JP5284213B2 - Plasma processing apparatus and tray for plasma processing apparatus - Google Patents

Description

  The present invention relates to a plasma processing apparatus and a tray for a plasma processing apparatus.

  Plasma processing apparatuses that perform dry etching, surface modification, ashing, etc. on a semiconductor substrate by generating plasma with microwaves and exposing the semiconductor device to the generated plasma are known (for example, patents) Reference 1).

  In this type of plasma processing apparatus, for example, in an ashing processing apparatus for ashing (ashing) a resist film formed on a semiconductor substrate using a plasma of a reactive gas, a plasma generation chamber is provided on the upper side of the chamber, A stage on which a semiconductor substrate is placed is provided on the lower side. The plasma generated in the plasma generation chamber is led out to a stage provided below. The semiconductor substrate placed on the stage is ashed by being preheated by the substrate heating means provided on the stage and exposed to plasma derived from the plasma generation chamber.

  By the way, in this kind of plasma processing apparatus, in order to improve production efficiency, a plurality of semiconductor substrates are accommodated in a tray, and the tray accommodating the plurality of semiconductor substrates is placed on a stage. An ashing process is performed on a plurality of semiconductor substrates accommodated in the tray at the same time.

JP 2005-122939 A

  In the plasma processing apparatus, the plurality of semiconductor substrates are preheated by the substrate heating means provided on the stage as described above in order to efficiently perform the plasma processing. However, since the plurality of semiconductor substrates are accommodated in the tray, they are heated by the substrate heating means provided on the stage via the tray.

  As a result, the heat conducted through the tray is dissipated in the tray, the heating efficiency to each semiconductor substrate is very poor, and it takes time to heat the semiconductor substrate to a predetermined temperature, and the production efficiency It becomes a problem when trying to improve.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a plasma processing apparatus capable of increasing the preheating efficiency of a processing substrate placed on a stage and improving the production efficiency. It is in providing the tray for plasma processing apparatuses.

According to the first aspect of the present invention, a plurality of processing substrates are accommodated in a holding tray, the holding tray is disposed on a stage in a chamber, and the plurality of sheets accommodated in the holding tray on the stage. A plasma processing apparatus for simultaneously processing the processing substrate, comprising heating means for heating the stage and heating the processing substrate through the stage, the holding tray including an outer frame, are arranged to cross each other inside the outer frame, wherein are formed from the machining of a plurality of supporting each part of the back surface of the substrate support rod, the upper surface of each of said plurality of support rods, said upper surface A plurality of holding pieces formed on different supporting rods, and a support rod on which each of the holding pieces is formed, and a portion where the supporting rods intersect with each other. the use substrate is held, before The stage forms a tray receiving groove having a shape similar to the outer shape of the holding tray on the mounting surface, and the outer frame of the tray and the support rod fit into the tray receiving groove, thereby allowing the holding tray to Each processing substrate accommodated is separated from the holding tray and placed in contact with the placement surface of the stage.

  According to the first aspect of the present invention, only the holding tray can be immersed in the tray receiving groove formed on the mounting surface of the stage, and the plurality of semiconductor substrates accommodated in the holding tray are simultaneously It can be mounted on the stage mounting surface.

Further, according to the invention described in claim 1, a plurality of semiconductor substrates that are mounted on the mounting surface of the stage is preheated at a mounting surface of the stage.

The invention according to claim 2, in the plasma processing apparatus according to claim 1, wherein the heating means is a high-frequency induction heating means, an induction coil wound outside of the stage, the high frequency to the induction coil It consists of a high-frequency power supply that supplies current.

According to the invention described in claim 2, stage by passing a high frequency current to the induction coil, it is heated at induction heating.
According to a third aspect of the present invention, in the plasma processing apparatus according to the first or second aspect , the lift member that protrudes and retracts from a through hole formed in the bottom surface of the tray receiving groove and supports the bottom surface of the holding tray. And elevating means for moving the lift member up and down.

According to the invention described in claim 3 , by moving the lift member downward, only the holding tray is immersed in the tray receiving groove, and a plurality of semiconductor substrates received in the holding tray are placed on the stage. The plurality of semiconductor substrates placed on the stage placement surface can be simultaneously accommodated in the holding tray by moving the lift member upward.

According to a fourth aspect of the present invention, there is provided a plasma processing apparatus for accommodating and mounting a plurality of processing substrates on a heated stage provided in a chamber or on a heated stage capable of plasma processing. A plurality of support rods, each of which includes an outer frame and a plurality of support rods arranged to intersect each other inside the outer frame and respectively supporting a part of the back surface of each processing substrate. A holding piece protruding from the upper surface is formed on the upper surface of each of the ridges, and a plurality of holding pieces formed on different supporting ridges are formed into a supporting ridge on which each of the holding pieces is formed, and the supporting ridge together with a portion cross each other to hold one of the bare board, the stage, the tray accommodating grooves of similar shape as the outer shape to be formed the outer frame and by said plurality of support rods to the mounting surface Forming the outer frame and the support rod By fit into accommodating grooves, each bare board is in contact disposed on the mounting surface of the stage.

According to the fourth aspect of the present invention, the plurality of processing substrates are accommodated in the outer frame, supported by the plurality of support rods and opened at the bottom.

According to the present invention, Ru can be improved in production efficiency raised preheating efficiency of the processing substrate placed on the stage.

The schematic sectional drawing of a plasma ashing apparatus. The perspective view for demonstrating a stage and the tray for holding | maintenance. The top view of a stage. Explanatory drawing which shows the state which supported the tray for holding | maintenance. Explanatory drawing which shows the state in which the semiconductor substrate was mounted.

Hereinafter, an embodiment embodied in a plasma ashing apparatus which is one of the plasma processing apparatuses of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a plasma ashing apparatus 1 as a plasma processing apparatus. The chamber 2 of the plasma ashing apparatus 1 has a rectangular parallelepiped shape and is made of aluminum (Al). A stage 5 is disposed and fixed on the inner bottom surface of the bottom plate 3 of the chamber 2 via a leg portion 4.

  The stage 5 has a quadrangular prism shape as shown in FIGS. 2 and 3, and an induction coil L (see FIG. 1) that constitutes heating means is wound around the outer periphery of the side surface. When the high frequency current is supplied to the induction coil L from the high frequency power supply G, that is, the stage 5 is heated by induction heating means including the induction coil L and the high frequency power supply G, and the placement surface 5a of the stage 5 is heated. A plurality of (four in this embodiment) semiconductor substrates W as processing substrates to be placed are preheated.

  The four semiconductor substrates W are accommodated in the holding tray 6 and placed on the stage 5 together with the holding tray 6. As shown in FIG. 2, the holding tray 6 includes a rectangular frame-like outer frame 7 and a plurality of the sides of the outer frames 7 facing each other so that the inner side of the outer frame 7 has a lattice shape. The supporting rod 8 is formed.

  The length of each side of the outer frame 7 is shorter than one side of the stage 5, and the cross-sectional shape of each side is a rectangle. Each support rod 8 has a rectangular cross-sectional shape, and its long side and short side are shorter than the long side and short side of the outer frame 7. In this embodiment, the lower surface 7a of the outer frame 7 and the lower surface 8a of each support rod 8 are the same surface. Accordingly, the upper surface 7b of the outer frame 7 is located higher than the upper surface 8b of each support rod 8.

  Further, the shape of each lattice space SP inside the outer frame 7 formed by each support rod 8 is smaller than the outer shape of the semiconductor substrate W. Accordingly, the four semiconductor substrates W are accommodated and arranged on the support rods 8 arranged in a lattice shape formed in the outer frame 7 without falling off the lattice space SP.

  In addition, on the upper surface 8 b of each support rod 8, holding pieces 9 for positioning and holding the four semiconductor substrates W are projectingly formed. Therefore, each semiconductor substrate W is fitted and arranged between the corresponding holding pieces 9, whereby the four semiconductor substrates W are positioned and held with respect to the holding tray 6.

  As shown in FIGS. 2 and 3, the stage 5 has a tray receiving groove 10 formed on the mounting surface 5 a thereof. The tray receiving groove 10 is formed to have the same shape as the outer shape when the holding tray 6 is viewed in plan. More specifically, the tray housing groove 10 includes a frame groove portion 11 that houses the outer frame 7 of the holding tray 6 and a support groove groove portion 12 that houses each support rod 8. The depth of the tray receiving groove 10 composed of the frame groove portion 11 and the support trough groove portion 12 is formed deeper than the length of the short side of the outer frame 7 of the holding tray 6 and is held in the frame groove portion 11 as shown in FIG. The outer frame 7 of the tray 6 is configured such that each support rod 8 is immersed in the support groove portion 12.

  Accordingly, the placement surface 5a is divided into a plurality of pieces in the tray receiving groove 10, and each divided placement surface 5a is divided into each lattice space SP inside the outer frame 7 formed by each support rod 8. Can be penetrated. As a result, when the holding tray 6 accommodating and holding the four semiconductor substrates W is fitted into the tray receiving groove 10, the outer frame 7 of the holding tray 6 is immersed in the frame groove portion 11, and By immersing the support rod 8, the four semiconductor substrates W are left behind and placed on the placement surface 5 a of the stage 5.

  Each divided mounting surface 5a is formed with a support wall 13 having a quadrangular arc shape. The quarter-arc-shaped support walls 13 formed on each placement surface 5a form a circular support wall by the four adjacent support walls 13, and are placed on the stage 5 in the circular support walls. Each semiconductor substrate W is accommodated and arranged.

  As shown in FIG. 3, through holes 10 b are formed at the four corners of the tray receiving groove 10 on the bottom surface 10 a of the tray receiving groove 10. Each of the through holes 10b is inserted with a lift pin LP as a lift member for supporting the holding tray 6, and each lift pin LP is lifted by a lift motor M1 as a lift means, and the bottom surface of the tray housing groove 10 is inserted. It protrudes from 10a, supports the bottom surface of the holding tray 6 (the bottom surface 7a of the outer frame 7), and moves the holding tray 6 up and down.

  When each lift pin LP is inserted into each through hole 10 b, the holding tray 6 comes into contact with the bottom surface 10 a of the tray housing groove 10. That is, the holding tray 6 is immersed in the tray accommodating groove 10 below the placement surface 5a. As a result, as shown in FIG. 5, the four semiconductor substrates W are placed on the placement surface 5 a of the stage 5. Then, the four semiconductor substrates W placed on the placement surface 5a of the stage 5 are preheated by the stage 5 heated by induction heating.

  On the other hand, when each lift pin LP is moved to a position above the placement surface 5a, the holding tray 6 immersed in the tray housing groove 10 is positioned above the placement surface 5a as shown in FIG. Lifted to.

  The top plate 14 forming the chamber 2 has a cylindrical body 15 projecting upward from the outside thereof, and a through hole 18 penetrating the outside and inside of the chamber 2 is formed at the center of the cylindrical body 15. .

  A waveguide 19 is connected and fixed to the upper surface 15 a of the cylindrical body 15. The waveguide 19 has a connecting hole 19 a formed at a position corresponding to the through hole 18, and a disk-shaped microwave transmission window 20 closes the upper opening of the through hole 18 in the connecting hole 19 a. It is arranged like this. The microwave transmission window 20 is a dielectric transmission window made of ceramics or quartz, and is tightly fixed to the upper surface 15 a of the cylindrical body 15. A microwave from a microwave oscillator (not shown) provided upstream of the waveguide 19 propagates through the waveguide 19 and is introduced into the through hole 18 through the microwave transmission window 20.

The lower opening of the through hole 18 is formed with a fitting recess 30 that is expanded to have an inner diameter larger than the inner diameter of the through hole 18.
The lower opening of the through hole 18 in which the fitting recess 30 is formed is closed by a disk-shaped lower lid 33. The lower lid 33 has a disc-shaped lower lid body 34 formed through the lead-out hole 33a in the center, and a flange portion 35 formed to extend to the lower outer peripheral surface of the lower lid body 34. In the lower lid 33, the lower lid body 34 is inserted into the through hole 18, and the flange portion 35 is fitted into the fitting recess 30.

  Then, by screwing the flange portion 35 to the back surface 30 a of the fitting recess 30, the lower lid 33 (upper surface of the flange portion 35) is against the top plate 14 (back surface 30 a of the fitting recess 30). Fastened and fixed.

Thereby, the plasma generation chamber S is partitioned and formed in a space formed by closing the upper and lower openings of the through hole 18 formed in the cylindrical body 15 with the microwave transmitting window 20 and the lower lid 33.
An annular annular groove 41 is formed on the outer peripheral surface of the lower lid body 34, and an annular passage is formed by the annular groove 41 and the inner peripheral surface 18 a of the through hole 18 that closes the annular groove 41. The annular groove 41 is formed at a position facing the opening of the gas introduction path 32 formed in the inner peripheral surface 18a of the through hole 18, and the plasma forming gas (oxygen) introduced from the gas introduction path 32 is annular. It is introduced into the passage (annular groove 41).

  A notch 42 is formed in the outer peripheral edge of the upper surface of the lower lid body 34 so as to communicate the plasma generation chamber S and the annular groove 41 (annular passage). The plasma forming gas (oxygen) introduced into the annular groove 41 is introduced into the plasma generation chamber S through the cut groove 42.

  The plasma forming gas (oxygen) introduced into the plasma generation chamber S is similarly excited by microwaves introduced through the microwave transmission window 20 and becomes oxygen plasma. The oxygen plasma generated in the plasma generation chamber S is led out toward the semiconductor substrate W placed on the lower stage 5 through a lead-out hole 33 a formed in the lower lid 33.

  A diffusion plate 43 is disposed below the lower lid main body 34 and at a position facing the opening of the lead-out hole 33a. The diffusion plate 43 is made of aluminum (Al), and is connected and fixed to the lower lid main body 34 with bolts 45 via a spacing member 44 made of aluminum (Al). The diffusion plate 43 disperses the oxygen plasma led out from the lead-out hole 33 a of the lower lid body 34, and the oxygen plasma is uniformly exposed to the four semiconductor substrates W placed on the placement surface 5 a of the stage 5. To be. In the four semiconductor substrates W, the resist film formed on the surface of the semiconductor substrate W is ashed with oxygen plasma.

  A cylindrical skirt 46 is attached to the inner bottom surface of the top plate 14 so as to surround the diffusion plate 43. The skirt 46 is made of aluminum (Al), and is guided to the semiconductor substrate W disposed below so that oxygen plasma derived from the diffusion plate 43 does not diffuse.

Next, the operation of the plasma ashing apparatus 1 configured as described above will be described.
Now, in a state where the lift pins LP are arranged at the upper position, a holding tray 6 containing four semiconductor substrates W is placed on the lift pins LP by a tray transfer device (not shown) as shown in FIG. When the holding tray 6 is arranged on the lift pins LP, as shown in FIG. 5, the lift pins LP are moved down until they are inserted into the through holes 10b formed in the bottom surface 10a of the tray receiving groove 10, and the holding tray 6 is lowered. Let

  As a result, the holding tray 6 is immersed in the tray receiving groove 10, and the lower surfaces 7 a and 8 a of the holding tray 6 are in contact with the bottom surface 10 a of the tray receiving groove 10. At this time, in the process in which the holding tray 6 is immersed in the tray accommodating groove 10, each divided mounting surface 5 a of the stage 5 passes through the lattice space SP and is supported by the support rod 8. Each semiconductor substrate W is brought into contact with the semiconductor substrate W, and the support rod 8 (holding tray 6) is separated. Then, as shown in FIG. 5, each semiconductor substrate W is placed on the placement surface 5 a of the stage 5.

  When each semiconductor substrate W is placed on the placement surface 5 a of the stage 5, the stage 5 is heated by induction heating, and the semiconductor substrate W placed on the placement surface 5 a is heated via the stage 5. When the semiconductor substrate W is preheated to a predetermined temperature, oxygen plasma generated in the plasma generation chamber S is supplied from above through the diffusion plate 43.

As a result, the resist film on the surface of the semiconductor substrate W is subjected to plasma processing (ashing) with plasma guided from above the semiconductor substrates W.
When the plasma processing (ashing) of each semiconductor substrate W is completed, the lift pins LP are moved up to lift the holding tray 6 to a position above the stage 5.

  At this time, in the process of moving up the holding tray 6, each semiconductor substrate W placed on the placement surface 5 a is accommodated in the holding tray 6 with its back surface engaged with the support rod 8. Move up.

  Then, the holding tray 6 containing each ashed semiconductor substrate W is recovered by the tray transfer device, and a new holding tray 6 is disposed on the lift pin LP, and thereafter the same processing is repeated. Become.

As described above, according to the present embodiment, the following effects can be obtained.
(1) According to the present embodiment, the tray receiving groove 10 is formed on the mounting surface 5a of the stage 5 so that only the holding tray 6 for positioning and holding the plurality of semiconductor substrates W is immersed therein. In the process in which the holding tray 6 is immersed in the tray housing groove 10, the mounting surface 5 a of the stage 5 comes into contact with each semiconductor substrate W that passes through the lattice space SP and is supported by the support rod 8. Then, each semiconductor substrate W and the support rod 8 (holding tray 6) are separated from each other. Each semiconductor substrate W was placed on the placement surface 5 a of the stage 5.

  Therefore, by heating the stage 5 by induction heating, each semiconductor substrate W can be directly heated without using the holding tray 6. As a result, the preheating efficiency for the semiconductor substrate W can be improved.

(2) According to this embodiment, since the stage 5 is heated by induction heating, efficient heating can be performed and the heating temperature can be easily controlled.
(3) According to the present embodiment, by simply moving the holding tray 6 up and down with the lift pins LP, the four semiconductor substrates W accommodated and held in the holding tray 6 are simultaneously placed on the placement surface 5a. Therefore, the work efficiency can be improved.

In addition, you may change the said embodiment as follows.
In the above embodiment, the holding tray 6 has the bottom surface supporting the semiconductor substrate W formed in a lattice shape. However, the holding tray 6 is not limited to this, and the holding tray 6 can accommodate and support a plurality of semiconductor substrates W. Any shape can be used as long as it can immerse itself only in the tray receiving groove 10.

  In the above embodiment, the holding tray 6 has the outer frame 7 immersed in the tray housing groove 10 (frame groove portion 11), but the support rod 8 only needs to be immersed in the tray housing groove 10 (support groove groove portion 12). Therefore, you may implement by the structure which does not immerse the outer frame 7 in the tray accommodation groove | channel 10 (frame groove part 11).

  In the above embodiment, the holding tray 6 is a tray that accommodates and holds four semiconductor substrates W, but is not limited thereto, and accommodates two, three, or five or more. It may be embodied in a tray.

In the above embodiment, the holding tray 6 has the holding piece 9 for positioning and holding the semiconductor substrate W formed on the upper surface 8b of the support rod 8, but this may be omitted.
In the above embodiment, the support wall 13 is formed on the divided mounting surface 5a of the stage 5, but this may be omitted.

In the above embodiment, the stage 5 is heated by induction heating. However, heating using a heater such as resistance heating or lamp heating may be used in addition to induction heating.
In the above embodiment, the plasma processing apparatus is embodied in the plasma ashing apparatus 1, but it is applied to a plasma processing apparatus that performs dry etching on the semiconductor substrate W using plasma, or plasma processing that performs surface modification You may apply to an apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Plasma ashing apparatus, 2 ... Chamber, 5 ... Stage, 5a ... Mounting surface, 6 ... Holding tray, 7 ... Outer frame, 7a ... Lower surface, 7b ... Upper surface, 8 ... Supporting rod, 8a ... Lower surface, 7b ... Upper surface, 9 ... holding piece, 10 ... tray accommodating groove, 10a ... bottom surface, 10b ... penetration hole, 11 ... frame groove portion, 12 ... support trough groove portion, 13 ... support wall, 14 ... top plate, 15 ... cylindrical body, 18 DESCRIPTION OF SYMBOLS ... Through-hole, 18a ... Inner peripheral surface, 19 ... Waveguide, 19a ... Opening part, 20 ... Microwave transmission window, 30 ... Fitting recessed part, 32 ... Gas introduction path, 33 ... Lower lid, 33a ... Derivation hole, 34 ... lower lid body, 35 ... flange, 41 ... annular groove, 42 ... cut groove, G ... high frequency power supply, L ... induction coil, LP ... lift pin, M1 ... lift motor, S ... plasma generation chamber, W ... semiconductor substrate .

Claims (4)

A plurality of processing substrates are accommodated in a holding tray, the holding trays are arranged on a stage in a chamber, and a plurality of processing substrates accommodated in the holding tray are simultaneously processed on the stage. A plasma processing apparatus,
A heating means for heating the stage and heating the processing substrate through the stage;
The retaining tray includes an outer frame, are arranged to cross each other on the inside of the outer frame is formed from a plurality of supporting rods for supporting said part of the back surface of the bare board, respectively,
A holding piece protruding from the upper surface is formed on the upper surface of each of the plurality of support rods,
A plurality of holding pieces formed on different support rods hold one processing substrate together with a support rod on which each of the holding pieces is formed, and a portion where the support rods intersect each other,
The stage forms a tray receiving groove having a shape similar to the outer shape of the holding tray on the mounting surface,
When the outer frame and the support rod of the tray are accommodated in the tray receiving groove, each processing substrate stored in the holding tray is separated from the holding tray and abuts on the mounting surface of the stage. A plasma processing apparatus, which is mounted. The plasma processing apparatus according to claim 1 ,
The plasma processing apparatus, wherein the heating means is a high-frequency induction heating means, and includes an induction coil wound around the outside of the stage and a high-frequency power source for supplying a high-frequency current to the induction coil. In the plasma processing apparatus according to claim 1 or 2 ,
A lift member that protrudes and retracts from a through hole formed in the bottom surface of the tray receiving groove and supports the bottom surface of the holding tray;
A plasma processing apparatus, comprising: lifting means for moving the lift member up and down. A tray for a plasma processing apparatus that accommodates and places a plurality of processing substrates on a heated stage provided in a chamber or on a heated stage capable of plasma processing,
An outer frame,
A plurality of support rods arranged to cross each other inside the outer frame and supporting a part of the back surface of each processing substrate,
A holding piece protruding from the upper surface is formed on the upper surface of each of the plurality of support rods,
A plurality of holding pieces formed on different support rods hold one processing substrate together with a support rod on which each of the holding pieces is formed, and a portion where the support rods intersect each other,
The stage forms a tray accommodating grooves of similar shape as the outer shape to be formed the outer frame and by said plurality of support rods on the mounting surface,
A plasma processing apparatus tray in which each processing substrate is placed in contact with a mounting surface of the stage when the outer frame and the support rod are accommodated in the tray receiving groove.

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