JP4861208B2 - Substrate mounting table and substrate processing apparatus - Google Patents

Description

  The present invention relates to a substrate processing apparatus for performing processing such as plasma processing on a substrate to be processed such as a semiconductor wafer, and a substrate mounting table used therefor.

  Conventionally, for example, in a semiconductor device manufacturing process, a semiconductor wafer as an object to be processed is subjected to film formation processing such as thermal oxidation, thermal nitridation, plasma oxidation, plasma nitridation, and CVD, etching, and ashing. Various substrate processes such as these are performed.

In such a substrate processing, a target substrate processing such as a semiconductor wafer is placed on a substrate mounting table provided in a processing container of a substrate processing apparatus, and a desired substrate processing is performed at a desired substrate temperature. Done in In order to maintain the substrate to be processed at a desired substrate temperature in this way, a heater is incorporated in the substrate mounting table, and the substrate mounting table has a heater for mounting and removing the substrate to be processed on the substrate mounting table. A lifter pin for lifting the substrate to be processed from the surface of the substrate mounting table is provided.
JP-A-9-205130 JP 2003-58700 A

  With reference to FIG. 1, the structure of the substrate mounting table conventionally used in the substrate processing apparatus will be specifically described. The substrate mounting table 301 is generally made of ceramic such as aluminum nitride (AlN), and a heater 302 is embedded therein, for example. Further, a lifter pin 303 made of, for example, quartz glass, which can move up and down, is inserted into the substrate mounting table 301. The lifter pin 303 is driven up and down by a drive mechanism 304, whereby the substrate W to be processed such as a semiconductor wafer is moved up and down. The

  That is, the substrate W to be processed is held on the substrate mounting table 301 in a state where the lifter pin 303 is in the lowered position, while the lifter pin 303 is in the raised position indicated by a two-dot chain line. The substrate W to be processed is transferred onto the lifter pins 303 by an arm (not shown) of the mechanism. Such a substrate mounting table 301 generates microwave plasma by radiating microwaves into a processing container via various processing apparatuses such as a plasma processing apparatus, for example, a planar antenna (slot antenna) having a large number of slots. The present invention can be applied to a plasma processing apparatus that performs plasma processing using this microwave plasma.

  However, when the substrate is mounted on the substrate mounting table 301 and plasma oxidation is performed by, for example, the microwave plasma processing apparatus using the above-described slot antenna, the substrate is unloaded from the mounting table after the substrate processing. Furthermore, it has been found that there is a problem that a large number of particles having a diameter of 0.16 μm or more and reaching several thousand particles are generated on the back surface of the substrate to be processed.

  The objective of this invention is providing the substrate processing apparatus provided with the substrate mounting base which can reduce the particle | grains of the back surface of the to-be-processed substrate mounted, and such a substrate mounting base.

According to a first aspect of the present invention, by embedding a heater in the interior, and the substrate mounting table body its upper surface is heated surface of the substrate, in the substrate mounting table body, is vertically movable through A lifter pin, and a recess having a bottom surface lower than the heating surface corresponding to the lifter pin is formed on the heating surface of the substrate mounting table main body. and lifter pins body, the distal end portion of the lifter pin main body, formed corresponding to the concave portion, it is possible retract and in the recess, and a head portion having a larger diameter than the lifter pin main body, wherein the head portion And a first state in which the upper end of the head supporting the substrate to be processed and a lower surface of the head facing the upper end of the head are engaged, and the lower surface of the lifter pin is engaged with the bottom surface of the recess. The lower surface of the head part Ri movable der and a second state in which rose from the bottom of the recess, wherein in the first state, the head portion upper from the substrate mounting table top, beyond the 0.0 mm, 0.5 mm A substrate mounting table that is separated by the following distance is provided.

  In the first aspect, in the first state, it is preferable that the upper end of the head unit is separated from the upper surface of the substrate mounting table by a distance of more than 0.0 mm and not more than 0.5 mm. It is more preferable that the distance is 1 mm or more and 0.4 mm or less, and it is more preferable that the distance is 0.2 mm or more and 0.4 mm or less.

  In the substrate mounting table according to the first aspect, the substrate mounting table body may be made of aluminum nitride, and the lifter pins may be made of quartz glass.

According to a second aspect of the present invention, a substrate processing chamber evacuated by an exhaust system, a substrate mounting table that is accommodated in the substrate processing chamber and holds and heats the substrate to be processed, and the substrate processing chamber a gas supply system for supplying process gas, a substrate processing apparatus including the substrate mounting table, embedded a heater therein, and a substrate mounting table main body that upper surface is heated surface of the substrate, A lifter pin inserted in the substrate mounting table body so as to be movable up and down, and a concave portion having a bottom surface lower than the heating surface corresponding to the lifter pin on the heating surface of the substrate mounting table body. is formed, the lifter pins includes a lifter pins body, the distal end portion of the lifter pin main body, formed corresponding to the concave portion, it is possible retract and in the recess and a head portion having a larger diameter than the lifter pin main body Having the head Has a head portion upper end that supports the substrate to be processed and a head portion lower surface facing the upper end of the head portion, and the lifter pin has a first state in which the lower surface of the head portion is engaged with the bottom surface of the recess. , Ri movable der and a second state in which said head lower surface rises from the bottom of the recess, from the in a first state, the head portion upper end, the substrate mounting table top, 0.0 mm And a substrate processing apparatus that is separated by a distance of 0.5 mm or less .

  A plasma processing apparatus can be applied as the substrate processing apparatus. In addition, as such a plasma processing apparatus, a dielectric window provided in a part of the substrate processing chamber so as to face a target substrate on the substrate mounting table, and outside the substrate processing chamber, An antenna provided in combination with the dielectric window can be used. In this case, the antenna may be a planar antenna, a plurality of slots may be formed, and microwaves may be introduced from the slots into the processing container via the antenna. As the substrate processing apparatus, any of an oxidation processing apparatus, a nitriding processing apparatus, an etching apparatus, and a CVD apparatus can be used.

  According to the first and second aspects of the present invention, when the lifter pin is lowered and is in the first state, the substrate to be processed is held by the lifter pin in a state of being separated from the upper surface of the substrate mounting table. As a result, the substrate to be processed does not come into direct contact with the surface of the substrate mounting table, and the problem of particle generation caused by such contact can be solved. In this case, the uniformity of the temperature distribution during the substrate processing can be maintained high by setting the separation distance of the substrate to be processed in the first state from the upper surface of the substrate mounting table within 0.4 mm. .

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
The substrate mounting table according to the first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 2 is a sectional view showing a substrate mounting table according to the present embodiment, and FIG. 3 is a plan view thereof. This substrate mounting table is applicable to various substrate processing apparatuses such as thermal oxidation treatment, thermal nitridation treatment, plasma oxidation treatment, plasma nitridation treatment, film formation treatment such as CVD, and etching and ashing.

As shown in FIG. 2, the substrate mounting table 20 has a substrate mounting table main body 22 made of a ceramic material such as aluminum nitride and having a concentric or spiral heater 23 shown in FIG. 3 embedded therein. Through holes 22a through which the lifter pins 24 are inserted are formed in the mounting body 22 at three locations. The lifter pin 24 is made of Al ₂ O ₃ , AlN, or quartz glass in consideration of corrosion resistance and heat resistance. The lifter pin 24 is driven up and down between a lowered position indicated by a solid line in FIG. 2 and an elevated position indicated by a two-dot line by an electric or gas pressure driven lifting mechanism 25.

  In the configuration of FIG. 2, the lifter pins 24 hold a substrate W to be processed such as a semiconductor wafer, and the back surface of the substrate W to be processed is in contact with the upper surface of the substrate mounting table body 22 even when the lifter pins 24 are lowered. First, the upper surface of the substrate mounting table body 22 functions as a heating surface for heating the substrate W to be processed. On the other hand, at the lifted position of the lifter pin 24, the substrate to be processed W is lifted upward from the upper surface of the substrate mounting table main body 22, and a substrate transport mechanism (not shown) is provided between the substrate to be processed W and the substrate mounting table main body 22. A space for inserting the robot arm is formed.

  In the example shown in FIG. 3, the heater 23 is composed of a pattern heater, and is actually composed of an inner heater portion 23a and an outer heater portion 23b that are driven independently from each other. The inner heater portion 23a and the outer heater portion 23b are formed separately from each other by patterning a metal material, such as W or Mo, by the slit 23c of an insulating space. Patterning is formed by vapor deposition or processing a plate. The inner heater portion 23a is connected to a power supply line (not shown) fed from a power source at an inlet contact 26a and an outlet contact 26b. Similarly, a similar power feed line is connected to the outer heater portion 23b. The side contact 27a and the output side contact 27b are connected, and a drive current flows. In the plan view of FIG. 3, the three through holes 22a are separated from each other by an angle of about 120 degrees, and therefore, the three lifter pins 24 inserted therethrough are also separated from each other by an angle of about 120 degrees.

  In the conventional substrate mounting table, as described above, the substrate to be processed is processed in a state where the substrate to be processed is mounted in an appropriate processing apparatus, but there is a problem that a large amount of particles are generated on the back surface of the object to be processed. There is. The problem of such particle generation is considered to be mainly caused by the displacement of the substrate to be processed and the adhesion of deposits to the substrate to be processed because the substrate to be processed is in direct contact with the surface of the substrate mounting table. It is done.

  In view of this, the present inventor, in the research that is the basis of the present invention, radiates microwaves into a processing vessel through various processing apparatuses such as a plasma processing apparatus and a planar antenna (slot antenna) having a large number of slots. In a plasma processing apparatus that generates wave plasma and performs plasma processing on a substrate to be processed by the microwave plasma, a conventional substrate mounting table as shown in FIG. 1 is used. The state of dust generation and the uniformity of the film formed on the surface of the substrate to be processed by the substrate processing were investigated.

  In this processing experiment, a silicon wafer (substrate) is used as the substrate W to be processed, a silicon oxide film having a thickness of 7 to 8 nm is formed on the silicon substrate, and Ar gas is applied at a substrate temperature of 400 ° C. under a pressure of 133.3 Pa. Oxygen gas and hydrogen gas are supplied at a flow rate of 500 mL / min (sccm) at a flow rate of 5 mL / min (sccm), and a microwave with a frequency of 2.45 GHz is supplied from a microwave antenna at a power of 4000 W. It was done by doing. Table 1 below shows the results of such a processing experiment. The height of the lifter pins, the number of particles attached to the back surface of the silicon substrate, and the average film of the silicon oxide film formed on the surface of the substrate to be processed Thickness and film thickness uniformity (1σ value / average film thickness) are shown. In Table 1, the pin height indicates the protruding height at which the lifter pin protrudes from the surface of the substrate mounting table, but this represents not the actual height but the input set value input to the lifting mechanism. Yes.

表１を参照するに、リフタピンの設定高さが０．１ｍｍの場合には、シリコン基板裏面に、粒径が０．１６μm以上のパーティクルが５８１３個観測されたのに対し、リフタピンの設定高さを０．２ｍｍとすることでパーティクル数は２２３９個まで減少し、さらに前記設定高さを０．３ｍｍとすることでパーティクル数は１２７３個まで減少するのがわかる。さらに前記設定高さを０．５ｍｍとすることでパーティクル数は４６３個まで減少し、前記設定高さを１．０ｍｍとすることでパーティクル数は３５０個まで減少することがわかる。

Referring to Table 1, when the lifter pin set height is 0.1 mm, 5813 particles having a particle diameter of 0.16 μm or more were observed on the back surface of the silicon substrate, whereas the lifter pin set height was It can be seen that the number of particles is reduced to 2239 by setting the height to 0.2 mm, and further the number of particles is reduced to 1273 by setting the set height to 0.3 mm. Further, it can be seen that the number of particles is reduced to 463 by setting the set height to 0.5 mm, and the number of particles is reduced to 350 by setting the set height to 1.0 mm.

  As described above, it was confirmed that the generation of particles on the back surface of the substrate to be processed can be suppressed by controlling the lifting mechanism so that the lifter pins protrude from the front surface of the substrate mounting table even during substrate processing. When the substrate to be processed W is held away from the surface of the substrate mounting table (ie, the heating surface) during substrate processing, if the distance between the back surface of the substrate to be processed and the heating surface becomes too large, There is a possibility that the uniformity of film formation may deteriorate.

  Therefore, referring to Table 1 above, when the lifter pin setting height is 0.1 mm, the thickness uniformity of the formed silicon oxide film is 1.4%, whereas the lifter pin setting height is 0.2 mm. In the case of 2 mm, the thickness uniformity of the formed silicon oxide film is 1.46%, 1.5% in the case of 0.3 mm, 2.3% in the case of 0.5 mm, and 1 in the case of 1.0 mm. .95%. FIG. 4 shows the relationship between the lifter pin setting height and the average film thickness, and the relationship between the lifter pin setting height and the film thickness uniformity.

  From Table 1 and FIG. 4, it can be seen that the set height of the lifter pins increases and the variation in film thickness tends to increase.

  In other words, the problem of dust generation on the back surface of the substrate to be processed is to avoid contact between the substrate to be processed and the substrate mounting table, and to hold the substrate to be processed on the lifter pins so that the substrate to be processed does not contact the substrate mounting table even during substrate processing. It was found that the uniformity of the substrate processing deteriorates when the distance between the substrate to be processed and the substrate mounting table increases during the substrate processing. This is because when the substrate is separated from the substrate mounting table, the radiant heat to the substrate is lowered, the temperature of the substrate is lowered, and the temperature distribution of the substrate is remarkably deteriorated. Furthermore, in the present invention, as shown in FIG. 4, it has been discovered that the uniformity of the substrate processing suddenly changes and deteriorates when the set height of the lifter pin exceeds 0.3 mm.

  As described above, the lifter pin height is the set height of the lifter pin set by the substrate lifting mechanism, and does not necessarily match the actual protruding height of the actual lifter pin on the substrate mounting table. Therefore, when the protrusion amount of the lifter pin is controlled by the substrate lifting mechanism using the conventional substrate mounting table of FIG. 1, the substrate to be processed may actually come into contact with the surface of the substrate mounting table. In order to avoid such a situation with certainty, the protrusion amount of the lifter pin must be set larger than necessary for safety. However, when the protrusion amount of the lifter pin is increased in this way, it is difficult to ensure the uniformity of the substrate processing at the same time even though dust generation on the back surface of the substrate to be processed can be suppressed. Although it is conceivable to form a protrusion directly on the surface of the substrate mounting table, it is very difficult in terms of machining accuracy.

  Therefore, in the present invention, as shown in FIG. 2, a concave portion 22b is formed on the surface of the substrate mounting base body 22, and further, the tip of the lifter pin 24 is partially stored in the concave portion 22b when the lifter pin 24 is in the lowered position. Thus, the head portion 24a is formed.

FIG. 5 is an enlarged view showing the head portion 24a in the lowered state. Referring to FIG. 5, the recess 22b that is formed on the substrate mounting table body 22 surface accommodating the head portion 24a partially has a depth h _1, the head portion 24a is in the recess 22b in the lowered position Further, the bottom surface of the head portion 24a is engaged with the bottom surface of the recess 22b and is seated. The shape of the head portion 24a is preferably a square shape or a circular shape, but a circular shape is particularly preferable. Typically, the diameter _{W 1} of the lifter pins 24 is 2 to 3 mm, the diameter _{W 2} of the head portion 24a is set to approximately 10 mm. The diameter W _1, the temperature distribution to degradation, can not be too large in this portion. Preferably it is 15 mm or less.

At that time, the height H of the head portion 24a is set larger than the depth _{h 1} of the recess 22b, as a result, the upper head portion 24a from the surface of the substrate mounting table body 22, the height _H-h 1 (= It protrudes by h ₂ ).

Table 2 and FIG. 6, in the substrate mounting table body 22, in the case of variously changing the protrusion height h _2, the number of diameters occurring in the target substrate W backside is more than 0.16μm particles, the substrate to be processed The film thickness of the silicon oxide film formed on the W surface and the film thickness uniformity of the silicon oxide film are shown. However, in the experiment of Table 2 and FIG. 6, the silicon oxide film is formed under the same conditions as described above.

表２を参照するに、＊印の試料は被処理基板Ｗの搬送をトランスファモジュールまでに留め、処理容器中への導入を行わなかった対照標準の実験であり、この場合には被処理基板Ｗ裏面における粒径が０．１６μm以上の粒子の数は１１９個に過ぎないことがわかる。

Referring to Table 2, the sample marked with * is a reference experiment in which the transfer of the substrate to be processed W was stopped by the transfer module and was not introduced into the processing container. It can be seen that the number of particles having a particle size of 0.16 μm or more on the back surface is only 119.

In contrast, the protrusion height h ₂ 0.0 mm, that is, if the target substrate W is in direct contact on the surface of the substrate mounting table body 22, the particles generated on the back surface of the substrate W to 3888 pieces I can see that.

On the other hand, when the protrusion height _{h 2} of the head portion 24a and 0.2mm and 0.4 mm, the number of the particles is 536 pieces and 572 pieces respectively, dust is seen being effectively suppressed.

Further Regarding the film thickness uniformity (1 [sigma value / average thickness), when the head portion protruding height h ₂ is 0.4 mm, the thickness variation as can be seen from Table 2 1.04% of thickness uniformity The results were also good. Thus, when the head portion protruding height h ₂ in the range of 0.2 to 0.4 mm, and at the same time it is possible to suppress the number of particles, it is possible to improve the film thickness uniformity Recognize. The head protrusion height of 0.2 to 0.4 mm corresponds to the warp amount of the substrate W to be processed, and by setting the head protrusion height within this range, even a warped substrate to be processed is a substrate. It seems that contact with the surface of the mounting table main body 22 can be avoided.

Further, as shown in FIG. 2 or FIG. 5, the substrate mounting table having a structure in which the protruding height of the head portion 24 a is mechanically determined by engaging the head portion 24 a with the recess 22 b formed in the substrate mounting table body 22. in 20, it is possible to determine the head portion protruding height _{h 2} reliably and precisely, to set the head portion protruding height _{h 2} in the range of for example 0.1~0.5mm exceeding 0.0mm Thus, the number of particles can be suppressed more effectively, and at the same time, a more uniform film can be formed.

  FIG. 7 shows the effect of suppressing the number of particles realized in the substrate mounting table 20 in FIGS. 2 and 5. In the conventional substrate mounting table 301 shown in FIG. It is a figure shown compared with the particle number suppression effect at the time of position control by the raising / lowering mechanism 304, and respond | corresponds to the said Table 1 and Table 2. FIG. In FIG. 7, ● corresponds to Table 2 using the substrate mounting table 20 of FIGS. 2 and 5, and ○ corresponds to Table 1 using the conventional substrate mounting table 301 of FIG. 1.

  Referring to FIG. 7, the protrusion amount of the head portion 24a is set to 0.1 to 0.5 mm by mechanical engagement between the head portion 24a of the lifter pin 24 and the concave portion 22b formed in the substrate mounting base body as in the present invention. It can be seen that when the control is precisely performed within the range, the generation of the particles is more effectively suppressed as compared with the case where the protruding amount of the lifter pin is controlled by the drive mechanism without forming such a head portion.

  Next, a substrate processing apparatus to which such a substrate mounting table is applied will be described. FIG. 8 is a cross-sectional view showing a configuration of a microwave plasma processing apparatus as a substrate processing apparatus provided with the substrate mounting table having the above configuration.

  As shown in FIG. 8, the microwave plasma processing apparatus 1 has a cylindrical processing container 10 having an upper opening. The processing container 10 is formed of a conductor member made of a metal such as aluminum or stainless steel or an alloy thereof.

  A dielectric plate 4 formed in a flat plate shape is disposed in the upper opening of the processing container 10. For example, quartz or ceramic having a thickness of about 20 to 30 mm is used for the dielectric plate 4. A sealing material (not shown) such as an O-ring is interposed between the processing container 10 and the dielectric plate 4 so that airtightness can be maintained. The dielectric plate 4 is supported by a ring-shaped upper plate 61.

  On the top of the dielectric plate 4, for example, a radial line slot antenna 50 which is one of planar antennas having a plurality of slots 50a is installed. The slot antenna 50 is connected to the microwave generator 56 via a waveguide 59 constituted by a waveguide 52, a mode converter 53 and a rectangular waveguide 54. The microwave generator 56 has a microwave generator, and the microwave generator generates a microwave of 300 M to 30 GHz, for example, 2.45 GHz. On the upper portion of the slot antenna 50, a slow wave material 55 made of a dielectric, for example, a laminate of quartz, ceramic, fluororesin or the like, is provided, and a conductor cover 57 constituting a cooling jacket is disposed thereon. With this conductor cover 57, microwaves can be shielded, and the slot antenna 50 and the dielectric plate 4 can be efficiently cooled. In addition, a matching circuit (not shown) that performs impedance matching may be provided in the middle of the rectangular waveguide to improve the power usage efficiency.

  Inside the waveguide 52, a shaft portion 51 made of a conductive material is connected to the central portion of the upper surface of the slot antenna 50. Thus, the waveguide 52 is configured as a coaxial waveguide, and radiates a high-frequency electromagnetic field into the processing container 10 via the dielectric plate 4. The slot antenna 50 is isolated and protected from the processing container 10 by the dielectric plate 4. For this reason, the slot antenna 50 is not exposed to plasma.

  FIG. 9 is a plan view showing the configuration of the slot antenna 50 in detail. As shown in this figure, the slot antenna 50 is formed in a T-shape so that a large number of slots 50a are concentric and adjacent slots 50a are orthogonal to each other.

  An exhaust part 11 is provided in the lower part of the processing container 10. The exhaust part 11 has hollow and airtight exhaust pipes 75 and 77. A turbo molecular pump 42 is connected to the lower part of the exhaust pipe 77 through a valve 43. The valve 43 is composed of a pressure control valve such as an open / close valve and an APC valve. In addition, a roughing exhaust port 73 for roughing the inside of the processing vessel 10 is provided on the lower side surface of the flange 77 a provided below the exhaust pipe 77, and the roughing exhaust port 73 is connected via a valve 39. A vacuum pump (not shown) is provided through the connected rough drawing line 40, and the exhaust line 41 of the turbo molecular pump 42 is connected to the vacuum pump.

  By evacuating through the roughing line 40 and the turbo molecular pump 42, the inside of the processing vessel 10 can be set to a desired degree of vacuum. Further, a gas injector 6 for introducing various processing gases into the processing container 10 is provided on the upper side wall of the processing container 10. In the illustrated example, the gas injector 6 has a ring shape in which gas holes are uniformly formed on the inner periphery. Alternatively, a nozzle shape or a shower shape may be used.

  The gas injector 6 includes, for example, a rare gas source 101 such as Ar, a nitrogen gas source 102, and an oxygen gas source 103. Each mass flow controller (MFC) 101a, 102a, 103a and each valve 101b, 101c, 102b are provided. , 102c, 103b, 103c and the common valve 104. The gas injector 6 is formed with a large number of gas discharge ports so as to surround a mounting table 8 to be described later. As a result, Ar gas, nitrogen gas, and oxygen gas are all in a process space in the processing vessel 10. Introduced.

The process gas is not limited to these, and various gases can be used depending on the process. For example, hydrogen, ammonia, NO, N ₂ O, H ₂ O, CF-based gas, or the like can be used. A gas source of an etching gas can be provided.

Inside the processing container 10 is provided a substrate mounting table 8 on which a processing target substrate W such as a semiconductor wafer is mounted. On the upper surface of the substrate mounting table 8, a concave portion (counterbore portion) having a depth of, for example, about 0.5 to 1 mm is formed slightly outside the outer diameter of the substrate W to be processed such as a semiconductor wafer. It is preferable to prevent the placement position from shifting. However, for example, when an electrostatic chuck is provided, it is held by an electrostatic force, so there is no need to provide a recess groove. The substrate mounting table 8 includes a substrate mounting table main body 8a, a lifter pin 14 for moving up and down a semiconductor wafer W that is a substrate to be processed inserted through the substrate mounting table main body 8a, and a lifting mechanism 15 that lifts and lowers the lifter pin 14. Have. A heating resistor 9 is embedded in the substrate mounting base body 8a. Electric power is applied to the heating resistor 9 to heat the substrate mounting base body 8a, and the substrate W to be processed is heated. The substrate mounting table body 8a is made of a ceramic such as AlN or Al ₂ O ₃ .

  The substrate mounting table 8 has the same structure as the substrate mounting table 20. That is, the head portion 14a is provided on the upper portion of the lifter pin 14, and the concave portion 8b corresponding to the concave portion 22b is stored in a position corresponding to the head portion 14a of the substrate mounting base body 8a. Is formed. The height of the head portion 14a and the depth of the concave portion 8b are set so that the tip portion of the head portion 14a is lowered from the surface of the substrate mounting table main body 8 when the lifter pin 14 is lowered while the head portion 14a is seated in the concave portion 8b. It protrudes by a distance of not less than 0 mm and not more than 0.5 mm, preferably by a distance of not less than 0.1 mm and not more than 0.4 mm, more preferably by a distance of not less than 0.2 mm and not more than 0.4 mm. As set.

  A lower electrode may be embedded in the substrate mounting table 8, and a high-frequency electric concentration (not shown) may be connected to the lower electrode via a matching box (not shown). In this case, the high frequency power source may be applied with a high frequency bias of 450 kHz to 13.65 MHz, for example, or may be connected with a direct current power source to be continuously biased.

  The mounting table fixing part 64 supports the substrate mounting table 8 via the support 16 and the like. The mounting table fixing portion 64 is formed of a metal such as Al or an alloy thereof, and the mounting table support 16 is formed of a ceramic such as AlN. The substrate mounting table 8 and the support 16 are integrated or joined by brazing or the like, so that a vacuum seal and a fixing screw are not required. The lower part of the mounting table support 16 is fixed to a support fixing part 81 made of a metal such as Al or an alloy thereof, for example, with a screw or the like via a fixing ring 80 made of a metal or an alloy such as Al. The gap between the mounting surface and the dielectric plate 4 can be adjusted. The mounting table support 16 and the support fixing portion 81 are hermetically sealed by an O-ring (not shown) or the like. The support fixing portion 81 is airtightly fixed to the mounting table fixing portion 64 with an O-ring (not shown) or the like.

  The mounting table fixing portion 64 is airtightly fixed to the side surface of the exhaust pipe 77 with an O-ring (not shown) or the like by screws or the like. Specifically, the side portion of the mounting table fixing portion 64 is connected to the inner side surface of the exhaust pipe 77. The lower part of the mounting table fixing part 64 is supported by a support member 84 having a function of a positioning member for horizontally positioning the substrate mounting table 8 via the mounting table fixing part 64 during assembly such as maintenance. The support member 84 is inserted into a fixing hole provided in the exhaust pipe 77 in an airtight manner from the outside, and is fixed to the exhaust pipe 77. A mounting table fixing portion 64 is attached to the end of the support member 84 through a locking member 68 provided below the mounting member so that the mounting table can be easily leveled.

  The support member 84 also functions as a positioning member. The substrate mounting table 8 is positioned by locking the lower portion of the mounting table fixing portion 64 to a locking portion provided in advance at the end of the support member 84 via a locking member 68. For example, as shown in FIG. 8, a concave portion is provided as an engaging portion on the upper end of the support member 84, and a convex portion formed at the lower portion of the engaging member 68 is inserted into the concave portion so as to be engaged. It may be. In this case, the locking member 68 may be fixed to the locking portion of the support member 84 with a screw or a bolt. Although not shown, a hole may be provided at the end of the support member 84 as a locking portion for the positioning member, and the lower portion of the mounting table fixing portion 64 may be inserted into the hole.

  A space 71 opened toward the side wall of the exhaust pipe 77 is provided inside the mounting table fixing portion 64, and this space 71 is connected to the atmosphere via an opening 71 a provided on the side surface of the exhaust pipe 77. Communicate. The space 71 communicates with the space 94 in the mounting table support 16 via the space 92 in the support fixing portion 81, and both are open to the atmosphere.

  In the space of the mounting table fixing part 64, wirings such as wiring for supplying electric power to the heating resistor provided in the substrate mounting table 8 and wiring of a thermocouple for measuring and controlling the temperature of the substrate mounting table 8 are arranged. It is installed. Note that the wirings are omitted in FIG. The wirings are drawn out of the plasma processing apparatus 1 from the opening 71a of the flange 75 through the space 94 in the mounting table support 16 and the space 71 in the mounting table fixing portion 64.

  Further, a cooling water channel 83 is embedded under the mounting table fixing part 64 so that cooling water can be introduced from the outside of the plasma processing apparatus 1. The cooling water prevents the heat of the substrate mounting table 8 from increasing the temperature of the mounting table fixing part 64 via the mounting table support 16.

  Thus, in the microwave plasma processing apparatus 1, the substrate mounting table 8 is fixed to the exhaust pipe 77 at a plurality of locations. Specifically, the substrate mounting table 8 is fixed at two locations, that is, a side portion and a bottom portion of the mounting table fixing unit 64 to which the substrate mounting table 8 is attached. The bottom portion of the mounting table fixing portion 64 is fixed to the exhaust pipe 77 via the locking member 68 and the support member 84. A side portion of the mounting table fixing portion 64 is fixed to the inner surface of the exhaust pipe 77. That is, the substrate mounting table 8 is fixed to the processing vessel 10 by being fixed to the exhaust pipe 77 by two fixing portions. Further, when performing maintenance, the substrate mounting table 8, the mounting table support 16, the support fixing unit 81, the mounting table fixing unit 64, and the like are provided in the recesses formed in the end portions of the support member 84 in the locking members 68. Since the protrusion is positioned by being pointed, it can be easily and horizontally attached.

  A baffle plate 10 a having a plurality of holes for uniformly exhausting the inside of the processing container is provided in the processing container 10 so as to surround the periphery of the mounting table 8. The baffle plate 10a is supported by a baffle plate support member 10b made of metal such as aluminum or stainless steel, and a baffle plate 10d made of quartz, for example, similar to the baffle plate 10a is disposed to prevent contamination (contamination). The A quartz liner 10 c that protects the processing container 10 is provided so as to cover the inner wall of the processing container 10. Thus, a clean environment can be formed by shielding the inside of the processing container 10 with the shield plate.

  A loading / unloading port 7 a for loading / unloading the substrate W to be processed is formed on the side wall of the processing container 10, and the loading / unloading port 7 a can be opened and closed by the gate valve 7.

  In the microwave plasma device 1 configured as described above, when microwaves are supplied to the radial line slot antenna 50 from the coaxial waveguide 52, the microwaves propagate in the antenna 50 while spreading in the radial direction, At this time, the wave is compressed by the slow wave material 55. Therefore, the microwave is radiated as a circularly polarized wave from the slot 50 a in a generally vertical direction to the radial slot antenna (planar antenna plate) 50.

  On the other hand, the nitrogen gas and oxygen gas together with the rare gas such as Ar, Kr, Xe, Ne, and the like are processed in the processing container 10 through the annular gas injector 6 from the rare gas source 101, the nitrogen gas source 102, and the oxygen gas source 103. Plasma is generated by microwaves that are uniformly introduced into the space and radiated into the process space, whereby the substrate W to be processed is subjected to plasma processing. The supplied processing gas is exhausted through the exhaust unit 11.

The microwave radiated into the processing space has a frequency on the order of GHz, for example, 2.45 GHz. By introducing such a microwave, 10 ¹¹ to 10 ¹³ / cm above the substrate W to be processed. ³ high density plasma is excited. The plasma excited by the microwave introduced through the antenna as described above is characterized by a low electron temperature of 0.5 to 7 eV or lower, and as a result, in the microwave plasma processing apparatus 1, the target substrate W is processed. And damage to the inner wall of the processing container 10 is avoided. Further, since radicals formed by plasma excitation flow along the surface of the substrate W to be processed and are quickly eliminated from the process space, recombination of radicals is suppressed, and a very uniform and effective substrate. Processing is possible at a low temperature of 550 ° C. or lower.

  For example, in the microwave plasma processing apparatus 1 shown in FIG. 8, when the experiment shown in FIG. 4 or 6 is performed, the substrate mounting table body 8a is heated to a temperature range of 100 to 600 ° C. Is reduced to a pressure range of 3 to 666.5 Pa, Ar gas is supplied from the gas injector 6 at a flow rate of 500 to 2000 mL / min (sccm), oxygen gas is supplied at a flow rate of 5 to 500 mL / min (sccm), and the planar antenna 50 is further supplied. To supply a microwave having a frequency of 2.45 GHz with a power of 1 to 3 kW.

  At this time, according to the present embodiment, as in the previous embodiment, the protrusion height of the lifter pins 14 engaged with the substrate platform main body 8a in the lowered state with respect to the main surface of the substrate platform main body 8a is 0. Since it is optimized to be more than 0.0 mm and not more than 0.5 mm, preferably not less than 0.1 mm and not more than 0.4 mm, more preferably not less than 0.2 mm and not more than 0.4 mm, refer to FIG. As described, particle generation is effectively suppressed.

  Although the above description has been made by taking a microwave plasma processing apparatus as an example, the substrate mounting table of the present invention can be used for plasma processing other than such microwave plasma processing, for example, ICP type, ECR type, parallel plate type. In addition, the present invention can be applied to a plasma treatment such as a surface reflection wave type and a magnetron type, and can be applied to other than the plasma treatment. Further, the present invention is not limited to the oxidation treatment as described above, and can be applied to various treatments such as nitriding treatment, CVD treatment, and etching treatment. Further, the object to be processed is not limited to the semiconductor wafer, but can be another substrate such as a glass substrate for FPD.

  In FIG. 5, it is also possible to form the upper surface of the head portion 24a of the lifter pin 24 into a shape protruding upward, such as a conical shape as shown in FIG.

It is a figure which shows the structure of the conventional substrate processing stand. It is sectional drawing which shows the structure of the substrate mounting base which concerns on the 1st Embodiment of this invention. It is a top view which shows the board | substrate mounting base of FIG. It is a figure which shows the experiment used as the foundation of the 1st Embodiment of this invention. It is a figure which expands and shows a part of substrate processing stand of FIG. It is another figure which shows the experiment used as the foundation of the 1st Embodiment of this invention. It is a figure which shows the effect of the 1st Embodiment of this invention. It is sectional drawing which shows the microwave plasma processing apparatus to which the substrate mounting base concerning the 1st Embodiment of this invention is applied. It is a top view which shows the planar antenna of the microwave plasma processing apparatus of FIG. It is a figure which shows the modification of the lifter pin of the substrate mounting base which concerns on the 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microwave plasma processing apparatus 4 Dielectric board 6 Gas injector 7 Gate valve 7a Carry-in / out port 8, 20, 301 Substrate mounting base 8a, 22 Substrate mounting base 8b, 22b Recess 9 Heating resistor 10 Processing container 10a, 10d Baffle plate 10b Baffle plate support member 10c Liner 11 Exhaust part 14, 24, 303 Lifter pins 14a, 24a Head part 15, 25, 304 Lifting mechanism 16 Mounting base support 22a Through hole 23 Heater 23a Inner heater part 23b Outer heater part 23c Slit 26a, 27a Inlet contacts 26b, 27b Outlet contacts 39 Valve 40 Roughing pump 41 Exhaust line 42 Turbo molecular pumps 43, 101b, 101c, 102b, 102c, 103b, 103c Valve 50 Radial line slot antenna 50a Slot 51 Shaft 52 Waveguide 53 Mode converter 54 Rectangular waveguide 55 Slow wave material 56 Microwave generator 57 Conductor cover 59 Waveguide 61 Upper plate 64 Mounting base fixing part 68 Locking members 71, 92, 94 Space 71a Opening 73 Exhaust port 75, 77 Exhaust pipe 77a Flange 81 Support fixing part 83 Cooling water passage 84 Support member 101 Noble gas source 102 Nitrogen gas source 103 Oxygen gas source 101a, 102a, 103a MFC

Claims (9)

Embedding a heater therein, and a substrate mounting table main body that upper surface is heated surface of the substrate,
In the substrate mounting table body, a lifter pin inserted in a vertically movable manner,
A substrate mounting table comprising:
A concave portion having a bottom surface lower than the heating surface is formed on the heating surface of the substrate mounting table body, corresponding to the lifter pins.
The lifter pins includes a lifter pins body, the distal end portion of the lifter pin main body, formed corresponding to the concave portion, it is possible retract and in the recess, and a head portion having a larger diameter than the lifter pin main body,
The head part has a head part upper end that supports the substrate to be processed, and a head part lower surface that faces the head part upper end,
The lifter pin, said head lower surface has a first engaged with the bottom surface of the recess, Ri movable der and a second state in which said head lower surface rises from the bottom of the recess,
In the first state, the upper end of the head unit is separated from the upper surface of the substrate mounting table by a distance of more than 0.0 mm and 0.5 mm or less . In the first state, the head portion upper end, from the substrate mounting table top, 0.1 mm or more, 0.4 mm spaced apart by a distance of less than, the mounting substrate according to claim 1 table. Before SL in a first state, the head portion upper end, from said substrate mounting table top, 0.2 mm or more, 0.4 mm spaced apart by a distance of less than the substrate mounting table of claim 2, wherein. Before SL substrate mounting table body is made of aluminum nitride, the lifter pins are made of quartz glass, a substrate mounting table of any one of claims 1 to 3. A substrate processing chamber exhausted by an exhaust system;
A substrate platform that is housed in the substrate processing chamber and holds and heats the substrate to be processed;
A gas supply system for supplying a processing gas into the substrate processing chamber, and a substrate processing apparatus comprising:
The substrate mounting table is
Embedding a heater therein, and a substrate mounting table main body that upper surface is heated surface of the substrate,
In the substrate mounting table body, a lifter pin inserted in a vertically movable manner,
With
A concave portion having a bottom surface lower than the heating surface is formed on the heating surface of the substrate mounting table body, corresponding to the lifter pins.
The lifter pins includes a lifter pins body, the distal end portion of the lifter pin main body, formed corresponding to the concave portion, it is possible retract and in the recess, and a head portion having a larger diameter than the lifter pin main body,
The head part has a head part upper end that supports the substrate to be processed, and a head part lower surface that faces the head part upper end,
The lifter pin, said head lower surface has a first engaged with the bottom surface of the recess, Ri movable der and a second state in which said head lower surface rises from the bottom of the recess,
In the first state, the upper end of the head unit is separated from the upper surface of the substrate mounting table by a distance of more than 0.0 mm and not more than 0.5 mm . The substrate processing apparatus according to claim 5, wherein the substrate processing apparatus is a plasma processing apparatus . Some of the prior SL substrate processing chamber, a dielectric window provided so as to face the target substrate on the substrate mounting table,
The substrate processing apparatus according to claim 6 , further comprising an antenna provided outside the substrate processing chamber and coupled to the dielectric window. The substrate processing apparatus according to claim 7, wherein the antenna is a planar antenna, a plurality of slots are formed, and microwaves are introduced into the processing container from the slots via the antenna. The substrate processing apparatus according to claim 5, wherein the substrate processing apparatus is any one of an oxidation processing apparatus, a nitriding processing apparatus, an etching apparatus, and a CVD apparatus .

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