and semiconductor device manufacturing method - Google Patents

Description

  The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a semiconductor manufacturing apparatus that simultaneously performs plasma processing on a plurality of processing substrates.

  2. Description of the Related Art Conventionally, there is known a batch type plasma processing apparatus that carries a boat holding a plurality of wafers into a processing chamber and performs plasma processing on the plurality of wafers simultaneously (see, for example, Patent Document 1).

5 and 6 show the configuration of a processing furnace constituting a batch type plasma processing apparatus as a conventional semiconductor manufacturing apparatus.
As shown in FIGS. 5 and 6, in the heat treatment furnace of the conventional example, a pair of protective tubes 8 are provided vertically along the inner wall surface of the process tube 7. The protective tube 8 is bent downward toward the outside of the process tube 7 and penetrates the process tube 7, and a pair of electrodes 9 are inserted into both protective tubes 8 from below the process tube 7.
Further, on the inner periphery of the process tube 7, a bowl-shaped partition wall 11 that forms the plasma chamber 10 is installed so as to airtightly surround both the protective tubes 8, and the partition wall 11 has a plurality of air outlets 12. They are arranged so as to face between the upper and lower wafers 6.

In such a conventional heat treatment furnace, a processing gas is supplied to the plasma chamber 10 and maintained at a predetermined pressure, and then high frequency power is supplied between both electrodes 9 by a high frequency power source 13. Thereby, the plasma 14 is formed in the plasma chamber 10 and the processing gas is activated.
Then, the electrically neutral active species (radicals) 15 are blown out from the blowout port 12 formed in the partition wall 11 and supplied to the processing chamber 16, thereby contacting each wafer 6 held in the boat 3. . The active species 15 in contact with the wafer 6 performs processing such as film formation on the surface of the wafer 6.

By the way, in recent years, demands for miniaturization processes have become more severe due to higher integration and higher performance of semiconductor devices, and the thermal history in the manufacturing process of semiconductor devices has also been reduced from the viewpoint of improving device characteristics. It is hoped to do. One of the important technologies for realizing these is a process using a high-density plasma source having an electron density of about 10 ¹¹ to 10 ¹³ cm ⁻³ . As disclosed in Patent Document 1, as a batch type plasma apparatus, an electrode is installed in a reaction tube and a high frequency is applied to the electrode, thereby generating capacitively coupled plasma (CCP) to react. There is a method to send active species into the room.
JP 2004-289166 A

  However, since the conventional batch type plasma processing apparatus is far from the generation position of the plasma 14 from the wafer 6, that is, the distance to the plasma chamber 10, the active species density in the vicinity of the surface of the wafer 6 is set within the wafer 6 surface. It is difficult to make it uniform. For the same reason, depending on the type of process gas, the active species generated may be deactivated during the supply, and there is a problem that the concentration of the active species is lowered and the efficiency is not good. . The non-uniformity of active species density adversely affects the uniformity of substrate processing, particularly in batch processing.

  The object of the present invention is made in view of the background as described above, and provides a semiconductor manufacturing apparatus capable of uniformizing the processing within and between the substrates while having a relatively simple structure. There is to do.

  According to an aspect of the present invention, there is provided a semiconductor manufacturing apparatus for plasma processing a plurality of substrates to be processed, wherein a processing container configured to be evacuated, and the plurality of substrates to be processed inserted into the processing container are multi-staged. A substrate holder for holding the substrate, a processing gas supply means for supplying a processing gas into the processing container, the plasma generating chamber for generating plasma communicating with the processing container, and the plasma generating chamber from the plasma generating chamber in the processing container. Provided is a semiconductor manufacturing apparatus comprising: an electron supply device for irradiating electrons between substrates to be processed held by the substrate holder; and a rotating device for rotating the substrate holder in the processing container. .

  According to the present invention, it is possible to uniformize the processing within and between the substrates while having a relatively simple structure.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 4 is an overall perspective view of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

  As shown in FIG. 4, the semiconductor manufacturing apparatus A, which is a batch type plasma apparatus, holds the cassette 100 as a substrate storage container on the front side inside the housing 101 with an external transfer device (not shown). A cassette stage 105 is provided as a tool transfer member. A cassette elevator 115 as lifting means is provided on the rear side of the cassette stage 105, and a cassette transfer machine 114 as transport means is attached to the cassette elevator 115. . A cassette shelf 109 as a means for placing the cassette 100 is provided on the rear side of the cassette elevator 115, and a spare cassette shelf 110 is also provided above the cassette stage 105. A clean unit 118 is provided above the spare cassette shelf 110 so that clean air is circulated inside the housing 101.

  A heat treatment furnace 5 is provided above the rear portion of the housing 101, and a substrate holding means for holding a semiconductor silicon wafer (hereinafter simply referred to as a wafer 6) as a substrate to be processed in a horizontal posture in multiple stages below the heat treatment furnace 5. A boat elevator 121 is provided as an elevating means for elevating and lowering the boat 3 as a heat treatment furnace 5. A seal cap 125 as a lid is attached to the tip of the elevating member 122 attached to the boat elevator 121 to support the boat 3 vertically. Between the boat elevator 121 and the cassette shelf 109, a transfer elevator 113 as an elevating means is provided, and a wafer transfer machine 112 as a transfer means is attached to the transfer elevator 113. Next to the boat elevator 121, a furnace port shutter 116 having an opening / closing mechanism and closing means for closing the wafer loading / unloading port 131 on the lower side of the heat treatment furnace 5 is provided.

  The cassette 100 loaded with the wafer 6 is loaded into the cassette stage 105 from an external transfer device (not shown) in an upward posture, and is rotated by 90 ° on the cassette stage 105 so that the wafer 6 is in a horizontal posture. Further, the cassette 100 is transported from the cassette stage 105 to the cassette shelf 109 or the spare cassette shelf 110 by cooperation of the raising / lowering operation of the cassette elevator 115, the transverse operation, the advance / retreat operation of the cassette transfer machine 114, and the rotation operation.

  The cassette shelf 109 has a transfer shelf 123 in which the cassette 100 to be transferred by the wafer transfer device 112 is stored. The cassette 100 used for transferring the wafer 6 is transferred by the cassette elevator 115 and the cassette transfer device 114. Transferred to the transfer shelf 123.

  When the cassette 100 is transferred to the transfer shelf 123, the wafers 6 are transferred from the transfer shelf 123 to the lowered boat 3 by the cooperation of the forward / backward movement operation, the rotation operation of the wafer transfer device 112, and the lifting / lowering operation of the transfer elevator 113. Is transferred.

  When a predetermined number of wafers 6 are transferred to the boat 3, the boat 3 is inserted into the heat treatment furnace 5 by the boat elevator 121, and the wafer loading / unloading port 131 of the heat treatment furnace 5 is airtightly closed by the seal cap 125. In the heat treatment furnace 5 that is hermetically closed, the wafer 6 is heated and a processing gas is supplied into the heat treatment furnace 5 so that the wafer 6 is processed.

  When the processing on the wafer 6 is completed, the wafer 6 is transferred from the boat 3 to the cassette 100 of the transfer shelf 123 by the reverse procedure of the above-described operation, and the cassette 100 is transferred from the transfer shelf 123 by the cassette transfer device 114. It is transferred to the cassette stage 105 and carried out of the housing 101 by an external transfer device (not shown).

  The furnace port shutter 116 hermetically closes the wafer loading / unloading port 131 of the heat treatment furnace 5 when the boat 3 is in the lowered state, and prevents outside air from being caught in the heat treatment furnace 5.

  The transport operation of the cassette transfer machine 114 and the like is controlled by the transport control means 124.

1 is a longitudinal sectional view showing a configuration of a heat treatment furnace of a semiconductor manufacturing apparatus according to an embodiment, and FIG. 2 is an XX sectional view in FIG.
As shown in FIGS. 1 and 2, the heat treatment furnace 5 extends up and down on the inner wall surface of the process tube 7 as a cylindrical evacuable processing container with a closed top, as in the conventional semiconductor manufacturing apparatus. A partition wall 11 is provided. A plasma generation chamber 17 partitioned in the process tube 7 is formed by the partition wall 11. A plurality of wafers 6 are arranged side by side on the boat 3 so that the front and back surfaces are directed vertically. More specifically, the boat 3 is arranged at the center of the process tube 7 so that the centers of the wafers 6 are aligned on the central axis of the process tube 7. The partition wall 11 is concentric with the process tube 7, and includes a central wall 11 a having a circular arc shape along the outer periphery of each wafer 6, and a connection wall 11 b that connects the central wall 11 a to the process tube 7.

  On the central wall 11a of the partition wall 11, a plurality of air outlets 12 for blowing out electrons are arranged. The air outlets 12 are arranged at equal intervals in the vertical direction at a height position between adjacent wafers 6 so that an electron beam can be ejected between a plurality of wafers 6 stacked in multiple stages vertically. Yes. The air outlet 12 is arranged so that the electron beam passes through the center of the wafer 6, but may be arranged so that the electron beam passes in a direction slightly deviated from the center of the wafer 6. The partition 11 hermetically partitions the processing chamber 46 and the plasma generation chamber 17 formed in the process tube 7 except for the air outlet 12.

  A flat grid electrode 19 and an anode electrode 20 extending vertically are provided in the plasma generation chamber 17. The grid electrode 19 and the anode electrode 20 are arranged to face each other, and the anode electrode 20 is provided to face the wall on the center side of the heat treatment furnace 5 in the partition wall 11. Both the grid electrode 19 and the anode electrode 20 are formed with electron passage holes 19 a and 20 a corresponding to the air outlet 12. The grid electrode 19 is connected to the negative electrode side of the DC power source 21, and the anode electrode 20 is connected to the anode side of the DC power source 21. Therefore, when a voltage is applied between the grid electrode 19 and the anode electrode 20 by the DC power source 21, an electric field for accelerating electrons is generated between the electron passage hole 19a and the electron passage hole 20a.

  An inductively coupled plasma (ICP) source having an electrode 22 made of a metal, carbon rod or the like is disposed outside the position corresponding to the plasma generation chamber 17 of the process tube 7. A metal shield 23 is interposed between the electrode 22 and the process tube 7. Both ends of the electrode 22 are connected to the high frequency power supply 13. Plasma is generated between the process tube 7 and the grid electrode 19. The plasma supply chamber 17, the grid electrode 19, the anode electrode 20, the DC power source 21, the electrode 22, the high frequency power source 13 and the like constitute an electron supply device (electron gun) 18.

  In this embodiment, an electron beam excited plasma (EBEP: Electron-Beam-Excited-Plasma) system is used as a plasma source in a vertical batch plasma processing apparatus. EBEP is a method in which electrons are directly irradiated between the wafers 6 by the electron gun 18 and the processing gas is ionized in the immediate vicinity of the wafers 6.

  The process tube 7 is provided with a gas introduction port 31 for supplying a processing gas and an exhaust pipe 32 for exhausting the inside of the process tube 7. The gas introduction port 31 supplies a processing gas into the process tube 7 through the plasma generation chamber 17. A gas supply system 33 including a gas supply source, piping and valves is connected to the gas introduction port 31 in order to supply a processing gas. The gas introduction port 31 and the gas supply system 33 constitute a processing gas supply apparatus. A pump 34 is connected to the exhaust pipe 32 through an automatic pressure control valve and piping so that the process tube 7 can be exhausted.

  The boat 3 is supported by bearings 35 so that the boat 3 can rotate around the center of the wafer 6. The boat 3 is rotated by a rotation drive mechanism 36 as a rotation device.

The operation of the heat treatment furnace 5 configured as described above will be described.
After the previous batch processing is completed, the boat 3 descends from the heat treatment furnace 5 and a plurality of wafers 6 are newly loaded on the boat 3 by the wafer transfer device 112. The boat 3 loaded with the wafers 6 is inserted into the heat treatment furnace 5, and the heat treatment furnace 5 is hermetically closed by the seal cap 125.
Then, the processing gas is supplied from the gas introduction port 37 to the processing chamber 46, and the gas for the electronic power source is supplied from the gas introduction port 31 into the plasma generation chamber 17. The pump 34 is evacuated to create a gas and pressure atmosphere suitable for plasma generation.

Then, the DC power source 21 and the high frequency power source 13 are operated while the heat treatment furnace 5 is heated by the heater 16. By applying a voltage to the high frequency power supply 13 and a voltage application to the DC power supply 21, an electron beam is generated by the electron supply device to generate EBEP (plasma gas 27). As shown in FIG. 3, ions 25 (A ⁺ ions in FIG. 3) and electrons 26 (e in FIG. 3) are mixed in the plasma generated in the plasma generation chamber 17, and the neutrality is maintained as a whole. Yes. When a voltage is applied between the grid electrode 19 and the anode electrode 20 by the DC power source 21, the electrons 26 in the plasma are subjected to trajectory correction by an electric field created by the negative voltage applied to the grid electrode 19. It converges on the passage hole 19a. Then, the electric field generated by the positive voltage (acceleration voltage) applied to the anode electrode 20 is accelerated toward the electron passage hole 20a of the anode electrode 20. The accelerated electrons are irradiated between the wafers 6 and 6 from the outlet 12 of the partition wall 11 as an electron bundle, that is, an electron beam (Electron-beam) 24. The irradiated electron beam 24 excites or ionizes the plasma gas 28 (B molecule in FIG. 3) with a certain probability in the immediate vicinity of the surface of the wafer 6. The excited or ionized plasma gas 27 (B ^{+ in} FIG. 3) processes the surface of the wafer 6.

  At this time, the boat 3 is rotated by the rotation drive mechanism 36 to ensure uniformity of the electron beam within the plane of the wafer 6 and between the planes of the wafer 6 and contact with the plasma gas 27 which is uniform within the plane of the wafer 6. Then, the plurality of wafers 6 are processed uniformly throughout.

  According to the semiconductor manufacturing apparatus of the present embodiment, the processing gas is activated in the immediate vicinity of the wafer 6, so that a necessary amount can be supplied to the surface of the wafer 6 even if the active species has a short lifetime. Further, since the wafer 6 is not exposed to the high energy plasma generated by CCP or the like, the wafer 6 itself is not damaged by the plasma. Furthermore, in the plasma generation chamber 17, it is sufficient to generate plasma only for extracting electrons, so there is no need to apply a high output high frequency, and there is a possibility that the quartz wall constituting the process tube 7 is sputtered. Low. Further, in this embodiment, an ICP source is used in the plasma generation chamber, and the ICP source is outside the process tube 7, so that the contamination source during processing is compared with the case of using a filament (ultra-high temperature metal). It is very clean.

  Further, in this embodiment, as described in JP-A-11-204292, electrons are not irradiated from the front of the single wafer 6, but in a direction along the surface of the wafer 6, for example, parallel to the surface. Is irradiated with an electron beam. When an electron beam is applied from directly above a wafer with a single wafer as in the same publication, it is necessary to widen the beam diameter, so parts such as lenses and electrodes are required, and the structure is complicated. It becomes difficult to make uniform. In this respect, in this embodiment, since the electron beam is irradiated in parallel with the surface, there is no such problem, and plasma can be generated in a wide range near the surface of the wafer 6. In addition, since the plurality of wafers 6 are rotated by rotating the boat 3, it is possible to supply plasma uniformly within and between the surfaces of the plurality of wafers 6.

  In addition, since the plasma is uniformly formed on each wafer 6 in this way, the film quality is improved when the plasma process is a film forming process, and the product throughput is achieved by being a batch type. Will also improve.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented.
For example, the plasma generation method in the plasma generation chamber 17 uses ICP by applying a high frequency as an example in the above embodiment, but is not limited to this, and is not limited to this. As long as the plasma generation method suppresses the sputtering effect as much as possible, other methods can be applied.
Further, the plasma gas in the plasma generation chamber 17 and the plasma gas 28 contributing to the reaction may be the same or different. In the case of being different, a different gas introduction port different from the gas introduction port 31 is required.
As the plasma gas, H ₂ , He, Ar, N ₂ , NH ₃ or the like can be applied.

As another example of the reaction process, for example, ammonia gas (NH ₃ ) is used as the plasma gas 27 and a silane-based gas is supplied from another nozzle (not shown). According to this method, a silicon nitride film (Si ₃ N ₄ ) can be formed by plasma CVD (Chemical Vapor Deposition) processing. Further, the present invention can be used not only for plasma CVD processing but also for plasma ALD (Atomic Layer Deposition) processing and removal of a natural oxide film on the wafer 6 by H2 active species using plasma.

  Hereinafter, preferred embodiments of the present invention will be additionally described.

A first aspect is a semiconductor manufacturing apparatus that plasma-processes a plurality of substrates to be processed, and holds a processing container configured to be evacuated and the plurality of substrates to be processed inserted into the processing container in multiple stages. A substrate holder, a processing gas supply means for supplying a processing gas into the processing container, the plasma generating chamber for generating plasma communicating with the processing container, and the substrate in the processing container from the plasma generating chamber A semiconductor manufacturing apparatus comprising: an electron beam gun for irradiating electrons between substrates to be processed held by a holder; and a rotating device that rotates the substrate holder within the processing container.
The substrate holder in the processing container is rotated to generate plasma in the plasma generation chamber. Electrons are emitted from the plasma generation chamber by an electron beam gun. The emitted electrons hit the processing gas between the substrates to be processed held by the substrate holder. Thereby, electron beam excitation plasma is generated. With this plasma, a plurality of substrates to be processed are subjected to plasma processing simultaneously. At this time, since the substrate holder is rotated by the rotating device, plasma is uniformly generated between the substrates to be processed, and the substrate to be processed is uniformly plasma-treated within and between the surfaces. In addition, since electrons are irradiated between the substrates to be processed, the configuration of the electron supply device is simplified, and the device structure can be easily compared.

  A second aspect is a semiconductor manufacturing apparatus according to the first aspect, in which the plasma generation chamber is provided in a processing container, whereby the size of the apparatus can be reduced.

  A third aspect is the semiconductor manufacturing apparatus according to the first or second aspect, wherein the plasma generation chamber has an inductively coupled plasma (ICP) source, thereby generating clean plasma containing electrons. Can be made.

It is a longitudinal cross-sectional view which shows the structure of the heat processing furnace of the semiconductor manufacturing apparatus in one Embodiment of this invention. It is XX sectional drawing in FIG. It is a figure explaining the electron beam excitation plasma in one embodiment of this invention. 1 is an overall perspective view of a semiconductor manufacturing apparatus according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the heat processing furnace in the semiconductor manufacturing apparatus of a prior art example. FIG. 6 is a sectional view taken along line XX in FIG. 5. It is explanatory drawing of the plasma source of the heat processing furnace in the semiconductor manufacturing apparatus of a prior art example.

Explanation of symbols

3 boat (substrate holder)
6 Wafer (Substrate to be processed)
7 Process tube (processing vessel)
17 Plasma generation chamber 18 Electron supply device 26 Electron 31 Gas introduction port (process gas supply device)
32 Exhaust pipe 33 Gas supply system (processing gas supply device)
36 Rotation drive mechanism (rotating device)

Claims (4)

A semiconductor manufacturing apparatus for plasma processing a plurality of substrates to be processed,
A processing vessel configured to be evacuated;
A substrate holder for holding the plurality of substrates to be processed inserted into the processing container in multiple stages;
A processing gas supply device for supplying a processing gas into the processing container;
A plasma generation chamber for generating plasma communicating with the processing vessel;
An electron supply device for irradiating electrons between the substrate to be processed held by the substrate holder in the processing container from the plasma generation chamber;
A rotating device for rotating the substrate holder in the processing container;
A semiconductor manufacturing apparatus comprising: A substrate processing method for plasma processing a plurality of substrates to be processed,
Holding a plurality of substrates to be processed inserted into a processing container configured to be evacuated in multiple stages;
Supplying a processing gas into the processing vessel;
Generating plasma in a plasma generation chamber communicating with the processing vessel;
Irradiating electrons between the substrate to be processed held by the substrate holder in the processing container from the plasma generation chamber;
Rotating the substrate holder in the processing vessel;
A substrate processing method . A substrate manufacturing method for plasma processing a plurality of substrates to be processed,
Holding a plurality of substrates to be processed inserted into a processing container configured to be evacuated in multiple stages;
Supplying a processing gas into the processing vessel;
Generating plasma in a plasma generation chamber communicating with the processing vessel;
Irradiating electrons between the substrate to be processed held by the substrate holder in the processing container from the plasma generation chamber;
Rotating the substrate holder in the processing vessel;
The manufacturing method of the board | substrate which has this . A method of manufacturing a semiconductor device for plasma processing a plurality of substrates to be processed,
Holding a plurality of substrates to be processed inserted into a processing container configured to be evacuated in multiple stages;
Supplying a processing gas into the processing vessel;
Generating plasma in a plasma generation chamber communicating with the processing vessel;
Irradiating electrons between the substrate to be processed held by the substrate holder in the processing container from the plasma generation chamber;
Rotating the substrate holder in the processing vessel;
A method for manufacturing a semiconductor device comprising:

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