CN113496862B - Plasma reactor and radio frequency power distribution adjusting method thereof - Google Patents
Plasma reactor and radio frequency power distribution adjusting method thereof Download PDFInfo
- Publication number
- CN113496862B CN113496862B CN202010255484.XA CN202010255484A CN113496862B CN 113496862 B CN113496862 B CN 113496862B CN 202010255484 A CN202010255484 A CN 202010255484A CN 113496862 B CN113496862 B CN 113496862B
- Authority
- CN
- China
- Prior art keywords
- ring
- conductive base
- plasma reactor
- variable impedance
- substrate
- 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
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32431—Constructional details of the reactor
- H01J37/32623—Mechanical discharge control means
- H01J37/32642—Focus rings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
- H01J37/32082—Radio frequency generated discharge
- H01J37/32174—Circuits specially adapted for controlling the RF discharge
- H01J37/32183—Matching circuits
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/67005—Apparatus not specifically provided for elsewhere
- H01L21/67011—Apparatus for manufacture or treatment
- H01L21/67017—Apparatus for fluid treatment
- H01L21/67063—Apparatus for fluid treatment for etching
- H01L21/67069—Apparatus for fluid treatment for etching for drying etching
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
- H01L22/10—Measuring as part of the manufacturing process
- H01L22/12—Measuring as part of the manufacturing process for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
- H01L22/20—Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
- H01L22/26—Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/32—Processing objects by plasma generation
- H01J2237/33—Processing objects by plasma generation characterised by the type of processing
- H01J2237/334—Etching
- H01J2237/3343—Problems associated with etching
- H01J2237/3348—Problems associated with etching control of ion bombardment energy
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Plasma & Fusion (AREA)
- Analytical Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Drying Of Semiconductors (AREA)
- Plasma Technology (AREA)
Abstract
A plasma reactor and a method of adjusting radio frequency power distribution, the plasma reactor comprising: the reaction cavity is internally provided with a conductive base, the conductive base is connected to a first radio frequency power supply device through a first matcher circuit, an electrostatic chuck is arranged on the conductive base, the electrostatic chuck adsorbs a substrate to be treated, and a plasma environment is formed on the substrate to be treated; the insertion ring is arranged on the periphery of the conductive base; a focus ring disposed over the insert ring, the focus ring surrounding the electrostatic chuck and being exposed to a plasma environment; the coupling ring comprises a bottom ring and a protruding part, the protruding part is positioned between the insertion ring and the conductive base, the bottom ring is positioned below the insertion ring, and the gap between the inner wall of the insertion ring and the outer wall of the conductive base is more than 0.02 mm and less than 10 mm; a device board located below the conductive base; a wire having a first end electrically connected to the conductive base or device board and a second end electrically connected to the insert ring, the variable impedance device being connected in series on the wire. The plasma reactor is RF-tunable and can reduce arcing.
Description
Technical Field
The invention relates to the technical field of semiconductor processing, in particular to a plasma reactor and a radio frequency power distribution adjusting method thereof.
Background
Semiconductor chips are increasingly being used in a variety of electronic devices, where semiconductor chip processing requires the use of a large number of plasma reactors for performing plasma etching or chemical vapor deposition processes on a substrate to be processed. Fig. 1a is a typical plasma reactor, comprising: the reaction chamber 10, the top of the reaction chamber 10 includes an insulating material window, an inductance coil 7 is arranged above the insulating material window, the inductance coil 7 is connected to a high-frequency (13 MHz and above) radio frequency power supply 6 through a radio frequency matcher 8, and at least one reaction gas source 11 sends reaction gas into the reaction chamber through a valve 95 and a gas nozzle 90 to form plasma to etch the substrate. The lower part of the inner part of the reaction chamber 10 comprises a base 20, and the base 20 is connected to a bias radio frequency source 4 through a bias radio frequency power matcher 5, wherein the low frequency radio frequency output by the bias radio frequency source 4 is generally lower than 2MHz. The susceptor 20 is usually anodized by surface oxidation of an aluminum alloy to form an anodized layer, or an insulating corrosion-resistant material layer is coated on the surface of the aluminum alloy to avoid a series of problems such as particle contamination caused by corrosion by etching gas in the reaction chamber 10. An electrostatic chuck 21 is provided on the upper surface of the base 20 for fixing a substrate 22. The lower periphery of the base 20 further includes a raised step portion on which the coupling ring 25 is disposed, and the rf energy distribution coupled to the edge region of the substrate is changed by selecting the material and shape and size of the coupling ring 25. A focus ring 23 is disposed above the coupling ring 25, wherein the inner wall of the focus ring 23 surrounds and abuts the substrate 22 and the upper surface of the focus ring 23 is exposed to the overlying plasma. Since the focus ring 23 is exposed to the plasma for a long time, the surface material of the focus ring 23 must be corroded after a period of plasma treatment, so the height of the focus ring 23 will be reduced, the reduced height will seriously affect the distribution and morphology of the sheath layer at the edge region of the substrate, and the difference between the etching rate and etching direction (EDGE TILTING) at the edge region of the substrate and the central region of the substrate will easily be caused, the processing uniformity of the substrate will be reduced, and the yield of the final chip will be affected.
Fig. 1b is a schematic diagram of low frequency rf power distribution in the plasma processor of fig. 1a, please refer to fig. 1b, in which the input low frequency rf power P0 couples P1 'power to the substrate via an equivalent capacitor C11 between the base 20 and the substrate 22 (see fig. 1 a), and simultaneously couples P2' to the focus ring 25 via an equivalent capacitor C12 between the base 20 and the coupling ring 25 and the focus ring 23. Where the value of C12 is difficult to adjust, P2 'will be much smaller than P1' and the power ratio is difficult to adjust.
In addition, with the existing plasma reactor, the arc discharge is serious, so that a new plasma reactor is needed to be developed in the industry to dynamically and precisely adjust the rf power distribution of the low-frequency rf power in the center of the substrate and the edge area of the substrate, thereby improving the uniformity of the substrate processing process and reducing the arc discharge phenomenon. Optimally, the adjusting device needs to have a simple structure and low cost, and can be applied to various plasma processing devices.
Disclosure of Invention
The invention provides a plasma reactor, which can simply and effectively adjust the radio frequency power of the edge area of a substrate, compensate the inclined etching (EDGE TILTING) of the edge of the substrate caused by the loss of a focusing ring in long-term use, and lighten the arc discharge.
The invention discloses a plasma reactor, comprising: the reaction chamber is internally provided with a conductive base, the conductive base is connected to a radio frequency power supply device through a matcher circuit, the conductive base is provided with an electrostatic chuck, the upper surface of the electrostatic chuck is used for adsorbing a substrate to be treated, and a plasma environment is arranged in the reaction chamber above the substrate to be treated; an insert ring disposed around the periphery of the conductive base; a focus ring disposed above the insert ring, the focus ring surrounding the electrostatic chuck and being exposed to the plasma environment; the coupling ring comprises a bottom ring and a protruding part, the protruding part is positioned between the insertion ring and the conductive base, the bottom ring is positioned below the insertion ring and the protruding part, and a gap between the inner side wall of the insertion ring and the outer side wall of the conductive base is more than 0.02 mm and less than 10 mm; a device board located below the conductive base; a wire having a first end electrically connected to the conductive base or device board and a second end electrically connected to the insert ring, the variable impedance device being connected in series on the wire.
Optionally, the frequency range of the radio frequency signal output by the radio frequency power supply device is as follows: 10 KHz-300 MHz.
Optionally, the conductive base and the coupling ring further have a transmission pin hole penetrating the conductive base and the coupling ring; an adapter and a transmission pin are sequentially connected in series on the lead between the variable impedance device and the insertion ring, the transmission pin is electrically connected with the insertion ring, the transmission pin is positioned in the transmission pin hole, and an insulating sleeve is sleeved outside the transmission pin; the adapter is located below the equipment board.
Optionally, an annular radio frequency buffer member is further arranged between the variable impedance device and the adapter, the annular radio frequency buffer member is located below the equipment board, the variable impedance device is electrically connected with the annular radio frequency buffer member through a wire, and the number of the adapters is at least 1; when the number of the adapters is plural, the adapters are uniformly distributed along the circumferential direction of the annular radio frequency buffer and are electrically connected with the annular distributor, and each of the adapters is electrically connected to different areas of the insert ring through different transmission pins.
Optionally, the variable impedance device is located on a central axis of the insert ring, and the number of the adapters is at least 1; when the number of the adapters is plural, the variable impedance device is electrically connected to each of the adapters by a plurality of wires, respectively, and each of the adapters is electrically connected to a different region of the insert ring by a different transmission pin.
Optionally, the outer sidewall of the conductive base includes at least one layer of plasma resistant insulating material.
Optionally, the material of the insulating material layer resistant to plasma corrosion includes: alumina or yttria.
Optionally, the variable impedance device includes at least one variable impedance device or variable inductance.
Optionally, the variable impedance device is located in an atmosphere below the equipment panel.
Optionally, the side wall of the reaction cavity is composed of a grounding metal, the grounding metal surrounds the electric field shielding space, and the variable impedance device is located in the electric field shielding space.
Optionally, the material of the coupling ring includes: at least one of silicon oxide or aluminum oxide.
Optionally, a gap is provided between the protruding portion and the conductive base.
Optionally, the gap between the protrusion and the conductive base is less than 3 millimeters.
Optionally, the material of the focusing ring includes: a conductor material or a semiconductor material, wherein no insert ring is arranged between the focusing ring and the coupling ring; a second end of the wire is electrically connected to the focus ring.
Optionally, a conductive layer is coated at the bottom of the focusing ring, and no insertion ring is arranged between the focusing ring and the coupling ring; the second end of the wire is electrically connected with the conductive layer.
Optionally, the insert ring is embedded in the coupling ring or in the focusing ring.
Optionally, the method further comprises: the gas spray head is positioned at the top of the reaction cavity, is arranged opposite to the conductive base and is used for conveying reaction gas into the reaction cavity, and the reaction gas forms plasma under the action of the radio frequency power supply device.
Correspondingly, the invention also provides a method for adjusting the radio frequency power distribution of the plasma reactor, which comprises the following steps: and a substrate etching effect monitoring step: detecting the etching effect of the edge area of the substrate, if the inclination angle of the etching hole at the edge of the substrate is within the preset angle range, continuing to execute the step of detecting the etching effect of the substrate, and if the inclination of the etching hole at the edge of the substrate exceeds the preset angle, entering the step of adjusting the variable impedance device; a variable impedance adjustment step: and adjusting the impedance parameter of the variable impedance device to change the radio frequency power transmitted to the focusing ring at the edge of the substrate, and entering the substrate etching effect monitoring step again.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
In the plasma reactor provided by the invention, a first end of a wire is electrically connected to the conductive base or the equipment board, a second end of the wire is electrically connected to the insert ring, and a variable impedance device is connected in series on the wire. Because the gap between the inner side wall of the insert ring and the outer side wall of the conductive base is larger than 0.02 mm, the gap between the inner side wall of the insert ring and the outer side wall of the conductive base is not too small, and the radio frequency power coupled to the focusing ring is not too large, so that the radio frequency power transmitted to the focusing ring can be effectively regulated by regulating the capacitance value of the variable impedance device, thereby changing the sheath height above the focusing ring, enabling the central region of the substrate to be processed and the sheath with the same height above the focusing ring, and further being beneficial to improving etching uniformity. Meanwhile, the gap between the inner side wall of the insert ring and the outer side wall of the conductive base is smaller than 10 mm, so that the gap between the inner side wall of the insert ring and the outer side wall of the conductive base is not too large, the difference of the phase difference between the radio frequency power reaching the central area of the substrate to be processed and the phase difference reaching the upper part of the focusing ring is smaller, and the arc discharge is reduced.
Drawings
FIG. 1a is a schematic diagram of a prior art plasma processor;
FIG. 1b is a schematic diagram of the low frequency RF power distribution in the plasma processor of FIG. 1 a;
FIG. 2 is a schematic diagram of a plasma processor according to the present invention;
FIG. 3 is a perspective view of one of the tuning mechanisms in the plasma processor of FIG. 2;
FIG. 4 is a schematic cross-sectional view of FIG. 3 taken along line A-A 1;
FIG. 5 is a schematic diagram of the RF power distribution in the plasma processor of FIG. 2;
FIG. 6 is a top view of another conditioning apparatus in the plasma processor of FIG. 2;
FIG. 7 is a schematic diagram of another embodiment of a plasma processor of the present invention;
FIG. 8 is a schematic diagram of a further embodiment of a plasma processor of the present invention;
FIG. 9 is a schematic diagram of a further embodiment of a plasma processor of the present invention;
Fig. 10 is a flow chart of a method of adjusting the rf power distribution of a plasma processor according to the present invention.
Detailed Description
The invention proposes a new plasma reactor comprising: the reaction chamber is internally provided with a conductive base, the conductive base is connected to a radio frequency power supply device through a matcher circuit, the conductive base is provided with an electrostatic chuck, the upper surface of the electrostatic chuck is used for adsorbing a substrate to be treated, and a plasma environment is arranged in the reaction chamber above the substrate to be treated; an insert ring disposed around the periphery of the conductive base; a focus ring disposed above the insert ring, the focus ring surrounding the electrostatic chuck and being exposed to the plasma environment; the coupling ring comprises a bottom ring and a protruding part, the protruding part is positioned between the insertion ring and the conductive base, the bottom ring is positioned below the insertion ring and the protruding part, and a gap between the inner side wall of the insertion ring and the outer side wall of the conductive base is more than 0.02 mm and less than 10 mm; a device board located below the conductive base; a wire having a first end electrically connected to the conductive base or device board and a second end electrically connected to the insert ring, the variable impedance device being connected in series on the wire. The plasma reactor is RF-tunable and reduces the risk of arcing.
In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.
Fig. 2 is a schematic diagram of a plasma processor according to the present invention.
Referring to fig. 2, a conductive base 120 is disposed at the bottom of the reaction chamber 100, the conductive base 120 is electrically connected to the rf power device 40 through a matcher 50, an electrostatic chuck 121 is disposed on the conductive base 120, the upper surface of the electrostatic chuck 121 is used for adsorbing a substrate 122 to be processed, and a plasma environment is disposed in the reaction chamber 100 above the substrate 122 to be processed; an insert ring 127 disposed around the periphery of the conductive base 120; a focus ring 123 disposed above the insert ring 127, the focus ring 123 surrounding the electrostatic chuck 121 and being exposed to the plasma environment; a coupling ring 125 including a bottom ring 125a and a protrusion 125b, the protrusion 125b being located between the insert ring 127 and the conductive base 120, the bottom ring 125a being located under the insert ring 127 and the protrusion 125b, a gap between an inner sidewall of the insert ring 127 and an outer sidewall of the conductive base 120 being greater than 0.02 mm and less than 10 mm; a device board 126 located below the conductive base 120; a wire 128 having a first end electrically connected to the conductive base 120 or the device board 126 and a second end electrically connected to the insert ring 127, the variable impedance device 124 being connected in series with the wire 128.
In this embodiment, the plasma reactor is a capacitively coupled plasma processor (CCP), the capacitively coupled plasma processor further comprising: the gas spray head 130 is located at the top of the reaction chamber 100, and the gas spray head 130 is disposed opposite to the conductive base 120 and is used for delivering a reaction gas into the reaction chamber 100, where the reaction gas forms a plasma under the action of the radio frequency power supply device 40; the gas showerhead 130 serves as an upper electrode of a capacitively coupled plasma processor and the conductive pedestal 120 serves as a lower electrode.
In other embodiments, the plasma reactor is an inductively coupled plasma out-of-processor (ICP) comprising: an insulating window positioned at the top of the reaction cavity; and an inductance coil positioned on the insulation window.
In the capacitively coupled plasma processor, high frequency power (13.56 Mhz or more, such as 27Mhz, 60Mhz, etc.) may be supplied to the conductive base 120 as the lower electrode, at which time the upper electrode is electrically grounded, or the high frequency power may be supplied to the upper electrode for converting the reaction gas into plasma for performing plasma treatment of the substrate to be treated. The capacitively coupled plasma processor further includes: low frequency power is applied to the lower electrode for deflecting the plasma toward the surface of the wafer to be processed.
In this embodiment, the insert ring 127 is disposed above the bottom ring 125a, the focus ring 123 is disposed on the insert ring 127, one end of the wire 128 is electrically connected to the insert ring 127, the other end is electrically connected to the conductive base 120, and a variable impedance device 124 is further connected in series between the wires 128. Since the gap between the inner sidewall of the insert ring 127 and the outer sidewall of the conductive base 120 is greater than 0.02 mm, so that the gap between the inner sidewall of the insert ring 127 and the outer sidewall of the conductive base 120 is not too small, the amount of coupling of the rf power to the focus ring 123 is not too large, and thus the rf power delivered to the focus ring 123 can be adjusted by adjusting the capacitance value of the variable impedance device 124; meanwhile, the gap between the inner side wall of the insert ring and the outer side wall of the conductive base is smaller than 10 mm, so that the gap between the inner side wall of the insert ring 127 and the outer side wall of the conductive base 120 is not too large, which is beneficial to reducing the discharge phenomenon between the insert ring 127 and the conductive base 120. And, after the gap between the insert ring 127 and the conductive base 120 is used to accommodate the protruding portion 125b of the coupling ring 125, there is still a small gap between the protruding portion 125b and the conductive base 120, specifically, the gap between the protruding portion 125b and the conductive base 120 is less than 3mm, and the gap between the protruding portion 125b and the conductive base 120 is also beneficial to allow enough space for the protruding portion 125b and the conductive base 120 to expand when the temperature changes.
The protruding portion 125b is disposed between the insert ring 127 and the conductive base 120, so that a gap between the protruding portion 125 and the conductive base 120 is smaller, which is beneficial to reducing arcing.
In addition, the protruding portion 125b is disposed between the insert ring 127 and the conductive base 120, so that the distance between the insert ring 127 and the conductive base 120 includes not only the gap between the protruding portion 125b and the conductive base 120, but also the top dimension of the protruding portion 125b and the height of the protruding portion 125b, so that when the gap between the protruding portion 125b and the conductive base 120 changes slightly, the distance difference between the insert ring 127 and the conductive base 120 is smaller at different phase angles, and the capacitance difference between the insert ring 127 and the conductive base 120 is smaller at different phase angles, thereby being beneficial to reducing the asymmetry problem at different phase angles.
The insert ring 127 is made of a conductive material such as aluminum or graphite. The insert ring 127 may be a complete ring or may be divided into a plurality of arc segments, which collectively surround the insert ring 127, and a gap or isolation member exists between each arc segment to electrically isolate each other.
The variable impedance device 124 includes a hybrid circuit of variable inductance and capacitance or other components to achieve the function of impedance adjustment, for example: motor capacitance.
The variable impedance device 124 is disposed in a vacuum space below the conductive base 120, and the variable impedance device 124 may be disposed in an atmosphere below the equipment plate 126 in the reaction chamber, so long as two ends of the conductive wire 128 pass through the equipment plate 126, the variable impedance device 124 disposed in the atmosphere is easier to dissipate heat and is easier to maintain. In addition, the variable impedance device 124 is disposed immediately below the equipment board 126 such that the length of the wire 128 is short to ensure that the phases of the radio frequency signals applied to the conductive base 120 and to the insert ring 127 are substantially the same such that substantially the same dc potential is achieved in the center and edge regions of the substrate, allowing for uniform processing of the center and edge regions of the substrate. The reaction chamber wall 100 is composed of a grounded metal surrounding an electric field shielding space, and the variable impedance device 124 can prevent the variable impedance device 124 from radiating a low frequency electric field to the outside environment even in the atmosphere under the equipment plate 126 within the electric field shielding space of the reaction chamber. The variable impedance device 124 is small and inexpensive and has a simple installation structure, as opposed to having to provide fluid access lines and mechanical drive means within the coupling ring 125.
The plasma processor further comprises: the variable impedance device 124, the adapter and the transmission pin constitute an adjustment device, which is described in detail below in connection with fig. 3 and 4:
Referring to fig. 3 and 4, fig. 4 is a schematic cross-sectional view of fig. 3 along line A-A1, wherein the conductive base 120 and the coupling ring 125 further have a transmission pin hole 140 (see fig. 4) passing through the conductive base 120 and the coupling ring 125; the wire 128 between the variable impedance device 124 and the insert ring 127 is further connected in series with an adapter 141 and a transmission pin 142 electrically connected with the variable impedance device 124, the transmission pin 142 is electrically connected with the insert ring 127, the transmission pin 142 is positioned in the transmission pin hole 140, and an insulating sleeve 146 (see fig. 4) is sleeved outside the transmission pin 142; the adapter 141 is located below the device board 126.
Fig. 5 is a schematic diagram of rf power distribution in the plasma processor of fig. 2.
The equivalent capacitance C21 coupled to the substrate 122 to be processed is large regardless of whether the frequency of the rf power supply device 40 is large or small, but:
When the frequency of the rf power supply device is 10 KHz-13.56 MHz, the equivalent capacitance C22 from the conductive base 120 to the focus ring 123 via the sidewall corrosion-resistant insulating layer and the coupling ring 125 is smaller, so that the rf power with larger power cannot be transmitted. The variable impedance device 124 does not transfer rf power by conventional coupling but directs rf power in the pedestal 120 directly to the lower surface of the target focus ring 123 by direct electrical connection, thus bypassing the impedance that severely affects low frequency rf power coupling. The variable impedance device 124 can automatically select a value range and an adjustment range according to needs, and the variable impedance device 124 can effectively adjust the rf power delivered to the focus ring 123 by simply adjusting the capacitance value, so as to change the height of the sheath layer above the focus ring 123, so that the central area of the substrate to be processed and the sheath layer above the focus ring 123 have the same height, thereby being beneficial to improving etching uniformity.
When the frequency of the rf power supply device is 10 KHz-13.56 MHz, in one embodiment, the number of adapters 141 is 1, the number of transmission pins 142 is also 1, and the variable impedance device 124 is electrically connected to the insert ring 127 sequentially through the adapters 141 and the transmission pins 142. Because the frequency of the rf power supply device is smaller, the rf power is input to the insert ring 127 through the 1 adapter 141 and the transmission pin 142, the rf power drops less, and the requirement can be satisfied, and the problem of asymmetry in different phase angles does not occur.
When the frequency of the rf power supply device is 10 KHz-13.56 MHz, in another embodiment, the number of the adapters 141 is plural, the number of the transmission pins 142 is plural, and one adapter 141 is electrically connected to different areas of the insert ring 127 through 1 transmission pin 142. The plurality of adapters 141 and the transmission pins 142 provide radio frequency power input to the insert ring 127 with less radio frequency power drop, which is more satisfactory, and which is less prone to asymmetry at different phase angles.
In this embodiment, when the number of the adapters 141 is plural, an annular rf buffer 145 (see fig. 3) is further included between the variable impedance device 124 and the adapters 141, the annular rf buffer 145 is located below the device board 126 (see fig. 2), the variable impedance device 124 is located below an edge area of the device board 126, and the variable impedance device 124 is electrically connected to the annular rf buffer 145 through a wire 128, and the annular rf buffer 145 is electrically connected to the adapters 141. The plurality of adapters 141 are uniformly distributed along the circumference of the annular rf buffer 145, and the annular rf buffer 145 is used for buffering the rf.
When the frequency of the rf power supply device is 13.56MHz to 300MHz, the equivalent capacitance C22 from the conductive base 120 to the focus ring 123 through the sidewall corrosion resistant insulating layer and the coupling ring 125 is larger, but not too large, so that the size of the rf power supplied to the focus ring 123 can be adjusted by adjusting the size of the variable impedance device 124, so as to change the height of the sheath layer at the focus ring 123, so that the center area of the substrate to be processed has the sheath layer with the same height as the sheath layer above the focus ring 123, thereby being beneficial to improving etching uniformity.
When the frequency of the rf power supply device is 13.56MHz to 300MHz, the number of the adapters 141 is plural, the number of the transmission pins 142 is plural, and one adapter 141 is electrically connected to the insert ring 127 through 1 transmission pin 142. The plurality of adapters 141 and the transmission pins 142 provide radio frequency power input to the insert ring 127 with less radio frequency power drop, which can meet the requirements without asymmetry problems at different phase angles.
In one embodiment, the variable impedance device 124 and the adapters 141 further include an annular rf buffer 145, the annular rf buffer 145 is located below the device board 126, the variable impedance device 124 is electrically connected to the annular rf buffer 145 through a wire 128, the plurality of adapters 141 are uniformly distributed along the circumference of the annular rf buffer, and the annular rf buffer 145 is used for buffering rf.
It should be noted that: when the number of the variable impedance devices 124 is 1, all the adapters 141 are electrically connected to the variable impedance devices 124; when the number of the variable impedance devices 124 is plural, and the number of the adapters 141 is plural, different adapters 141 may be electrically connected to different variable impedance devices 124.
Meanwhile, the gap between the inner side wall of the insert ring 127 and the outer side wall of the conductive base 120 is smaller than 10mm, so that the difference between the phase difference of the rf power reaching the central area of the substrate 122 to be processed and the phase difference of the rf power reaching the upper portion of the focus ring 123 is smaller, which is beneficial to reducing the risk of arc discharge.
Fig. 6 is a top view of another tuning device in the X-direction of the 2-plasma processor.
Referring to fig. 6, the variable impedance device 124 is located on the central axis of the insert ring 127 (see fig. 2), the number of the adapters 141 is plural, and the variable impedance device 124 is electrically connected to each of the adapters 141 through a plurality of wires 128.
In other embodiments, the number of adapters is 1.
In this embodiment, if there is enough space below the equipment plate 126 to place the adjusting device, the adjusting device is placed on the central axis of the insert ring 127, the variable impedance device 124 is electrically connected to each of the adapters 141 through a plurality of wires 128, and the difference in phase difference between the variable impedance device 124 and each of the adapters 141 is smaller, which is advantageous for further reducing the risk of arcing.
Fig. 7 is a schematic view of another embodiment of a plasma processor according to the present invention.
Referring to fig. 7, a conductive layer 190 is coated on the bottom of the focusing ring 123, and one end of the variable impedance device 124 is connected to the conductive base 120, and the other end is connected to the conductive layer 190.
In this embodiment, since the gap between the conductive layer 190 and the conductive base 120 is not too small, so that the rf power coupled to the focus ring is not too large, the rf power delivered to the focus ring 123 can be effectively adjusted by adjusting the capacitance value of the variable impedance device 124, so that the height of the sheath layer above the focus ring 123 is changed, and the central area of the substrate to be processed and the sheath layer above the focus ring 123 have the same height, thereby improving etching uniformity. Meanwhile, the gap between the inner sidewall of the conductive layer 190 and the outer sidewall of the conductive base 120 is smaller than 10 mm, so that the difference between the phase difference of the rf power reaching the central region of the substrate to be processed and the phase difference of the rf power reaching the upper portion of the focus ring 123 is smaller, which is beneficial to reducing the risk of arc discharge.
Fig. 8 is a schematic structural view of a further embodiment of the plasma processor of the present invention.
In this embodiment, the materials of the focusing ring 123' include: the focus ring 123 'is made of a conductive material (e.g., aluminum, etc.) or a semiconductor material (e.g., silicon or silicon carbide, etc.), and thus the insert ring 127 is not required to be additionally provided, so that the second end of the wire 128 is directly connected to the focus ring 123'.
In this embodiment, since the gap between the focus ring 123' and the conductive base 120 is not too small, so that the rf power coupled to the focus ring 123' is not too large, the rf power delivered to the focus ring 123' can be effectively adjusted by adjusting the capacitance value of the variable impedance device 124, and the height of the sheath layer above the focus ring 123' is changed, so that the center region of the substrate to be processed and the sheath layer above the focus ring 123' have the same height, which is beneficial for improving the etching uniformity. Meanwhile, the gap between the inner side wall of the focusing ring 123 'and the outer side wall of the conductive base 120 is smaller than 10 mm, so that the difference between the phase difference of the rf power reaching the central area of the substrate to be processed and the phase difference of the rf power reaching the upper portion of the focusing ring 123' is smaller, which is beneficial to reducing the risk of arc discharge.
Fig. 9 is a schematic view of a further embodiment of a plasma processor according to the present invention.
In this embodiment, the insert ring 127 is embedded in the upper half of the coupling ring 125 made of insulating material, so that the equivalent capacitance coupled from the lower electrode 120 to the focus ring 123 is much smaller than the variable impedance device 124 shown in fig. 2, but is much larger than the C12 in the prior art shown in fig. 1, so that the rf power supplied to the focus ring 123 can be adjusted by adjusting the size of the variable impedance device 124 to change the height of the sheath layer at the focus ring 123, so that the central region of the substrate to be processed has the same height of the sheath layer over the focus ring, thereby improving etching uniformity.
In other embodiments, the insert ring is embedded in the focus ring.
Fig. 10 is a flow chart of a method of adjusting the rf power distribution of a plasma processor according to the present invention.
Referring to fig. 10, step S1: and a substrate etching effect monitoring step: detecting the etching effect of the edge area of the substrate, if the inclination angle of the etching hole at the edge of the substrate is within the preset angle range, continuing to execute the step of detecting the etching effect of the substrate, and if the inclination of the etching hole at the edge of the substrate exceeds the preset angle, entering the step of adjusting the variable impedance device; step S2: a variable impedance adjustment step: and adjusting the impedance parameter of the variable impedance device to change the radio frequency power transmitted to the focusing ring at the edge of the substrate, and entering the substrate etching effect monitoring step again.
When the variable impedance device is in an initial value in the initial state of the reaction cavity, after long-time plasma treatment is carried out, the difference between the treatment effect and the center of the edge region of the substrate is detected, the controller can automatically change the numerical value of the variable impedance device in real time according to the set parameters, so that more low-frequency radio frequency power is transmitted to the focusing ring at the edge of the substrate, the height of the sheath layer at the focusing ring is changed, the center region of the substrate to be treated is provided with the sheath layer with the same height as the sheath layer above the focusing ring, and the etching uniformity is improved. The most typical treatment effect is the inclination (EDGE TILTING) of the etching holes in the edge area of the substrate, once the upper surface of the focusing ring is not worn to reduce the height, the sheath layer in the edge area is correspondingly reduced, and therefore, the etching holes in the edge area of the substrate can be inclined to an inward direction. And continuously detecting the effect of substrate processing until the uniformity of the processing effect is offset beyond a preset threshold value again, and adjusting the capacitance value of the variable impedance device again according to the detected data. Therefore, the invention can keep the stability of the plasma effect for a long time without changing the focusing ring for a long time and only changing the parameter setting of the variable impedance device without needing a liquid pipeline or a mechanical driving device in a vacuum environment.
While the present invention has been described in detail through the foregoing description of the preferred embodiment, it should be understood that the foregoing description is not to be considered as limiting the invention. Many modifications and substitutions of the present invention will become apparent to those of ordinary skill in the art upon reading the foregoing. Accordingly, the scope of the invention should be limited only by the attached claims.
Claims (18)
1. A plasma reactor, comprising:
the reaction chamber is internally provided with a conductive base, the conductive base is connected to a radio frequency power supply device through a matcher circuit, the conductive base is provided with an electrostatic chuck, the upper surface of the electrostatic chuck is used for adsorbing a substrate to be treated, and a plasma environment is arranged in the reaction chamber above the substrate to be treated;
an insert ring surrounding the periphery of the conductive base, wherein a gap between an inner side wall of the insert ring and an outer side wall of the conductive base is greater than 0.02 mm and less than 10 mm;
a focus ring disposed above the insert ring, the focus ring surrounding the electrostatic chuck and being exposed to the plasma environment;
A coupling ring including a bottom ring and a protrusion, the protrusion being located between the insert ring and the conductive base, the bottom ring being located below the insert ring and the protrusion;
a device board located below the conductive base;
A wire having a first end electrically connected to the conductive base or device board and a second end electrically connected to the insert ring, the variable impedance device being connected in series on the wire.
2. The plasma reactor of claim 1 wherein said rf power supply means outputs an rf signal in a frequency range of: 10 KHz-300 MHz.
3. The plasma reactor of claim 1 wherein said conductive base and coupling ring further have a transfer pin hole extending therethrough; an adapter and a transmission pin are sequentially connected in series on the lead between the variable impedance device and the insertion ring, the transmission pin is electrically connected with the insertion ring, the transmission pin is positioned in the transmission pin hole, and an insulating sleeve is sleeved outside the transmission pin; the adapter is located below the equipment board.
4. The plasma reactor of claim 3 wherein an annular radio frequency buffer is further disposed between said variable impedance device and said adapter, said annular radio frequency buffer being positioned below said equipment plate, said variable impedance device being electrically connected to said annular radio frequency buffer by a wire, said number of adapters being at least 1; when the number of the adapters is plural, the adapters are uniformly distributed along the circumferential direction of the annular radio frequency buffer and are electrically connected with the annular distributor, and each of the adapters is electrically connected to different areas of the insert ring through different transmission pins.
5. The plasma reactor of claim 3 wherein said variable impedance device is located on a central axis of said insert ring, said number of adapters being at least 1; when the number of the adapters is plural, the variable impedance device is electrically connected to each of the adapters by a plurality of wires, respectively, and each of the adapters is electrically connected to a different region of the insert ring by a different transmission pin.
6. The plasma reactor of claim 1 wherein the outer sidewall of said conductive base comprises at least one layer of insulating material that is resistant to plasma erosion.
7. The plasma reactor of claim 6 wherein said layer of plasma resistant insulating material comprises: alumina or yttria.
8. The plasma reactor of claim 1 wherein said variable impedance means comprises at least one variable capacitance or variable inductance.
9. The plasma reactor of claim 1 wherein said variable impedance device is located in an atmospheric environment below said equipment plate.
10. The plasma reactor of claim 1 wherein said reaction chamber side wall is comprised of a grounded metal surrounding an electric field shielding space, said variable impedance device being located within said electric field shielding space.
11. The plasma reactor of claim 1 wherein said coupling ring material comprises: at least one of silicon oxide or aluminum oxide.
12. The plasma reactor of claim 1 wherein said projection has a gap with said conductive base.
13. The plasma reactor of claim 12 wherein the gap between said projection and the conductive base is less than 3 millimeters.
14. The plasma reactor of claim 1 wherein said focus ring material comprises: a conductor material or a semiconductor material, wherein no insert ring is arranged between the focusing ring and the coupling ring; a second end of the wire is electrically connected to the focus ring.
15. The plasma reactor of claim 1 wherein the bottom of the focus ring is coated with a conductive layer, no insert ring being disposed between the focus ring and the coupling ring; the second end of the wire is electrically connected with the conductive layer.
16. The plasma reactor of claim 1 wherein said insert ring is embedded in a coupling ring or in a focus ring.
17. The plasma reactor of claim 1 further comprising: the gas spray head is positioned at the top of the reaction cavity, is arranged opposite to the conductive base and is used for conveying reaction gas into the reaction cavity, and the reaction gas forms plasma under the action of the radio frequency power supply device.
18. A method of adjusting the rf power distribution of a plasma reactor according to any one of claims 1 to 17, comprising the steps of:
And a substrate etching effect monitoring step: detecting the etching effect of the edge area of the substrate, if the inclination angle of the etching hole at the edge of the substrate is within the preset angle range, continuing to execute the step of detecting the etching effect of the substrate, and if the inclination of the etching hole at the edge of the substrate exceeds the preset angle, entering the step of adjusting the variable impedance device;
a variable impedance adjustment step: and adjusting the impedance parameter of the variable impedance device to change the radio frequency power transmitted to the focusing ring at the edge of the substrate, and entering the substrate etching effect monitoring step again.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010255484.XA CN113496862B (en) | 2020-04-02 | 2020-04-02 | Plasma reactor and radio frequency power distribution adjusting method thereof |
| TW110110057A TWI767618B (en) | 2020-04-02 | 2021-03-19 | Plasma reactor and method for adjusting radio frequency power distribution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010255484.XA CN113496862B (en) | 2020-04-02 | 2020-04-02 | Plasma reactor and radio frequency power distribution adjusting method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113496862A CN113496862A (en) | 2021-10-12 |
| CN113496862B true CN113496862B (en) | 2024-09-06 |
Family
ID=77994070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010255484.XA Active CN113496862B (en) | 2020-04-02 | 2020-04-02 | Plasma reactor and radio frequency power distribution adjusting method thereof |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN113496862B (en) |
| TW (1) | TWI767618B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114373665B (en) * | 2021-12-22 | 2025-03-07 | 江苏鲁汶仪器股份有限公司 | An ion beam etching system with endpoint detection function |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN211350572U (en) * | 2020-04-02 | 2020-08-25 | 中微半导体设备(上海)股份有限公司 | Plasma reactor |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200626020A (en) * | 2001-12-13 | 2006-07-16 | Tokyo Electron Ltd | Ring mechanism, and plasma processor using the ring mechanism |
| KR101171422B1 (en) * | 2008-06-19 | 2012-08-06 | 도쿄엘렉트론가부시키가이샤 | Focus ring and plasma process apparatus |
| JP5399151B2 (en) * | 2008-10-27 | 2014-01-29 | 東京エレクトロン株式会社 | Inductively coupled plasma processing apparatus, plasma processing method, and storage medium |
| CN201465987U (en) * | 2009-07-03 | 2010-05-12 | 中微半导体设备(上海)有限公司 | Plasma treatment device |
| JP6276919B2 (en) * | 2013-02-01 | 2018-02-07 | 株式会社日立ハイテクノロジーズ | Plasma processing apparatus and sample stage |
| CN104752143B (en) * | 2013-12-31 | 2017-05-03 | 中微半导体设备(上海)有限公司 | Plasma treating device |
| US10002782B2 (en) * | 2014-10-17 | 2018-06-19 | Lam Research Corporation | ESC assembly including an electrically conductive gasket for uniform RF power delivery therethrough |
| CN108206143B (en) * | 2016-12-16 | 2020-09-25 | 中微半导体设备(上海)股份有限公司 | Plasma processor, etching uniformity adjusting system and method |
| US11424104B2 (en) * | 2017-04-24 | 2022-08-23 | Applied Materials, Inc. | Plasma reactor with electrode filaments extending from ceiling |
| CN109216144B (en) * | 2017-07-03 | 2021-08-06 | 中微半导体设备(上海)股份有限公司 | Plasma reactor with low-frequency radio frequency power distribution adjusting function |
| CN109994355B (en) * | 2017-12-29 | 2021-11-02 | 中微半导体设备(上海)股份有限公司 | Plasma reactor with low-frequency radio frequency power distribution adjusting function |
-
2020
- 2020-04-02 CN CN202010255484.XA patent/CN113496862B/en active Active
-
2021
- 2021-03-19 TW TW110110057A patent/TWI767618B/en active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN211350572U (en) * | 2020-04-02 | 2020-08-25 | 中微半导体设备(上海)股份有限公司 | Plasma reactor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113496862A (en) | 2021-10-12 |
| TW202139254A (en) | 2021-10-16 |
| TWI767618B (en) | 2022-06-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109216144B (en) | Plasma reactor with low-frequency radio frequency power distribution adjusting function | |
| TWI771541B (en) | Plasma Reactor with Low Frequency RF Power Distribution Adjustment | |
| US6887340B2 (en) | Etch rate uniformity | |
| KR100900585B1 (en) | Focus ring and plasma processing apparatus | |
| KR100752800B1 (en) | Substrate holding structure for semiconductor processing, and plasma processing device | |
| CN110197787B (en) | Plasma processing apparatus and method for manufacturing mounting table | |
| KR100455091B1 (en) | Plasma Treatment Equipment | |
| KR102218686B1 (en) | Plasma processing apparatus | |
| KR101283830B1 (en) | Improvement of etch rate uniformity using the independent movement of electrode pieces | |
| KR101480738B1 (en) | Annular baffle | |
| US5846331A (en) | Plasma processing apparatus | |
| CN211350572U (en) | Plasma reactor | |
| CN211507566U (en) | Plasma processing device with radio frequency power distribution adjusting function | |
| CN113496862B (en) | Plasma reactor and radio frequency power distribution adjusting method thereof | |
| JP5064708B2 (en) | Plasma processing equipment | |
| KR20210140927A (en) | Large Area Dry Etching Device | |
| CN113013009A (en) | Plasma processing device with radio frequency power distribution adjusting function and adjusting method | |
| TW202232566A (en) | Plasma processing apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |