JP7103340B2 - Ceramic heater - Google Patents

Description

The present disclosure relates to ceramic heaters. This application claims priority based on Japanese application 2017-136821 filed on July 13, 2017, and incorporates all the contents described in the Japanese application.

In semiconductor manufacturing equipment that manufactures semiconductor devices such as LSI, various thin film treatments such as film formation treatment and etching treatment typified by CVD and sputtering are applied to the semiconductor substrate (semiconductor wafer) to be processed. .. Since these thin film treatments are generally performed in a state where the semiconductor substrate is heated to a predetermined temperature, the semiconductor substrate mounted on the mounting surface is placed in the vacuum chamber in which the treatment is performed. A ceramic heater, also called a susceptor, that heats from the lower surface is mounted.

As shown in Patent Document 1, for example, the above-mentioned ceramic heater has a substrate mounting table made of a ceramic disk-shaped member having a flat substrate mounting surface on the upper surface, and a cylindrical shape that supports the substrate mounting table from the lower surface side. It is composed of a support member of. Inside the substrate mounting table, heating circuits such as a resistance heating element and an electric heating coil made of a patterned metal thin film are embedded in a plane parallel to the substrate mounting surface. Electrode terminals inserted from the lower surface side of the board mount are electrically connected to both ends of the heat generating circuit. Power is supplied to the heat generating circuit from an external power source via the electrode terminal and the power supply line connected to the electrode terminal.

In a ceramic heater having such a structure, it is required to improve the heat equalizing property on the substrate mounting surface and uniformly heat the semiconductor substrate over the entire surface so that the quality of the semiconductor device to be a product does not vary. .. Therefore, the circuit pattern of the heat generating circuit is made precise so that temperature unevenness does not occur, or the substrate mounting surface is divided into a plurality of zones and the heat generating circuits arranged in each of them are individually fed to each zone. The temperature is finely controlled.

Japanese Unexamined Patent Publication No. 2003-17224

The ceramic heater of the present disclosure includes a substrate mounting table made of disk-shaped ceramics having a substrate mounting surface on the upper surface, and a plurality of substrates embedded in a plurality of zones of the substrate mounting table when viewed from the substrate mounting surface side. A heating circuit, a plurality of electrode terminals connected to the ends of a plurality of heating circuits, a plurality of feeding parts connected to the plurality of electrode terminals, and a tubular shape connected to the center of the lower surface of the board mounting table. It includes a support and a disk-shaped insulator arranged inside the tubular support so as to face the substrate mounting table. The plurality of feeding parts are arranged inside the cylindrical support so as to extend from the plurality of electrode terminals toward the insulator, and are collected at the center of the insulator along the insulator to form an insulator substrate. It extends from the surface opposite to the surface facing the mounting table.

FIG. 1 is a vertical cross-sectional view of an embodiment of the ceramic heater according to the present disclosure. FIG. 2 is a plan view showing a circuit pattern of a plurality of heat generating circuits included in the ceramic heater of FIG. FIG. 3A is a partial vertical cross-sectional view of the multi-electrode integrated structure portion of the ceramic heater of FIG. FIG. 3B is a bottom view of the multi-electrode integrated structure portion of the ceramic heater of FIG. FIG. 4 is a vertical cross-sectional view of a conventional ceramic heater.

Since the atmosphere inside the vacuum chamber becomes a corrosive environment during the above thin film treatment, it is preferable to isolate the electrode terminals located on the lower surface side of the substrate mounting table from the atmosphere inside the vacuum chamber. Therefore, conventionally, the upper and lower ends of the tubular support that supports the substrate mount from the lower surface side are airtightly joined to the lower surface of the substrate mount and the bottom of the vacuum chamber, respectively, and the electrode terminals are attached to the inside of the tubular support. It is being installed.

However, when the substrate mounting surface is divided into a plurality of zones and a plurality of heat generating circuits are embedded in each of the zones, a plurality of electrode terminals connected to the ends of the plurality of heat generating circuits, and their and an external power supply are used. It is necessary to store a plurality of feeder lines connecting the and in a narrow space inside the tubular support. As a result, these plurality of feeder lines are complicated inside the tubular support, and the work at the time of assembly and inspection becomes complicated, and the connection position may be mistaken or a short circuit may occur.

[Issues to be solved by this disclosure]
The present disclosure has been made in view of such circumstances, and a plurality of feeder lines for supplying power to a plurality of heat generating circuits embedded in a plurality of zones defined on a mounting surface of a board mounting table. It is an object of the present invention to provide a ceramic heater for heating a semiconductor substrate, which can be stored inside a tubular support provided on the lower surface side of the substrate mounting table without complication.

First, the embodiments of the present disclosure will be listed and described. The ceramic heater of the present disclosure includes a substrate mounting table made of disk-shaped ceramics having a substrate mounting surface on the upper surface, and a plurality of substrates embedded in a plurality of zones of the substrate mounting table when viewed from the substrate mounting surface side. A heating circuit, a plurality of electrode terminals connected to the ends of a plurality of heating circuits, a plurality of feeding parts connected to the plurality of electrode terminals, and a tubular shape connected to the center of the lower surface of the board mounting table. It includes a support and a disk-shaped insulator arranged inside the tubular support so as to face the substrate mounting table. The plurality of feeding parts are arranged inside the cylindrical support so as to extend from the plurality of electrode terminals toward the insulator, and are collected at the center of the insulator along the insulator to form an insulator substrate. It extends from the surface opposite to the surface facing the mounting table. As a result, a plurality of power feeding portions for supplying power to the plurality of heat generating circuits embedded inside the board mounting table are housed inside the cylindrical support provided on the lower surface side of the board mounting table without complication. be able to.

In the above-mentioned ceramics heater, each of the plurality of feeding parts extends from the first feeding line extending downward inside the tubular support and the surface of the insulator opposite to the surface facing the substrate mount. It consists of a second feeder to be output and a conductive portion interposed between the first feeder and the second feeder, and the conductive portion extends from the center of the insulator to the outer edge on the lower surface of the insulator. It is preferable that the cable is provided so as to do so. This makes it possible to mitigate the interference between the feeding portions inside the cylindrical support. In addition, the connection position of each power feeding unit can be easily grasped at the time of assembly or inspection.

Further, in the above-mentioned ceramic heater, it is preferable that at least one of the first feeder line and the second feeder is connected to the insulator by screwing, riveting, welding, or brazing. As a result, the feeding line can be reliably connected to the conductor, so that problems such as short circuits are less likely to occur. Further, in the above-mentioned ceramic heater, it is preferable that the first feeder is made of a stranded wire and the second feeder is made of a conductive rod-shaped body. As a result, thermal stress is less likely to occur in the feeder line when the ceramic heater is heated or cooled, and the work during assembly and inspection becomes easier.

Next, as a specific example of the ceramic heater 10 of the present disclosure, a ceramic heater for heating a substrate mounted in a vacuum chamber of a semiconductor manufacturing apparatus that performs etching processing, CVD processing, etc. on a semiconductor substrate will be described. As shown in FIG. 1, the ceramic heater 10 of the present disclosure includes a substantially disk-shaped substrate mounting table 1 preferably made of ceramics, which is provided with a substrate mounting surface 1a on which a semiconductor substrate is mounted on the upper surface, and the substrate mounting. A substantially cylindrical tubular support 2 joined to the central portion of the lower surface of the pedestal 1 and preferably made of ceramics to support the substrate pedestal 1 from the lower surface side, and a substrate mounted inside the tubular support 2. It has a disk-shaped insulator 3 arranged so as to face the pedestal 1.

Examples of the ceramics used as the material of the substrate mounting table 1 and the tubular support 2 include aluminum nitride, silicon nitride, silicon carbide, and aluminum oxide. Among these, aluminum nitride having high thermal conductivity is preferable. It is preferable that the substrate mounting table 1 and the tubular support 2 are made of the same material. As a result, the substrate mounting table 1 and the cylindrical support 2 can be similarly expanded and contracted during heating and cooling. Therefore, it is possible to prevent problems such as warpage of the substrate mounting surface 1a due to thermal stress and damage to the joint portion between the substrate mounting base 1 and the tubular support 2.

The upper and lower ends of the tubular support 2 have flanges that are bent outward. Sealing materials such as O-rings and gaskets (not shown) are provided on the annular end surface of the flange portion. The upper and lower ends of the tubular support 2 are airtightly joined to the lower surface of the substrate mounting table 1 and the bottom of the vacuum chamber (not shown) by means of connecting means such as screws penetrating the flange portion. This makes it possible to isolate the inside of the tubular support 2 from the corrosive gas atmosphere in the vacuum chamber.

In the ceramic heater 10 of the present disclosure, as shown in FIG. 2, the substrate mounting surface 1a of the substrate mounting table 1 is evenly divided into six in the circumferential direction. A plurality of concentric curved portions and straight portions connecting adjacent ones of these curved portions are connected in a zigzag shape so as to cover each of the six fan-shaped zones defined by this. Heat generating circuits 11 to 16 having a fan-shaped circuit pattern are embedded respectively.

In each of the above six heat generating circuits 11 to 16, individual electrode terminals 21 to 26 are electrically connected to one end thereof. A common electrode terminal 20 is electrically connected to the other end of the heating circuits 11 to 16. The ends of the heat generating circuits 11 to 16 and the electrode terminals 20 to 26 can be connected by, for example, a joining method such as caulking, welding, brazing, or screwing. A total of 6 electrode terminals 21 to 26 and 1 common electrode terminal 20 partially project from the lower surface side of the substrate mounting table 1, and 7 power supply bodies 30 to 36 are connected to the projecting portions as a plurality of power supply portions. is doing.

The seven feeders 30 to 36 are composed of the first feeders 30a to 36a, the second feeders 30b to 36b, and the conductors 30c to 36c interposed between the two feeders, respectively. The six feeding bodies 31 to 36, excluding the feeding body 30 for the common electrode terminal 20 located at the center of the substrate mounting surface 1a, extend downward inside the tubular support 2 and then form a circle. After being collected at the center of the insulator 3 along the plate-shaped insulator 3, it extends from the surface of the insulator 3 opposite to the surface facing the substrate mounting table 1 to the lower end side of the tubular support 2. It is supposed to be put out. In the ceramic heater of the present disclosure, the common electrode terminal 20 is located at the center of the substrate mounting surface 1a as shown in the circuit pattern of FIG. Therefore, the feeding body 30 does not have a structure in which the feeding body 30 is gathered at the center of the insulator 3 along the insulating body 3. On the other hand, depending on the position of the common electrode terminal 20, the structure may be such that the common electrode terminals 20 are gathered at the center of the insulator 3 along the insulator 3 as in the case of the six feeders 31 to 36.

The seven power feeding bodies 30 to 36 will be specifically described. First feed lines 30a to 36a made of, for example, metal stranded wires are electrically connected to the protruding portions of the seven electrode terminals 20 to 26, respectively. The first feeder lines 30a to 36a hang down from the inside of the tubular support 2 in a substantially vertical direction toward the insulator 3 located below the inside of the tubular support 2. The insulator 3 is provided with seven through holes at positions substantially directly below the electrode terminals 20 to 26. The tip portions of the first feeder lines 30a to 36a pass through these through holes and are fixed to one end portions of the conductors 30c to 36c provided on the lower surface side of the insulator 3 so as to be conductive. The outer diameter of the insulator 3 is formed to be several mm smaller than the inner diameter of the tubular support 2. As a result, they are arranged so as to be suspended from the first feeder lines 30a to 36a in a movable state inside the tubular support 2.

Of the seven conductors 30c to 36c, the conductors 31c to 36c excluding the conductor 30c located at the center of the insulator 3 are insulators on the lower surface side of the insulator 3 as shown in FIGS. 3A and 3B. It is provided so as to extend uniformly in the radial direction (radial direction) of 3. In addition, in FIG. 3A, the strip-shaped conductors 30c to 36c are fitted into the rectangular grooves provided at seven places on the lower surface side of the insulator 3, respectively. However, the form of the conductors 30c to 36c is not limited to this. The conductor may be fixed to the lower surface of a flat insulating plate having no groove, or a thin-film conductor may be formed by a metallizing method or the like. Further, the extending direction and length of the conductors 31c to 36c on the lower surface of the insulator 3 are as shown in FIG. 3B if the conductors extend from the central portion to the outer edge portion of the insulator 3. It is not limited to the case where it extends uniformly in the radial direction with a certain length. That is, the lengths of the conductors 31c to 36c may be different depending on the positions of the electrode terminals 21 to 26. Alternatively, the extending directions of the conductors 31c to 36c may be non-uniform.

The tips of the seven first feeders 30a to 36a are the ends of the six conductors 31c to 36c opposite to the center side of the insulator 3, except for the first feeder 30a for the common electrode terminal 20. It is electrically connected to the part. In the six conductors 31c to 36c, six second feeder lines 31b to 36b extending to the outside of the tubular support 2 are electrically connected to the central end of the insulator 3. As a result, in the six feeding bodies 31 to 36, they are collected at the center of the insulator 3 inside the tubular support 2. Therefore, it is possible to connect the entire seven power feeding bodies including the power feeding body 30 to the external power source as an integrated form.

As described above, the common electrode terminal 20 is located at the center of the substrate mounting surface 1a. Therefore, in the conductor 30c, the first feeder line 30a is electrically connected to one end of the insulator 3 on the center side. A second feeder line 30b is electrically connected to the other end of the insulator 3 on the opposite side. However, the connection position may be reversed depending on the position of the common electrode terminal 20. Further, when the end of the heat generating circuit is replaced with an individual electrode terminal instead of the common electrode terminal, the number of feeding bodies is twelve. Therefore, the twelve second feeders extend to the outside of the tubular support 2.

Each of the seven second feeders 30b to 36b may be a stranded metal wire similar to the first feeders 30a to 36a. Alternatively, a so-called pin structure made of a conductive rod-shaped body may be used. In this way, the seven second feeder lines 30b to 36b have a pin structure, and the tip of the feeder line on the external power supply side can be collectively engaged with the second feeder group of the pin structure. By adopting the structure, it is possible to simplify the structure of the connection portion with the power supply line on the external power supply side. The conductors 30c to 36c are preferably connected to at least the first feeder lines 30a to 36a or the second feeder lines 30b to 36b by screwing, riveting, welding, or brazing.

By adopting the multi-electrode integrated structure described above, the problem of the conventional ceramic heater 100 shown in FIG. 4 can be solved. That is, in the conventional ceramic heater 100, as shown in FIG. 4, the feeder lines 130 to 136 electrically connected to the electrode terminals 120 to 126 provided on the lower surface of the substrate mounting table 101 are cylinders without any particular restraint. It is randomly stored inside the shape support 102. Therefore, there may be a problem that a short circuit occurs between the feeder lines 130 to 136, or that the connection position of the feeder lines 130 to 136 is mistaken during assembly or inspection. In addition, the lengths of the feeder lines 130 to 136 extending from the lower end of the tubular support 102 may vary, making it difficult to connect to an external power source.

On the other hand, by adopting the multi-electrode integrated structure portion of the ceramic heater of the present disclosure, a plurality of feeder lines for feeding a plurality of heat generating circuits embedded inside the substrate mount are provided inside the tubular support. Even if it is stored in, these feeders will not be complicated, and assembly and inspection will be easy. Further, it is possible to prevent problems such as connection mistakes and short circuits of the feeding lines.

It should be understood that the embodiments disclosed here are exemplary in all respects and are not restrictive in any way. The present invention is not limited to these examples, and is indicated by the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

1,101 Board mounting base 1a, 101a Board mounting surface 2,102 Cylindrical support 3 Insulators 11 to 16 Heat generation circuits 20, 120 Common electrode terminals 21 to 26, 121 to 126 Individual electrode terminals 30 to 36 Feeding Body 30a to 36a 1st feeder line 30b to 36b 2nd feeder line 30c to 36c Conductor 130 to 136 feeder line 10,100 Ceramics heater

Claims (4)

A board mounting table made of disk-shaped ceramics having a board mounting surface on the upper surface,
When viewed from the board mounting surface side, a plurality of heat generating circuits embedded in each of the plurality of zones of the board mounting table, and a plurality of heat generating circuits.
A plurality of electrode terminals connected to the ends of the plurality of heat generating circuits, respectively,
A plurality of power feeding units connected to the plurality of electrode terminals, respectively,
A tubular support connected to the center of the lower surface of the board mounting table, and
A disk-shaped insulator arranged inside the cylindrical support so as to face the substrate mounting table is provided.
The plurality of feeding portions are arranged inside the tubular support so as to extend from the plurality of electrode terminals toward the insulator.
A ceramic heater that is collected at the center of the insulator along a surface of the insulator opposite to the surface of the insulator facing the substrate mounting table and extends from the surface of the insulator. Each of the plurality of power feeding units
A first feeder extending downward inside the cylindrical support,
It is composed of a second feeder extending from the opposite surface and a conductive portion interposed between the first feeder and the second feeder.
The ceramic heater according to claim 1, wherein the conductive portion is provided on the lower surface of the insulator so as to extend from the central portion of the insulator toward the outer edge portion. At least one of the first feeders or the second feeder is connected to the insulator by screwing, riveting, welding, or brazing.
The ceramic heater according to claim 2. The first feeder is made of stranded wire.
The second feeder is made of a conductive rod-shaped body.
The ceramic heater according to claim 2 or 3.

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