JP5602915B2 - Semiconductor manufacturing apparatus and semiconductor manufacturing method - Google Patents

Description

  The present invention relates to a semiconductor manufacturing apparatus and a semiconductor manufacturing method for forming a film by supplying a process gas while heating a semiconductor wafer.

  In recent years, along with demands for lowering the cost and higher performance of semiconductor devices, there has been a demand for higher quality such as improvement in film thickness uniformity as well as high productivity in the wafer film forming process.

  In order to satisfy such a requirement, a method is used in which a single-wafer type epitaxial film forming apparatus is used, for example, a process gas is supplied while rotating at a high speed of 900 rpm or higher and heated from the back surface using a heater.

  At this time, in order to obtain film thickness uniformity, it is necessary to uniformly heat the wafer with a heater. For example, in addition to the in-heater for heating the entire surface of the wafer, an out-heater for heating the outer peripheral portion where the temperature falls (See, for example, Patent Document 1).

  In recent years, in order to further improve productivity, for example, a large-diameter wafer having a diameter of 300 mm has been used. A heater for heating such a large diameter wafer is also required to have a large diameter.

  However, a heater member made of, for example, SiC expands due to heat. And there exists a problem that a fixed location will be stressed and damaged by thermal stress. Further, particularly when the diameter of the heater is increased and the heater member is enlarged, there is a problem that the heater position accuracy is significantly lowered and uniform temperature control becomes difficult due to warpage or the like.

Japanese Patent Laid-Open No. 10-208855 ([0017] [0018], FIG. 8, etc.)

  As described above, the heater member used in the semiconductor manufacturing apparatus is damaged due to thermal stress, and the productivity decreases due to an increase in maintenance frequency. Further, when the diameter of the heater member is increased as the wafer diameter is increased, the heater position accuracy is significantly lowered, and uniform temperature control is difficult due to warpage or the like.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor manufacturing apparatus and a semiconductor manufacturing method that can uniformly heat a wafer, perform high-productivity, and perform uniform film formation.

A semiconductor manufacturing apparatus according to one embodiment of the present invention includes a reaction chamber into which a wafer is introduced, a gas supply mechanism that is disposed above the reaction chamber and supplies a process gas, and a gas discharge mechanism that discharges gas from the reaction chamber. a susceptor for holding the wafer, is disposed so as to be separated with the wafer, the plurality of elements so as to be rotationally symmetrical about axis an axis passing through the center of the wafer are arranged separately Rutotomoni, the plurality of elements circumferential central portion a plurality of electrodes which respectively was set vignetting is respectively connected to a common wiring parts between adjacent elements, by applying a voltage through a wiring part and a plurality of electrodes A heater that generates heat and heats the wafer and a rotation drive mechanism that rotates the wafer are provided.

  The semiconductor manufacturing apparatus of one embodiment of the present invention includes a first wiring component having a first connection surface connected to an electrode and a second connection surface connected to the first wiring component. The second connection surface includes a second wiring component that is perpendicular to the first connection surface, and a third connection surface that is connected to the second wiring component. It is preferable that the connection surface further includes a third wiring component that is perpendicular to the first connection surface and the second connection surface.

  In the semiconductor manufacturing apparatus of one embodiment of the present invention, it is preferable that the connection positions of the first to third connection surfaces can be changed.

  In the semiconductor manufacturing apparatus of one embodiment of the present invention, the heater may include electrodes that are divided at least at the center portion and the outer peripheral portion and supply current independently.

In the semiconductor manufacturing method of one embodiment of the present invention, the wafer is held in the reaction chamber, the process gas is supplied to the surface of the wafer, the gas is discharged from the reaction chamber, and the reaction chamber has a predetermined pressure. adjusted to rotate the wafer, a plurality of elements so as to be rotationally symmetrical about axis an axis passing through the center of the wafer are arranged separately Rutotomoni, respectively in the central portion of the circumferential direction of the plurality of elements plural electrodes provided may be relative to a heater that is connected to a common wiring parts between adjacent elements, the voltage sign pressurized via the wiring part and a plurality of electrodes, thereby heating the heater And heating the wafer to form a film on the surface of the wafer.

  In the semiconductor manufacturing method of one embodiment of the present invention, the electrode and the first wiring component are connected at the first connection surface, and the first wiring component and the second wiring component are connected to each other. The second connection surface is connected to the second connection surface perpendicular to the connection surface, and the second wiring component and the third wiring component are connected to each other on the first connection surface and the third connection surface perpendicular to the second connection surface. It is preferable to heat the wafer by connecting and applying a voltage to the heater through the third wiring component, the second wiring component, the first wiring component, and the electrode, and causing the heater to generate heat.

  According to the present invention, the wafer can be uniformly heated by the heater, and uniform film formation can be performed with high productivity in the manufacturing process of the semiconductor device.

It is a figure which shows the cross section of the semiconductor manufacturing apparatus of 1 aspect of this invention. It is a top view of the outheater in 1 aspect of this invention. It is a side view of the outheater in one mode of the present invention. It is a top view of a heater in one mode of the present invention. It is a side view of a heater in one mode of the present invention. It is a side view of a heater in one mode of the present invention. It is a figure which shows the pattern of the element of the heater in 1 aspect of this invention. It is a figure which shows the connection part of the booth bar in 1 aspect of this invention. It is a figure which shows the structure of the element of the heater in 1 aspect of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of the semiconductor manufacturing apparatus of this embodiment. As shown in the figure, a gas supply mechanism for supplying a process gas including a source gas such as TCS and dichlorosilane onto the wafer w from above the reaction chamber 11 in the reaction chamber 11 in which the wafer w is formed. A gas supply port 12 connected to (not shown) is installed. A gas discharge port connected to a gas discharge mechanism (not shown) for discharging gas to, for example, two places below the reaction chamber 11 and controlling the pressure in the reaction chamber 11 to be constant (normal pressure). 13 is installed.

  A rectifying plate 14 for supplying the process gas supplied from the gas supply port 12 to the wafer w in a rectified state is installed in the upper part of the reaction chamber 11.

  Below the reaction chamber 11, a rotation drive mechanism 15 for rotating a wafer w composed of a motor (not shown), a rotation shaft (not shown), and the like, and a rotation drive mechanism 15 are connected to the wafer w. A susceptor 16 is provided for holding the susceptor. Below the susceptor 16, an in-heater 17a for heating a wafer w made of, for example, SiC is installed. Furthermore, between the susceptor 17 and the in-heater 17a, an out-heater 17b for heating the peripheral portion of the wafer w made of, for example, SiC is installed. A disc-shaped reflector 18 for efficiently heating the wafer w is installed below the in-heater 17a.

  FIG. 2 is a top view of the outheater, and FIG. 3 is a side view thereof. As shown in the figure, the outheater 17b is divided into four elements 21a, 21b, 21c, and 21d. Each element 21a, 21b, 21c, 21d has a structure in which the inner peripheral side and the outer peripheral side are connected at the end, and the central portion on the inner peripheral side is separated. In the separated central portions, they are connected to and held by the electrodes 22a and 23a, the electrodes 22b and 23b, the electrodes 22c and 23c, and the electrodes 22d and 23d, respectively. The gaps d between the elements 21a, 21b, 21c, 21d are equal, for example, about 6 mm.

  The electrode 22a is connected to the electrode 23b via the wiring component 24d, and the electrode 22b is connected to the electrode 23c via the wiring component 24b. The electrode 22c is connected to the electrode 23d via the wiring component 24c, and the electrode 22d is connected to the electrode 23a via the wiring component 24a. The wiring component 24d has an external connection terminal 25a, and the wiring component 24b has an external connection terminal 25b, which are connected to external electrodes (not shown).

  For example, a Si epitaxial film is formed on the wafer w using such a semiconductor manufacturing apparatus. First, for example, a φ300 mm wafer w is introduced into the reaction chamber 11 and placed on the susceptor 16. Then, the temperature of the in-heater 17a is controlled to about 1400 ° C., and the temperature of the out-heater 17b is controlled to about 1500 ° C. so that the temperature of the wafer w becomes 1100 ° C.

  At this time, in the outheater 17b having a large outer diameter, each element is heated to 1500 ° C., for example, by applying a voltage to the external connection terminals 25a and 25b connected to the external electrodes (not shown). The By heating, each element thermally expands in the end direction (circumferential direction) around each electrode to which the element is fixed, and the gap d between each element is, for example, about 2 mm. The outer periphery of the wafer w is stably and uniformly heated without warping.

  Then, the wafer w is rotated at, for example, 900 rpm by the rotation driving mechanism 15 and the process gas is supplied from the gas supply port 12 through the rectifying plate 14 in a rectified state onto the wafer w. The process gas is prepared to have a TCS concentration of 2.5%, for example, and supplied at, for example, 50 SLM.

  On the other hand, gas such as excess TCS-containing process gas, dilution gas, and reaction by-product HCl is discharged from the gas discharge port 13, and the pressure in the reaction chamber 11 is controlled to be constant (for example, normal pressure). To do.

  In this way, an Si epitaxial film is grown on the wafer w. At this time, since thermal stress is suppressed, the warpage of the outheater is suppressed and the distance from the wafer w is kept constant, so that a more uniform film thickness can be obtained. And it becomes possible to suppress the damage by the thermal stress of the outheater which arises because it fixes to an electrode, to reduce the maintenance frequency, and to suppress the fall of productivity.

  Further, in order to increase the diameter of the outheater having the largest diameter corresponding to the φ300 mm wafer, it is necessary to process SiC or the like so as to have a diameter of, for example, φ500 mm. However, it is difficult to stably form such a large-diameter member (material removal), and the manufacturing cost may increase. By dividing into, for example, four parts as in the present embodiment, it is possible to stably remove the material with existing technology.

  In the present embodiment, the element is divided for the outheater, but is not necessarily limited to the outheater. For example, it can be applied to an in-heater. In the in-heater, when it corresponds to a φ300 mm wafer, it becomes about φ300 mm, but since it is similarly fixed by an electrode, thermal stress can be suppressed by dividing each element. Therefore, by suppressing warpage and breakage and reducing the maintenance frequency, it is possible to obtain uniform film formation and to suppress reduction in productivity.

  In addition, when a mid heater is provided between the out heater and the in heater, it can be applied to the mid heater.

  In the present embodiment, the heater is divided into four parts. However, the heater is not limited to four parts and may be rotationally symmetric, but in order to stably supply power and perform uniform heating, More preferably, it is divided into even numbers. However, from the viewpoint of stably forming the heater, it is preferable to divide into three or more. In addition, it is preferable that uniform spacing is provided between the elements in order to perform uniform heating.

(Embodiment 2)
In this embodiment, the configuration of the semiconductor manufacturing apparatus is the same as that of the first embodiment, but the booth bar, which is a wiring member to which the electrode is fixed, is divided into three parts, and each is connected by a plane having a vertical plane orientation. This is different from the first embodiment.

  FIG. 4 shows a top view of the heater, and FIGS. 5A and 5B show side views thereof. As shown in the figure, the heater 41 is composed of, for example, a SiC-based material, and is a resistance heating heater element 42 divided into two at the center, and a pair of electrodes for supplying current to the element 42. The electrode rods 43a and 43b are integrated by welding or the like. It should be noted that the illustrated pattern of the element 42 is only an example, and any pattern can be used as long as it can uniformly heat the semiconductor substrate and can respond to a temperature change. For example, a heater 61 as shown in FIG. Can be used. The same applies to the patterns shown below.

  The electrode rods 43a and 43b are fixed so as to be in surface contact with a booth bar 45, which is a wiring member made of Mo, carbon, or the like, by a bolt 44 made of an SiC-based material or the like on the connection surface 45c. Further, the booth bar 45 is fixed so as to be in surface contact with the booth bar 46 and the connection surface 46c, and the booth bar 46 is fixed with the booth bar 47 and the connection surface 47c. At this time, the surface orientations of the connection surfaces 45c, 46c, and 47c are vertical.

  The booth bar 47 is fixed to the electrode rod 50 by a bolt 49 at the external connection terminal 48. The electrode rod 50 is held by a base disk (not shown) and connected to a temperature control mechanism (not shown).

  In FIG. 7, the connection part of the booth bar 46 and the booth bar 47 is shown. As shown in the figure, the booth bar 47 sandwiched between the bolt 44 and the booth bar 46 is provided with an opening (broken line) larger than the bolt diameter. Therefore, the connection position can be moved in the plane direction (X, Y direction and θ direction) within the range of the difference in diameter.

  The connection position between the electrode bar 43a and the booth bar 45 and the connection position between the booth bar 45 and the booth bar 46 can be similarly moved in the plane direction (X, Y direction, and θ direction).

  Then, for example, an Si epitaxial film is formed on the wafer w using such a semiconductor manufacturing apparatus.

  In particular, in order to perform the high-precision temperature control required when forming a thick film, it is necessary to install the heater at a predetermined position with high mounting accuracy so that the temperature distribution does not vary even when the wafer rotates at high speed. is there. However, a manufacturing error occurs on the heater side, such as a welding error that occurs when the heater element and the electrode rod are integrated by welding. Further, if a load is applied to the heater when the heater is attached to install it at a predetermined position, the heater may be warped or cracked due to thermal stress when the temperature is raised.

  However, as in this embodiment, by making the connection position variable in three different directions and its rotation direction, the manufacturing error of the heater can be absorbed and high mounting accuracy can be obtained without applying a load to the heater. Is possible. Accordingly, since the distance from the wafer w is kept constant with high accuracy, a more uniform film thickness can be obtained. Furthermore, since thermal stress is suppressed, warpage, cracking, and breakage of the heater are suppressed, maintenance frequency can be reduced, and reduction in productivity can be suppressed.

(Embodiment 3)
In this embodiment, the configuration of the semiconductor manufacturing apparatus is the same as that of the first embodiment, but the heater is separated into a central portion and an outer peripheral portion, and an intermediate portion is provided with a predetermined gap between them. These are different from the second embodiment in that they are divided into a plurality of parts as in the first embodiment.

  That is, as shown in FIG. 8, an in-heater 71 is provided at the center, an out-heater 72 is provided at the outer periphery, and a mid-heater 73 is provided with a predetermined gap therebetween. At this time, it is necessary to set a gap so that the heaters do not come into contact with each other due to thermal expansion and do not short-circuit, and the heaters are too open to affect the temperature distribution. With such a configuration, the heaters can be separated and each heater can be installed with high mounting accuracy. By controlling each heater independently, the temperature in the wafer surface can be controlled to be more accurate and uniform, and the film thickness uniformity can be improved. In addition, although it is preferable that the mid heater 73 which is an intermediate | middle part is installed from a viewpoint of temperature control, you may be comprised from the in heater 71 and the out heater 72. FIG.

  Further, since the in-heater 71, the out-heater 72, and the mid-heater 73 are divided into a plurality of parts, similarly to the first embodiment, the in-heater 71, the out-heater 72, and the mid-heater 73 can be stably formed even with a large diameter and reduce thermal stress. be able to. Note that, from the viewpoint of reducing thermal stress, it is preferable that all the heaters are divided, but it is not always necessary that all the heaters are divided. If the large-diameter outheater is divided as described above, the effect can be obtained in the divided heater.

  In these embodiments, SiC is used as the heater element, but welding with the electrode is possible, which is preferable in terms of workability and high-temperature stability. For SiC, a sintered body can be used, and high purity SiC may be coated. Also, carbon coated with high purity SiC can be used.

  According to these embodiments, a film such as an epitaxial film can be stably formed on the semiconductor wafer w with high productivity. As well as improving the yield of the wafer, it is possible to improve the yield of the semiconductor device formed through the element formation process and the element isolation process and to stabilize the element characteristics. In particular, an excellent element can be obtained by being applied to an epitaxial formation process of a power semiconductor device such as a power MOSFET or IGBT that requires a thick film growth of 100 μm or more in an N-type base region, a P-type base region, an insulating isolation region, or the like. It becomes possible to obtain characteristics.

In the present embodiment, the case of forming the Si single crystal layer (epitaxial film) has been described. However, the present embodiment can also be applied when forming the poly-Si layer. Further, the present invention can also be applied to film formation other than Si film such as SiO ₂ film and Si ₃ N ₄ film, and compound semiconductor such as GaAs layer, GaAlAs and InGaAs. Various other modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 11 ... Reaction chamber 12 ... Gas supply port 13 ... Gas discharge port 14 ... Current plate 15 ... Rotation drive mechanism 16 ... Susceptor 17a, 71 ... Inheater 17b, 72 ... Outheater 18 ... Reflector 21a, 21b, 21c, 21d, 42 ... Elements 22a, 22b, 22c, 22d, 23a, 23b, 23c, 23d ... Electrodes 24a, 24b, 24c, 24d ... Wiring components 25a, 25b, 48 ... External connection terminals 41, 61 ... Heaters 43a, 43b ... Electrode rods 44, 49 ... Bolts 45, 46, 47 ... Booth bars 45c, 46c, 47c ... Connection surface 50 ... Electrode rod 73 ... Mid heater

Claims (6)

A reaction chamber into which the wafer is introduced;
A gas supply mechanism disposed at the top of the reaction chamber for supplying process gas;
A gas discharge mechanism for discharging gas from the reaction chamber;
A susceptor for holding the wafer;
Is disposed so as to apart from the wafer, the wafer plurality of elements such that the axis a rotational symmetry around axis passing through the center of and spaced apart from each other Rutotomoni, circumferential center of the plurality of elements A plurality of electrodes provided in each of the sections are connected to a common wiring component between adjacent elements , respectively, and generate heat by applying a voltage through the wiring component and the plurality of electrodes. A heater for heating ;
A rotational drive mechanism for rotating the wafer;
A semiconductor manufacturing apparatus comprising: A first wiring component having a first connection surface connected to the electrode;
A second connection surface connected to the first wiring component, the second connection surface being a second wiring component perpendicular to the first connection surface;
A third connection surface connected to the second wiring component, the third connection surface being perpendicular to the first connection surface and the second connection surface; Parts,
The semiconductor manufacturing apparatus according to claim 1, further comprising:   The semiconductor manufacturing apparatus according to claim 2, wherein each of the first to third connection surfaces can change a connection position.   4. The semiconductor manufacturing apparatus according to claim 2, wherein the heater is divided into at least a central portion and an outer peripheral portion, and has an electrode for supplying a current independently. Hold the wafer in the reaction chamber,
Supplying a process gas to the surface of the wafer;
Gas is discharged from the reaction chamber, and the reaction chamber is adjusted to a predetermined pressure,
Rotate the wafer,
The wafer plurality of elements such that the axis a rotational symmetry around axis passing through the center of and spaced apart from each other Rutotomoni, a plurality of electrodes each provided in a central portion of the circumferential direction of the plurality of elements for heater are connected to a common wiring parts between adjacent elements, voltage sign pressurizing the through the wiring part and the plurality of electrodes, said wafer by heating said heater A method of manufacturing a semiconductor, comprising heating to form a film on the surface of the wafer. The electrode and the first wiring component are connected at a first connection surface, and the first wiring component and the second wiring component are connected at a second connection surface perpendicular to the first connection surface. And connecting the second wiring component and the third wiring component on the first connection surface and a third connection surface perpendicular to the second connection surface, A voltage is applied to the heater through the wiring component, the second wiring component, the first wiring component, and the electrode, and the heater is heated to heat the wafer. The semiconductor manufacturing method according to claim 5 .

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