CN113851366A

CN113851366A - Inductively coupled plasma apparatus and method of operating the same

Info

Publication number: CN113851366A
Application number: CN202011229741.9A
Authority: CN
Inventors: 廖耕颍; 董怀仁; 林子平; 陈柏仁; 邱兆村; 吴泰进; 林玉珠; 任啟中; 周俊伟
Original assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
Current assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
Priority date: 2020-11-06
Filing date: 2020-11-06
Publication date: 2021-12-28

Abstract

An inductively coupled plasma apparatus and method of operating the same, the inductively coupled plasma apparatus includes a chamber, a coil, and a wafer pedestal. The reaction chamber is provided with a body and a dielectric plate body, wherein the body and the dielectric plate body define a space, the dielectric plate body is provided with a groove, and the groove faces the space. The coil is arranged on the surface of the dielectric plate body, which faces away from the space. The wafer pedestal is arranged in the space.

Description

Inductively coupled plasma apparatus and method of operating the same

Technical Field

The present disclosure relates to an inductively coupled plasma apparatus and a method of operating the same.

Background

In recent years, semiconductor integrated circuits (semiconductor integrated 1-d circuits) have undergone exponential growth. With advances in integrated circuit materials and design techniques, multiple generations of integrated circuits are produced, with each generation having smaller, more complex circuits than the previous generation. As integrated circuits are developed, the functional density (i.e., the number of interconnected devices per chip area) typically increases as the geometries (i.e., the smallest elements or lines that can be produced during the fabrication process) shrink.

Generally, such a downscaling process provides the benefits of increased production efficiency and reduced manufacturing cost, however, the downscaling process also increases the complexity of manufacturing and producing integrated circuits. In order to realize these advances, corresponding developments in integrated circuit fabrication processes and manufacturing equipment are needed. In one example, a plasma etching process is performed on a wafer using a plasma manufacturing system. In a plasma etching process, a plasma generates volatile etching products by chemical reaction between elements of a material being etched from a wafer surface and reactive species generated by the plasma.

Disclosure of Invention

Some embodiments of the present disclosure provide an inductively coupled plasma apparatus including a reaction chamber, a coil, and a wafer pedestal. The reaction chamber is provided with a body and a dielectric plate body, wherein the body and the dielectric plate body define a space, the dielectric plate body is provided with a groove, and the groove faces the space. The coil is arranged on the surface of the dielectric plate body, which faces away from the space. The wafer pedestal is arranged in the space.

Some embodiments of the present disclosure provide an inductively coupled plasma apparatus including a reaction chamber, a coil, and a wafer pedestal. The reaction chamber is provided with a body and a dielectric plate body, wherein the body and the dielectric plate body define a space, the dielectric plate body comprises a first convex part, a second convex part and at least one concave part, the concave part is positioned between the first convex part and the second convex part, and the thickness of the first convex part and the thickness of the second convex part are larger than that of the concave part. The coil is disposed on a surface of the dielectric plate body facing away from the space, wherein the coil overlaps the second protrusion in a direction perpendicular to the surface of the dielectric plate body. The wafer pedestal is arranged in the space.

Some embodiments of the present disclosure provide a method of operating an inductively coupled plasma apparatus. The method comprises the following steps: introducing a first protective gas into a space of a reaction chamber, wherein the reaction chamber has a body and a dielectric plate defining the space, wherein the dielectric plate has a groove facing the space; performing a first plasma process after introducing the first protective gas into the space of the reaction chamber to form a first protective layer on an inner surface of the reaction chamber; after the first protective layer is formed, a wafer is placed on a wafer base; introducing a process gas into the space of the reaction chamber; performing a second plasma process on the wafer after introducing the process gas into the space of the reaction chamber; removing the wafer from the wafer pedestal; and performing a cleaning process to remove the first passivation layer.

Drawings

Aspects of the present disclosure can be understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that the various features are not drawn to scale as is standard in industry practice. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1A is a schematic diagram of an inductively coupled plasma apparatus in accordance with some embodiments of the present disclosure;

FIG. 1B is a schematic cross-sectional view of a dielectric plate and a coil of the inductively coupled plasma apparatus of FIG. 1A;

FIG. 1C is a schematic top view of a dielectric plate of the inductively coupled plasma apparatus of FIG. 1A;

FIG. 1D is a schematic top view of the coil of the inductively coupled plasma apparatus of FIG. 1A;

fig. 2 is a cross-sectional view of a dielectric plate and a coil in accordance with some embodiments of the present disclosure;

fig. 3 is a cross-sectional view of a dielectric plate and a coil in accordance with some embodiments of the present disclosure;

fig. 4A is a cross-sectional view of a dielectric plate and a coil in accordance with some embodiments of the present disclosure;

FIG. 4B is a top view of the dielectric plate of FIG. 4A;

FIG. 4C is a schematic top view of the coil of FIG. 4A;

fig. 5A is a cross-sectional view of a dielectric plate and a coil in accordance with some embodiments of the present disclosure;

FIG. 5B is a top view of the dielectric plate of FIG. 5A;

FIG. 5C is a schematic top view of the coil of FIG. 5A;

fig. 6A-6D are schematic diagrams of a method of operating an inductively coupled plasma apparatus at various stages according to some embodiments of the present disclosure.

[ notation ] to show

100 inductively coupled plasma apparatus

110 reaction chamber

110S closed space

112, main body

112GO gas outlet

114 dielectric plate body

114O gas inlet

114R groove

114D depth

114T thickness

114A upper surface

114B lower surface

114BA: a portion of the lower surface

114BB part of the lower surface

114BC part of the lower surface

116 plasma baffle

120 wafer pedestal

130 coil

130A first coil

130B second coil

140 gas conveyer

180 supporting seat

W is wafer

ES plasma power supply

R1-R5 regions

GS gas supply source

PG is a gas

FG process gas

CG gas

PL protective film

FL byproduct film

WLA wire

WLB wire

WL is wire

PIA input terminal

PIB input terminal

PI input terminal

POA output terminal

POB output terminal

PO output end

Detailed Description

The following disclosure is intended to provide many different embodiments, or examples, for implementing different features of the provided subject matter. Many components and arrangements are described below in order to simplify the present disclosure with regard to specific embodiments. These embodiments are, of course, merely examples and are not intended to limit the disclosure. For example, the statement that a first feature is formed over a second feature includes various embodiments, which encompass both a first feature being in direct contact with the second feature, and additional features being formed between the first and second features, such that direct contact between the two is not made. Moreover, in various embodiments, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and is not intended to in any way limit the scope of the various embodiments and/or configurations discussed.

Furthermore, spatially relative terms, such as "lower," "below," "beneath," "under," "upper," "over," and the like, may be used herein to describe a relationship of an element or feature to another element or feature as illustrated. In use or operation, the spatially relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. Alternatively, the devices may be rotated (90 degrees or at other angles) and the spatially relative descriptors used herein interpreted accordingly.

In inductively coupled plasma apparatus, a dielectric plate is disposed between the induction coil and the plasma, such as at the periphery or top of the chamber. A radio frequency current is input into the coil by using a radio frequency source to generate an induced radio frequency magnetic field, and then a radio frequency electric field which is opposite to the radio frequency current is induced in the cavity by the radio frequency magnetic field. Therefore, the radio frequency source can be responsible for generating plasma through inductive coupling and controlling the density of the plasma. Quartz or ceramic materials are selected as dielectric plate bodies, so that energy provided by a radio frequency source can be effectively introduced into electrons in the cavity.

Fig. 1A is a schematic diagram of an inductively coupled plasma apparatus 100 in accordance with some embodiments of the present disclosure. In some embodiments, the inductively coupled plasma apparatus 100 is operable to perform a plasma etching process, such as plasma etching of metals, dielectrics, semiconductors, and/or masking materials (mask materials) from the surface of the wafer W. In some embodiments, the inductively coupled plasma apparatus 100 is operable to perform a deposition process, such as plasma depositing metal, dielectric, semiconductor and/or masking materials on the surface of the wafer W. In some embodiments, the inductively coupled plasma apparatus 100 is operable to perform a plasma process (treatment), such as plasma processing of metal, dielectric, semiconductor and/or masking material on the surface of the wafer W.

In some embodiments, the inductively coupled plasma apparatus 100 includes a reaction chamber 110, a wafer pedestal 120, a coil 130, and a gas delivery 140. In some embodiments, the reaction chamber 110 includes a body 112 and a dielectric window 114. The body 112 and the dielectric plate 114 define a closed space 110S of the chamber 110. In some embodiments, the enclosed space 110S of the reaction chamber 110 is insulated from the outside environment and can be maintained in a suitable state, such as a vacuum or a pressure lower than atmospheric pressure.

In some embodiments, the wafer pedestal 120 is disposed in the reaction chamber 110 and is used to support the wafer W. The wafer pedestal 120 may include an electrostatic chuck (not shown) and/or a clamping ring (not shown) to hold the wafer W during processing. The wafer pedestal 120 may also include cooling and/or heating elements (not shown) for controlling the temperature of the wafer pedestal 120. The wafer pedestal 120 may also provide a backside gas to the wafer W to increase thermal conduction between the wafer W and the wafer pedestal 120. In some embodiments, the material of the wafer pedestal 120 may be aluminum or other suitable material, and the lift pins may pass through the wafer pedestal 120 to secure the wafer W.

In some embodiments, the wafer pedestal 120 may further include an electrode coupled to a Radio Frequency (RF) generator. During plasma processing, an RF generator may be applied to the electrode to provide a bias to the process gas and help excite it into a plasma. In addition, the electrodes in the wafer pedestal 120 may maintain a plasma during the plasma processing process.

In some embodiments, the wafer W may be a silicon wafer. In other embodiments, the wafer W may include other elemental (or compound) semiconductor materials, alloy semiconductor materials, or other semiconductor chips, as well as other suitable substrates. For example, compound semiconductor materials include, but are not limited to, silicon carbide, gallium arsenide, gallium phosphide, indium arsenide, and/or indium antimonide. For example, alloy semiconductor materials include, but are not limited to, SiGe, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, and/or GaInAsP.

In some embodiments, the coil 130 is disposed on the upper surface 114A of the dielectric plate 114 facing away from the enclosed space 110S. The coil 130 is electrically coupled to a plasma power source ES. The plasma power ES is a radio frequency power source that provides current to the coil 130 to generate radio frequency energy. The dielectric plate 114 allows RF energy provided by the plasma power ES to be transmitted from the coil 130 to the enclosed space 110S of the chamber 110.

In some embodiments, the gas delivery device 140 is disposed on the dielectric plate 114. For example, the dielectric plate 114 has a gas inlet 114O connected to the gas delivery 140. The gas delivery unit 140 is connected to a gas supply source GS and is configured to provide process gases or other suitable gases (e.g., cleaning gases, shielding gases, etc.) to the enclosed space 110S of the chamber 110. In various embodiments, the process gas may be an etching gas, a deposition gas, a treatment gas, a carrier gas (e.g., nitrogen, argon, etc.), other suitable gases, and combinations thereof. The number of gas conveyors 140 may be one or more. In some embodiments, the injection port of the gas delivery device 140 and the gas inlet port 114O may be located substantially at the center of the coil 130. In some other embodiments, the injection port of the gas delivery device 140 and the gas inlet port 114O may be located off-center from the coil 130.

Thus, by using the coil 130 to transmit the RF energy to the enclosed space 110S of the chamber 110 through the dielectric plate 114, the process gas in the enclosed space 110S of the chamber 110 can form inductively coupled plasma, thereby performing etching, deposition, and/or other plasma processes on the wafer W.

In a plasma etching process, since the coils 130 are not uniformly arranged, the energy intensity distribution is different, and the generated plasma may have a non-uniform problem, thereby causing non-uniform etching, deposition, and/or other plasma processes on the wafer W. Furthermore, in some steps, a protective film (e.g., SiCl) is formed on the inner surface of the enclosed space 110S of the reaction chamber 110 (including the sidewall of the body 112, the lower surface of the dielectric plate 114, the surface of the wafer pedestal 120, etc.) by using plasma_xO_yOr high molecular polymer, etc.), the non-uniform plasma may result in non-uniform thickness of the protective film accumulated on the lower surface of the dielectric plate 114 due to the difference in energy intensity distribution. For example, current may be input from the inner and outer turns of the coil 130, such that the lower surface of the dielectric plate 114 may accumulate thicker protective film in and near the area where the inner turns of the coil 130 are located (e.g., the area between the inner and outer turns) than elsewhere. In the cleaning process, the thickness difference of the protective film may cause film residue, which is easy to peel off in the subsequent process to cause defects. Alternatively, the thickness difference of the protective film may cause the dielectric plate 114 to be damaged by etching of the cleaning gas during the cleaning process.

In some embodiments of the present disclosure, the dielectric plate 114 has protruding regions R1 and R3 and a recessed region R2, the regions R1 and R3 overlap with the coil 130 in a vertical direction (e.g., a direction perpendicular to the upper surface 114A of the dielectric plate 114), and the region R2 does not overlap with the coil 130 in the vertical direction. In other words, the dielectric plate body 114 has the groove 114R, and the groove 114R does not overlap with the coil 130 in the vertical direction. Thus, the regions R1 and R3 where the coil 130 is disposed face the thicker dielectric plate 114, which can reduce the energy intensity in the regions; the region R2 where no coil 130 is located faces the thinner dielectric plate 114, which increases the energy intensity in this region. Therefore, in the plasma process, the energy intensity distribution of the regions R1-R3 is uniform, and the generated plasma is more uniform. Thus, the uniformity of etching, deposition, and/or other plasma processes on the wafer W may be improved. In addition, when plasma is used to form a protective film on the inner surface of the closed space 110S of the reaction chamber 110, a protective film with a uniform thickness can be obtained, thereby preventing the residual film or the damage of the dielectric plate 114 caused by the cleaning process.

In some embodiments, the dielectric plate 114 may be made of quartz, ceramic, and/or dielectric material that is transparent to electromagnetic signals. The electromagnetic signal may be visible light, infrared light, ultraviolet light, X-ray light, and/or other electromagnetic signals. Electromagnetic signals through the dielectric plate 114 may be used to monitor process conditions in the enclosed space 110S, such as the presence of plasma, the presence of process gas species, and/or the presence of etch/deposition residue materials. The dielectric plate body 114 may comprise a suitable shape, such as a round plate, a square plate, or other suitable shape. In some embodiments, the dielectric plate 114 may be transparent. In some embodiments, the dielectric plate 114 may also be referred to as a dielectric window (dielectric window).

In some embodiments, the coil 130 may be a planar multi-turn helical coil (non-planar multi-turn helical coil), a non-planar multi-turn helical coil (planar multi-turn helical coil), or a coil with other suitable shapes. In some embodiments, the coil 130 may form a plasma antenna. In other embodiments, the plasma antenna may comprise a plurality of plates adapted for capacitively coupled plasma (capacitively coupled plasma). In other embodiments, the plasma may be sustained by other plasma antennas, such as an Electron Cyclotron Resonance (ECR), parallel plate, spiral (helicon), spiral resonator (helicon), or other plasma antennas. The plasma power ES may be, for example, a Radio Frequency (RF) power.

In some embodiments, the inductively coupled plasma apparatus 100 may further include a support base 180 for supporting the inner and outer coils of the coil 130. The material of the support base 180 may be ceramic or other suitable material. For example, the coil 130 may be fixed below the supporting base 180 by a suitable means (e.g., a screw, not shown). In some embodiments, the supporting base 180 may be fixed on the dielectric plate 114 by a suitable method, so as to fix the relative positions of the coil 130 and the dielectric plate 114. For example, in the present embodiment, the coil 130 may not contact the dielectric plate 114 by fixing the relative positions of the coil 130 and the dielectric plate 114 through the support base 180. Alternatively, in some other embodiments, the coil 130 may contact the upper surface 114A of the dielectric plate 114 by fixing the relative positions of the coil 130 and the dielectric plate 114 on the support base 180. In some embodiments, the support base 180 may also have an opening for the gas delivery device 140 to pass through.

In some embodiments, the body 112 may comprise a plurality of elements, which may be formed of aluminum, iron, stainless steel (e.g., inconel), alumina, or other suitable material. The sidewalls on both sides of the body 112 may be symmetrically designed to improve plasma uniformity. In some embodiments, the body 112 may include a gas outlet 112GO that may be connected to a suction pump (not shown) to evacuate air from the enclosed space 110S at a suitable point in time. In some embodiments, the inductively coupled plasma apparatus 100 may further include a plasma baffle 116 to confine the plasma symmetrically around the wafer W. In some embodiments, the gas and by-products can be conveyed through the plasma baffle 116 to the gas outlet 112GO for discharge. The plasma baffle 116 may be coated with an Alternative Chamber Material Evaluation (ACME) film, wherein the film may comprise an aluminum material, such as anodized aluminum, and the film may be configured to reduce defects.

In some embodiments, the gas delivery device 140 may comprise portions of plastic, stainless steel (e.g., inconel), and the material of the dielectric plate 114 (e.g., quartz or ceramic). The gas delivery device 140 may adjust the velocity of the input gas to improve plasma uniformity, which may improve critical dimension uniformity and etch uniformity.

Fig. 1B is a cross-sectional view of the dielectric plate 114 and the coil 130 of the inductively coupled plasma apparatus 100 of fig. 1A. Fig. 1C is a top view of the dielectric plate 114 of fig. 1A. Fig. 1D is a schematic top view of the coil 130 of fig. 1A.

In some embodiments, the thickness of the regions R1, R3 of the dielectric plate 114 is greater than the thickness of the region R2 of the dielectric plate 114. Specifically, the dielectric plate body 114 has a flat upper surface 114A and an uneven lower surface 114B, wherein the lower surface 114B can be divided into partial lower surfaces 114BA, 114BB, 114BC according to the regions R1, R2, R3. In some embodiments, the lower surfaces 114BA and 114BC of the regions R1 and R3 of the dielectric plate 114 are lower, and the lower surface 114BB of the region R2 of the dielectric plate 114 is higher. In some embodiments, portions of the lower surfaces 114BA and 114BC of the regions R1 and R3 of the dielectric plate 114 may be substantially flush.

In some embodiments, the bottom surface (e.g., a portion of the lower surface 114BB) of the groove 114R and the sidewall of the groove 114R may form a proper angle; the sidewalls of the recess 114R may be suitably angled with respect to portions of the lower surfaces 114BA, 114BC of the regions R1, R3. These included angles may be right, acute or obtuse. As such, the cross-section of the groove 114R may be rectangular, trapezoidal, inverted trapezoidal, or other suitable shape. In the present embodiment, the cross section of the groove 114R may be rectangular, wherein in the cross section, the width of the groove 114R along the direction of the upper surface 114A may be greater than or equal to the depth 114D, or the width of the groove 114R along the direction of the upper surface 114A may be smaller than the depth 114D. In some other embodiments, the cross-section of the groove 114R can be other suitable shapes.

In this embodiment, the depth 114D of the recess 114R may be about 1/4 times to about 1/2 times the overall thickness 114T of the dielectric plate body 114. If the depth 114D of the recess 114R is less than 1/4 times the thickness 114T of the dielectric plate 114, it may be difficult to achieve the goal of promoting plasma uniformity. If the depth 114D of the recess 114R is greater than 1/2 times the thickness 114T of the dielectric plate body 114, it may be difficult to maintain the mechanical strength of the dielectric plate body 114.

In some embodiments, the coil 130 includes a first coil 130A and a second coil 130B, which may be disposed around each other. At the same or different time points, the first coil 130A and the second coil 130B may be applied with currents of different directions and/or different magnitudes, respectively, to control the distribution or other characteristics of the induced plasma. In the present embodiment, the first coil 130A is of a segmented spiral design, wherein a wire WLA is also provided to connect a plurality of unconnected segments of the first coil 130A. Similarly, the second coil 130B is of a segmented, spiral design, wherein a wire WLB is also provided to connect a plurality of unconnected segments of the second coil 130B. The conductive lines WLA and WLB may be disposed above the coil 130 without interfering with the action of the coil 130 on the plasma below. In some embodiments, one current may enter from the input terminal PIA of the coil 130A and exit from the output terminal POA, and the other current may enter from the input terminal PIB of the coil 130B and exit from the output terminal POB, wherein the input terminals PIA and PIB may be disposed in the region R1, and the output terminals POA and POB may be disposed in the region R3.

In some embodiments of the present disclosure, the dielectric plate 114 may have a convex portion (e.g., the regions R1, R3) corresponding to the coil 130 and a concave portion (e.g., the region R2) not corresponding to the coil to improve the uniformity of the energy provided by the coil 130 through the dielectric plate 114 and thus the uniformity of the plasma. For example, in the present embodiment, the first coil 130A and the second coil 130B are designed as a spiral with separated inner and outer coils, and are connected to the inner and outer coils of the first coil 130A through a wire WLA, and the wire WLB is connected to the inner and outer coils of the second coil 130B.

In the present embodiment, the inner circles of the first coil 130A and the second coil 130B are disposed on the region R1, and the outer circles of the first coil 130A and the second coil 130B are disposed on the region R3, wherein the regions R1 and R3 are separated by the groove 114R. In other words, the recess 114R of the dielectric plate 114 is disposed in a closed ring shape, so that the regions R1 and R3 are not connected. A wire WLA connecting the inner ring to the outer ring of the first coil 130A across the groove 114R; the wire WLB connects the inner ring to the outer ring of the second coil 130B across the groove 114R. In other embodiments, the dielectric plate 114 may have other designs depending on the configuration of the coil 130, and is not limited to the embodiments illustrated herein.

Fig. 2 is a cross-sectional view of a dielectric plate and a coil in accordance with some embodiments of the present disclosure. This embodiment is similar to the embodiment of fig. 1A to 1D, with the difference that: in the present embodiment, the thickness of the projected region R3 is smaller than the thickness of the projected region R1. In other words, a portion of the lower surface 114BA of the region R1 of the dielectric plate body 114 may be lower than a portion of the lower surface 114BC of the region R3 of the dielectric plate body 114. This arrangement makes the height around the groove 114R different. Thus, the input ports PIA and PIB (see fig. 1D) face the region R1 of the thicker dielectric plate 114, and the output ports POA and POB (see fig. 1D) face the region R3 of the thinner dielectric plate 114, which is beneficial to improving the uniformity of plasma. Other details of this embodiment are substantially as described above and will not be further described herein.

Fig. 3 is a cross-sectional view of a dielectric plate and a coil in accordance with some embodiments of the present disclosure. This embodiment is similar to the embodiment of fig. 1A to 1D, with the difference that: in the present embodiment, the cross section of the groove 114R may be circular or elliptical. For example, a portion of the lower surface 114BB of the groove 114R may be semi-circular or arcuate. In other embodiments, the cross section of the groove 114R can be designed to have other suitable shapes according to requirements. Other details of this embodiment are substantially as described above and will not be further described herein.

Fig. 4A is a cross-sectional view of a dielectric plate 114 and a coil 130 according to some embodiments of the present disclosure. Fig. 4B is a top view of the dielectric plate 114 of fig. 4A. Fig. 4C is a schematic top view of the coil 130 of fig. 4A. This embodiment is similar to the embodiment of fig. 1A to 1D, with the difference that: in the present embodiment, the coil 130 is designed in a substantially continuous spiral shape, and the groove 114R of the dielectric plate 114 is provided in a non-closed loop shape to match the design of the coil 130.

For example, in the present embodiment, the coil 130 continuously extends from the region R1 to the region R3. To match the shape of the coil 130, a convex region R1 where the inner coil of the coil 130 is located is connected to a convex region R3 where the outer coil of the coil 130 is located. In other words, the regions R1 and R3 are not separated by the groove 114R, and the recessed region R2 between the regions R1 and R3 is disposed in a non-closed ring shape. By this design, the dielectric plate 114 may have a convex portion (e.g., the regions R1, R3) corresponding to the coil 130 and a concave portion (e.g., the region R2) not corresponding to the coil to improve the uniformity of the energy provided by the coil 130 through the dielectric plate 114 and thus the uniformity of the plasma.

In this embodiment, a current can enter from the input terminal PI of the coil 130 and exit from the output terminal PO, wherein the input terminal PI and the output terminal PO can be disposed in the region R1. In some embodiments, the outer ring of the coil 130 may be connected to the output terminal PO of the inner ring through a conducting wire WL. The conductive line WL may be disposed above the coil 130 without interfering with the action of the coil 130 on the plasma below. Other details of this embodiment are substantially as described above and will not be described herein.

Fig. 5A is a cross-sectional view of a dielectric plate 114 and a coil 130 according to some embodiments of the present disclosure. Fig. 5B is a top view of the dielectric plate 114 of fig. 5A. Fig. 5C is a schematic top view of the coil 130 of fig. 5A. This embodiment is similar to the embodiment of fig. 1A to 1D, with the difference that: in this embodiment, the first coil 130A and the second coil 130B respectively include three separate spiral segments, such as an inner coil, a middle coil, and an outer coil, wherein the inner coil, the middle coil, and the outer coil of the first coil 130A are connected through a wire WLA, and the inner coil, the middle coil, and the outer coil of the second coil 130B are connected through a wire WLB.

In the present embodiment, the inner, middle and outer rings of the first and

second coils

130A and 130B are respectively disposed in the regions R1, R3 and R5 protruded from the dielectric plate 114. The dielectric plate body 114 also has recessed regions R2, R4 to separate the regions R1, R3, R5. In other words, the dielectric plate 114 includes two annular grooves 114R. By this design, the dielectric plate 114 may have protrusions (e.g., regions R1, R3, R5) corresponding to the coil 130 and recesses (e.g., regions R2, R4) not corresponding to the coil to improve the uniformity of the energy provided by the coil 130 through the dielectric plate 114 and thus the uniformity of the plasma.

In some embodiments, one current may enter from the input terminal PIA of the first coil 130A and exit from the output terminal POA, and the other current may enter from the input terminal PIB of the second coil 130B and exit from the output terminal POB, where the input terminals PIA and PIB may be disposed in the region R1 and the output terminals POA and POB may be disposed in the region R5. In the present embodiment, one wire WLA crosses over one groove 114R to connect the inner coil to the middle coil of the first coil 130A, and the other wire WLA crosses over the other groove 114R to connect the middle coil to the outer coil of the first coil 130A. Similarly, one wire WLB connects the inner to middle turns of the second coil 130B across one notch 114R, and the other wire WLB connects the middle to outer turns of the second coil 130B across the other notch 114R. The conductive lines WLA and WLB may be disposed above the coil 130 (see the configuration of the conductive lines WL in FIG. 4A) without interfering with the action of the coil 130 on the plasma below. Other details of this embodiment are substantially as described above and will not be described herein.

Fig. 6A-6D are schematic diagrams of a method of operating an inductively coupled plasma apparatus 100 at various stages according to some embodiments of the present disclosure. This description is intended by way of example only and is not intended to further limit what is claimed. It should be understood that additional steps may be added before, during, and after the steps of fig. 6A-6D, and that some of the steps mentioned below may be replaced or eliminated for another portion of the method embodiments. In some embodiments, the order of steps/procedures may be changed.

First, referring to fig. 6A, an inductively coupled plasma apparatus 100 is provided. The inductively coupled plasma apparatus 100 includes a reaction chamber 110 (including a body 112 and a dielectric plate 114), a wafer pedestal 120, a coil 130, and a gas delivery 140. The detailed configuration of the inductively coupled plasma apparatus 100 can be as described in any of the above embodiments, and is not described herein.

Next, referring to FIG. 6B, a plasma deposition process is performed using the inductively coupled plasma apparatus 100 to perform a reactionThe inner surface of the enclosed space 110S of the chamber 110 (e.g., the lower surface of the dielectric plate 114, the sidewall of the body 112, or the upper surface of the wafer pedestal 120) is coated with a protective film PL. For example, the gas conveyor 140 may introduce a suitable gas PG into the enclosed space 110S, and then control the coil 130 to perform an inductively coupled plasma process to generate plasma, thereby forming the protective film PL. In some embodiments, the gas PG may be SiCl₄Or other suitable gas, and the material of the protective film PL may be SiCl_xO_y. In some embodiments, during the plasma deposition process, current is supplied to the coil 130 such that the coil 130 transfers energy to the enclosed space 110S, thereby increasing the energy of the process gas FG to generate and/or maintain a plasma. In some embodiments, the uniformity and other characteristics of the plasma may be controlled by controlling the coil 130 so that the plasma deposition process is substantially isotropic. In some embodiments of the present disclosure, the shape of the dielectric plate 114 is designed according to the configuration of the coil 130, and by this design, the shape of the dielectric plate 114 is beneficial to improve the uniformity of the plasma, so that the thickness of the protection film PL is uniform.

In the process of plating the protective film PL, no wafer is disposed on the wafer susceptor 120 in the sealed space 110S of the reaction chamber 110. The process of the plating film PL is only for plating the inner surface of the reaction chamber 110.

Then, referring to fig. 6C, the wafer W is placed on the wafer pedestal 120 in the closed space 110S of the reaction chamber 110, and then a suitable plasma process, such as a plasma etching process, is performed on the wafer W using the inductively coupled plasma apparatus 100. In the present embodiment, the plasma etching process includes using the gas transporter 140 to transport the process gas FG into the enclosed space 110S and to provide a current to the coil 130, such that the coil 130 transmits energy to the enclosed space 110S, thereby increasing the energy of the process gas FG to generate and/or maintain a plasma. In some embodiments, the coil 130 and electrodes in the wafer pedestal 120 may control plasma uniformity and other characteristics such that the plasma etch process is anisotropic or isotropic with respect to the wafer W. After the plasma etching process is performed on the wafer W, the wafer W is removed, and the next wafer is placed in the closed space 110S of the reaction chamber 110, so that the plasma etching process is performed on the next wafer. In other embodiments, the plasma process performed on the wafer W may be a plasma deposition process or a plasma treatment process, but is not limited to a plasma etching process.

After performing the plasma processes on a plurality of wafers W (e.g., a plurality of wafers in the same step), process byproducts may be formed on the inner surface of the enclosed space 110S of the reaction chamber 110 (e.g., the lower surface of the dielectric plate 114, the sidewall of the body 112, or the upper surface of the wafer pedestal 120). For example, on the protective film PL, a byproduct film FL is formed.

Next, referring to fig. 6D, the wafer W is removed from the wafer pedestal 120 in the enclosed space 110S of the reaction chamber 110, and then a byproduct cleaning process is performed using the inductively coupled plasma apparatus 100. For example, an appropriate cleaning gas CG may be introduced into the enclosed space 110S to react with the byproduct film FL and the protective film PL (see fig. 6D) and remove the byproduct film FL and the protective film PL. For example, the cleaning gas CG may be a fluorine-containing gas or other suitable gas. In some embodiments, it can be said that the by-product film FL and the protective film PL are removed by etching the by-product film FL and the protective film PL using the cleaning gas CG. In some embodiments, the gas CG may be input to the enclosed space 110S of the reaction chamber 110 by a gas conveyer 140. Alternatively, in other embodiments, the gas CG may be input to the enclosed space 110S of the reaction chamber 110 through another gas inlet. In some embodiments, the byproduct cleaning process is not a plasma process. In other words, the cleaning gas CG is not used to generate plasma during the byproduct cleaning process. For example, no current is provided to the coil 130 during the byproduct cleaning process. In some embodiments, the byproduct cleaning process may be substantially isotropic.

In some embodiments, after the byproduct cleaning process is performed, the byproduct film FL and the protection film PL are removed to expose the inner surface of the reaction chamber 110, such as the lower surface of the dielectric plate 114, the sidewall of the body 112, or the upper surface of the wafer pedestal 120. In various embodiments of the present disclosure, the shape of the dielectric plate 114 is designed according to the arrangement of the coil 130, and by this design, the plasma uniformity can be improved, thereby improving the thickness uniformity of the protective film PL. Thus, the by-product cleaning process can be prevented from causing film residue or damage to the dielectric plate 114.

After the byproduct cleaning process is performed, the gas CG in the enclosed space 110S may be pumped out through the gas outlet 112GO (see fig. 1A) to recover the cleaning of the enclosed space 110S of the reaction chamber 110. At this time, the state of the inductively coupled plasma apparatus 100 is substantially the same as that of FIG. 6A.

Next, the steps of fig. 6B to 6D may be performed again. For example, referring again to fig. 6B, on the inner surface of the closed space 110S of the reaction chamber 110 (e.g., the lower surface of the dielectric plate body 114), the protective film PL is plated. Thereafter, referring to fig. 6C again, a next wafer (e.g., a wafer of a next lot) is placed in the closed space 110S of the reaction chamber 110, and then a plasma process is performed on the next wafer (e.g., a wafer of a next lot). Next, the next wafer (e.g., the wafer of the next step) is removed from the enclosed space 110S of the reaction chamber 110, and a byproduct cleaning process is performed to remove the protective film PL and the process byproducts again with reference to fig. 6D.

Based on the above discussion, it can be seen that the present disclosure provides a number of advantages. However, it is to be understood that other embodiments may provide additional advantages, and that not all advantages need be disclosed herein, and that not all embodiments require a particular advantage. One advantage of the present invention is that designing the dielectric plate with protrusions corresponding to the coil and recesses not corresponding to the coil promotes plasma uniformity and thus plasma etching, deposition or other processes on the wafer. Thereby, for example, a higher uniformity performance can be achieved in plasma etching. Another advantage of the present disclosure is that by designing the dielectric plate with the convex portion corresponding to the coil and the concave portion not corresponding to the coil, uniformity of plasma can be enhanced, uniformity of deposition of the protective film on the dielectric plate can be enhanced, and thus, film residue or damage of the dielectric plate due to a cleaning process can be avoided.

The foregoing outlines features of various embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. It will also be appreciated by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

1. An inductively coupled plasma apparatus, comprising:

a reaction chamber having a body and a dielectric plate, wherein the body and the dielectric plate define a space, and the dielectric plate has a groove facing the space;

a coil arranged on a surface of the dielectric plate body opposite to the space; and

a wafer pedestal disposed in the space.

2. The inductively coupled plasma apparatus of claim 1, wherein at least a portion of the coil does not overlap the recess in a direction perpendicular to the surface of the dielectric plate.

3. The inductively coupled plasma apparatus of claim 1, wherein the recess is an annular groove.

4. The inductively coupled plasma apparatus of claim 1, wherein the dielectric plate has a gas inlet, and the recess of the dielectric plate surrounds the gas inlet.

5. The inductively coupled plasma apparatus of claim 1, wherein the depth of the recess is equal to or less than half the thickness of the dielectric plate.

6. An inductively coupled plasma apparatus, comprising:

a reaction chamber having a body and a dielectric plate, wherein the body and the dielectric plate define a space, the dielectric plate includes a first protrusion, a second protrusion and at least one recess, the recess is located between the first protrusion and the second protrusion, and the thickness of the first protrusion and the second protrusion is greater than the thickness of the recess;

a coil disposed on a surface of the dielectric plate facing away from the space, wherein the coil overlaps the second protrusion in a direction perpendicular to the surface of the dielectric plate; and

a wafer pedestal disposed in the space.

7. The inductively coupled plasma apparatus of claim 6, wherein the surface of the dielectric plate facing away from the space is a flat surface.

8. The inductively coupled plasma apparatus of claim 6, wherein the coil does not overlap the recess in the direction perpendicular to the surface of the dielectric plate body.

9. A method of operating an inductively coupled plasma apparatus, comprising:

introducing a first protective gas into a space of a reaction chamber, wherein the reaction chamber has a body and a dielectric plate defining the space, wherein the dielectric plate has a groove facing the space;

performing a first plasma process after introducing the first protective gas into the space of the reaction chamber to form a first protective layer on an inner surface of the reaction chamber;

after the first protective layer is formed, a wafer is placed on a wafer base;

introducing a process gas into the space of the reaction chamber;

performing a second plasma process on the wafer after introducing the process gas into the space of the reaction chamber;

removing the wafer from the wafer pedestal; and

a cleaning process is performed to remove the first passivation layer.

10. The method of claim 9, further comprising:

introducing a second shielding gas into the space of the chamber after the cleaning process; and

after introducing the second protective gas into the space of the reaction chamber, a third plasma process is performed to form a second protective layer on the inner surface of the reaction chamber.