JP4838552B2 - Substrate processing apparatus and semiconductor integrated circuit manufacturing method - Google Patents

Description

The present invention relates to a substrate processing apparatus and a method for manufacturing a semiconductor integrated circuit , and more particularly to a plasma processing apparatus that performs a predetermined process using plasma generated by high-frequency power and a method for manufacturing a semiconductor integrated circuit using the apparatus. Is.

  For example, in the manufacture of semiconductor integrated circuits, plasma is used to promote ionization, chemical reaction, and the like of process gases in CVD, etching, ashing, and sputtering processes. Conventionally, methods for generating plasma in a semiconductor manufacturing apparatus include a parallel plate method, a high frequency induction method, a helicon wave method, and an ECR method. The parallel plate method is a method of generating plasma between both electrodes by grounding one of a pair of parallel plate electrodes and capacitively coupling the other to a high frequency power source. The high frequency induction method is a method of generating plasma by applying a high frequency to a spiral or spiral antenna to create a high frequency electromagnetic field, and causing electrons flowing in the electromagnetic field space to collide with neutral particles in the gas. The helicon wave method generates a special electromagnetic wave (helicon wave) that travels parallel to the magnetic field by a specially shaped antenna within a uniform magnetic field made of coils, and uses the Landau damping effect associated with this helicon wave to create a velocity. In this method, plasma is generated by a controllable electron flow. In the ECR method, a microwave having a frequency equal to the cyclotron frequency of an electron (2.45 GHz) is guided through a waveguide in a uniform magnetic field formed by a coil, and a resonance phenomenon is caused. In this method, plasma is generated by absorption. As these plasma generation methods, there are a single-wafer method for processing the objects to be processed one by one and a method for processing a plurality of objects to be processed in batches.

  As a conventional plasma processing apparatus, a plurality of gases that are accommodated in a processing tube in a state in which a plurality of substrates to be processed are stacked in a vertical direction and are sized to supply a processing gas to the processing tube evenly in the height direction. A structure in which a processing gas is supplied from a gas supply nozzle provided with supply pores in a vertical direction is used. In addition, a high-frequency application electrode including a first electrode connected to a high-frequency power source and a second electrode grounded is provided on the outer periphery of the processing tube. The first electrode and the second electrode are provided so as to alternately extend in the horizontal direction.

  In this way, a high frequency is applied to the first electrode in a state where the processing gas is uniformly introduced from the plurality of gas supply pores whose sizes are adjusted so as to supply the processing gas evenly in the height direction. In this case, since the electric field around the first electrode is strong, the gas supply pores become locally hot, and even if the nozzle is made of quartz, there is a high possibility that contaminants will be scattered on the substrate to be processed. Furthermore, there is a problem that the plasma density is also increased locally, causing processing unevenness of the substrate to be processed.

Accordingly, a main object of the present invention is to provide a substrate processing apparatus capable of suppressing local plasma abnormality occurring in a gas supply pipe at a position where high-frequency power is applied, and a method for manufacturing a semiconductor integrated circuit using the apparatus. There is to do.

According to the present invention,
A processing tube accommodated in a state in which a plurality of substrates are laminated;
Heating means arranged outside the processing tube and surrounding the processing tube;
In order to supply a desired processing gas into the processing tube, a gas supply tube extending in the stacking direction of the substrate;
A gas activation unit disposed between the processing tube and the heating unit and disposed to surround the processing tube;
The gas activation means includes
At least one has a first electrode group and a second electrode group to which high-frequency power is applied, and the electrodes of the first electrode group and the electrodes of the second electrode group are alternately arranged. And
Furthermore, each of the electrodes of the first electrode group and the electrodes of the second electrode group has a plurality of stripe portions each having a shape extending in the same direction as the extending direction of the gas supply pipe ,
A substrate processing apparatus is provided in which the gas supply pipe is provided in a space between the stripe portion of the first electrode and the stripe portion of the second electrode .
Note that high-frequency power may be applied to both the first electrode group and the second electrode group.
Moreover, according to the present invention,
A processing tube accommodated in a state in which a plurality of substrates are laminated;
Heating means arranged outside the processing tube and surrounding the processing tube;
In order to supply a desired processing gas into the processing tube, a gas supply tube extending in the stacking direction of the substrate;
A gas activation unit disposed between the processing tube and the heating unit and disposed to surround the processing tube;
The gas activation means includes
At least one has a first electrode group and a second electrode group to which high-frequency power is applied, and the electrodes of the first electrode group and the electrodes of the second electrode group are alternately arranged. And
Furthermore, each of the electrodes of the first electrode group and the electrodes of the second electrode group has a plurality of stripe portions each having a shape extending in the same direction as the extending direction of the gas supply pipe,
The gas supply pipe uses a substrate processing apparatus provided in a space between the stripe portion of the first electrode and the stripe portion of the second electrode,
The processing tube accommodated in a stacked state is heated by the heating means, gas is supplied to the processing tube, the pressure in the processing tube is kept constant, and the electrode of the first electrode group And a step of supplying power between the electrodes of the second electrode group and treating the substrate with the generated plasma.

According to the present invention, there are provided a substrate processing apparatus capable of suppressing local plasma abnormality occurring in a gas supply pipe at a position to which high-frequency power is applied, and a method for manufacturing a semiconductor integrated circuit using the apparatus .

  Next, a preferred embodiment of the present invention will be described.

  In a preferred embodiment of the present invention, in a batch type plasma processing apparatus that applies a high frequency (13.56 MHz) to an electrode placed on the outer periphery of a processing tube to convert the processing gas into plasma and plasma-process the processing substrate. A bar or band-like high-frequency power application side electrode and ground side electrode are alternately placed in a direction perpendicular to the main surface of the substrate, in the same direction as the substrate stacking direction, or in the same direction as the extending direction of the gas supply nozzle Has been.

  The gas ejection port of the gas supply nozzle placed in the processing tube in the plasma generation region by alternately placing the high-frequency application side electrode and the ground side electrode in the same direction as the extending direction of the gas supply nozzle Interference can be easily prevented, and local electric field concentration can be suppressed.

  Then, ring-shaped electrodes are placed on the upper and lower sides of the processing tube for the purpose of electrical joining of the electrodes on which the high-frequency application side electrode and the ground side electrode are alternately placed. The high-frequency application side electrode and the ring-shaped electrode, and the ground-side electrode and the ring-shaped electrode are each made into an integral structure to improve the reliability of the mechanical electrode connection surface.

  The preferred embodiments of the present invention will now be described in more detail with reference to the drawings.

  1 and 2 are schematic longitudinal sectional views for explaining a processing furnace of a substrate processing apparatus according to a preferred embodiment of the present invention. FIG. 3 shows a processing furnace of a substrate processing apparatus according to a preferred embodiment of the present invention. It is a schematic cross-sectional view for demonstrating. FIG. 1 shows the configuration of electrodes placed on the outer surface of the reaction chamber 1, FIG. 2 shows a cross section of the reaction chamber 1, and FIG. 3 shows a cross section of the reaction chamber as viewed from above. .

  The reaction chamber 1 is hermetically configured with a processing tube 2 and a seal cap 3, and a heater 4 is provided around the processing tube 2 so as to surround the reaction chamber 1. The processing tube 2 is made of a dielectric material such as quartz. A first electrode 18 connected to the high-frequency power source 5 and a second electrode 19 connected to the ground are alternately arranged on the outer periphery of the processing tube 2 in stripes perpendicular to the object 16 to be processed. The AC power output from the power source 5 can be applied via the matching unit 10. As the frequency of the AC power, a high frequency of 13.56 MHz is often used.

  The reaction chamber 1 is connected to a pump 13 via an exhaust pipe 11 and a pressure adjusting valve 12 so that the gas inside the reaction chamber 1 can be exhausted. A gas introduction port 14 is provided in communication with the reaction chamber 1, and a plurality of gas supply pores whose sizes are adjusted to uniformly supply the processing gas in the height direction are provided on the side surface inside the reaction chamber 1. 15 is provided extending in the vertical direction so that the processing gas can be introduced more evenly.

  Inside the reaction chamber 1, a boat 17 that can be horizontally mounted, for example, about 100 to 150, is provided so that the semiconductor wafers 16 that are also objects to be processed can be batch-processed.

  The first electrode 18 includes a plurality of stripe portions 31 and one strip portion 32. Both the stripe part 31 and the belt | band | zone part 32 are thin plate shape. One end of each of the plurality of stripe portions 31 is connected to the strip portion 32 in common. The other end of each of the plurality of stripe portions 31 is released. The band portion 32 is attached to the upper portion of the processing tube 2 so as to extend in the horizontal direction. The plurality of stripe portions 31 are arranged in parallel to each other in the vertical direction. One of the other ends of the plurality of stripe portions 31 extends to the lowermost end of the processing tube 2, and then connected to the high frequency power source 5 through the matching unit 10.

  The second electrode 19 includes a plurality of stripe portions 41 and one band portion 42. Both the stripe part 41 and the band part 42 are thin plate-like. One end of each of the plurality of stripe portions 41 is commonly connected to the belt portion 42. The other end of each of the plurality of stripe portions 41 is released. The belt portion 42 is attached to the lower portion of the processing tube 2 so as to extend in the horizontal direction. The plurality of stripe portions 41 are arranged in parallel to each other in the vertical direction. One of the ends of the plurality of stripe portions 41 extends to the lowest end of the quartz tube, and is then grounded.

As described above, since the plurality of stripe portions 31 and the second electrode 19 of the first electrode 18 extend the plurality of stripe portions 41 in the same direction as the extending direction of the gas supply nozzle 21, The electrodes 18 and 19 can be arranged without intersecting the gas supply pores 15 of the supply nozzle 21, and local abnormalities in the gas supply pores 15 when high-frequency power is applied can be suppressed, so Contamination could be prevented and processing uniformity was improved.
Preferably, the gas supply nozzle 21 is provided in a space between the stripe portion 31 of the first electrode 18 and the stripe portion 41 of the second electrode 19 when viewed from the right or left side of FIG.

  In addition, band portions 32 and 42 that are band-like rings are provided on the upper and lower portions of the reaction chamber 1, and the first electrode 18 has an integrated structure of a plurality of stripe portions 31 and one band portion 32. Since the plurality of stripe portions 41 and one band portion 42 are integrated with each other, the joint portion in the heater heating region can be eliminated, and the reliability is improved.

  The first electrode 18 and the second electrode were made of a thin plate such as Ni. For example, the thickness was set to 0.5 mm to give flexibility.

  The plurality of stripe portions 31 (18a to 18h) of the first electrode 18 and the plurality of stripe portions 41 (19a to 19h) of the second electrode 19 are alternately arranged over the entire outer periphery of the processing tube 2. . Thus, since it arrange | positions over the perimeter, the to-be-processed substrate uniformity of a plasma processing can be improved, and the plasma processing rate of a to-be-processed substrate can also be improved.

  The operation of the apparatus of the preferred embodiment of the present invention will now be described.

  In order to load the workpiece 16 into the boat 17 while the reaction chamber 1 is at atmospheric pressure, the seal cap 3 is lowered by the elevator mechanism 121 (see FIG. 4), and the robot for transferring the workpiece (wafer transfer machine 112). 4 and FIG. 5), after the required number of objects 16 to be processed are placed on the boat 17, the seal cap 3 is raised and inserted into the reaction chamber 1.

  Electric power is supplied to the heater 4 to heat members in the reaction chamber 1 such as the object 16 to a predetermined temperature. If the temperature of the heater 4 is excessively lowered during the conveyance of the object to be processed, it takes a considerable amount of time to raise the temperature to a predetermined value within the reaction chamber 1 and stabilize it after the conveyance of the object 16 to be processed. For this reason, normally, the temperature of the workpiece 16 is lowered to a temperature that does not hinder the conveyance, and the conveyance is performed in a state where the temperature is maintained.

  At the same time, the gas inside the reaction tube 1 is exhausted by a pump 13 through an exhaust pipe 11 from an exhaust port (not shown). When the object to be processed 16 reaches a predetermined temperature, a reactive gas is introduced into the reaction chamber 1 from the gas introduction port 14, and the pressure in the reaction chamber 1 is maintained at a constant value by the pressure adjustment valve 12.

  When the inside of the reaction chamber 1 reaches a predetermined pressure, AC power output from the high-frequency power source 5 is supplied to the first electrode 18 via the matching unit 10 to generate plasma between the electrodes, thereby processing the object 16 to be processed. I do.

  Next, an outline of the substrate processing apparatus according to a preferred embodiment of the present invention will be described with reference to FIGS.

  A cassette stage 105 is provided on the front side of the inside of the housing 101 as a holder transfer member that transfers the cassette 100 as a substrate storage container to and from an external transfer device (not shown). Is provided with a cassette elevator 115 as lifting means, and a cassette transfer machine 114 as a conveying 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 processing furnace 40 is provided above the rear portion of the casing 101, and a boat 17 as a substrate holding unit that holds the wafers 16 as substrates in a horizontal posture in multiple stages is raised and lowered to the processing furnace 40 below the processing furnace 40. A boat elevator 121 as an elevating means is provided, and a seal cap 3 as a lid is attached to the tip of an elevating member 122 attached to the boat elevator 121 to support the boat 17 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. A furnace opening shutter 116 as a shielding member that has an opening / closing mechanism and closes the lower surface of the processing furnace 40 is provided beside the boat elevator 121.

  The cassette 100 loaded with the wafer 16 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 16 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 to which the wafer 16 is transferred 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 wafer 16 is transferred from the transfer shelf 123 to the lowered boat 17 by the cooperation of the forward / backward movement and rotation operation of the wafer transfer device 112 and the lifting / lowering operation of the transfer elevator 113. Transfer.

  When a predetermined number of wafers 16 are transferred to the boat 17, the boat 17 is inserted into the processing furnace 40 by the boat elevator 121, and the processing furnace 40 is airtightly closed by the seal cap 3. The wafer 16 is heated in the hermetically closed processing furnace 40 and a processing gas is supplied into the processing furnace 40 to process the wafer 16.

  When the processing on the wafer 16 is completed, the wafer 16 is transferred from the boat 17 to the cassette 100 of the transfer shelf 123 by the reverse procedure of the operation described above, 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 closes the lower surface of the processing furnace 40 when the boat 17 is in the lowered state, and prevents outside air from being caught in the processing furnace 40.

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

(Comparative example)
6 and 7 are schematic longitudinal sectional views for explaining a processing furnace of a substrate processing apparatus for comparison, and FIG. 8 is a schematic cross section for explaining a processing furnace of a substrate processing apparatus for comparison. FIG. 6 shows the configuration of the electrodes placed on the outer surface of the reaction chamber 1, FIG. 7 shows the cross section of the reaction chamber 1, and FIG. 8 shows the cross section of the reaction chamber as viewed from above. .

  The reaction chamber 1 is hermetically configured with a processing tube 2 and a seal cap 3, and a heater 4 is provided around the processing tube 2 so as to surround the reaction chamber 1. The processing tube 2 is made of a dielectric material such as quartz. On the outer periphery of the processing tube 2, first electrodes 6 a to 6 d connected to the high-frequency power source 5 and second electrodes 7 a to 7 e connected to the ground are arranged alternately in a strip shape in multiple stages, The electrode column 8 is attached to the electrode column 8 and the electrode column 9, and the electrode column 8 can apply the AC power output from the high frequency power source 5 via the matching unit 10. The electrode support 9 is connected to ground.

  The reaction chamber 1 is connected to a pump 13 via an exhaust pipe 11 and a pressure adjusting valve 12 so that the gas inside the reaction chamber 1 can be exhausted. The reaction chamber 1 is provided with a gas introduction port 14, and a plurality of gas supply pores 15 whose sizes are adjusted to supply the reaction gas in the height direction evenly on the side surface inside the reaction chamber 1. It is possible to introduce evenly from the gas supply nozzle 21 provided with.

  Inside the reaction chamber 1, a boat 17 that can be horizontally mounted, for example, about 100 to 150, is provided so that the semiconductor wafers 16 that are also objects to be processed can be batch-processed.

  In this comparative example, the process gas is introduced uniformly from the gas supply nozzle 21 having a plurality of gas supply pores 15 whose sizes are adjusted so as to supply the process gas to the reaction chamber 1 in the height direction evenly. When a high frequency is applied to the first electrodes 6a to 6d, the electric field around the first electrodes 6a to 6d is strong, so that the gas supply pores 15 are locally high in temperature, even if they are made of quartz. There is a high possibility that contaminants are scattered on the object to be processed, and the plasma density is also increased locally, causing processing unevenness of the object to be processed.

  In addition, the first electrodes 6a to 6d and the second electrodes 7a to 7e placed on the outer periphery of the reaction chamber 1 need to be mechanically connected to the electrode support 8 and the electrode support 9, and are provided on the outer periphery of the electrode. There are also problems such as expansion / deformation due to heat of the heater 4 and contact failure due to oxidation of the connection surface.

It is a schematic longitudinal cross-sectional view for demonstrating the processing furnace of the substrate processing apparatus of preferable Example of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the processing furnace of the substrate processing apparatus of preferable Example of this invention. It is a schematic cross-sectional view for demonstrating the processing furnace of the substrate processing apparatus of preferable Example of this invention. It is a schematic perspective view for demonstrating the substrate processing apparatus of the preferable Example of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus of the preferable Example of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the processing furnace of the substrate processing apparatus for a comparison. It is a schematic longitudinal cross-sectional view for demonstrating the processing furnace of the substrate processing apparatus for a comparison. It is a schematic cross-sectional view for demonstrating the processing furnace of the substrate processing apparatus for a comparison.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reaction chamber 2 ... Processing tube 3 ... Seal cap 4 ... Heater 5 ... High frequency power supply 6a-6d ... 1st electrode 7a-7e ... 2nd electrode 8 ... Electrode support | pillar 9 ... Electrode support | pillar 10 ... Matching device 11 ... Exhaust Pipe 12 ... Pressure adjustment valve 13 ... Pump 14 ... Gas introduction port 15 ... Gas supply pore 16 ... Object to be processed (silicon wafer)
DESCRIPTION OF SYMBOLS 17 ... Boat 18 (18a-18h) ... 1st electrode 19 (19a-19h) ... 2nd electrode 20 ... High frequency electric power application electrode 21 ... Gas supply nozzle 31, 41 ... Stripe part 32, 42 ... Band part 40 ... Processing furnace 100 ... cassette 101 ... casing 105 ... cassette stage 109 ... cassette shelf 110 ... preliminary cassette shelf 112 ... wafer transfer machine 113 ... transfer elevator 114 ... cassette transfer machine 115 ... cassette elevator 116 ... furnace port shutter 118 ... Clean unit 121 ... Boat elevator 122 ... Elevating member 123 ... Transfer shelf 124 ... Transport control means

Claims (3)

A processing tube accommodated in a state in which a plurality of substrates are laminated;
Heating means arranged outside the processing tube and surrounding the processing tube;
In order to supply a desired processing gas into the processing tube, a gas supply tube extending in the stacking direction of the substrate;
A gas activation unit disposed between the processing tube and the heating unit and disposed to surround the processing tube;
The gas activation means includes
At least one has a first electrode group and a second electrode group to which high-frequency power is applied, and the electrodes of the first electrode group and the electrodes of the second electrode group are alternately arranged. And
Furthermore, each of the electrodes of the first electrode group and the electrodes of the second electrode group has a plurality of stripe portions each having a shape extending in the same direction as the extending direction of the gas supply pipe ,
The gas supply pipe is a substrate processing apparatus provided in a space between a stripe portion of the first electrode and a stripe portion of the second electrode . 2. The substrate processing apparatus according to claim 1, wherein the first electrode group has one end of the plurality of stripe portions connected to a strip portion, and the strip portion and the stripe portion are integrally formed. A processing tube accommodated in a state in which a plurality of substrates are laminated;
  Heating means arranged outside the processing tube and surrounding the processing tube;
  In order to supply a desired processing gas into the processing tube, a gas supply tube extending in the stacking direction of the substrate;
  A gas activation unit disposed between the processing tube and the heating unit and disposed to surround the processing tube;
  The gas activation means includes
  At least one has a first electrode group and a second electrode group to which high-frequency power is applied, and the electrodes of the first electrode group and the electrodes of the second electrode group are alternately arranged. And
  Furthermore, the electrodes of the first electrode group and the electrodes of the second electrode group each have a plurality of stripe portions each having a shape extending in the same direction as the extending direction of the gas supply pipe,
  The gas supply pipe uses a substrate processing apparatus provided in a space between the stripe portion of the first electrode and the stripe portion of the second electrode,
  The processing tube accommodated in a stacked state is heated by the heating means, gas is supplied to the processing tube, the pressure in the processing tube is kept constant, and the electrode of the first electrode group And a step of supplying a power between the electrodes of the second electrode group and processing the substrate with the generated plasma.

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