JP6856334B2 - heater - Google Patents

Description

The present invention relates to a heater.

As a heater, for example, a ceramic heater for a semiconductor manufacturing apparatus described in Patent Document 1 is known. The ceramic heater for a semiconductor manufacturing apparatus described in Patent Document 1 includes a laminate of a plurality of ceramic substrates having a heating surface on the upper surface, a heat generating resistor provided between layers of the laminate, and a plasma electrode (internal electrode). ing.

In recent years, heaters are required to further improve the heat equalizing property on the heating surface.

Japanese Unexamined Patent Publication No. 2004-146567 Japanese Unexamined Patent Publication No. 2006-12847

For the connection between the internal electrode and the external power supply, for example, as described in Patent Document 2, a recess is formed on the lower surface of the ceramic substrate so that a part of the internal electrode is exposed, and a power supply terminal is inserted into this recess. It is done by. However, when the above configuration is adopted in the ceramic heater for a semiconductor manufacturing apparatus described in Patent Document 1, it is difficult to improve the soaking property on the heating surface. Specifically, if the power supply terminal is brought into contact with the internal electrode, heat may be discharged from the power supply terminal to the outside. Therefore, the temperature of the region of the heating surface directly above the power supply terminal may be lower than that of the other regions.

The heater according to one aspect of the present invention includes a first ceramic layer, a heat generating resistor provided on the first ceramic layer, a second ceramic layer laminated on the first ceramic layer via an adhesive layer, and the like. An internal electrode provided inside the second ceramic layer, a lead connected to the internal electrode, and a lead provided from the second ceramic layer through the adhesive layer to the first ceramic layer, and the above. It is characterized in that it is connected to a lead and has an electrode terminal provided on the first ceramic layer, and the electrode terminal is provided on a side surface of the first ceramic layer .

According to the heater of one aspect of the present invention, the electrode terminals are provided on the first ceramic layer instead of the second ceramic layer on which the internal electrodes are provided, and the internal electrodes and the electrode terminals are connected by leads. Thereby, the heat equalizing property in the second ceramic layer can be improved.

It is sectional drawing which shows the example of a heater. It is a schematic diagram which shows the pattern of the heat generation resistor among the heaters. It is sectional drawing which shows the other example of a heater. It is sectional drawing which shows the other example of a heater.

FIG. 1 is a cross-sectional view showing an example of the heater 10. As shown in FIG. 1, the heater 10 is laminated on the first ceramic layer 1, the heat generating resistor 2 provided on the first ceramic layer 1, and the first ceramic layer 1 via the adhesive layer 3. It includes a second ceramic layer 4 and an internal electrode 5 provided inside the second ceramic layer 4. In the heater 10 of the present embodiment, the upper surface of the second ceramic layer 4 is a heating surface 6 for heating the sample.

The first ceramic layer 1 is a member provided with a heat generating resistor 2. The first ceramic layer 1 is made of, for example, a ceramic material such as alumina, aluminum nitride, silicon nitride, or yttria. The heater 10 is, for example, a member having a rectangular shape when viewed in a plan view. In this case, the first ceramic layer 1 and the second ceramic layer 4 are also rectangular. For example, in the case of a rectangular shape, the dimensions of the first ceramic layer 1 can be set to 10 to 120 mm in length, 10 to 120 mm in width, and 1 to 10 mm in thickness. Further, in the case of a disk shape, the diameter can be set to 50 mm to 450 mm and the thickness can be set to 1 to 10 mm.

Further, the first ceramic layer 1 may have irregularities on the lower surface. Since the first ceramic layer 1 has irregularities on the lower surface, the heat dissipation property on the lower surface can be improved. As a result, the temperature of the heater 10 can be lowered quickly. As the unevenness, for example, a plurality of juxtaposed grooves can be used. The groove is formed so as to extend along the lateral direction or the vertical direction of the first ceramic layer 1, for example, and is formed on the entire lower surface of the first ceramic layer 1. The first ceramic layer 1 can be produced, for example, by laminating green sheets and sintering them.

The heat generation resistor 2 is a member for heating the sample placed on the heating surface 6 on the upper surface of the second ceramic layer 4. The heat generating resistor 2 is provided on the first ceramic layer 1. In the heater 10 of the present embodiment, the heat generating resistor 2 is provided on the upper surface of the first ceramic layer 1. In other words, the heat generating resistor 2 is provided on the surface of the first ceramic layer 1 facing the second ceramic layer 4. The heat generating resistor 2 may be provided inside the first ceramic layer 1.

By applying a voltage to the heat generation resistor 2, the heat generation resistor 2 can be heated. The heat generated by the heat generating resistor 2 is transmitted inside the adhesive layer 3 and the second ceramic layer 4 and reaches the upper surface (heating surface 6) of the second ceramic layer 4. As a result, the sample placed on the heating surface 6 can be heated.

As shown in FIG. 2, the heat generating resistor 2 is a linear pattern having a plurality of folded portions, and is formed on substantially the entire upper surface of the first ceramic layer 1. As a result, it is possible to prevent variations in the heat distribution on the heating surface 6. Although FIG. 2 is not a cross-sectional view, the heat generating resistor 2 is hatched for the purpose of assisting understanding.

The heat generation resistor 2 contains a conductor component and a glass component. The conductor component includes, for example, a metal material such as silver-palladium, platinum or gold. In order to prevent the glass component from foaming, a metal that can be sintered in the atmosphere may be selected as the metal material. Further, the glass component contains oxides of materials such as silicon, aluminum, bismuth, calcium, boron and zinc. The heat generation resistor 2 can be produced by screen-printing a conductive paste on the surface of the green sheet to be the first ceramic layer 1 and sintering the conductive paste.

The second ceramic layer 4 is a plate-shaped member having a heating surface 6 on the upper surface. The second ceramic layer 4 is a member that comes into contact with the object to be heated. Further, the second ceramic layer 4 is a member for reducing the unevenness of heat transmitted from the heat generating resistor 2 and transmitting it to the heating surface 6. The second ceramic layer 4 heats an object to be heated such as a silicon wafer or a silicon wafer chip on the heating surface 6 on the upper surface.

The second ceramic layer 4 is made of a ceramic material such as alumina, aluminum nitride, silicon nitride or yttria. In particular, the second ceramic layer 4 may be made of the same material as the first ceramic layer 1. As a result, the coefficient of thermal expansion of the first ceramic layer 1 and the second ceramic layer 4 can be brought close to each other, so that the thermal stress generated between the first ceramic layer 1 and the second ceramic layer 4 can be reduced.

For example, in the case of a rectangular shape, the dimensions of the second ceramic layer 4 can be set to 10 to 120 mm in length, 10 to 120 mm in width, and 1 to 10 mm in thickness. Further, in the case of a circular shape, the diameter can be set to 50 mm to 450 mm and the thickness can be set to 1 to 10 mm.

Similar to the first ceramic layer 1, the second ceramic layer 4 can be produced, for example, by laminating green sheets and sintering them.

The lower surface of the second ceramic layer 4 faces the upper surface of the first ceramic layer 1 with the adhesive layer 3 interposed therebetween. The second ceramic layer 4 and the first ceramic layer 1 are adhered to each other via the adhesive layer 3. The first ceramic layer 1 and the second ceramic layer 4 are formed so that the side surfaces are flush with each other, for example.

The heater 10 further includes an internal electrode 5 inside the second ceramic layer 4. In the heater 10 of the present embodiment, the internal electrode 5 is a temperature sensor. The temperature sensor consists of, for example, a conductor pattern. The temperature can be measured by measuring the change in the resistance value of this conductor pattern. When the temperature sensor is composed of a conductor pattern, for example, it is routed in almost the entire plane direction in a repeatedly bent shape. The conductor pattern consists of a metallic material such as tungsten, molybdenum or platinum.

The internal electrode 5 can be produced by screen-printing a conductive paste between the layers of a plurality of green sheets to be the second ceramic layer 4 and sintering the conductive paste.

By embedding the temperature sensor in the second ceramic layer 4, for example, the temperature can be measured at a portion closer to the heating surface 6 as compared with the case where the temperature sensor is embedded in the first ceramic layer 1.

The following method can be used for temperature control of the heater 10. Specifically, the temperature can be measured by providing the temperature sensor described above inside the second ceramic layer 4. By adjusting the voltage applied to the heat generating resistor 2 based on the temperature of the second ceramic layer 4 measured as described above, the heat generated by the heat generating resistor 2 is generated so that the temperature of the heating surface 6 becomes constant. Can be controlled.

The adhesive layer 3 is a member for adhering the first ceramic layer 1 and the second ceramic layer 4. The adhesive layer 3 is provided between the upper surface of the first ceramic layer 1 and the lower surface of the second ceramic layer 4. In the heater 10 of the present embodiment, the adhesive layer 3 adheres the first ceramic layer 1 and the second ceramic layer 4 together with the heat generating resistor 2. The adhesive layer 3 is made of, for example, a resin material such as a silicone resin or an epoxy resin. The thickness of the adhesive layer 3 can be set to, for example, 0.01 to 0.3 mm. Further, the adhesive layer 3 may contain a filler such as alumina or aluminum nitride.

In the heater 10 of the present embodiment, as shown in FIG. 1, by providing the heat generating resistor 2 on the upper surface of the first ceramic layer 1, the heat generated by the heat generating resistor 2 can be generated only by the second ceramic layer 4. It can also be diffused in the adhesive layer 3. Thereby, the heat equalizing property on the heating surface 6 can be improved.

The heater 10 further includes a lead 7 and an electrode terminal 8.

The lead 7 is a member for electrically connecting the internal electrode 5 and the electrode terminal 8. The lead 7 has a smaller heat capacity than the electrode terminal 8 for the purpose of reducing heat drawing from the second ceramic layer 4. Specifically, the electrode terminal 8 is made of, for example, a rod-shaped member, while the lead 7 is a printed pattern-shaped or through-hole-shaped member. Leads 7 are provided from the second ceramic layer 4 through the adhesive layer 3 to the first ceramic layer 1. The lead 7 is composed of, for example, silver, palladium, tungsten, molybdenum or a compound containing them as a main component.

In the heater 10 shown in FIG. 1, the lead 7 is a through-hole-shaped member. One end of the lead 7 is connected to the internal electrode 5 inside the second ceramic layer 4, and the other end is connected to the electrode terminal 8 inside the first ceramic layer 1. The lead 7 extends from the second ceramic layer 4 through the adhesive layer 3 to the first ceramic layer 1. The lead 7 and the heat generating resistor 2 are electrically insulated from each other.

When the lead 7 has a through-hole shape, the lead 7 can be manufactured by, for example, the following method.

The following method can be used for the portions of the leads 7 located inside the first ceramic layer 1 and the second ceramic layer 4. Specifically, when the first ceramic layer 1 and the second ceramic layer 4 are produced, a hole having a diameter of 0.3 to 1 mm is made in the green sheet, and the conductive paste is poured into the hole. By sintering this, a through-hole-shaped reed 7 can be formed. Examples of the conductive paste include a paste containing tungsten, molybdenum, silver-palladium or the like as a main component.

Tungsten or molybdenum pins having a diameter of about 0.3 to 1 mm can be used for the portion of the lead 7 located inside the adhesive layer 3. Specifically, by joining the above pins to a part of the leads 7 exposed on the upper surface of the first ceramic layer 1 and the lower surface of the second ceramic layer 4, the positions are located on the adhesive layer 3 of the leads 7. It is possible to form a part to be used.

The electrode terminal 8 is a member for connecting the internal electrode 5 and the external power supply. The electrode terminal 8 is made of, for example, a rod-shaped member. Since the electrode terminal 8 has a rod shape rather than a pattern or through hole shape, a certain strength can be ensured when the electrode terminal 8 is connected to an external circuit.

Since the electrode terminal 8 is a member for connecting to an external power source, the external terminals are joined and used. At this time, in order to ensure the joint strength and the reliability of the electrical connection, the electrode terminal 8 is set to have a larger width and thickness than the lead 7. Therefore, the electrode terminal 8 has a higher rigidity than the lead 7. Further, the electrode terminal 8 has a larger heat capacity than the lead 7.

The electrode terminal 8 is made of a metal material such as tungsten or molybdenum.

In the heater 10 shown in FIG. 1, a recess 9 is provided on the lower surface of the first ceramic layer 1. A lead 7 is pulled out from the bottom surface of the recess 9. The electrode terminal 8 is inserted into the recess 9 on the lower surface of the first ceramic layer 1 and is electrically connected to the lead 7. In the heater 10 shown in FIG. 1, the electrode terminal 8 is inserted in the recess 9, but the present invention is not limited to this. Specifically, the lead 7 may be connected to the lower surface of the first ceramic layer 1 and the electrode terminal 8 may be attached to the lower surface of the first ceramic layer 1.

In the heater 10 of the present embodiment, the electrode terminal 8 is provided on the first ceramic layer 1 instead of the second ceramic layer 4 on which the internal electrode 5 is provided, and the internal electrode 5 and the electrode terminal 8 are connected by the lead 7. It is connected. As a result, the heat drawn by the electrode terminals 8 can be reduced, so that the heat equalizing property of the second ceramic layer 4 can be improved.

Further, as shown in FIG. 3, the electrode terminal 8 may be provided on the side surface of the first ceramic layer 1. By providing the electrode terminal 8 on the side surface of the first ceramic layer 1, it is possible to reduce the possibility that the heat soaking property is lowered on the central side of the upper surface (heating surface 6) of the second ceramic layer 4. In the heater 10 shown in FIG. 3, a recess 9 is provided on the side surface of the first ceramic layer 1, and a lead 7 is provided so as to be exposed in the recess 9. The electrode terminal 8 is inserted into the recess 9 on the side surface of the first ceramic layer 1 and is electrically connected to the lead 7.

In the heater 10 shown in FIG. 3, the electrode terminal 8 is inserted in the recess 9, but the present invention is not limited to this. Specifically, the lead 7 may be connected to the side surface of the first ceramic layer 1 and the electrode terminal 8 may be attached to the side surface of the lead 7 to connect the lead 7 and the electrode terminal 8.

Further, as shown in FIG. 4, the reed 7 may be provided from the side surface of the second ceramic layer 4 to the side surface of the first ceramic layer 1 through the side surface of the adhesive layer 3. As a result, the lead 7 can be kept away from the heat generating resistor 2, so that it is possible to reduce the heat generated from the heat generating resistor 2 from escaping to the outside through the lead 7. As a result, the heat equalizing property on the upper surface of the second ceramic layer 4 can be improved.

When the leads 7 have a patterned shape, the leads 7 can be formed by, for example, the following method. Specifically, a part of the internal electrode 5 is extended to the side surface of the second ceramic layer 4, and the internal electrode 5 is exposed on the side surface of the second ceramic layer 4. A conductive resin paste containing silver or the like as a main component is applied from the side surface of the second ceramic layer 4 to the side surface of the first ceramic layer 1 through the side surface of the adhesive layer 3 so as to overlap the exposed internal electrode 5. To do. The lead 7 can be formed by curing this. Since the leads 7 have a patterned shape, heat drawing by the leads 7 can be reduced as compared with the case where the leads 7 are made of pins or the like. Thereby, the heat equalizing property on the upper surface of the second ceramic layer 4 can be improved. Examples of the pattern shape include a film shape.

Further, the lead 7 may be made of a material having a thermal conductivity lower than that of the electrode terminal 8. As a result, heat drawing from the lead 7 can be further reduced, so that the heat equalizing property on the upper surface of the second ceramic layer 4 can be improved. If the electrode terminal 8 is made of, for example, copper, for example, silver palladium, tungsten or molybdenum can be used as the lead 7.

1: First ceramic layer 2: Heat generation resistor 3: Adhesive layer 4: Second ceramic layer 5: Internal electrode 6: Heating surface 7: Lead 8: Electrode terminal 9: Recessed portion 10: Heater

Claims (4)

A first ceramic layer, a heat generating resistor provided on the first ceramic layer, a second ceramic layer laminated on the first ceramic layer via an adhesive layer, and provided inside the second ceramic layer. The internal electrode is connected to the internal electrode, and the lead provided from the second ceramic layer through the adhesive layer to the first ceramic layer is connected to the lead and the lead is connected to the lead. It is equipped with an electrode terminal provided on one ceramic layer.
A heater characterized in that the electrode terminals are provided on the side surface of the first ceramic layer. The lead from said side surface of the second ceramic layer, through a side of the adhesive layer, heater according to claim 1, characterized in that provided to the side surface of the first ceramic layer. The heater according to claim 2 , wherein the leads have a patterned shape. The heater according to any one of claims 1 to 3 , wherein the lead is made of a material having a thermal conductivity lower than that of the electrode terminal.

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