JP2003133233A - Substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing apparatus capable of forming a uniform film on a substrate with excellent reproducibility by eliminating tempera ture distribution in the plane of a substrate being treated. SOLUTION: The substrate processing apparatus comprises a reaction chamber 9, a susceptor 7 mounting a substrate 13 to be treated, a gas introduction part 2, an electrode 30 for an electrostatic chuck buried in the susceptor 7, a heater 36 opposed to the susceptor 7, a rotary shaft 38 rotatably supporting the susceptor 7 on the heater 36, a fixed shaft 42 provided in the rotary shaft 38 and supporting the heater 36, and a slip ring 43 provided on the rotary shaft and connecting an electrode 45 and the electrode for the electrostatic chuck.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus for manufacturing a semiconductor device by forming an oxide film, a metal film and the like on a substrate such as a silicon wafer, and more particularly, to a semiconductor manufacturing apparatus. The present invention relates to a single-wafer CVD apparatus for performing a film forming process. A semiconductor integrated circuit is formed on a substrate such as a silicon wafer, and a source gas is introduced into a reaction chamber maintained at a low pressure and heated by one of semiconductor manufacturing apparatuses for manufacturing a semiconductor device. Single-wafer CV that generates a desired film on a single substrate
There is a D device. FIG. 5 schematically illustrates a conventional single-wafer CVD apparatus. A gas inlet 2 is formed at the ceiling of the vacuum vessel 1 defining the reaction chamber 9, and a heating stage 3 is provided at the bottom of the vacuum vessel 1 opposite to the gas inlet 2. I have. A shower plate 4 having a large number of gas dispersion holes 5 is provided on the lower surface of the gas introduction unit 2, and a gas introduction pipe 6 communicates with the gas introduction unit 2. [0005] The upper surface of the heating stage 3 is a susceptor 7, and a heater 8 is provided below the susceptor 7. A gate valve 11 for carrying in and out the substrate is provided on a side surface of the vacuum vessel 1, and an exhaust port 12 is provided on a bottom face of the vacuum vessel 1. [0006] The substrate 13 carried in through the gate valve 11 is placed on the susceptor 7 and heated by the heater 8 through the susceptor 7. The reaction chamber 9 is maintained at a low pressure, and the source gas supplied from the gas introduction pipe 6 is uniformly dispersed by the gas dispersion holes 5 and introduced into the reaction chamber 9 to perform a required film forming process. Done. The gas after the treatment is exhausted from the exhaust port 12, and the inside of the reaction chamber 9 is maintained at a constant pressure. When the processing is completed, the introduction of the raw material gas is stopped, and after the reaction chamber 9 is purged with an inert gas such as nitrogen gas, the substrate 13 is carried out of the gate valve 11. With the recent miniaturization and high integration of semiconductor integrated circuits, high yields are required for wafers. Further, in order to manufacture low-cost chips, in order to increase the number of chips obtained from one wafer, the diameter of the wafer is increasing. Further, in order to cope with the improvement of the yield and the increase in the diameter of the wafer, it is essential to further improve the film forming quality. In the above-described conventional substrate processing apparatus, unevenness in the flow of the raw material gas or uneven heating temperature when the substrate 13 is heated via the susceptor 7 cannot be avoided, resulting in a high yield and a large wafer diameter. I can not cope. Japanese Patent Application Laid-Open No. 2000-286328 discloses a substrate processing apparatus for improving the uniformity of processing within a wafer surface. The substrate processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-286328 will be briefly described with reference to FIG. In FIG. 6, the same components as those shown in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. A tray support 15 is provided on the inner wall of the vacuum vessel 1, and a ring 16 is placed on the tray support 15. The ring 16 has an inverted L-shape at a position divided into three equal parts on the circumference. A wafer support 17 is provided.
The substrate 13 is placed on 7. The bottom of the vacuum vessel 1 has a circular opening 18.
Is provided around the opening 18 and an inner cylindrical portion 19 protruding upward is provided. The inner cylindrical portion 19 has an outer cylindrical portion 21.
Are externally fitted, and a susceptor 7 is provided at an upper end of the outer cylindrical portion 21. A step 7 a is formed on the upper surface of the susceptor 7, and the step 7 a is removably fitted to the ring 16. At the periphery of the step 7a, a concave portion 7b into which the horizontal portion of the wafer support 17 is fitted is formed. The opening 18 is closed by a transmission window 22 made of quartz.
Is protruding. A shaft 24 vertically extending from the center of the lower surface of the susceptor 7 penetrates the cylindrical portion 23,
The lower end of the shaft 24 is connected to a drive unit 25. The drive unit 25 is capable of rotating and moving up and down the susceptor 7 via the shaft 24. Below the transmission window 22, the cylindrical portion 23
Heating section 26 with donut-shaped lamps arranged around
The susceptor 7 is heated by radiant heat through the transmission window 22. FIG. 6 shows a state where the susceptor 7 is lowered. The substrate 13 is placed on the wafer supporting portion 17 by a transfer device (not shown), the susceptor 7 is raised by the driving portion 25, and the step portion 7 a is fitted into the ring portion 16, and Is the susceptor 7
Placed on top. Further, the susceptor 7 is rotated by the driving unit 25. The susceptor 7 is heated by the heating unit 26 through the transmission window 22, and the substrate 13 is heated by the susceptor 7. A source gas is introduced from the gas introduction pipe 6, and a film forming process is performed on the substrate 13. When the film forming process is completed, the susceptor 7 is lowered, and the processed substrate 13 is carried out. In the substrate processing apparatus shown in FIG. 6, the substrate 13 being processed is rotated via the susceptor 7, so that the film forming quality is made uniform. However,
In the substrate processing apparatus shown in FIG. 6, the heating unit 26 is located below the transmission window 22 and is separated from the susceptor 7, and is most separated when the substrate 13 is heated. The heating section 26 has a donut shape, and the heat density of the central portion is reduced by heat radiation. Further, a shaft 24 is provided below the susceptor 7, and the shaft 24 becomes a shadow of heat radiation. Therefore, it is difficult to uniformly heat the susceptor 7, and there is a problem that a temperature distribution in the surface of the substrate 13 is easily generated. The present invention has been made in view of the above circumstances, and provides a substrate processing apparatus capable of eliminating a temperature distribution in a surface of a substrate to be processed and forming a uniform film on the substrate with good reproducibility. According to the present invention, there is provided a reaction chamber, a susceptor for mounting a substrate to be processed, a gas introduction section, an electrode for an electrostatic chuck embedded in the susceptor, and a susceptor. A rotating shaft that rotatably supports the susceptor with respect to the heater, a fixed shaft provided in the rotating shaft to support the heater, a power supply provided on the rotating shaft, The present invention relates to a substrate processing apparatus provided with a slip ring for connecting an electrode for an electric chuck. Embodiments of the present invention will be described below with reference to the drawings. The first embodiment will be described with reference to FIG. 1, the same components as those shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted. The interior of the vacuum vessel 1 includes a reaction chamber 9 and the reaction chamber 9.
A continuous heating stage storage section 28 is formed below the
The heating stage 3 is provided so as to be able to move up and down between the heating stage storage section 28 and the reaction chamber 9. The heating stage storage section 28 has a slightly larger diameter than the heating stage 3, the reaction chamber 9 has a larger diameter than the heating stage storage section 28, and the heating stage 3 is stored in the reaction chamber 9. In this state, a space serving as an exhaust duct is formed around the heating stage storage section 28. An exhaust port 29 communicating with the reaction chamber 9 is provided on a side wall of the vacuum vessel 1, and a substrate carrying port 31 communicating with the heating stage housing section 28 is provided. It is opened and closed by a gate valve 11 having a structure. An exhaust line (not shown) is connected to the exhaust port 29. The exhaust line is provided with a pressure adjusting valve and a vacuum pump so that the reaction chamber 9 can be adjusted to a predetermined pressure. A gas inlet 2 is provided above the vacuum vessel 1. The gas introduction section 2 comprises a shower plate 4 having a large number of gas dispersion holes 5 formed therein, an upper lid 33, a dispersion plate 34 which is a porous plate, and a gas introduction pipe 6. The gas reservoir 32 forms a part of the ceiling of the container 1 and forms a gas reservoir 32 with the upper lid 33.
Divides the gas reservoir 32 up and down, and the gas introduction pipe 6 communicates with an upper space partitioned by the dispersion plate 34. The heating stage 3 is formed in a hollow body by a heating section case 35, which is a cylindrical container having a bottom, and a disk-shaped susceptor 7 closing the upper end of the heating section case 35. A disk-shaped heater 36 provided opposite thereto and a reflection plate 37 surrounding the heater 36 from below.
Is stored. A hollow rotating shaft 38 communicates with the center of the bottom of the heating unit case 35, and the rotating shaft 38 is connected to the vacuum vessel 1.
The lower end is airtightly closed by a fixed end plate 41 via a rotary bearing 39. A hollow fixed shaft 42 is provided concentrically within the rotating shaft 38, and the upper end of the fixed shaft 42 is connected to the heater 36, and the lower end is connected to the fixed end plate 41. A slip ring 4 is provided between the rotating shaft 38 and the fixed shaft 42.
3 are provided. The reflecting plate 37 is heated by the heater 36 at the bottom and side walls of the heating section case 35, and shields the heat to prevent the temperature from rising more than necessary. The susceptor 7 is formed of a heat-resistant and dielectric ceramic having a thickness of about several mm to 10 mm, and its surface is protected according to the type of gas flowing into the reaction chamber 9. The coating is applied in order to do.
The coating may be performed to change the thermal emissivity of the susceptor 7. In that case, it is necessary to make the thermal emissivity different between the portion where the substrate 13 is placed and the portion where the substrate 13 is not placed. Normally, the temperature of the peripheral portion of the susceptor 7 is made higher than that of the center by reducing the heat radiation rate on the front side of the peripheral portion where the substrate 13 is not mounted and reducing the amount of heat radiation. A plurality of electrostatic chuck electrodes 30a and 30b are embedded in the susceptor 7. The electrode 30
a and the electrode 30b are electrically insulated by a dielectric (ceramic) constituting the susceptor 7,
The electrode 30a and the electrode 30b are connected to the rotating side of the slip ring 43 via wires 44a and 44b, respectively, and the fixed side of the slip ring 43 is connected to a power supply 45 for electrostatic chuck. Thus, the power supply 45 causes the electrode 30a
A predetermined voltage is applied between the electrode and the electrode 30b. When a voltage is applied between the electrode 30a and the electrode 30b, electric charges are charged, and the substrate 13 can be attracted to the upper surface of the susceptor 7 by electrostatic force. If the substrate 13 is attracted to the susceptor 7 by electrostatic force,
Even if the substrate 13 is warped, the substrate 13
The substrate 13 and the susceptor 7
Can be forcibly made uniform. The heater 36 has a disk shape, and is provided below the susceptor 7 and substantially in parallel with the susceptor 7 with a gap of 1 to 30 mm. The heater 36 has a thickness
It is divided into a plurality of zones 36a, 36b concentrically (approximately 2 mm in the drawing). Each of the zones 36a and 36b is connected to a power source 50 via wirings 50a and 50b disposed in the fixed shaft 42, respectively.
Temperature detectors 46a and 46b such as thermocouples for detecting the temperatures of the portions corresponding to 6a and 36b are provided on the susceptor 7, and the wiring (not shown) connected to the temperature detectors 46a and 46b is the fixed shaft. 42 and connected to a heating controller (not shown). The power supply 50 is connected to a heating control unit (not shown), and controls the temperature of the temperature detectors 46a and 46b to a predetermined value based on the temperature detection signals from the temperature detectors 46a and 46b. The amount of generated heat is controlled independently for each of the zones 36a and 36b.
Heat is transmitted from the heater 36 to the susceptor 7 by radiation and gas conduction. The smaller the gap between the heater 36 and the susceptor 7 and the higher the pressure in the heating stage 3, the greater the amount of heat transfer due to gas conduction. However, if the gap between the heater 36 and the susceptor 7 is too small, a small change in the gap results in a large change in the amount of heat transfer. Therefore, it is preferable that the gap is at least 1 mm or more. On the other hand, if the distance between the heater 36 and the susceptor 7 is too wide, if the heat generation amount of the outer zone 36b is increased in order to increase the temperature around the susceptor 7, the zone 36b
Heat is also transmitted to the center of the susceptor 7 due to heat radiation from the susceptor 7, making zone control difficult, and an appropriate temperature distribution cannot be obtained. Therefore, the gap between the heater 36 and the susceptor 7 is desirably about 30 mm at the maximum. A rotating bearing 47 is provided at the extension of the rotating shaft 38.
The flange 48 is fitted airtightly through the
And an expandable bellows 49 between the bottom surface of the vacuum vessel 1 and
Is provided to hermetically seal the through portion of the rotating shaft 38. The flange 48 is connected to a lifting mechanism (not shown) so as to be able to move up and down.
Is connected to a rotating mechanism that moves up and down integrally with the flange 48 so as to be rotatable. Thus, the heating stage 3 is vertically movable and rotatable. The inside of the fixed shaft 42 is communicated with an inert gas supply source (not shown) at the lower end side, and purge gas holes 51 are formed at required positions of the fixed shaft 42, at the lower and upper portions in the figure. An inert gas is introduced into the inside of the heating stage 3 through the purge gas hole 51, and the pressure is controlled to be slightly higher than that of the reaction chamber 9. By keeping the inside of the heating stage 3 at a slightly higher pressure than the reaction chamber 9, the raw material gas introduced into the reaction chamber 9 is prevented from entering the inside of the heating stage 3. Further, the inside of the bellows 49 is also connected to an inert gas supply source (not shown) through the flange 48, and the inert gas is supplied to the reaction chamber 9 from the gap of the through portion of the rotating shaft 38. It is introduced so that an unnecessary film is not particularly deposited on the lower half wall surface of the reaction chamber 9. A push-up pin 52 movably in the vertical direction is provided on the heating unit case 35 so as to be urged downward. The upper end of the push-up pin 52 has the reflection plate 37, the heater 36,
It can pass through the susceptor 7 and can protrude from the upper surface of the susceptor 7. The push-up pins 52 are provided at at least three places and can support the substrate 13 placed on the susceptor 7. Further, the lower part of the push-up pin 52 penetrates through the bottom of the heating part case 35 and projects further downward, and a flange 53 is formed at the lower part,
The heating stage 3 is connected to the vacuum vessel 1 by the flange 53.
A stopper is provided below the push-up pins 52 so that the push-up pins 52 do not fall downward in a state where the push-up pins 52 are separated from the bottom of the heating section case 35. The upper end does not protrude from the upper surface of the susceptor 7. Also, the flange 53
Has a function of closing the gap of the lower penetration portion, and has a role of reducing leakage of the purge gas from the inside of the heating stage 3 to the reaction chamber 9. Next, the processing procedure of the substrate 13 will be described. First, before carrying the substrate 13 into the reaction chamber 9, the heating stage 3 is raised to the film-forming position shown in FIG. 1, the heater 36 is heated, and the susceptor 7 is heated to a predetermined temperature. Heat so that it becomes. At the same time, an inert gas such as N2 is introduced from the gas introducing pipe 6 through the dispersion plate 34 and the shower plate 4 so that the pressure in the reaction chamber 9 becomes substantially the same as that during the film forming process. Room 9
The inert gas is supplied evenly into the inside. The flange 4 is moved by a lifting mechanism (not shown).
8. The heating stage 3 is lowered to the heating stage storage section 28 via the rotating shaft 38 (see FIG. 2). In this state, the upper surface of the susceptor 7 is located below the substrate transfer port 31. The lower end of the push-up pin 52 abuts against the bottom surface of the heating stage storage unit 28, and is further pushed up.
The upper end of the push-up pin 52 is located at an intermediate position of the substrate transfer port 31. The substrate 13 placed on a transport jig (not shown)
Is carried in through the substrate transfer port 31 and is placed on the upper end of the push-up pin 52. After the transfer jig is retracted, the heating stage 3 is raised to the film forming position. As the heating stage 3 is raised, the push-up pins 52 are lowered, and the substrate 13 is placed on the susceptor 7. When the power supply 45 is turned on, a predetermined voltage is applied between the electrodes 30a and 30b for the electrostatic chuck via the slip ring 43 to electrostatically attract the substrate 13. The substrate 13 is heated by the susceptor 7 kept at a high temperature. When the temperature of the substrate 13 reaches a predetermined temperature, the raw material gas is introduced from the upper gas introduction pipe 6 instead of the inert gas while rotating the rotation shaft 38 at a predetermined rotation speed by a rotation mechanism (not shown). The raw material gas is homogenized by the dispersion plate 34 and the shower plate 4,
It is supplied so as to be sprayed on the substrate 13. When the substrate 13 is electrostatically attracted to the susceptor 7, the warped substrate 13 is also forcibly brought into close contact with the susceptor 7, and the gap between the substrate 13 and the susceptor 7 becomes uniform. The amount of heat transferred from the susceptor 7 to the substrate 13 can be made uniform within the surface of the substrate 13. Further, the substrate 13 is rotated via the heating stage 3, that is, the susceptor 7, and heating can be performed while changing the position of the substrate 13 with respect to the heater 36 every moment. Performance and temperature reproducibility can be improved. The raw material gas flowing from the shower plate 4 is sprayed on the substrate 13 to change its direction, flows substantially parallel to the substrate 13, and is exhausted from the exhaust port 29. The pressure in the reaction chamber 9 is controlled by a pressure adjusting valve (not shown).
The internal pressure is adjusted to a predetermined value, and the flow rate is adjusted so that the partial pressure of the source gas (silicon-containing gas) becomes a predetermined value. When a film having a desired thickness is deposited, the introduction of the raw material gas is stopped, and the inert gas is introduced again from the gas introduction unit 2. After the reaction chamber 9 is replaced with the inert gas, the heating stage 3 is lowered, and the substrate 13 is carried out of the substrate carrying port 31 in a procedure opposite to the carrying-in. After completion of the film formation on the substrate 13, an etching gas is supplied every time or at an appropriate period to remove unnecessary films deposited on the wall surface of the reaction chamber 9, particularly on the surface of the reflection plate 37. In the first embodiment, the purge gas holes 51 are provided at a plurality of locations (up and down in the figure) along the axial direction of the fixed shaft 42.
In order to surely purge the gas inside, it may be provided only near the lower slip ring 43. FIG. 3 shows a second embodiment. The hollow portion is closed at a position above the position where the slip ring 43 of the fixed shaft 42 is provided,
A purge gas nozzle 54 communicating below the closed position of the fixed shaft 42 is provided. The purge gas nozzle 54 is bent downward, and the lower end is located near the upper surface of the slip ring 43. The purge gas is blown out from the purge gas nozzle 54 near the upper surface of the slip ring 43 and flows to the downstream heating stage 3. Therefore, gas purging can be performed reliably and efficiently. In the embodiment described above, the position of the slip ring 43 is determined by the rotation shaft 38 and the fixed shaft 42.
As shown in FIG. 4, the slip ring 43 is provided so as to be externally fitted to a lower end portion of the rotating shaft 38 (a portion extending below the flange 48 in the drawing). Is also good. As described above, according to the present invention, the reaction chamber, the susceptor on which the substrate to be processed is placed, the gas introduction section,
An electrode for an electrostatic chuck embedded in the susceptor, a heater opposed to the susceptor, a rotating shaft rotatably supporting the susceptor with respect to the heater, and supporting the heater provided in the rotating shaft. The substrate to be heated by the heater via the susceptor is provided with a fixed shaft and a slip ring provided on the rotating shaft and connecting a power supply and the electrode for the electrostatic chuck. The substrate to be processed is brought into close contact with the susceptor by an electrostatic chuck, heat transfer is uniform over the entire surface of the substrate, and uniformity of film formation on the substrate surface is improved. The reproducibility of each is improved, and excellent effects such as improvement in yield and stable product quality are exhibited.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a first embodiment of the present invention. FIG. 2 is an operation explanatory view of the first embodiment. FIG. 3 is a sectional view showing a second embodiment of the present invention. FIG. 4 is an explanatory view of a main part showing a third embodiment of the present invention. FIG. 5 is a schematic view of a conventional substrate processing apparatus. FIG. 6 is a sectional view of another conventional example. [Description of Signs] 1 Vacuum container 2 Gas introduction unit 3 Heating stage 4 Shower plate 7 Susceptor 9 Reaction chamber 13 Substrate 30 Electrode 36 Heater 38 Rotating shaft 42 Fixed shaft 43 Slip ring 45 Power supply 50 Power supply 51 Purge gas hole 52 Push-up pin

Continuation of front page    (72) Inventor Tomoji Watanabe             502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref.             Inside Ritsumeikan Machinery Research Laboratory F term (reference) 4K030 CA04 CA12 GA02 GA06 KA24                 5F031 CA02 FA01 FA07 HA02 HA16                       HA33 HA37 HA58 HA59 JA01                       JA21 JA51 MA28 NA04 NA05                       NA20 PA18 PA30                 5F045 AA06 BB02 DP03 DQ05 EK07                       EM05 EM10

Claims (1)

Claims: 1. A reaction chamber, a susceptor on which a substrate to be processed is placed, a gas introduction unit, an electrode for an electrostatic chuck embedded in the susceptor, and a heater opposed to the susceptor. A rotating shaft that rotatably supports the susceptor with respect to the heater, a fixed shaft provided in the rotating shaft and supporting the heater, a power supply provided on the rotating shaft, and an electrode for the electrostatic chuck. And a slip ring for connecting the substrates.