CN213936112U - Lower electrode assembly and plasma processing equipment - Google Patents
Lower electrode assembly and plasma processing equipment Download PDFInfo
- Publication number
- CN213936112U CN213936112U CN202021937100.4U CN202021937100U CN213936112U CN 213936112 U CN213936112 U CN 213936112U CN 202021937100 U CN202021937100 U CN 202021937100U CN 213936112 U CN213936112 U CN 213936112U
- Authority
- CN
- China
- Prior art keywords
- heating
- electrostatic chuck
- wafer
- region
- heating device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Drying Of Semiconductors (AREA)
- Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
Abstract
The embodiment of the application discloses a lower electrode assembly and plasma processing equipment, the lower electrode assembly comprises an electrostatic chuck for adsorbing a wafer, a first heating device which is positioned on one side of the electrostatic chuck, which deviates from the wafer, and used for heating the electrostatic chuck, and a second heating device which is arranged outside the electrostatic chuck, wherein the heating effect of the first heating device on a first area is greater than that on a second area, and the heating effect of the second heating device on the second area is greater than that on the first area, so that the difference of the heating effects of the first heating device on the first area and the second area on the surface of the wafer can be adjusted by using the second heating device, the difference between the etching rate of the first area and the etching rate of the second area on the surface of the wafer is reduced, and the etching uniformity of the first area and the second area on the surface of the wafer is improved, thereby improving the etching uniformity of the surface of the wafer.
Description
Technical Field
The present disclosure relates to plasma processing technologies, and particularly to a lower electrode assembly and a plasma processing apparatus.
Background
With the development of plasma processing technology, plasma processing equipment applying the technology is also continuously improved, and the current plasma processing equipment comprises a reaction chamber, an electrostatic chuck positioned in the reaction chamber, and a freezer Heater (namely, a Chiller Heater) positioned below the electrostatic chuck and used for heating the electrostatic chuck, wherein the freezer Heater regulates and controls the temperature of a wafer positioned above the electrostatic chuck by regulating and controlling the temperature of the electrostatic chuck, so that the etching reaction rate of the surface of the wafer is controlled. However, when the existing plasma processing equipment carries out plasma processing on the wafer, the etching uniformity of the surface of the wafer is poor.
SUMMERY OF THE UTILITY MODEL
In order to solve the above technical problem, embodiments of the present application provide a lower electrode assembly and a plasma processing apparatus, so as to improve etching uniformity of a wafer surface when the wafer is subjected to plasma processing.
In order to solve the above problem, the embodiment of the present application provides the following technical solutions:
a lower electrode assembly comprising:
the electrostatic chuck adsorbs a wafer, and the surface of the wafer comprises a first area and a second area, wherein the distance from each point of the first area to the center of the wafer is less than the distance from each point of the second area to the center of the wafer;
the first heating device is positioned on one side, away from the wafer, of the electrostatic chuck and used for heating the electrostatic chuck, and the heating effect of the first heating device on the first area is greater than that of the second area;
and the second heating device comprises at least one heating unit, the second heating device is arranged outside the electrostatic chuck, and the effect of the second heating device on heating the second area is greater than that of the first area.
Optionally, a size of the electrostatic chuck in a first direction is smaller than a size of the wafer in the first direction, the first direction is parallel to the upper surface of the electrostatic chuck, and the center of the upper surface of the electrostatic chuck points to an edge of the electrostatic chuck.
Optionally, the second region wraps the first region, and a projection of the first region on the electrostatic chuck coincides with the electrostatic chuck.
Optionally, the lower electrode assembly further includes a focus ring, the focus ring is annularly disposed outside the electrostatic chuck, and the second heating device is located at the bottom of the focus ring.
Optionally, the second heating device includes a heating unit, a projection of the heating unit on a preset plane is annular, and a projection of the electrostatic chuck on the preset plane is located in an area surrounded by an inner ring of the annular;
the preset plane is parallel to the plane of the electrostatic chuck.
Optionally, the second heating device includes at least two heating units, and the at least two heating units are uniformly distributed along the circumferential direction of the electrostatic chuck.
Optionally, each of the at least two heating units is independently controlled.
Optionally, the second heating device includes four heating units, wherein projections of two heating units in a preset plane are symmetrical about an X axis, and projections of the other two heating units in the preset plane are symmetrical about a Y axis;
the preset plane is parallel to the plane where the electrostatic chuck is located, and the X axis and the Y axis are located in the preset plane and are perpendicular to each other.
A plasma processing apparatus, comprising:
a cavity;
a lower electrode assembly positioned within the cavity, the lower electrode assembly being any of the lower electrode assemblies described above.
Optionally, the plasma processing apparatus further includes a first temperature control device, which controls a heating temperature of the first heating device.
Optionally, the plasma processing apparatus further includes a second temperature control device for controlling a heating temperature of the second heating device, where the second temperature control device includes at least one temperature control unit, and the number of the temperature control units is less than or equal to the number of the heating units.
Optionally, the number of the temperature control units is equal to the number of the heating units, and the temperature control units correspond to the heating units one to one.
Compared with the prior art, the technical scheme has the following advantages:
the lower electrode assembly provided by the embodiment of the application comprises an electrostatic chuck for adsorbing a wafer, a first heating device which is arranged on one side of the electrostatic chuck, which deviates from the wafer, and is used for heating the electrostatic chuck, and a second heating device which is arranged on the outer side of the electrostatic chuck, wherein the first heating device has a heating effect on the first area which is greater than that on the second area, and the second heating device has a heating effect on the second area which is greater than that on the first area, so that the second heating device can be used for adjusting the difference of the heating effects of the first heating device on the first area and the second area of the surface of the wafer, the difference between the temperature of the first area and the temperature of the second area of the surface of the wafer is reduced, and the etching uniformity of the first area and the second area of the surface of the wafer is improved, thereby improving the etching uniformity of the surface of the wafer.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic cross-sectional view of a lower electrode assembly according to one embodiment of the present application;
fig. 2 is a schematic view illustrating that, in the lower electrode assembly according to an embodiment of the present disclosure, projections of three heating units in a plane where the electrostatic chuck is located are uniformly distributed on a circular ring concentric with the electrostatic chuck;
fig. 3 is a schematic view illustrating that, in the lower electrode assembly according to an embodiment of the present disclosure, projections of four heating units in a plane where the electrostatic chuck is located are uniformly distributed on a circular ring concentric with the electrostatic chuck;
fig. 4 is a schematic cross-sectional structure diagram of a plasma processing apparatus according to an embodiment of the present disclosure.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways than those described herein, and it will be apparent to those of ordinary skill in the art that the present application is not limited to the specific embodiments disclosed below.
As described in the background section, when the conventional plasma processing apparatus performs plasma processing on a wafer, the etching uniformity of the wafer surface is poor.
The inventor researches and discovers that the poor etching uniformity of the wafer surface is mainly reflected in that the etching rates of the central area and the edge area of the wafer surface are different, the etching rate of the wafer surface is related to the temperature of the wafer surface, and in the actual plasma etching process, the temperature of the central area of the wafer surface is higher than that of the edge area of the wafer.
It should be noted that, in some plasma etching processes, the higher the wafer temperature is, the faster the etching rate is, the lower the wafer temperature is, the slower the etching rate is, and in some plasma etching processes, the higher the wafer temperature is, the slower the etching rate is, the lower the wafer temperature is, the faster the etching rate is, which depends on whether the plasma etching process is an endothermic process or an exothermic process.
In view of the above, embodiments of the present application provide a lower electrode assembly, as shown in fig. 1, the lower electrode assembly includes:
the electrostatic chuck 1 adsorbs a wafer 2, and the surface of the wafer 2 comprises a first area and a second area, wherein the distance from each point of the first area to the center of the wafer 2 is less than the distance from each point of the second area to the center of the wafer 2;
the first heating device 3 is positioned on one side, away from the wafer 2, of the electrostatic chuck 1 and is used for heating the electrostatic chuck 1, and the heating effect of the first heating device 3 on the first area is greater than that of the second area;
the second heating device 4, the second heating device 4 includes at least one heating unit, the second heating device 4 is established the electrostatic chuck 1 outside, the second heating device 4 to the effect of second region heating is greater than to the effect of first region heating.
Optionally, in an embodiment of the present application, the first heating device 3 is a refrigerator heater, which is not limited in the present application, as the case may be.
The lower electrode assembly provided by the embodiment of the application comprises an electrostatic chuck for adsorbing a wafer, a first heating device which is arranged on one side of the electrostatic chuck, which deviates from the wafer, and is used for heating the electrostatic chuck, and a second heating device which is arranged on the outer side of the electrostatic chuck, wherein the first heating device has a heating effect on the first area which is greater than that on the second area, and the second heating device has a heating effect on the second area which is greater than that on the first area, so that the second heating device can be used for adjusting the difference of the heating effects of the first heating device on the first area and the second area of the surface of the wafer, the difference between the temperature of the first area and the temperature of the second area of the surface of the wafer is reduced, and the etching uniformity of the first area and the second area of the surface of the wafer is improved, thereby improving the etching uniformity of the surface of the wafer.
Researches find that in the production and manufacturing process of semiconductor wafers, before plasma etching is carried out on the wafers, the wafers need to be adsorbed and fixed through an electrostatic chuck, and the temperature of the wafers above the electrostatic chuck is regulated and controlled by regulating and controlling the temperature of the electrostatic chuck.
Because plasma has the damage to the electrostatic chuck in the etching process, and too big electrostatic chuck's cost is higher, therefore, for reasons such as the life of extension electrostatic chuck and reduce the cost of manufacture of electrostatic chuck, in an embodiment of this application, the size of electrostatic chuck in first direction A is less than or equal to the size of wafer in first direction A, wherein, first direction A is on a parallel with the upper surface of electrostatic chuck, and by the center of the upper surface of electrostatic chuck points to the edge of electrostatic chuck.
When the wafer is heated by the electrostatic chuck, the electrostatic chuck is generally divided into a central heating zone and a plurality of annular heating zones annularly arranged around the central heating zone, and the wafer is heated in each heating zone area.
When the size of the electrostatic chuck along the first direction A is equal to the size of the wafer along the first direction A, the central area of the wafer can be heated by at least two heating belts of the electrostatic chuck, and the edge-most area of the wafer can only receive the heating effect of one heating belt of the outermost heating belt of the electrostatic chuck, so that the temperature of the edge area of the wafer is lower than that of the central area of the wafer, and the etching rates of the edge area and the central area of the wafer are different.
Based on this, in this embodiment, the second region wraps the first region, the second region is a region of the wafer corresponding to the outermost heating belt of the electrostatic chuck, and the second heating device is arranged outside the electrostatic chuck so that the second area is closer to the second heating device than the first area, so that the heating effect of the second heating means on the second area is greater than the heating effect of the second heating means on the first area, the difference of the heating effect of the first heating device on the first area and the second area on the surface of the wafer is adjusted, the difference between the temperature of the first area and the temperature of the second area on the surface of the wafer is reduced, the etching uniformity of the first area and the second area on the surface of the wafer is improved, and therefore the etching uniformity of the surface of the wafer is improved.
When the size of the electrostatic chuck in the first direction a is smaller than the size of the Wafer in the first direction a, the edge of the Wafer (referred to as "WE" for short) is not in direct contact with the electrostatic chuck, so that the temperature of the edge region of the Wafer cannot be directly adjusted by adjusting the temperature of the electrostatic chuck, the temperature of the central region of the Wafer can only be adjusted by adjusting the temperature of the electrostatic chuck, and the temperature of the edge region of the Wafer is affected by the temperature of the central region of the Wafer, so that when the first heating device heats the Wafer through the electrostatic chuck, the heating effect of the first heating device on the first region is greater than the heating effect on the second region. Therefore, when the plasma processing equipment performs plasma processing on the wafer, the etching rate at the edge of the wafer cannot be directly adjusted by regulating and controlling the temperature of the electrostatic chuck, so that the etching rate at the edge of the wafer and the etching rate at the center of the wafer are basically kept consistent.
In this regard, in an alternative embodiment of the present application, the second region wraps around the first region, a projection of the first region on the electrostatic chuck coincides with the electrostatic chuck, and the second heating means is disposed outside the first heating means such that the second region is closer to the second heating means than the first region, so that the heating effect of the second heating means on the second area is greater than the heating effect of the second heating means on the first area, the difference of the heating effect of the first heating device on the first area and the second area on the surface of the wafer is adjusted, the difference between the temperature of the first area and the temperature of the second area on the surface of the wafer is reduced, the etching uniformity of the first area and the second area on the surface of the wafer is improved, and therefore the etching uniformity of the surface of the wafer is improved.
In another optional embodiment of the present application, the second region wraps the first region, and a projected area of the first region on the electrostatic chuck is smaller than an area of the upper surface of the electrostatic chuck, for example, the second region includes a region corresponding to an outermost heating band of the electrostatic chuck in the wafer in addition to a region corresponding to a projected area of the wafer outside the electrostatic chuck, which is not limited in this application, as the case may be.
On the basis of any one of the above embodiments, in an embodiment of the present application, the second heating device is annularly disposed outside the electrostatic chuck, so that the effect of heating at each position in the second region is relatively uniform, and the etching uniformity at each position in the second region is improved.
It should be noted that although the second heating device is disposed outside the electrostatic chuck, and is closer to the second region and farther from the first region, it does not mean that the second heating device only has a heating effect on the second region and does not have a heating effect on the first region, depending on the heating capacity of the second heating device. Specifically, when the heating capacity of the second heating device is strong, the second heating device has a heating effect on both the first region and the second region, but the heating effect of the second heating device on the second region is greater than the heating effect of the second heating device on the first region; when the heating capacity of the second heating device is weak, the second heating device only has a heating effect on the second area, and the heating effect on the first area is very small and can be ignored.
Based on any of the above embodiments, in one embodiment of the present application, and as further illustrated in fig. 1, the lower electrode assembly includes a focus ring 5, the focus ring 5 being annularly disposed outside the electrostatic chuck 1 to focus plasma during plasma processing onto the wafer 2.
On the basis of the above embodiment, in an embodiment of the present application, the focus ring 5 has thermal conductivity, and optionally, the second heating device 4 may be located at the bottom of the focus ring 5, so that the second heating device 4 heats the focus ring 5, and then the thermal conductivity of the focus ring 5 annularly disposed outside the electrostatic chuck 1 is utilized to transfer heat to the second region of the wafer 2, so as to heat the second region, thereby utilizing the thermal conductivity of the focus ring to improve uniformity of heated effect at each position in the second region. In addition, in the embodiment of the present application, the second heating device 4 is located at the bottom of the focus ring 5, so that the second heating device 4 is convenient to install and has less influence on the chamber of the plasma processing apparatus.
In yet another embodiment of the present application, the second heating device 4 may be disposed on top of the focus ring 5, such that the second heating device 4 is closer to the second region of the wafer, thereby improving the heating efficiency of the second heating device 4 on the wafer 2.
In another embodiment of the present application, the second heating device 4 may be disposed on an outer sidewall of the focus ring 5 far away from the electrostatic chuck 1, so that the second heating device 4 heats the focus ring 5, and the heat conductivity of the focus ring 5 annularly disposed on the outer side of the electrostatic chuck 1 transfers the heat to the second region of the wafer 2, so as to improve the uniformity of the heating effect at each position in the second region by using the heat conductivity of the focus ring, and simultaneously reduce the distance between the second heating device and the second region of the wafer, and improve the heated effect of the second region. In other embodiments of the present application, the second heating device 4 may also be disposed on the inner sidewall of the focus ring 5 close to the electrostatic chuck 1, so that the second heating device 4 is closer to the second region of the wafer, thereby improving the heating efficiency of the second heating device 4 on the wafer 2. It should be noted that, in the embodiment of the present application, the top and the bottom of the focus ring 5 are disposed opposite to each other, and the sidewall of the focus ring is connected to the top and the bottom of the focus ring, wherein the outer sidewall of the focus ring is the side wall of the focus ring that deviates from a side surface of the electrostatic chuck, and the inner sidewall of the focus ring is the side surface of the focus ring that faces the electrostatic chuck.
Optionally, in an embodiment of the present application, the second heating device is fixedly connected to the focus ring, and the second heating device is in direct contact with at least a partial region of the focus ring, so as to improve the thermal conductivity between the second heating device and the focus ring. Optionally, in an embodiment of the present application, the second heating device is fixed to the focus ring by screws, which is not limited in this application, as the case may be.
On the basis of any one of the above embodiments, in an embodiment of the present application, the second heating device includes a heating unit, a projection of the heating unit on a predetermined plane is in an annular shape, and a projection of the electrostatic chuck on the predetermined plane is located in an area surrounded by an inner ring of the annular shape, so that a heated effect at each position in the second area is relatively uniform, and thus uniformity of the heated effect at each position in the second area is improved. The preset plane is parallel to the plane of the electrostatic chuck.
Optionally, in the embodiment of the present application, the heating unit is a heating belt (i.e., heater ball).
It should be noted that, in an embodiment of the present application, a projection of the heating unit on the predetermined plane may be in a closed ring shape, and in other embodiments of the present application, a projection of the heating unit on the predetermined plane may also be in an unclosed ring shape, such as an opening on the ring shape, which is not limited in this application, as the case may be.
Optionally, on the basis of the foregoing embodiment, in an embodiment of the present application, the wafer is a circular wafer, the electrostatic chuck is a circular electrostatic chuck, and correspondingly, a projection of the second heating device on a preset plane is in a shape of a circular ring, so that distances between positions in the second area, which are the same as the center of the wafer, and the second heating device are the same, and uniformity of heating at different positions in the circumferential direction of the second area by the second heating device is improved. However, this is not limited in this application, and in other embodiments of the present application, when the wafer and the electrostatic chuck are square, the projection of the heating unit on the preset plane is in the shape of a square ring, as long as it is ensured that the shape defined by the projection of the heating unit on the preset plane matches the shapes of the electrostatic chuck and the wafer. It should be noted that, when the wafer and the electrostatic chuck are circular, the first direction is a radial direction of the wafer or the electrostatic chuck; when the wafer and the electrostatic chuck are square, the first direction is the side length direction of the wafer or the electrostatic chuck, or the diagonal direction of the wafer or the electrostatic chuck; when the wafer and the electrostatic chuck are in an irregular shape, the first direction may be a maximum dimension direction of the wafer or the electrostatic chuck, or may be any direction in a plane where the wafer or the electrostatic chuck is located.
In another embodiment of the present application, the second heating device includes at least two heating units, and the at least two heating units are uniformly distributed along the circumferential direction of the electrostatic chuck, so that the heated effect at each position in the second area is more uniform, and the uniformity of the heated effect at each position in the second area is improved.
In the embodiment of the present application, when the electrostatic chuck is circular, the circumferential direction of the electrostatic chuck refers to the circumferential direction of the electrostatic chuck, and when the electrostatic chuck is square, the circumferential direction of the electrostatic chuck refers to the extending direction of the boundary line of the electrostatic chuck, such as the circumferential direction of the square.
On the basis of the implementation, in an embodiment of the present application, the electrostatic chuck is a circular electrostatic chuck, the wafer is a circular wafer, and accordingly, the second heating device includes that the at least two heating units are in a circular ring shape in the projection of the preset plane, so that the distance between the second region and each position where the center of the wafer is the same as the distance between the second heating devices, and the uniformity of the heating effect of the second heating device on different positions in the circumferential direction of the second region is improved. The shape defined by the projections of the at least two heating units included in the second heating device in the preset plane is matched with the shapes of the electrostatic chuck and the wafer.
It should be noted that the electrostatic chuck and the heating unit may or may not be in direct contact, and the application is not limited thereto as long as the heating unit is not in direct contact with the wafer. In a preferred embodiment of the present application, a gap is formed between the electrostatic chuck and the heating unit in a plane of the wafer, so as to prevent the heating unit from directly contacting the wafer, thereby affecting a balance of the wafer attraction by the electrostatic chuck.
The following description will be given by taking the electrostatic chuck as a circular electrostatic chuck and the wafer as a circular wafer.
As shown in fig. 2, in an embodiment of the present application, on the basis of any of the above embodiments, the second heating device 4 includes three heating units 41, and projections of the three heating units 41 on a predetermined plane are uniformly distributed on a circular ring concentric with the electrostatic chuck, so that distances between positions in the second region that are the same from the center of the wafer and the second heating device are the same, and uniformity of heating of different positions in the circumferential direction of the second region by the second heating device is improved, wherein the predetermined plane is parallel to a plane of the electrostatic chuck.
On the basis of any of the above embodiments, in an embodiment of the present application, the second heating device 4 includes four heating units 41, wherein projections of two heating units 41 in a predetermined plane are symmetric about an X axis, and projections of two other heating units 41 in the predetermined plane are symmetric about a Y axis, wherein the predetermined plane is parallel to a plane in which the electrostatic chuck is located, and the X axis and the Y axis are located in the predetermined plane and perpendicular to each other, so that distances between positions in the second region that are the same from the center of the wafer and the second heating device are the same, and uniformity of heating by the second heating device to different positions in the circumferential direction of the second region is improved.
Alternatively, in an embodiment of the present application, projections of two of the heating units 41 symmetrical about the X axis in the preset plane and projections of two of the heating units 41 symmetrical about the Y axis in the preset plane may be located on the same circular ring, as shown in fig. 3. In other embodiments of the present application, the projections of the two heating units symmetrical about the X axis in the preset plane and the projections of the two heating units 41 symmetrical about the Y axis in the preset plane may also be located on different circular rings, which is not limited in this application, as the case may be.
It should be noted that, in the embodiment of the present application, the second region of the wafer surface may include at least two sub-regions. Specifically, in this embodiment of the present application, the second region of the wafer surface includes four sub-regions, i.e., a first sub-region, a second sub-region, a third sub-region and a fourth sub-region, which are connected end to end, where projections of the first sub-region and the third sub-region in the preset plane are symmetric with respect to an X axis, and projections of the second sub-region and the fourth sub-region in the preset plane are symmetric with respect to a Y axis; the four heating units are respectively a first heating unit, a second heating unit, a third heating unit and a fourth heating unit, wherein projections of the first heating unit and the third heating unit in the preset plane are symmetrical about an X axis, projections of the second heating unit and the fourth heating unit in the preset plane are symmetrical about a Y axis, the first heating unit corresponds to the first subregion, the second heating unit corresponds to the second subregion, the third heating unit corresponds to the third subregion, and the fourth heating unit corresponds to the fourth subregion.
In other embodiments of the present application, the second heating device may further include five heating units, six heating units, or more heating units, so as to improve uniformity of heating effect at each position in the second region, which is not limited in the present application, as the case may be. Correspondingly, in this embodiment of the application, the second region of the wafer surface may further include five first sub-regions, a second sub-region, a third sub-region, a fourth sub-region, and a fifth sub-region, which are connected end to end, or the second region of the wafer surface may further include six first sub-regions, a second sub-region, a third sub-region, a fourth sub-region, a fifth sub-region, and a sixth sub-region, which are connected end to end, or the second region of the wafer surface may further include more sub-regions, which are connected end to end, as long as it is ensured that each sub-region corresponds to one heating unit. However, the present application is not limited thereto, and in other embodiments of the present application, at least two sub-regions correspond to one heating unit, or one sub-region corresponds to at least two heating units, as the case may be.
Optionally, in an embodiment of the present application, a projection of each of the at least two heating units in the preset plane may have a shape of a sector ring, a square, a rectangle, or a circle, which is not limited in this application, as the case may be. Wherein the fan ring is a part of a circular ring which is cut by a fan.
On the basis of any one of the above embodiments, in an embodiment of the present application, each of the at least two heating units is independently controlled, so that each heating unit can individually regulate and control the temperature of different sub-regions in the second region corresponding to the heating unit, thereby improving the accuracy of temperature regulation and control of different sub-regions of the second region. In other embodiments of the present application, at least two of the at least two heating units are controlled in a unified manner, as the case may be, in order to reduce the complexity of the plasma processing apparatus.
Accordingly, the present application also provides a plasma processing apparatus, as shown in fig. 4, including:
a cavity 10;
a lower electrode assembly 20 located in the cavity 10, wherein the lower electrode assembly 20 is the lower electrode assembly described in any one of the above.
The plasma processing apparatus using the lower electrode assembly provided by the embodiment of the present application includes an electrostatic chuck for adsorbing a wafer, a first heating device located on a side of the electrostatic chuck departing from the wafer and heating the electrostatic chuck, and a second heating device located outside the electrostatic chuck, wherein the first heating device has a heating effect on the first region greater than a heating effect on the second region, and the second heating device has a heating effect on the second region greater than a heating effect on the first region, so that the second heating device can be used to adjust a difference between the heating effects of the first heating device on the first region and the second region of the wafer surface, reduce a difference between a temperature of the first region and a temperature of the second region of the wafer surface, and improve etching uniformity of the first region and the second region of the wafer surface, thereby improving the etching uniformity of the surface of the wafer.
On the basis of the above embodiments, in an embodiment of the present application, a dimension of the electrostatic chuck along the first direction a is equal to a dimension of a wafer along the first direction a, in the embodiment of the present application, the second region wraps the first region, the second region is a region of the wafer corresponding to an outermost heating belt of the electrostatic chuck, and the second heating device is disposed outside the electrostatic chuck, so that the second region is closer to the second heating device than the first region, so that a heating effect of the second heating device on the second region is greater than a heating effect of the second heating device on the first region, so as to adjust a difference between heating effects of the first heating device on the first region and the second region of the wafer surface, and reduce a difference between a temperature of the first region of the wafer surface and a temperature of the second region, and improving the etching uniformity of the first area and the second area on the surface of the wafer, thereby improving the etching uniformity of the surface of the wafer.
In another embodiment of the present application, the dimension of the electrostatic chuck in the first direction a is smaller than the dimension of the wafer in the first direction a, in this embodiment, the second region wraps the first region, the projection of the first region on the electrostatic chuck coincides with the electrostatic chuck, and the second heating device is disposed outside the first heating device, so that the second region is closer to the second heating device than the first region, so that the heating effect of the second heating device on the second region is greater than the heating effect of the second heating device on the first region, so as to adjust the difference of the heating effects of the first heating device on the first region and the second region of the wafer surface, reduce the difference between the temperature of the first region and the temperature of the second region of the wafer surface, and improve the etching uniformity of the first region and the second region of the wafer surface, thereby improving the etching uniformity of the surface of the wafer.
In other optional embodiments of the present application, the dimension of the electrostatic chuck in the first direction a is smaller than the dimension of the wafer in the first direction a, the second region wraps the first region, the area of the projection of the first region on the electrostatic chuck is smaller than the area of the upper surface of the electrostatic chuck, and if the second region includes a region corresponding to the outermost heating band of the electrostatic chuck in the wafer in addition to a region corresponding to the projection of the wafer outside the electrostatic chuck, the present application is not limited thereto, and the size is determined as the case may be.
On the basis of any one of the above embodiments, in an embodiment of the present application, the second heating device is annularly disposed outside the electrostatic chuck, so that the effect of heating at each position in the second region is relatively uniform, and the etching uniformity at each position in the second region is improved.
Based on any of the above embodiments, in one embodiment of the present application, and as further shown in fig. 1, the lower electrode assembly includes a focus ring 5, and the focus ring 5 is disposed around the outside of the electrostatic chuck 1 to focus plasma onto the wafer 2.
On the basis of the above embodiment, in an embodiment of the present application, the focus ring 5 has thermal conductivity, and optionally, the second heating device 4 may be located at the bottom of the focus ring 5, so that the second heating device 4 heats the focus ring 5, and then the thermal conductivity of the focus ring 5 annularly disposed outside the electrostatic chuck 1 is utilized to transfer heat to the second region of the wafer 2, so as to heat the second region, thereby utilizing the thermal conductivity of the focus ring to improve uniformity of heated effect at each position in the second region. In addition, in the embodiment of the present application, the second heating device 4 is located at the bottom of the focus ring 5, so that the second heating device 4 is convenient to install and has less influence on the chamber of the plasma processing apparatus.
In yet another embodiment of the present application, the second heating device 4 may be disposed on top of the focus ring 5, such that the second heating device 4 is closer to the second region of the wafer, thereby improving the heating efficiency of the second heating device 4 on the wafer 2.
In another embodiment of the present application, the second heating device 4 may be disposed on an outer sidewall of the focus ring 5 far away from the electrostatic chuck 1, so that the second heating device 4 heats the focus ring 5, and the heat conductivity of the focus ring 5 annularly disposed on the outer side of the electrostatic chuck 1 transfers the heat to the second region of the wafer 2, so as to improve the uniformity of the heating effect at each position in the second region by using the heat conductivity of the focus ring, and simultaneously reduce the distance between the second heating device and the second region of the wafer, and improve the heated effect of the second region. In other embodiments of the present application, the second heating device 4 may also be disposed on the inner sidewall of the focus ring 5 close to the electrostatic chuck 1, so that the second heating device 4 is closer to the second region of the wafer, thereby improving the heating efficiency of the second heating device 4 on the wafer 2.
Optionally, in an embodiment of the present application, the second heating device is fixedly connected to the focus ring, and the second heating device is in direct contact with at least a partial region of the focus ring, so as to improve the thermal conductivity between the second heating device and the focus ring. Optionally, in an embodiment of the present application, the second heating device is fixed to the focus ring by screws, which is not limited in this application, as the case may be.
On the basis of any one of the above embodiments, in an embodiment of the present application, the second heating device includes a heating unit, a projection of the heating unit on a predetermined plane is in an annular shape, and a projection of the electrostatic chuck on the predetermined plane is located in an area surrounded by an inner ring of the annular shape, so that a heated effect at each position in the second area is relatively uniform, and thus uniformity of the heated effect at each position in the second area is improved. The preset plane is parallel to the plane of the electrostatic chuck.
It should be noted that, in an embodiment of the present application, a projection of the heating unit on the predetermined plane may be in a closed ring shape, and in other embodiments of the present application, a projection of the heating unit on the predetermined plane may also be in an unclosed ring shape, such as an opening on the ring shape, which is not limited in this application, as the case may be.
Optionally, on the basis of the foregoing embodiment, in an embodiment of the present application, the wafer is a circular wafer, the electrostatic chuck is a circular electrostatic chuck, and correspondingly, a projection of the second heating device on a preset plane is in a shape of a circular ring, so that distances between positions in the second area, which are the same as the center of the wafer, and the second heating device are the same, and uniformity of heating at different positions in the circumferential direction of the second area by the second heating device is improved. However, this is not limited in this application, and in other embodiments of the present application, when the wafer and the electrostatic chuck are square, the projection of the heating unit on the preset plane is in the shape of a square ring, as long as it is ensured that the shape defined by the projection of the heating unit on the preset plane matches the shapes of the electrostatic chuck and the wafer.
It should be noted that, when the wafer and the electrostatic chuck are circular, the first direction is a radial direction of the wafer or the electrostatic chuck; when the wafer and the electrostatic chuck are square, the first direction is the side length direction of the wafer or the electrostatic chuck, or the diagonal direction of the wafer or the electrostatic chuck; when the wafer and the electrostatic chuck are in an irregular shape, the first direction may be a maximum dimension direction of the wafer or the electrostatic chuck, or may be any direction in a plane where the wafer or the electrostatic chuck is located.
In another embodiment of the present application, the second heating device includes at least two heating units, and the at least two heating units are uniformly distributed along the circumferential direction of the electrostatic chuck, so that the heated effect at each position in the second area is more uniform, and the uniformity of the heated effect at each position in the second area is improved.
In the embodiment of the present application, when the electrostatic chuck is circular, the circumferential direction of the electrostatic chuck refers to the circumferential direction of the electrostatic chuck, and when the electrostatic chuck is square, the circumferential direction of the electrostatic chuck refers to the extending direction of the boundary line of the electrostatic chuck, such as the circumferential direction of the square.
On the basis of the implementation, in an embodiment of the present application, the electrostatic chuck is a circular electrostatic chuck, the wafer is a circular wafer, and accordingly, the second heating device includes that the at least two heating units are in a circular ring shape in the projection of the preset plane, so that the distance between the second region and each position where the center of the wafer is the same as the distance between the second heating devices, and the uniformity of the heating effect of the second heating device on different positions in the circumferential direction of the second region is improved. The shape defined by the projections of the at least two heating units included in the second heating device in the preset plane is matched with the shapes of the electrostatic chuck and the wafer.
It should be noted that the electrostatic chuck and the heating unit may or may not be in direct contact, and the application is not limited thereto as long as the heating unit is not in direct contact with the wafer. In a preferred embodiment of the present application, a gap is formed between the electrostatic chuck and the heating unit in a plane of the wafer, so as to prevent the heating unit from directly contacting the wafer, thereby affecting a balance of the wafer attraction by the electrostatic chuck.
The following description will be given by taking the electrostatic chuck as a circular electrostatic chuck and the wafer as a circular wafer.
As shown in fig. 2, based on any of the above embodiments, in an embodiment of the present application, the second heating device 4 includes three heating units 41, and projections of the three heating units 41 on a predetermined plane are uniformly distributed on a circular ring concentric with the electrostatic chuck, so that distances between positions in the second region that are the same from the center of the wafer and the second heating device are the same, and uniformity of heating of different positions in the circumferential direction of the second region by the second heating device is improved, wherein the predetermined plane is parallel to a plane of the electrostatic chuck.
On the basis of any of the above embodiments, in an embodiment of the present application, the second heating device 4 includes four heating units 41, wherein projections of two heating units 41 in a predetermined plane are symmetric about an X axis, and projections of two other heating units 41 in the predetermined plane are symmetric about a Y axis, wherein the predetermined plane is parallel to a plane in which the electrostatic chuck is located, and the X axis and the Y axis are located in the predetermined plane and perpendicular to each other, so that distances between positions in the second region that are the same from the center of the wafer and the second heating device are the same, and uniformity of heating by the second heating device to different positions in the circumferential direction of the second region is improved.
Alternatively, in an embodiment of the present application, the projections of the two heating units 41 symmetrical about the X axis in the preset plane and the projections of the two heating units 41 symmetrical about the Y axis in the preset plane may be located on the same circular ring, as shown in fig. 3. In other embodiments of the present application, the projections of the two heating units symmetrical about the X axis in the preset plane and the projections of the two heating units 41 symmetrical about the Y axis in the preset plane may also be located on different circular rings, which is not limited in this application, as the case may be.
It should be noted that, in the embodiment of the present application, the second region of the wafer surface may include at least two sub-regions. Specifically, in this embodiment of the present application, the second region of the wafer surface includes four sub-regions, i.e., a first sub-region, a second sub-region, a third sub-region and a fourth sub-region, which are connected end to end, where projections of the first sub-region and the third sub-region in the preset plane are symmetric with respect to an X axis, and projections of the second sub-region and the fourth sub-region in the preset plane are symmetric with respect to a Y axis; the four heating units are respectively a first heating unit, a second heating unit, a third heating unit and a fourth heating unit, wherein projections of the first heating unit and the third heating unit in the preset plane are symmetrical about an X axis, projections of the second heating unit and the fourth heating unit in the preset plane are symmetrical about a Y axis, the first heating unit corresponds to the first subregion, the second heating unit corresponds to the second subregion, the third heating unit corresponds to the third subregion, and the fourth heating unit corresponds to the fourth subregion.
In other embodiments of the present application, the second heating device may further include five heating units, six heating units, or more heating units, so as to improve uniformity of heating effect at each position in the second region, which is not limited in the present application, as the case may be. Correspondingly, in this embodiment of the application, the second region of the wafer surface may further include five first sub-regions, second sub-regions, third sub-regions, fourth sub-regions, and fifth sub-regions, which are connected end to end, or the second region of the wafer surface may further include six first sub-regions, second sub-regions, third sub-regions, fourth sub-regions, fifth sub-regions, and sixth sub-regions, which are connected end to end, or the second region of the wafer surface may further include more sub-regions, which are connected end to end, as the case may be.
Optionally, in an embodiment of the present application, a projection of each of the at least two heating units in the preset plane may have a shape of a sector ring, a square, a rectangle, or a circle, which is not limited in this application, as the case may be. Wherein the fan ring is a part of a circular ring which is cut by a fan.
On the basis of any one of the above embodiments, in an embodiment of the present application, each of the at least two heating units is independently controlled, so that each heating unit can individually regulate and control the temperature of different sub-regions in the second region corresponding to the heating unit, thereby improving the accuracy of temperature regulation and control of different sub-regions of the second region. In other embodiments of the present application, at least two of the at least two heating units are controlled in a unified manner, as the case may be, in order to reduce the complexity of the plasma processing apparatus.
On the basis of any of the foregoing embodiments, in an embodiment of the present application, the plasma processing apparatus further includes a first temperature control device, which controls a heating temperature of the first heating device to adjust a temperature of the electrostatic chuck, so as to control a temperature of the first region of the wafer.
On the basis of any of the foregoing embodiments, in an embodiment of the present application, the plasma processing apparatus further includes a second temperature control device that controls a heating temperature of the second heating device, where the second temperature control device includes at least one temperature control unit, and the number of the temperature control units is less than or equal to the number of the heating units.
On the basis of any one of the above embodiments, in an embodiment of the present application, the number of the temperature control units is equal to the number of the heating units, and the temperature control units are in one-to-one correspondence with the heating units, so that the heating units in the at least two heating units are independently controlled, and thus each heating unit can independently regulate and control the temperature of different sub-areas in the second area corresponding to the heating unit, and further the accuracy of regulating and controlling the temperature of different sub-areas in the second area is improved.
In the embodiment of the application, in the etching process of the plasma processing equipment, when the situation of uneven etching occurs at a certain position of the second area, the temperature of the heating unit corresponding to the sub-area where the position is located can be controlled to adjust the temperature of the sub-area, so that the etching rate of the sub-area is adjusted, the etching rate of the sub-area is consistent with the etching rate of other areas, and the etching uniformity of different areas on the surface of a wafer is improved.
In other embodiments of the present application, in order to reduce the complexity of the plasma processing apparatus, the number of the temperature control units is smaller than the number of the heating units, so that at least two of the at least two heating units are controlled by the same temperature control unit, as the case may be.
Optionally, in an embodiment of the present application, the second temperature control device controls the maximum heating temperature that can be reached by the second heating device to be greater than the maximum heating temperature that can be reached by the first temperature control device to control the first heating device, and the second temperature control device controls the minimum heating temperature that can be reached by the second heating device to be less than the minimum heating temperature that can be reached by the first temperature control device to control the first heating device, so as to increase the heating temperature range that can be reached by the second heating device to control the second heating device, so that the temperature of the second region and the temperature substrate of the first region can be made to be consistent by the second heating device no matter how different the heating effects of the first heating device on the first region and the second region are; however, the present application is not limited thereto, and in other embodiments of the present application, the maximum heating temperature that the second temperature control device can control the second heating device to reach may be equal to the maximum heating temperature that the first temperature control device can control the first heating device to reach, the minimum heating temperature that the second temperature control device can control the second heating device to reach may be equal to the minimum heating temperature that the first temperature control device can control the first heating device to reach, or the maximum heating temperature that the second temperature control device can control the second heating device to reach may be less than the maximum heating temperature that the first temperature control device can control the first heating device to reach, the minimum heating temperature that the second temperature control device can control the second heating device to reach may be greater than the minimum heating temperature that the first temperature control device can control the first heating device to reach, as the case may be.
To sum up, in the plasma processing apparatus and the lower electrode assembly provided in the embodiment of the present application, in addition to the electrostatic chuck for adsorbing a wafer and the first heating device for heating the electrostatic chuck, the second heating device is further provided outside the electrostatic chuck, wherein the first heating device is greater than the heating effect of the second region to the heating effect of the first region, and the second heating device is greater than the heating effect of the first region to the heating effect of the second region, so that the second heating device can be used to adjust the difference between the heating effects of the first heating device on the first region and the second region of the wafer surface, reduce the difference between the temperature of the first region and the temperature of the second region of the wafer surface, and improve the etching uniformity of the first region and the second region of the wafer surface, thereby improving the etching uniformity of the surface of the wafer.
It is noted that, in the present application, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
All parts in the specification are described in a mode of combining parallel and progressive, each part is mainly described to be different from other parts, and the same and similar parts among all parts can be referred to each other.
In the above description of the disclosed embodiments, features described in various embodiments in this specification can be substituted for or combined with each other to enable those skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (12)
1. A lower electrode assembly, comprising:
the electrostatic chuck adsorbs a wafer, and the surface of the wafer comprises a first area and a second area, wherein the distance from each point of the first area to the center of the wafer is less than the distance from each point of the second area to the center of the wafer;
the first heating device is positioned on one side, away from the wafer, of the electrostatic chuck and used for heating the electrostatic chuck, and the heating effect of the first heating device on the first area is greater than that of the second area;
and the second heating device comprises at least one heating unit, the second heating device is arranged outside the electrostatic chuck, and the effect of the second heating device on heating the second area is greater than that of the first area.
2. The lower electrode assembly of claim 1, wherein a dimension of the electrostatic chuck in a first direction is smaller than a dimension of the wafer in the first direction, the first direction being parallel to an upper surface of the electrostatic chuck and directed from a center of the upper surface of the electrostatic chuck to an edge of the electrostatic chuck.
3. The lower electrode assembly of claim 2, wherein the second region wraps around the first region, and a projection of the first region onto the electrostatic chuck coincides with the electrostatic chuck.
4. The lower electrode assembly of claim 1, further comprising a focus ring disposed outside the electrostatic chuck, wherein the second heating device is located at a bottom of the focus ring.
5. The lower electrode assembly of claim 1, wherein the second heating device comprises a heating unit, a projection of the heating unit on a predetermined plane is annular, and a projection of the electrostatic chuck on the predetermined plane is located in a region enclosed by an inner ring of the annular;
the preset plane is parallel to the plane of the electrostatic chuck.
6. The lower electrode assembly of claim 1, wherein the second heating device comprises at least two heating units evenly distributed circumferentially along the electrostatic chuck.
7. The lower electrode assembly of claim 6, wherein each of the at least two heating units is independently controlled.
8. The lower electrode assembly of claim 1, wherein the second heating device comprises four heating units, wherein projections of two of the heating units in a predetermined plane are symmetrical about an X-axis, and projections of two other of the heating units in the predetermined plane are symmetrical about a Y-axis;
the preset plane is parallel to the plane where the electrostatic chuck is located, and the X axis and the Y axis are located in the preset plane and are perpendicular to each other.
9. A plasma processing apparatus, comprising:
a cavity;
a lower electrode assembly located within the cavity, the lower electrode assembly being as claimed in any one of claims 1 to 8.
10. The plasma processing apparatus according to claim 9, further comprising a first temperature control device that controls a heating temperature of the first heating device.
11. The plasma processing apparatus according to claim 9, further comprising a second temperature control device that controls a heating temperature of the second heating device, wherein the second temperature control device includes at least one temperature control unit, and the number of the temperature control units is less than or equal to the number of the heating units.
12. The plasma processing apparatus of claim 11, wherein the number of the temperature control units is equal to the number of the heating units, and the temperature control units correspond to the heating units one to one.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021937100.4U CN213936112U (en) | 2020-09-07 | 2020-09-07 | Lower electrode assembly and plasma processing equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021937100.4U CN213936112U (en) | 2020-09-07 | 2020-09-07 | Lower electrode assembly and plasma processing equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN213936112U true CN213936112U (en) | 2021-08-10 |
Family
ID=77161511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021937100.4U Active CN213936112U (en) | 2020-09-07 | 2020-09-07 | Lower electrode assembly and plasma processing equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN213936112U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117672801A (en) * | 2023-12-05 | 2024-03-08 | 苏州恩腾半导体科技有限公司 | Temperature-controlled plasma etching system and temperature control method |
-
2020
- 2020-09-07 CN CN202021937100.4U patent/CN213936112U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117672801A (en) * | 2023-12-05 | 2024-03-08 | 苏州恩腾半导体科技有限公司 | Temperature-controlled plasma etching system and temperature control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9076828B2 (en) | Edge ring for a thermal processing chamber | |
| WO2016036496A1 (en) | Susceptor and pre-heat ring for thermal processing of substrates | |
| KR20220025146A (en) | Thermal processing susceptor | |
| JPH03108323A (en) | Heating method for heater assembly and substrate | |
| KR20130141506A (en) | Chamber lid heater ring assembly | |
| KR102277859B1 (en) | Apparatus for self centering preheat member | |
| CN213936112U (en) | Lower electrode assembly and plasma processing equipment | |
| KR20210087547A (en) | Edge ring temperature and bias control | |
| US7033445B2 (en) | Gridded susceptor | |
| TWM448051U (en) | Electrostatic chuck capable of sectionally regulating temperature | |
| CN113981531B (en) | Preheating ring and substrate processing equipment | |
| WO2021072200A1 (en) | Wafer heater with backside and integrated bevel purge | |
| US20220319899A1 (en) | Pedestal heater for Spatial Multi-Wafer Processing Tool | |
| JP2014527716A (en) | Substrate support unit, substrate processing apparatus, and method for manufacturing substrate support unit | |
| US20110052159A1 (en) | Apparatus for uniform thermal processing | |
| US7262390B2 (en) | Apparatus and adjusting technology for uniform thermal processing | |
| TWI817056B (en) | Lower electrode assembly, plasma processing device using same and working method thereof | |
| JPH10150050A (en) | Circular heating plate of heating chamber for manufacturing semiconductor device | |
| JPH0227715A (en) | Heating stage for vapor growth device | |
| CN104576484A (en) | Tray structure in semiconductor equipment | |
| CN111383882B (en) | Plasma processing apparatus and substrate holder for the same | |
| JP2565156Y2 (en) | Semiconductor manufacturing apparatus and wafer mounting table thereof | |
| CN113838780A (en) | Wafer partition heating device and control method | |
| TWI771714B (en) | Plasma processing device | |
| JPS60263428A (en) | Susceptor for vapor growth device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |