JP7586682B2 - Retaining device - Google Patents

Description

This disclosure relates to a holding device for holding an object.

There is known a heating device (also called a "susceptor") that holds an object (e.g., a semiconductor wafer) and heats it to a predetermined temperature (e.g., about 400 to 800°C). Heating devices are used as part of semiconductor manufacturing equipment such as film deposition equipment (CVD film deposition equipment, sputtering film deposition equipment, etc.) and etching equipment (plasma etching equipment, etc.).

In general, a heating device includes a ceramic member having a surface (hereinafter referred to as the "holding surface") that is approximately perpendicular to a predetermined direction, and a surface (hereinafter referred to as the "rear surface") opposite to the holding surface. A heater electrode made of a resistance heating element such as tungsten (W) or molybdenum (Mo) is disposed inside the ceramic member. A conductive connection member (also called an "electrode pad"), at least a portion of which is exposed on the rear surface of the ceramic member, is electrically connected to the heater electrode. A metal power supply member is joined to the connection member by a joint formed of a brazing material. When a voltage is applied to the heater electrode via the power supply member and the connection member, the heater electrode generates heat, and the object held on the holding surface of the ceramic member is heated. For example, a sample holder described in JP 2015-159232 A (Patent Document 1 below) is known as such a heating device.

JP 2015-159232 A

The sample holder is equipped with an external terminal connection pin with a sharp tip, and a second electrode against which the tip of the external terminal connection pin is pressed. The surface of the second electrode is not necessarily flat, but has a slight undulation. The undulation is caused, for example, by variations in the thickness of the second electrode itself, or by the second electrode being partially subjected to stress due to the pushing up of vias stacked inside the substrate. For this reason, the tip of the external terminal connection pin and the surface of the second electrode come into point contact, reducing the contact area and resulting in high resistance, which may cause scorching of both the external terminal connection pin and the second electrode.

The holding device of the present disclosure is a holding device comprising: a plate-shaped member having a first surface substantially perpendicular to a first direction and a second surface opposite the first surface; an electrode including an internal electrode portion disposed inside the plate-shaped member and an external connection portion exposed on the second surface side of the plate-shaped member; and a probe capable of passing electricity through the internal electrode portion via the external connection portion, wherein the external connection portion and an end of the probe are electrically connected by a fiber electrode.

This disclosure makes it possible to prevent burning of both the external connection part and the probe.

FIG. 1 is a perspective view that illustrates a heating device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the internal structure of the heating device. FIG. 3 is an enlarged cross-sectional view showing the fiber electrode and its vicinity in FIG. FIG. 4 is an enlarged cross-sectional view showing the vicinity of the fiber electrode in the modified example.

[Description of the embodiments of the present disclosure]
(1) The holding device of the present disclosure comprises a plate-shaped member having a first surface substantially perpendicular to a first direction and a second surface opposite the first surface, an electrode including an internal electrode portion disposed inside the plate-shaped member and an external connection portion exposed on the second surface side of the plate-shaped member, and a probe capable of passing electricity through the internal electrode portion via the external connection portion, wherein the external connection portion and an end of the probe are electrically connected by a fiber electrode.

Because the external connection part and the end of the probe are electrically connected by a fiber electrode, it is possible to prevent the external connection part and the end of the probe from coming into point contact. This makes it possible to prevent both the external connection part and the probe from becoming burnt.

(2) It is preferable that the fiber electrode is sandwiched between the external connection portion and the end of the probe in the first direction and is not joined to the external connection portion.
When the fiber electrode is joined to the external connection portion, there is a possibility that the two may come into point contact, resulting in high resistance and causing scorching of both the fiber electrode and the external connection portion. Therefore, by not joining the fiber electrode to the external connection portion as described above, point contact can be prevented and scorching can be prevented.

(3) It is preferable that the second surface of the plate-like member has a recess that is recessed toward the first surface, and the fiber electrode is disposed in the recess in a compressed state.
Since the fiber electrode can be placed in the recess in a compressed state, the fiber electrode can be easily positioned, and when pressing the end of the probe against the fiber electrode, there is no need to hold the fiber electrode down with one hand to prevent it from falling out of the recess.

(4) It is preferable that the external connection portion is connected to a common electrode that is electrically connected to the ground sides of the plurality of internal electrode portions.
This can prevent both the external connection portion and the probe from being burned on the common electrode side where the current is concentrated.

[Details of the embodiment of the present disclosure]
Specific examples of the retaining device of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

<Heating device>
The holding device of the present disclosure is a heating device 100 that holds an object (e.g., a semiconductor wafer W) and heats it to a predetermined processing temperature (e.g., 400 to 800° C.), and is also called a susceptor. The heating device 100 is used as a part of a semiconductor manufacturing device such as a film forming device (CVD film forming device, sputtering film forming device, etc.) or an etching device (plasma etching device, etc.). As shown in FIG. 1, the heating device 100 includes a holder 10 and a columnar support 20. The heating device 100 corresponds to the "holding device" in the claims. The technology disclosed in this specification can be applied to electrostatic chucks, holding devices, etc. in addition to heating devices.

<Holding body>
As shown in Fig. 2, the holder 10 is a substantially disk-shaped member having a holding surface S1 that is substantially perpendicular to the vertical direction and a back surface S2 opposite to the holding surface S1. The holder 10 is formed of an insulating material such as ceramics whose main component is aluminum nitride (AlN) or _alumina ( _Al2O3 ). The main component here means the component with the highest content (weight ratio). The diameter of the holder 10 is, for example, about 100 mm or more and 500 mm or less. The holder 10 corresponds to the "plate-shaped member" in the claims, the vertical direction corresponds to the "first direction" in the claims, the holding surface S1 corresponds to the "first surface" in the claims, and the back surface S2 corresponds to the "second surface" in the claims.

An electrode 40 is embedded inside the holder 10. The electrode 40 includes a resistive heating element 50, vias 52A and 52B, a common electrode 55, and a metallized conductor 60.

The resistive heating element 50 is a heater electrode that heats the holder 10, and is formed from a conductive material such as tungsten or molybdenum. When viewed from above, the resistive heating element 50 forms a linear pattern that extends in a generally concentric manner. Both ends of the linear pattern of the resistive heating element 50 are connected to the upper end of the first via 52A via via pads. The resistive heating element 50 corresponds to the "internal electrode portion" in the claims.

A common electrode 55 is provided below the multiple resistive heating elements 50. The common electrode 55 is electrically connected to the lower end (ground side) of the first via 52A of each of the multiple resistive heating elements 50. The common electrode 55 is connected to a conductive metallized conductor 60 through a second via 52B. The metallized conductor 60 is disposed near the center of the holder 10.

A plurality of terminal holes 12 are formed on the rear surface S2 of the holder 10. Each terminal hole 12 is recessed toward the holding surface S1. A terminal side electrode 62 is provided at the upper end of each terminal hole 12.

The terminal side electrode 62 is a portion of the metallized conductor 60 (the inner portion IP described below) exposed on the rear surface S2 side of the holder 10. The resistive heating element 50 and the metallized conductor 60 are electrically connected via the vias 52A, 52B, the common electrode 55, etc. The terminal hole 12 corresponds to the "recess" in the claims, and the terminal side electrode 62 corresponds to the "external connection portion" in the claims.

<Metallized conductor>
The metallized conductor 60 is formed to include a metal material and a ceramic material. The metal material included in the metallized conductor 60 is, for example, tungsten or molybdenum. The ceramic material included in the metallized conductor 60 is, for example, aluminum nitride or alumina. The ceramic material included in the metallized conductor 60 is preferably a ceramic material having a thermal expansion coefficient close to that of the ceramic material that is the main component of the holder 10.

The metallized conductor 60 is, for example, a substantially circular, flat member when viewed from above. However, the metallized conductor 60 has a shape in which the outer periphery is bent diagonally upwards all around. In other words, the metallized conductor 60 is composed of an outer periphery portion OP that is bent in this way and located inside the holder 10, and an inner portion IP that is a substantially flat plate-like portion other than the outer periphery portion OP.

As shown in FIG. 3, the area corresponding to the inner and outer periphery OP of the metallized conductor 60 is covered by an insulating member 13 such as a ceramic material constituting the holder 10, while the area corresponding to the inner part IP is exposed on the back surface S2 side of the holder 10. The lower surface of the inner part IP is the terminal side electrode 62. The diameter of the inner part IP of the metallized conductor 60 is, for example, about 3 mm or more and 12 mm or less, and the thickness of the metallized conductor 60 is, for example, about 0.005 mm or more and 0.15 mm or less. In addition, the maximum thickness (maximum cover thickness) of the insulating member 13 covering the outer periphery OP is, for example, about 0.005 mm or more and 0.1 mm or less. The material of the insulating member 13 is the same as the material of the holder 10. Since the insulating member 13 is made of the same material as the holder 10, the insulating member 13 and the holder 10 can be formed integrally.

<Columnar Support>
2, the columnar support 20 is a substantially cylindrical member extending in the vertical direction. Like the holder 10, the columnar support 20 is formed of an insulating material such as ceramics mainly composed of aluminum nitride or alumina. The outer diameter of the columnar support 20 is, for example, about 30 mm or more and 90 mm or less, and the height of the columnar support 20 (length in the vertical direction) is, for example, about 100 mm or more and 300 mm or less.

The holder 10 and the columnar support 20 are arranged so that the back surface S2 of the holder 10 and the top surface S5 of the columnar support 20 face each other in the vertical direction. The columnar support 20 is joined near the center of the back surface S2 of the holder 10 via a joint 30 formed from a known joining material.

The columnar support 20 is formed with a through hole 22 that opens to the rear surface S2 side of the holder 10. The through hole 22 is a hole that extends in the vertical direction and has a substantially constant inner diameter along the extension direction, and has a substantially circular cross section. A plurality of electrode terminals 24 are housed in the through hole 22. When viewed from above, the electrode terminal 24 is a substantially circular columnar member, and is formed from a conductive material such as nickel (Ni). The diameter of the electrode terminal 24 is, for example, about 2 mm or more and 6 mm or less. The upper end of the electrode terminal 24 is a tapered end 26. The electrode terminal 24 corresponds to the "probe" in the claims.

<Fiber electrode>
A fiber electrode 70 is housed in a compressed state inside the terminal hole 12. The fiber electrode 70 is made of a metal such as copper, and is composed of entangled core wires with a diameter of about 0.1 mm. The end 26 of the electrode terminal 24 is inserted into the fiber electrode 70 from below. The electrode terminal 24 is pressed against the fiber electrode 70 by a biasing member such as a spring. The fiber electrode 70 is not joined (brazed) to the terminal electrode 62, and is sandwiched between the terminal electrode 62 and the end 26 of the electrode terminal 24 in the vertical direction.

Because the fiber electrode 70 is flexible, even if the surface of the terminal electrode 62 has unevenness of about 100 μm, it can make point or line contact to match the shape of the unevenness, so that a sufficient contact area with the terminal electrode 62 can be ensured. Similarly, even if the surface of the end 26 of the electrode terminal 24 has unevenness, it can make point or line contact to match the shape of the unevenness, so that a sufficient contact area with the end 26 of the electrode terminal 24 can be ensured.

<Example>
The resistance value of the heating device 100 was measured before and after a heat cycle test.
Measurement conditions: The measurement was performed in a vacuum at a temperature of 450° C. and with an applied current of 20.1 A.

The workpiece alone shows a resistance value measured under the above measurement conditions without the fiber electrode 70 and before the heat cycle test.
The "before test" indicates the resistance value measured under the above measurement conditions before the heat cycle test.
After the test, the resistance value measured under the above measurement conditions after the heat cycle test is shown.

Measurement results: No scorching occurred on the terminal electrode 62 or the end 26 of the electrode terminal 24, and no increase in resistance due to the use of the fiber electrode 70 was confirmed. The increase in resistance after the test was due to an increase in the work temperature, and it can be determined that there is no problem.

In this embodiment, the end 26 of the electrode terminal 24 is not connected to the terminal electrode 62 by brazing, so deterioration of the connection (brazed portion) due to heat cycle testing does not occur, and increases in resistance and breakage can be avoided.

As described above, the heating device 100 of this embodiment is a heating device 100 including a holding body 10 having a holding surface S1 that is approximately perpendicular to the vertical direction and a back surface S2 opposite the holding surface S1, a resistance heating body 50 arranged inside the holding body 10, an electrode 40 including a terminal side electrode 62 exposed on the back surface S2 side of the holding body 10, and an electrode terminal 24 that can pass electricity through the resistance heating body 50 via the terminal side electrode 62, and the terminal side electrode 62 and the end 26 of the electrode terminal 24 are electrically connected by a fiber electrode 70.

The terminal side electrode 62 and the end 26 of the electrode terminal 24 are electrically connected by the fiber electrode 70, so that the terminal side electrode 62 and the end 26 of the electrode terminal 24 can be prevented from coming into point contact. Therefore, it is possible to prevent both the terminal side electrode 62 and the electrode terminal 24 from becoming burnt.

The fiber electrode 70 is preferably sandwiched between the terminal electrode 62 and the end 26 of the electrode terminal 24 in the vertical direction, and is not joined to the terminal electrode 62 .
If the fiber electrode 70 is joined to the terminal electrode 62, there is a possibility that the two may come into point contact, resulting in high resistance and causing scorching of both the fiber electrode 70 and the terminal electrode 62. Therefore, by not joining the fiber electrode 70 to the terminal electrode 62 as described above, point contact can be prevented and scorching can be prevented.

The rear surface S2 of the holder 10 is provided with a terminal hole 12 recessed toward the holding surface S1, and the fiber electrode 70 is preferably disposed in the terminal hole 12 in a compressed state.
Since the fiber electrode 70 can be placed in the terminal hole 12 in a compressed state, the fiber electrode 70 can be easily positioned, and when the end 26 of the electrode terminal 24 is pressed against the fiber electrode 70, there is no need to hold the fiber electrode 70 down with a hand to prevent it from falling out of the terminal hole 12.

The terminal electrode 62 is preferably connected to a common electrode 55 that is electrically connected to the ground side of each of the multiple resistance heating elements 50 .
This can prevent both the terminal side electrode 62 and the electrode terminal 24 from being burned on the common electrode 55 side where the current collects.

[Details of the modified example of the present disclosure]
Next, a heating device 200 in a modified example will be described with reference to FIG. 4. The heating device 200 in the modified example is a device in which the configuration of the electrode 40 in the heating device 100 in the embodiment is partially modified. An electrode 240 is embedded inside the holder 210 in the modified example. The electrode 240 is made of a resistance heating element 50. The electrode 240 includes an internal heating portion disposed inside the holder 10 and an external heating portion exposed on the back side of the holder 10. A part of the external heating portion is exposed inside the terminal hole 12, and this exposed portion is the terminal side electrode 256. The fiber electrode 70 is not joined (brazed) to the terminal side electrode 256, and is sandwiched between the terminal side electrode 256 and the end 26 of the electrode terminal 24 in the vertical direction.

<Other embodiments>
(1) In the above embodiment, the end 26 of the electrode terminal 24 is tapered. However, it may be round or flat.

(2) In the above embodiment, the fiber electrode 70 is not brazed to the terminal electrode 62, but the fiber electrode 70 may be joined to the terminal electrode 62 by ultrasonic welding or resistance welding.

(3) In the above embodiment, the fiber electrode 70 is placed in the terminal hole 12 in a compressed state, but the fiber electrode 70 may be placed in the terminal hole 12 without being compressed.

(4) In the above embodiment, the terminal side electrode 62 is connected to the common electrode 55, but the ground sides of the multiple resistive heating elements 50 may each be electrically connected to a terminal side electrode.

10: Holder (plate-shaped member) 12: Terminal hole (recess) 13: Insulating member 20: Columnar support 22: Through hole 24: Electrode terminal (probe) 26: End 30: Joint 40: Electrode 50: Resistive heating element (internal electrode portion) 52A: First via 52B: Second via 55: Common electrode 60: Metallized conductor 62: Terminal electrode (external connection portion)
70: Fiber electrode 100: Heating device (holding device)
200: Heating device (holding device) 210: Holder 240: Electrode 256: Terminal electrode (external connection part)
IP: Inner part S1: Holding surface (first surface) S2: Back surface (second surface) S5: Top surface W: Semiconductor wafer

Claims (4)

a plate-like member having a first surface substantially perpendicular to a first direction and a second surface opposite to the first surface;
an electrode including an internal electrode portion disposed inside the plate-like member and an external connection portion exposed on the second surface side of the plate-like member;
A probe capable of conducting electricity to the internal electrode portion via the external connection portion,
A holding device, wherein the external connection portion and the end of the probe are electrically connected by a fiber electrode. The holding device according to claim 1, wherein the fiber electrode is clamped between the external connection part and the end of the probe in the first direction and is not joined to the external connection part. The second surface of the plate-like member is provided with a recess that is recessed toward the first surface,
3. The holding device according to claim 1, wherein the fiber electrode is disposed in the recess in a compressed state. The holding device according to any one of claims 1 to 3, wherein the external connection portion is connected to a common electrode that is electrically connected to the ground side of each of the multiple internal electrode portions.

Images