TWI821770B - Heating element, substrate carrying element and plasma processing device thereof - Google Patents

Abstract

A heating element, a substrate carrying element and a plasma processing device thereof, wherein the heating element includes: a first insulating layer; a first sub-heating area located in the first insulating layer and including a plurality of first heaters; Insulation layer; a second sub-heating area, located in the second insulation layer, including a plurality of second heaters, one second heater connected in series to a first heater through a first wire; a plurality of power supply lines , one of the power supply lines is electrically connected to a plurality of first heaters; there are a plurality of power return lines, and one of the power return lines is electrically connected to a plurality of second heaters. The heating element can achieve a better temperature distribution on the substrate while using fewer lead wires.

Description

Heating element, substrate carrying element and plasma processing device thereof

The present invention relates to the field of semiconductors, and in particular to a heating element, a substrate carrying element and a plasma processing device thereof.

There is a plasma environment inside the plasma processing device, and the surface of the substrate is processed in the plasma environment. In the process of surface treatment of the substrate, it is necessary to strictly control the temperature of each position of the substrate, so that the temperature distribution of the substrate is uniform both in the radial direction and the phase angle direction, so that the critical dimension of the substrate (Critical Dimension, CD) to achieve the desired effect.

However, with the continuous development of semiconductor technology, the critical dimensions (CD) of the substrate are expected to become smaller and smaller. Even a small range of temperature fluctuations may cause the formed CD to an unacceptable level. Therefore, a heating element is urgently needed. It can precisely control the uniformity of the substrate temperature distribution, and at the same time, it can also make the heating element have fewer lead wires to reduce the need for filters.

The technical problem solved by the present invention is to provide a heating element, a substrate carrying element and a plasma processing device thereof, which can enable the substrate to achieve better temperature distribution stability while using fewer lead wires.

In order to solve the above technical problems, the present invention provides a heating element, including: a first insulating layer; a first sub-heating area located in the first insulating layer and including a plurality of first heaters; a second insulating layer; The auxiliary heating area is located in the second insulation layer and includes a plurality of second heaters. A second heater is connected in series to a first heater through a first wire. a plurality of power supply lines, one of which is electrically connected to a plurality of first heaters; and a plurality of power return lines, one of which is electrically connected to a plurality of second heaters.

Preferably, the corresponding areas of the first sub-heating area and the second sub-heating area are sub-heating areas; different sub-heating areas are connected to different pairs of power supply lines and power return lines.

Preferably, in the same heating circuit, the projection of the first sub-heating area on the first insulating layer partially overlaps with the projection of the second sub-heating area on the first insulating layer.

Preferably, the projected area of the first sub-heating area on the first insulating layer is larger than the projected area of the second sub-heating area on the first insulating layer.

Preferably, the projection of the first sub-heating area in one of the heating circuits on the first insulating layer partially overlaps the projection of the second sub-heating area in the adjacent heating circuit on the first insulating layer.

Preferably, the first heater is a first heating wire, and the second heater is a second heating wire.

Preferably, the projection patterns of the first heating wire and the second heating wire on the first insulation layer completely overlap.

Preferably, a first switch is provided between each power supply line and the first heater; a second switch is provided between each power return line and the second heater.

Preferably, it also includes: a latch corresponding to each of the first switches, the latch is connected to a common control bus, is connected to the controller through the control bus, and accepts control from the controller Signal; the control signal includes the address information of the sub-heating area that requires output power correction, and the target heating power value of the sub-heating area under the address. Each latch outputs a driving signal to the first switch connected to it. , the driving signal is used to control the working duration of the first switch in each cycle.

Preferably, it also includes: a third insulating layer located above the first insulating layer and the second insulating layer or located below the first insulating layer and the second insulating layer; a main heating area located in the third insulating layer. Within three insulation layers.

Preferably, it also includes: a fourth insulating layer; a third sub-heating area located in the fourth insulating layer and including a plurality of third heaters, the third heater is connected to the first heater through a second wire electrically connected to the second heater.

Preferably, the projection of the third sub-heating area on the first insulating layer partially overlaps with the projection of the first sub-heating area and/or the second sub-heating area on the first insulating layer.

Correspondingly, the present invention also provides a substrate carrying element, including: a cooling plate; a heating element located on the cooling plate; and an electrostatic chuck located above the heating element for adsorbing the substrate.

Preferably, the first insulating layer is located on the cooling plate, and the second insulating layer is located on the first insulating layer.

Preferably, the second insulating layer is located on the cooling plate, and the first insulating layer is located on the second insulating layer.

Correspondingly, the present invention also provides a plasma processing device, including: a reaction chamber, in which is a plasma environment; the above-mentioned substrate carrying element is located at the bottom of the reaction chamber, and the plasma in the plasma environment is used for To treat the surface of the substrate.

Preferably, the plasma processing device is an inductively coupled plasma processing device or a capacitively coupled plasma processing device.

Compared with the conventional technology, the technical solution of the embodiment of the present invention has the following beneficial effects: in the plasma processing device provided by the technical solution of the present invention, the first sub-heating area is located in the first insulating layer, and the third Two auxiliary heating areas are located in the second insulating layer. The first auxiliary heating area includes a plurality of first heaters. The second auxiliary heating area includes a plurality of second heaters. One second heater passes through a A first wire is connected to a first heater, a power supply wire is connected to a plurality of first heaters, and a power return wire is connected to The plurality of second heaters reduces the overall number of power supply lines and power return lines, which is beneficial to reducing the number of filters required. In addition, the first sub-heating area and the second sub-heating area are controlled by a pair of power supply lines and power return lines to heat the corresponding areas of the substrate, which is conducive to better temperature control of the substrate and improves the temperature distribution of the substrate. The uniformity is better.

Furthermore, at the cold spot position, the projected overlap area of the first sub-heating area and the second sub-heating area on the first insulation layer is larger, which is beneficial to increasing the temperature at the small-scale cold spot position; at the hot spot position, the first sub-heating area is made The projected overlapping area of the sub-heating area and the second sub-heating area on the first insulation layer is small, which is beneficial to preventing the temperature at the hot spot from being too high. In summary, the uniformity of temperature distribution on the substrate surface can be improved.

10:Gas supply device

100:Plasma treatment device

101:Reaction chamber

108a: First insulation layer

108b: Second insulation layer

110:Pedestal

115:Electrostatic chuck

116:Electrode

117:Cooling plate

118:Insulation structure

119: Cooling channel

130:Insulation window

140:Inductor coil

145:RF power supply

160:Plasma environment

200a: Main heating area

200b: Sub heating area

200b1: First sub-heating area

200b2: Second heating area

201:First wire

300: First heating wire

301: Second heating wire

d: first spacing range

W: substrate

Figure 1 is a schematic structural diagram of a plasma processing device of the present invention; Figure 2 is a schematic structural diagram of a substrate carrying element in the plasma processing device of the present invention; Figure 3 is a schematic cross-sectional view of a heating element in the substrate carrying element of the present invention; Figure 4 is a top view along line A-A1 of Figure 3; Figure 5 is a bottom view along line B-B1 of Figure 3; Figure 6 is a schematic diagram of the positional relationship between the first sub-heating area and the second sub-heating area in the present invention; FIG. 7 is a schematic diagram of the positional relationship between another first sub-heating area and a second sub-heating area in the present invention; and FIG. 8 is a schematic diagram of the projection of the first heater and the second heater on the first insulating layer.

The technical solution of the present invention provides a heating element, a substrate carrying element and a plasma processing device thereof, including: a first sub-heating area located in the first insulating layer and including a plurality of first heaters; a second insulating layer; The second auxiliary heating area is located in the second insulation layer and includes a plurality of second heaters. One second heater is connected in series to one through a first wire. a first heater; a plurality of power supply lines, one of which is electrically connected to a plurality of first heaters; a plurality of power return lines, one of which is electrically connected to a plurality of second heaters. The heating element can reduce the number of power supply lines and power return lines, and can make the temperature uniformity of the substrate better.

In order to make the above objects, features and beneficial effects of the present invention more obvious and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Figure 1 is a schematic structural diagram of a plasma processing device of the present invention.

Referring to FIG. 1 , the plasma processing apparatus 100 includes: a reaction chamber 101 containing a plasma 160 ; and a substrate carrying element located at the bottom of the reaction chamber 101 for carrying the substrate W.

In this embodiment, the plasma processing device 100 is an inductively coupled plasma etching device, and a substrate transfer port (not shown in the figure) is provided on the side wall of the reaction chamber 101. The substrate transfer port is To realize the transfer of the substrate in and out. The inductively coupled plasma etching device further includes: an insulating window 130 located on the side wall of the reaction chamber 101 and an inductor coil 140 located on the insulated window 130. The inductor coil 140 passes through a matching network (not shown in the figure). ) is electrically connected to the radio frequency power supply 145. The plasma processing device 100 also includes a gas supply component (not shown in the figure), which is connected to the gas supply device 10 and used to transport reaction gas into the reaction chamber 101 . The radio frequency power of the radio frequency power supply 145 drives the inductor 140 to generate a strong high-frequency alternating magnetic field, so that the reaction gas in the reaction chamber 101 is ionized to generate plasma 160 . The plasma 160 contains a large number of active particles such as electrons, ions, excited atoms, molecules, and free radicals. The active particles can undergo various physical and chemical reactions with the surface of the substrate W, making the surface of the substrate W The morphology changes, that is, the etching process is completed.

In other embodiments, the plasma processing apparatus 100 is a capacitively coupled plasma etching apparatus.

The substrate carrying component includes: a base 110 and an electrostatic chuck 115 located on the base 110 . In the process of processing the substrate W, it is necessary to accurately control the radial direction and difference of the substrate W. Only the temperature distribution at the phase angle can obtain the desired critical dimension (CD) of the substrate W. Therefore, a heating area and a cooling channel are provided in the base 110, and the heating area is used to perform heating on the substrate W. The heating and cooling channels are used to circulate cooling liquid, and the cooling liquid is used to cool the substrate W. Through the cooperative use of the heating area and the cooling channel, the temperature of the substrate W reaches a desired temperature, thereby producing the desired critical dimension processing result.

The substrate carrying element is described in detail as follows: Figure 2 is a schematic structural diagram of a substrate carrying element in the plasma processing device of the present invention.

Please refer to Figure 2. The substrate carrying element includes a base 110. The base 110 includes a cooling plate 117 and a heating element located on the cooling plate 117. A cooling channel 119 is provided in the cooling plate 117. , the cooling channel 119 is used to circulate cooling liquid, the heating element includes an insulating structure 118 and a heating area located in the insulating structure 118, the heating area is used to heat the substrate W; the electrostatic chuck 115, Located on the heating element, an electrode 116 is disposed inside the heating element. The electrode 116 is used to generate electrostatic attraction to support and fix the substrate W during the manufacturing process.

In this embodiment, the heating area includes: a main heating area 200a and an auxiliary heating area 200b. The main heating area 200a is used to quickly bring the temperature of the substrate W to near the expected temperature, and is used to temperature the substrate W. For coarse adjustment, the sub-heating area 200b is used to fine-tune the temperature of the substrate W, which is beneficial to reducing the temperature difference of the substrate W at different phase angles and/or different radial directions, so as to improve the consistency of the temperature distribution of the substrate W.

In this embodiment, the main heating area 200a is located below the auxiliary heating area 200b, and the distance between the auxiliary heating area 200b and the electrostatic chuck 115 reduces the heat loss during heat conduction in the auxiliary heating area 200b.

In other embodiments, the primary heating area is located above the secondary heating area.

In this embodiment, the sub-heating area 200b has two layers, namely a first sub-heating area and a second sub-heating area.

In other embodiments, the sub-heating area has two or more layers, which is not limited here.

In this embodiment, the insulation structure 118 includes a first insulation layer, a second insulation layer and a third insulation layer, the first sub-heating area is located in the first insulation layer, and the second sub-heating area Located in the second insulating layer, the main heating area is located in the third insulating layer.

The heating element is described in detail as follows: Figure 3 is a schematic cross-sectional view of a heating element among the substrate carrier elements of the present invention; Figure 4 is a top view along line A-A1 of Figure 3; Figure 5 is a bottom view along line B-B1 of Figure 3 Figure.

Please refer to Figures 3 to 5. The heating element includes: a first insulating layer 108a; a first sub-heating area 200b1, which is located in the first insulating layer 108a and includes a plurality of first heaters; a second insulating layer 108b; The second auxiliary heating area 200b2 is located in the second insulation layer 108b and includes a plurality of second heaters. A second heater is connected in series to a first heater through a first wire 201; a plurality of power supply lines, One power supply line is connected to a plurality of first heaters to form a row; a plurality of power return lines are connected to a plurality of second heaters to form a row; a power supply line, the first heater, and the first wire 201. The second heater and a power return line form a heating circuit for adjusting the temperature of the corresponding area on the substrate.

The heating element also includes: a third insulating layer (not shown in the figure); and a main heating area (not shown in the figure) located in the third insulating layer.

In this embodiment, the first sub-heating area 200b1 is located in the first insulating layer 108a, and the second sub-heating area 200b2 is located in the second insulating layer 108b, so that a certain area of the substrate W is controlled. The temperature of the zone corresponds to a power supply line and a power return line that are not coplanar.

In this embodiment, the second insulating layer 108b is located above the cooling plate, the first insulating layer 108a is located above the second insulating layer 108b, and a power supply line is connected to the first insulating layer 108b. A plurality of first heaters in one auxiliary heating area 200b1 form a row (see Figure 4), and a power return line connects a plurality of second heaters in the second auxiliary heating area 200b2 to form a row (see Figure 5). The areas corresponding to the first sub-heating area 200b1 and the second sub-heating area 200b2 are sub-heating areas. Different sub-heating areas are connected to different pairs of power supply lines and power return lines. Therefore, they can be heated through specific power supply lines and The power return line is used to control the temperature of the corresponding heating area of the substrate. Moreover, by designing the power supply lines and power return lines in this way, the overall required number of power supply lines and power return lines can be reduced, thereby reducing the number of filters required. In addition, a through hole is provided in the cooling plate 117, and the power supply line and the power return line are connected to the outside world through the through hole. Since the number of the power supply line and the power return line is small, the cooling plate The number of through holes provided on 117 is small, which can reduce the interference to the temperature of the substrate W, the manufacturing cost, and the complexity of the substrate carrying components.

In other embodiments, the first insulating layer is located above the cooling plate, the second insulating layer is located above the first insulating layer, and a power supply line connects several of the first sub-heating areas. One heater forms a column, and a power return line connects several second heaters in the second sub-heating area to form a row.

The above examples take the sub-heating area as having two layers as an example. In fact, the number of layers in the sub-heating area is not limited. For example, it also includes: a fourth insulating layer; and a third sub-heating area located within the fourth insulating layer. , including a plurality of third heaters, the third heaters are electrically connected to the first heater and the second heater through second wires. The third sub-heating area has a third projection on the first insulating layer, the first sub-heating area has a first projection on the first insulating layer, and the second sub-heating area has a third projection on the first insulating layer. There is a second projection on the first insulating layer, and the positions of the first sub-heating area, the second sub-heating area and the third sub-heating area can be arranged according to actual needs, so that the temperature distribution on the surface of the substrate W is more uniform. .

In one embodiment, a first switch is provided between each of the power supply lines and the first heater; a second switch is provided between each of the power return lines and the second heater.

In one embodiment, the heating element further includes: a latch set corresponding to each first switch, the latch is connected to a common control bus, is connected to the controller through the control bus, and accepts input from The control signal of the controller; the control signal includes the address information of the sub-heating area that requires output power correction, and the target heating power value of the sub-heating area under the address. Each latch outputs a driving signal to its connected The first switch, the driving signal is used to control the working time of the first switch in each cycle, that is, the working duty cycle, so as to control the heating power of the sub-heating area. Each latch controls the heating power of the sub-heating area according to the preset heating power signal by controlling the working duty cycle of the first switch connected to it, and at the same time determines whether the current output drive signal needs to be changed based on the received control signal. If the control signal received by the latch of an address does not specify that the sub-heating area needs to be modified, the latch maintains the original drive signal to the first switch. If the control signal received by the other latch requires When the power of the sub-heating area is adjusted, the latch adjusts the output driving signal accordingly according to the control signal. The driving signal controls the working duty cycle of the first switch to adjust the heating power input to the sub-heating area.

Figure 6 is a schematic diagram of the positional relationship between a first sub-heating area and a second sub-heating area in the present invention.

In this embodiment, a schematic explanation is provided by taking the example of four first sub-heating areas 200b1 provided in the first insulating layer 108a and four second sub-heating areas 200b2 provided in the second insulating layer 108b. , the number of the first sub-heating area 200b1 and the second sub-heating area 200b2 is not limited here. A power supply line, a first heater, a first conductor, a second heater and a power return line form a heating circuit.

In this embodiment, the projected area of the first sub-heating area 200b1 on the first insulating layer is larger than the projected area of the second sub-heating area 200b2 on the first insulating layer. In the same heating circuit, the The projection of the first sub-heating area 200b1 on the first insulating layer partially overlaps with the projection of the second sub-heating area 200b2 on the first insulating layer, so that the area between adjacent first sub-heating areas 200b1 can be heated by the second sub-heating area 200b1. The heating area 200b2 can be heated according to the actual situation. It is actually necessary to adjust the area size of the second sub-heating area 200b2 covering the adjacent first sub-heating area 200b1, which is beneficial to improving the consistency of the substrate temperature in the corresponding areas of the first sub-heating area 200b1 and the second sub-heating area 200b2.

In other embodiments, the projection of the first sub-heating area on the first insulating layer does not overlap with the projection of the second sub-heating area on the first insulating layer.

Figure 7 is a schematic diagram of the positional relationship between another first sub-heating area and a second sub-heating area in the present invention.

In this embodiment, the projection of the first sub-heating area 200b1 in one heating circuit on the first insulating layer is the same as the projection of the second sub-heating area in the adjacent heating circuit on the first insulating layer. Partially overlap, and the second sub-heating area 200b2 has a larger projected area than the first sub-heating area 200b1, then a large area of rough temperature control can be achieved through the second sub-heating area 200b2, and the first sub-heating area can be roughly controlled. The size of the projected overlapping area of the area 200b1 and the second sub-heating area 200b2 on the first insulating layer, that is, the area size of the first sub-heating area 200b1 above the large-area second sub-heating area 200b2 is used to fine-tune the above-mentioned large-area part. The small temperature difference is beneficial to improving the consistency of the surface temperature of the substrate.

Figure 8 is a schematic projection view of a first heater and a second heater on the first insulation layer.

In this embodiment, the first heater is a first heating wire 300, and the second heater is a second heating wire 301. The first heating wire 300 has a first spacing range d between adjacent sides of the projection pattern on the first insulation layer 108a, and the projection pattern of the second heating wire 301 on the first insulation layer 108a falls on the first insulation layer 108a. within a spacing range d. It is difficult to cover the entire first insulation layer 108a by using the first heating wire 300 alone during processing, especially when the first spacing range d between adjacent first heating wires 300 is particularly small, which affects the processing accuracy. is a challenge. By making the projection pattern of the second heater 301 fall within the first spacing range d, that is, the first heating wire 300 and the second heating wire 301 are disposed in a staggered manner, the projection pattern of the first heating wire 300 can be aligned with the second heating wire 301 . The spacing between the projected patterns of the heating wire 301 is small, so that the corresponding areas of the substrate The area can be better controlled by temperature, improving the temperature uniformity of the substrate. When the area corresponding to the first heater and the second heater is a hot spot position, the coverage area of the first heating wire 300 and the second heating wire 301 here can be reduced.

In other embodiments, the projection pattern of the first heating wire on the first insulation layer overlaps with the projection pattern of the second heating wire on the first insulation layer, which is suitable for cold spot locations, such as the location of the coolant inlet. The lower temperature is conducive to increasing the temperature in a small range of cold spots.

Although the present invention is disclosed as above, the present invention is not limited thereto. Anyone with ordinary knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be based on the scope defined by the patent application scope.

10:Gas supply device

100:Plasma treatment device

101:Reaction chamber

110:Pedestal

115:Electrostatic chuck

130:Insulation window

140:Inductor coil

145:RF power supply

160:Plasma environment

W: substrate

Claims (17)

A heating element for a substrate carrying element, the substrate carrying element is used to carry a substrate, which includes: a first insulating layer; a first auxiliary heating area located in the first insulating layer, including a plurality of a first heater; a second insulating layer, the second insulating layer is located above or below the first insulating layer; a second sub-heating area, located in the second insulating layer, including a plurality of second heaters , a second heater is connected in series to a first heater through a first wire; a plurality of power supply lines, wherein one of the power supply lines connects a plurality of the first heaters to form a row; and a plurality of power supplies Return lines, one of the power return lines connects a plurality of the second heaters to form a row; one of the power supply lines, the first heater, the first wire, the second heater and one of the power return lines form A heating circuit is used to regulate the temperature of corresponding areas on the substrate. The heating element according to claim 1, wherein the area corresponding to the first sub-heating area and the second sub-heating area is a sub-heating area; different sub-heating areas are connected to different pairs of the power supply line and the power supply Back online. The heating element according to claim 1, wherein in the same heating circuit, the projection of the first sub-heating area on the first insulating layer is the same as the projection of the second sub-heating area on the first insulating layer. Partially overlapping. The heating element according to claim 1, wherein the projected area of the first sub-heating area on the first insulating layer is larger than the projected area of the second sub-heating area on the first insulating layer. The heating element according to claim 1, wherein the projection of the first sub-heating area in one of the heating circuits on the first insulating layer is the same as that of the second adjacent heating circuit. The projection of the sub-heating area on the first insulation layer partially overlaps. The heating element according to claim 1, wherein the first heater is a first heating wire, and the second heater is a second heating wire. The heating element according to claim 6, wherein the projection patterns of the first heating wire and the second heating wire on the first insulation layer completely overlap. The heating element of claim 2, wherein a first switch is provided between each power supply line and the first heater; a second switch is provided between each power return line and the second heater. switch. The heating element according to claim 8, further comprising: a latch corresponding to each first switch, the latch being connected to a common control bus, and connected to A controller, and receives a control signal from the controller; the control signal includes an address information of the sub-heating area that requires output power correction, and a target heating power value of the sub-heating area at the address. , each latch outputs a driving signal to the first switch connected thereto, and the driving signal is used to control the working duration of the first switch in each cycle. The heating element according to claim 1, further comprising: a third insulating layer located above the first insulating layer and the second insulating layer or below the first insulating layer and the second insulating layer. ; A main heating area located within the third insulation layer. The heating element according to claim 1, further comprising: a fourth insulating layer; a third auxiliary heating area located in the fourth insulating layer, including a plurality of third heaters, one of which A second wire is electrically connected to the first heater or the second heater. The heating element according to claim 11, wherein the projection of the third sub-heating area on the first insulating layer is the same as the projection of the first sub-heating area and/or the second sub-heating area on the first insulating layer. The projections partially overlap. A substrate carrying component, which includes: A cooling plate; a heating element as described in any one of claims 1 to 12, located on the cooling plate; and an electrostatic chuck, located above the heating element, for adsorbing the substrate. The substrate carrying component of claim 13, wherein the first insulating layer is located on the cooling plate, and the second insulating layer is located on the first insulating layer. The substrate carrying component of claim 13, wherein the second insulating layer is located on the cooling plate, and the first insulating layer is located on the second insulating layer. A plasma processing device, which includes: a reaction chamber, in which is a plasma environment; and a substrate carrying element as described in any one of claim 13 to claim 15, located at the bottom of the reaction chamber , the substrate carrying element is used to carry the substrate, and the plasma in the plasma environment is used to process the surface of the substrate. The plasma processing device according to claim 16, wherein the plasma processing device is an inductively coupled plasma processing device or a capacitively coupled plasma processing device.