JP2001523042A - Multi-electrode electrostatic chuck with fuse in hollow cavity - Google Patents

Abstract

(57) Abstract: A breakage-resistant electrostatic chuck 20 for holding a substrate 35 during processing of the substrate 35 has one or more electrodes 25 coated with an insulator 30. Reference numeral 25 has the ability to electrostatically hold the substrate 35 when a voltage is applied. Power bus 40 has one or more output terminals 45 for conducting voltage to electrodes 25. Fuse 50 is positioned within hollow cavity 55 in insulator 30 and electrically connects electrode 25 to output terminal 45 of power bus 40 in series. Each of the fuses 50 is electrically connected to the output terminal 45 when the insulator 30 covering the electrode 25 destroys the electrode 25 and the plasma discharge current flows through the fuse 50 by being exposed to the plasma process atmosphere. Can be intermittent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Cross reference]

This application is directed to Kumar et al., US Pat. No. 575, issued May 12, 1998.
No. 1357, US patent application Ser. No. 08 / 965,121, filed Nov. 6, 1997 by Clinton et al., Which is a continuation-in-part application of the title of the invention "Multi-electrode Chuck With Fuses". Electros
A partial continuation application for "Tatic Chuck Having Fuses In Hollow Cavities."

[0002]

TECHNICAL FIELD OF THE INVENTION

 The present invention relates to an electrostatic chuck for holding a substrate in a process environment.

[0003]

[Prior art]

Electrostatic chucks are used to hold a substrate, such as a silicon wafer, during processing of the substrate in a process chamber. A typical electrostatic chuck includes an insulated electrode that is electrically biased with a voltage relative to the substrate. During processing of a substrate, a process gas is introduced into a process chamber, and in certain processes, an electrically charged plasma is formed from the process gas. In a monopolar chuck, the voltage applied to the electrodes and the charged plasma nuclide above the substrate induces opposite electrostatic charges in the electrodes and the substrate, resulting in an electrostatic charge that holds the substrate electrostatically to the chuck. Attraction is obtained. In bipolar chucks, both plasma and non-plasma processes maintain two or more electrodes at different potentials to hold the substrate electrostatically.

[0004] Typically, electrostatic chucks have metal electrodes covered with a thin layer of insulator that maximizes electrostatic attraction. However, this thin insulator layer can be destroyed by debris of the substrate having sharp edges or corroded in the process environment, exposing the electrodes of the chuck. Such breakdown is particularly apt to occur when the insulator is made of a soft polymer material having low breakdown resistance. Even if only one electrode is exposed by the insulator pinhole, an arc is generated between the electrode and the plasma, and the entire chuck needs to be replaced. Breakage of the electrostatic chuck during substrate processing results in significant cost loss of the entire substrate.

[0005] One solution to the aforementioned destruction problem is to provide at least one power bus for supplying voltage to the electrodes of the chuck, as disclosed in US Pat. No. 5,751,357 commonly assigned to Kumar et al. The use of a plurality of individual fuses that electrically connect the electrodes in series ensures that the chuck is resistant to damage from corrosion of the insulator. Based on the plasma discharge current flowing through the fuse,
As the insulator destroys the electrodes and exposes them to the plasma process environment, the fuse burns out, electrically disconnecting the electrodes from the power bus. However, because the fuse is embedded in the insulator layer, the burned-out fuse results in a link of conductive residue that forms a weak conductive path between the electrode and the power bus. This residue conduction path allows the plasma to discharge continuously through the fuse, causing plasma instability in the chamber, resulting in non-uniform processing of the substrate and / or static electricity holding the substrate. Substrate movement by weakening the power.

[0006] It is desirable to have an electrostatic chuck that is resistant to damage from destruction due to substrate debris and damage from corrosion in a corrosive process environment. It is also desirable to have a chuck that is tolerant to breakage and that allows the chuck to continue to hold a substrate despite multiple breaks in the insulator layer. Further, it is desirable to have an electrostatic chuck that allows for corrosion or breakage of the insulator covering the electrode without allowing the plasma current to continue to discharge through the electrode.

[0007]

[Summary of the present invention]

The present invention provides a breakage-resistant electrostatic chuck that holds a substrate in a process environment, the chuck tolerating electrode failure without allowing the plasma to continue to discharge through the failed electrode of the chuck. I do. One version of the chuck comprises an insulator having a surface on which to receive the substrate. Embedded in the insulator:
(I) an electrode for electrostatically holding the substrate when a voltage is applied to the electrode; (ii) a power bus having an output terminal for leading a voltage to the electrode; and (iii) an electrode to an output terminal from the power bus. And a fuse arranged in a hollow cavity confined in an insulator. The fuse is low enough that the insulator destroys the electrode and exposes it to the plasma process environment, so that when the current discharge from the plasma flows through the fuse, the amp is low enough to electrically interrupt the electrode from the output terminal. Number rating (an
amperage rating). Preferably, the hollow cavity surrounding the fuse is sized large enough to receive the residue from the burnout of the fuse without forming a conductive path between the electrode and the output terminal of the power bus. Has surface area.

In a preferred version, the electrostatic chuck comprises a plurality of electrodes, output terminals, fuses, and hollow cavities embedded in the insulator, and holds the substrate even if some electrodes are interrupted by the fuses. Continue, provide electrode redundancy. More preferably, the insulator of the chuck has a plurality of layers including a cover layer and a support layer. The support layer supports the electrodes, power bus, and fuse. The upper surface of the cover layer has an insulator for insulating the electrodes, and the lower surface of the cover layer has a hollow cavity arranged around the fuse on the support layer.

In another version, an electrostatic chuck has at least one first insulator layer having a plurality of electrodes that electrostatically hold a substrate when a voltage is applied to the electrodes, and an upper surface of the insulator layer. Is adapted to receive a substrate thereon. Further, one or more of the second insulator layers includes a power bus having a plurality of output terminals for conducting voltage to the electrodes, and a plurality of fuses disposed in a hollow cavity in the insulating layer, wherein each fuse is , At least one electrode is provided for connection to an output terminal of the power bus. The first and second insulator layers can be joined together and formed in one piece, or otherwise separated from each other and made non-contact.

In another aspect, the invention includes a method of forming a breakage-resistant electrostatic chuck having electrodes connected to an output terminal from a power bus via a fuse confined in a hollow cavity. The method includes: (a) forming electrodes, power buses, and fuses on an insulating support layer; (b) forming hollow cavities in the insulating cover layer; (3) each hollow cavity. Bonding the insulative cover layer to the insulative support layer so that the insulated cover is aligned and positioned over the fuse. The cover layer can include one or more adhesive and insulating layers.
Preferably, layers of conductor and resistor material are deposited on the insulating support layer and etched to form a plurality of electrodes each connected from the power bus to the output terminal via a fuse.

[0011] The features, aspects and advantages of the present invention will be better understood with reference to the following detailed description, appended claims, and accompanying drawings which illustrate versions of the invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

The invention is useful for multi-electrode structures, such as capacitors, batteries, electrostatic chucks, and the like. Although the present invention is described in considerable detail along with an electrostatic chuck useful for holding a substrate in a process environment, many other versions of the present invention may be used without departing from the scope of the present invention. It should be clear to those skilled in the art. Therefore, the spirit and scope of the present invention should not be limited to the description of the preferred versions contained herein.

As schematically illustrated in FIG. 1, the electrostatic chuck 20 of the present invention comprises a plurality of electrodes 25 a-h, such as monopolar or bipolar electrodes, embedded or covered by an insulator 30. . The electrodes 25a-h electrostatically hold the substrate 35 when a voltage is applied to the electrodes 25a-h. A single potential or bias may be applied to each individual site of the electrodes 25a-h, as shown in FIG. 1, or a different potential or bias may be applied to each individual electrode, such as in a bipolar electrostatic chuck. Is applied to the part. In yet another embodiment, the electrodes 25 are biased in any of the above variations, i.e., one group of electrodes is provided with one potential and at least one other group of electrodes is provided with a different potential. Is done. Power bus 40 includes one or more output terminals 45a-h that conduct voltage to electrodes 25a-h. One or more fuses 50a-h are respectively disposed within hollow cavities 55a-h confined in insulator 30. Each fuse (e.g., fuse 50a) has at least one electrode 25a connected in series to output terminal 45a, and insulator 30 on electrode 25a destroys electrode 25a and exposes it to the plasma process environment. When current discharges from the plasma and flows through electrode 25a and fuse 50a, electrode 25a is disconnected from output terminal 45a. Preferably, each of the hollow cavities 55a-h in the insulator 30 is aligned over the fuse and the fuse 50a-h without forming a conductive path between the electrodes 25a-h and the output terminals 45a-h of the power bus 40. -Have a surface area set large enough to accept or contain debris from the h-cut.

As shown in FIG. 2, the electrostatic chuck 20 is fixed on a support 60 in a process chamber 65 that forms an enclosure for processing a substrate 35. Optionally, the electrostatic chuck 20 includes a base 80 having a hole 85 therethrough,
It is useful to support electrodes 25a-h and insulator 30. An electrical connector 90 electrically connects the power bus 40 to a voltage source. The electrical connector 90 has (i)
A) electrical leads 95 extending through holes 85 in base 80; and (ii) electrical contacts 100 that electrically engage voltage supply terminals 105 at the interface between base 80 and support 60. The first voltage source 110 supplies a voltage to the voltage supply terminal 105 for operating the chuck 20. The first voltage source 110 typically has one
Approximately 100 to 300 connected to a high voltage readout device through a 0 MΩ resistor
Includes a circuit with a 0 volt high voltage DC source. The 1MΩ resistor in the circuit
A 500 pF capacitor is provided as an AC filter to limit the current flowing through the circuit.

A second voltage source 115 is connected to the support 60 in the process chamber 65. At least a portion of the support 60 is typically conductive and functions as a process electrode or cathode that forms a plasma in the chamber 65. The second voltage source 115 electrically biases the support 60 against a surface 120 that is electrically grounded in the chamber 65 to generate a plasma formed from a process gas in the chamber 65 or to generate energy. To form an electric field. Insulating flange 125
Is disposed between the support 60 and the ground plane 120 to electrically insulate the support 60 from the ground plane 120. Normally, the second voltage source 115 is
A high-frequency impedance that matches the impedance of the line voltage with the impedance of the line voltage is provided in series with the isolation capacitor.

To operate the chuck 20, the process chamber 65 is evacuated and maintained at a sub-atmospheric pressure. The substrate 35 is placed on the chuck 20 and the chuck 2
The zero electrodes 25a-c are electrically biased against the substrate 35 by the first voltage source 110. Thereafter, a process gas is introduced into the chamber 65 via the gas inlet 70 and the plasma is activated by activating the second voltage source 115 or using an alternative plasma generation source such as an induction coil (not shown). To form a process gas. In operation of a monopolar electrode chuck (i.e., when a single potential is applied to the electrodes of the chuck), the voltage applied to the electrodes 25a-c creates an electrostatic charge that accumulates at the electrodes 25a-c and causes Provides a charged nuclide of opposite polarity that accumulates on the substrate 35. The accumulated opposite electrostatic charge results in an electrostatic attraction that electrostatically holds the substrate 35 to the chuck 20.

To regulate the temperature of the substrate 35 held on the chuck 20, a heat transfer fluid source 140 can be used to supply a heat transfer fluid source to the groove 145 in the insulator 30 of the chuck. . The substrate 35 held on the chuck 20 covers and seals the groove 145, preventing the heat transfer fluid from leaking. The heat transfer fluid in the groove 145 is
Can be used to heat or cool and adjust the temperature of the substrate 35 to maintain the substrate 35 at a constant temperature during the process. Typically, grooves 145 form a pattern of intersecting channels that extend through insulator 30. The heat transfer fluid is typically a gas, such as helium, held at a pressure of about 1 to 10 Torr in the groove.

The multi-electrode chuck 20 of the present invention is resistant to damage resulting from erosion or destruction of the insulator 30 on the electrodes 25a-c. If the sharp edge debris breaks a portion of the insulator 30 covering a particular electrode (eg, electrode 25a), the electrostatic charge on the substrate 35 will pass through the exposed electrode 25a and the fuse connected to the electrode. Flow through 50a. The current flowing through fuse 50a as a result of the electrostatic discharge is
Oa is automatically switched off in a relatively short time, and the electrode 25a is electrically disconnected from the output terminal 45a of the power bus 40. However, the remaining electrodes 25b-c, still insulated by the insulator 30, provide a large contact area for the electrodes that operate the substrate 35 to the chuck 20 and keep it electrostatically held. In this manner, the assembly of the fuse 50a and the corresponding electrode 25a functions as an independently operated micro-electrostatic chuck having a small contact area, from the independently powered output terminal 45 of the power bus 40. Get that power supply. As described above, the electrostatic chuck 20 of the present invention
If the portion of the insulator 30 that covers the electrode 25 breaks or erodes, it provides significant advantages by retaining the substrate 35 and resisting catastrophic failure.

Further, as shown in FIGS. 3 a and 3 b, the fuse 50 is located in a hollow cavity 55 in the insulator layer 30. Without the hollow cavity 55 around the location of the fuse 50, the fuse would blow and form a small piece or molten liquid of the debris in the insulator 30, even if the debris was slightly conductive. Forming a conductive path that remains in contact with and leads the arc across the debris. The hollow cavity 55 encloses the fuse 50, and the electrode 25 and the output terminal 45 of the power bus 40.
A volume having a surface area set large enough to receive debris from blowing or melting of fuse 50 without forming a conductive path between the fuse and fuse 50.

Preferably, the hollow cavity 55 has a width of about 0.25 to about 5 times the length of the fuse 50, more preferably about 0.5 to about 2 times the length of the fuse 50, which is
(Which can be of any size, including diameter, height, depth, or width). Preferably, the volume of the confined hollow cavity 55 is about 0.0000
1 mm ³ (0.6 mils ³ ) to about 10 mm ³ (= 600,000 mils ³ ),
More preferably, from about 0.00016mm ³ (= 10mils ³⁾ from about 5mm ³ (= 300,000mils ^3). More preferably, the hollow cavity is shaped as a cylinder, such as a flat disk, with a height of about 0.01 mm (= 0.5 mils) to about 0.25 mm (= 10 mils), and about 0.1 mm (= 5mil
s) to a diameter of about 5 mm (= 200 mils). The surface area of the cavity 55 must be large enough to receive the fuse shards on a dissipative surface area that reduces the likelihood of a conductive connection formed by the shards. Preferably, the surface area of the hollow cavity 55 is from about 0.001 mm ² (= 15 mils ² ) to about 100 mm ² (= 155,000 mils ² ), more preferably, about 0.03 mm ² (= 50 m ² ).
ils ² ) to about 45 mm ² (= 70,000 mils ² ). For example, as shown in FIGS. 3a and 3c, the hollow cavity 55 in the insulator 30 has a diameter approximately equal to the length of the fuse 50 and half the combined thickness of the upper insulator layers 30b and 30c. Cylinders of equal height; or may have the shape of a hemisphere or sphere with a radius equal to about half the length of the fuse (as shown in FIG. 3b).

Referring to FIG. 3b, for ease of manufacture, insulator 30 preferably comprises a plurality of layers, including first and second layers. The first support layer 30a supports the electrode 25, the power bus 40, the output terminal 45, and the fuse 50. Second cover layer 30
b comprises a plurality of hollow cavities 55 in an insulator layer covering and surrounding the electrodes 25, the power bus 40, the output terminals 45, and the fuses 50. An advantage of the present invention is that the fuse 50 and the electrode 25 can be formed directly on an uninterrupted flat surface of the support layer 30a;
0b. Also, the layers can be made of different materials or of different thicknesses, providing different dielectric, semiconductive or insulating properties in the two layers. For example, one of the cover layers 30c is fabricated from a semi-conductive ceramic material to form a Johnsen-Rahbek type electrostatic chuck where electrostatic charge leaks from the electrode 25 and accumulates in the ceramic material, An electrostatic charge forms below the surface of the chuck 20; on the other hand, the lower layer 30b is made of a more insulating material.
In another embodiment, shown in FIG. 3c, a second cover layer 30b having a plurality of hollow cavities 55 disposed around the fuse 50 includes a third insulator layer 30c covering the adhesive layer 30b and a support layer 30a. It consists of an adhesive layer that is bonded to the substrate.

A bipolar version of the electrostatic chuck 20 of the present invention will be described with reference to the embodiment shown in FIG. In the bipolar version, the chuck 20 includes an insulator 30 that covers the first group of electrodes 146 and the second group of electrodes 148 sized and configured to serve as a bipolar electrode. The groups of electrodes 146, 148 are capable of electrostatically holding the substrate 35 when a voltage is applied to the electrodes. A first power bus 40a having a first set of output terminals 45a supplies a voltage to a first group of electrodes 146. Second set of output terminals 45b
A second power bus 40b having a voltage supply to the second group of electrodes 148. A plurality of fuses 50a connect electrodes 25a in series to output terminals 45a from power buses 40a and 40b. Each fuse 50a is located in a hollow cavity 55a confined in insulator 30, and insulator 30 on the electrode destroys the electrode,
When exposed to the process environment and the plasma discharge current is caused to flow through the fuse 50 connected to the electrode, the electrode 25a is disconnected from the output terminal 45a.

In the bipolar version, the first voltage source 110 is connected to the first and second power bus 4
A differential voltage is supplied to 0a and 40b. In a preferred configuration, the first voltage source 110
Comprises two DC power supplies, which supply a negative voltage to the first electrode 146 and a positive voltage to the second electrode, such that the electrodes maintain different potentials with respect to each other. The opposing potentials of the electrode groups 146 and 148 induce opposing electrostatic charges on the electrode groups 146 and 148 and the substrate 35 held on the chuck 20 without using the plasma in the process chamber 65, The substrate 35 is electrostatically held on the chuck 20. The bipolar electrode configuration is advantageous for non-plasma processes where there are no charged plasma nuclides that serve as charge carriers for electrically biasing the substrate 35.

An alternative version of the chuck 20 is described that provides ease of manufacture, increased reliability, and maximizes the electrostatic clamping force generated by the electrodes. In the version illustrated in FIG. 5, the power bus 40 comprises a flat conductive layer spaced from the electrodes 25 that supply the voltage to operate all the electrodes 25. Each fuse 50 connects at least one electrode site 25 to a power bus 40 in series. Preferably, the fuse 50 comprises a resistive coating 150 on a hole 155 extending between the electrode 25 and the flat conductive layer, the resistive coating 150 comprising, for example, a conductive film serving as a resistive element. Or with a thin coating of a resistive material. This version can be easily manufactured by depositing a resistive coating 150 over a hole 155 formed in the insulator 30 layer over which the resistive fuse element covers the flat conductive layer; Alternatively, it has certain manufacturing advantages because it can be made large enough in shape and size to prevent the molten residue from solidifying into a conductive connection.

In the version shown in FIG. 6, the output terminal 45 of the power bus 40 is substantially flush with the electrode 25. The electrodes 25 are coplanar, so that the electrostatic contact area of the electrodes 25 is located on a single plane. The output terminal 45 is arranged between the electrodes 25 at a distance from the electrodes and on the same plane as the electrode surface. In this formation, the fuse 50 is connected to the electrode 2
5, thereby reducing the overall thickness of the electrode 25 and insulator layer 30 and maximizing the electrostatic attraction of the chuck 20.

In the versions shown in FIGS. 7 and 8, the chuck 20 includes (i) one or more outer electrodes 25 a on the outer edge of the insulator 30 and (ii) one or more center electrodes on the central portion of the insulator 30. And an electrode 25b. A first power bus 40a having a first set of output terminals 45a provides a voltage to the outer electrode 25a and a second set of output terminals 4a.
A second power bus 40b having 5b supplies a voltage to the center electrode 25b. Fuses 50a-b electrically connect electrodes 25a-b in series to output terminals 45a-b from power buses 40a and 40b, as shown. The fuse 50a is connected to the outer electrode 25a when any one of the outer electrodes 25a is exposed to the process environment.
Is electrically disconnected from the power bus 40a. This version, shown in FIG. 8, allows separate monitoring and supply of voltage to the outer electrode 25a and the center electrode 25b. The outer electrode 25a is particularly important when the heat transfer fluid is used to regulate the temperature of the substrate 35 held on the chuck 20, because the outer electrode 25a may be a heat transfer fluid leak. This is because the outer periphery of the chuck is hermetically sealed so as to prevent the problem. Outer electrode 25a
If the substrate breaks, heat transfer fluid retained beneath the substrate leaks, causing heating to the perimeter of the substrate and consequent damage. This chuck configuration allows for a higher voltage to be applied to the outer electrode 25a to increase the electrostatic holding force on the outer edge of the chuck 20, or one or more of the outer electrodes 25a are exposed to the plasma environment. Allows for chuck replacement.

In any of the versions described herein, as shown in FIG. 7, the electrostatic chuck 20 includes a plurality of electrodes 25a that electrostatically hold the substrate by applying a voltage to the electrodes.
At least one first insulator 30a having -b may be provided. The top surface of insulator 30a is a flat surface shaped and sized to receive a substrate thereon. One or more second insulators 30b may include a single or multiple power bus 4
0a and 40b, each having a plurality of output terminals 45a-b for conducting voltage to the electrodes. The plurality of fuses 50a-b are disposed in a hollow cavity in the second insulator 30b. Each fuse 50a-b connects at least one electrode 25a-b in series to output terminals 45a-b of power buses 40a and 40b. The first insulator 30a and the second insulator 30b can be joined together to form a single structure, or can be separate non-adjacent structures.

[0028] Another aspect of the invention provides a system for early detection of electrode breakage and optional counting. In this system, a current detector 175 is electrically connected in series to the power bus 40 and detects the flow of current through the fuses 50a-h, as shown in FIG. When the insulator 30 destroys the electrode 25a and exposes it to the process environment, the charged plasma ions discharge through the electrode and supply a current flowing through the fuse 50a adjacent to the electrode 25a. The current detector 175 is connected to the fuse 50a.
Detects the current before electrically disconnecting the electrode 25a from the output terminal 45a of the power bus 40. A suitable current detector 175 comprises an ammeter connected in series to the power bus 40. Monitoring current surge through the current detector 175 provides an indication of the number of electrodes 25a-h exposed to the process environment or the number of disconnected electrodes 25a-h. In this way, the current detector 175 can be used to provide an early warning of the failure of one or more of the electrodes 25 and to allow the chuck to be replaced before catastrophic failure occurs during the process.

Preferably, an electrical counter 180 is connected to the current detector 175 to count the number of current surges through the current detector 175 and the electrodes 25 exposed to the process environment
It provides an estimate of the number of ah, or the number of disconnected electrodes 25a-h. Counter 180 may be a conventional counter capable of counting the number of current discharges through current detector 175. The counter typically includes a register that counts the impulses generated by the analog-to-digital converter and generates a position reading. Optionally, an analog / digital converter 185 is used in series before the counter 180 to convert the analog current output to a digital current output. A conventional analog-to-digital converter 185 includes electronic circuitry that receives a scaled analog voltage and generates a binary code number proportional to the analog input. Analog to digital converter 185 provides a binary output that represents the analog input at precise repeating time intervals. Normal electric counters and analog / digital converters can be used.

In the chuck version illustrated in FIG. 8, separate current detectors 175 a and 17
5b and optional separate electrical counters 180a and 180b are used to detect current flow at the outer electrode 25a and the center electrode 25b of the chuck 20, respectively. The use of two current detectors allows separate detection of breakage of the outer electrode 25a and the center electrode 25b. In this manner, the current detector 175a can be used to provide an early warning of the failure of one or more perimeter electrodes 25a and to allow the chuck to be replaced before the chuck 20 fails during the process.

The different features and components of chuck 20 and illustrative methods of manufacturing the chuck are described below. However, other manufacturing methods can be used to form the chuck 20, and the present invention should not be limited to the example methods described herein.

As shown in FIG. 2, the base 80 of the chuck 20 used to support the electrodes 25 a-c and the insulator 30 typically maximizes heat transfer and provides a large holding surface. , A shape and a size corresponding to the shape and the size of the substrate 35. For example, when the substrate 35 has a disk shape, the base 80 having a right cylindrical shape is preferable. Typically, the base 80 is made of aluminum and has a diameter of about 100 mm to 225 mm and a diameter of about 1.5 cm.
It has a cylindrical shape with a thickness of from 2 cm. The upper and lower surfaces of the plate are polished using conventional polishing techniques until the surface roughness of the plate is less than 1 μm, so that the base 80 can evenly contact the support 60 and the substrate 35, Substrate 35 and support 6
0 enables efficient heat transfer. The base 80 has an electrical connector 90 with minimal clearance.
It also has a hole sized enough to be inserted through it, and a suitable gap is about 5
mm.

Insulator 30 is large enough to cover and house all electrodes 25 a-c, fuses 50 a-c, output terminals 45 a-c and power bus 40 of chuck 20, as shown in FIG. It may be an integral insulator 30 sheet that is set to this. Alternatively, the insulator may be formed from multiple layers as shown in FIGS. 3b-c. Insulator 3
The zero resistivity is (i) low enough to allow fast electrostatic charge accumulation and dissipation providing fast response times, and (ii) electrodes that may damage devices formed on substrate 35. Must be large enough to prevent leakage of the voltage applied to 25a-c. Typically, the insulator 30 will be between about 10 ¹³ Ωcm and 10 ²⁰ Ωc.
m and a dielectric constant of at least about 3, more preferably at least about 4. The appropriate thickness of the insulator 30 depends on the electrical resistivity and dielectric constant of the insulator. For example, if the insulator 30 has a dielectric constant of about 3.5, the thickness of the insulator 30 is typically from about 10 μm to about 500 μm, and more usually about 10 μm.
It is from 0 μm to about 300 μm. A suitable insulator 30 material is usually at least about 3.9 V / μm (100 V / mil), more usually at least about 39 V / mil.
It has a dielectric breakdown strength of μm (1000 V / mil). In a preferred configuration, FIG.
a to 9g, the insulator 30 has a two-layer stack structure,
i) a first insulator layer 30a below the electrode 25; and (ii) a second insulator layer 30b on the electrode 25. Preferably, each insulator layer 30a-b has a substantially equivalent thickness ranging from about 50 μm to about 100 μm.

Preferably, the insulator 30 is made of polyimide, polyketone, polyetherketone,
Polysulfone, polycarbonate, polystyrene, nylon, polyvinyl chloride,
Polypropylene, polyether sulfone, polyethylene terephthalate, fluoroethylene propylene copolymer, cellulose, triacetate, silicone,
And an electrically insulating polymer material such as rubber. More preferably, insulator 30 is between about 200 and about 400 V / μm (5,000 to 10,000).
(V / mil), which allows the use of thin 30 layers of insulator, thereby maximizing electrostatic attraction. Also, the polyimide is elastic enough to deform slightly under electrostatic clamping pressure,
When a heat transfer fluid is introduced into the microscopic gap between the substrate 35 and the resilient polyimide, it enhances heat transfer. The polyimide dielectric layer is commonly formed by spin coating or bonding a polyimide film onto the electrode 25.

Alternatively, insulator 30 may be made of a ceramic material (i) Al ₂ O ₃ , BeO
_{, SiO 2, Ta 2 O 5} , ZrO 2, CaO, MgO, oxides such as _{TiO 2, BaTiO 3, (ii} ) AlN, TiN, BN, Si 3 N 4, nitrides etc., (iii) Zr
Borides such as B ₂ , TiB ₂ , VB ₂ , W ₂ B ₃ , LaB ₆ , (iv) silicides such as MoSi ₂ , and (v) diamond. The ceramic insulator is usually formed by sputtering, flame spraying, CVD, or solution coating to form a thin ceramic film on the electrode surface. Alternatively, the ceramic insulator is
It can be formed by embedding the electrode 25 therein and sintering the ceramic block.

Preferably, the insulator 30 withstands temperatures above 50 ° C., more preferably above 100 ° C., so that the chuck 20 can be used for high temperature processes. Also, the insulator 30 has a high thermal conductivity so that heat generated at the substrate 35 during the process can be dissipated through the chuck 20 and a suitable thermal conductivity is at least about 0.10 W / m / K. In addition, a protective film (not shown)
0 to protect the insulator 30 from chemical attack when the chuck 20 is used in an aggressive process environment.

The electrode 25 is made of an electrically conductive material such as copper, nickel, chromium, aluminum, and alloys thereof. Usually, the thickness of the electrode 25 is about 1
μm to about 100 μm, more usually 1 μm to 50 μm. Preferably, electrode 25 has a contact area of about 10 ^-4 to 10 ^-1 times the area of substrate 35. 2
For a substrate 35 having a diameter of 6 to 8 inches (00 to 300 mm), preferably each portion of the electrode 25 has a contact area of at least about 20 mm ² , more preferably about 50 to about 1000 mm ² .

The shape and size of the area covered by the electrodes 25 change according to the size and shape of the substrate 35. For example, if the substrate 35 is disk-shaped, as shown in FIG. 10a, the locations of the electrodes 25 are organized in a disk-shaped configuration to maximize the total area of the electrodes 25 under the substrate 35. Preferably, the electrode 25 is between about 50 and about 500 c
m ² , more usually 80 to 380 cm ² .

For the bipolar electrode configuration shown in FIG. 4, the contact area of each group of electrodes 146 and 148 is substantially identical and coplanar with each other, so that the electrodes are identical on the substrate 35. Generates electrostatic clamping force. Normally, the total contact area of each group of electrodes (or sites of electrodes) from about 50 to about 250 cm ^2, more preferably from about 100 to about 200 cm ^2. The first group of electrodes 146 and the second group of electrodes 148 may each have a semicircular region, as shown in FIG.
Alternatively, the first group of electrodes 146 may comprise at least one inner circle electrode and the second group of electrodes 148 may comprise at least one outer circle electrode, as shown in FIG. it can. Electrode isolation void 1
90 is used to electrically isolate groups of electrodes 146, 148 from each other. In one advantageous configuration, the electrode isolation void 190 is sized and configured to serve as a groove for holding a heat transfer fluid that regulates the temperature of the substrate 35 on the chuck 20. A groove can be formed in the isolation void 190 by cutting the insulator 30 over the isolation void so that the groove extends partially into the insulator 30 or as shown in FIG. The insulator 30 then retracts into the isolation void 190, forming a groove located between the electrodes 25a-c. This configuration allows for the use of isolation voids 190 between the electrodes to hold the heat transfer fluid without the need for additional grooves cut through the electrodes, thereby reducing the effective area of the electrodes 25 and the electrostatic force. To maximize

The electrical connector 90 is connected to the power bus 40 or the first and second power buses 40a, 40
b is used to electrically connect to the first voltage source 110. For bipolar electrodes, a separate electrical connector 90 is provided separately and electrically to the first group of electrodes 14.
6 is used to connect the first power bus 40a and the second group of electrodes 148 to the second power bus 40b. For both monopolar and bipolar electrodes, the electrical connector 90 is substantially identical and will be described only once to avoid repetition. The electrical connector 90 includes an electrical lead 95 extending through the hole 85 at the base 80 and an electrical contact 100. Typically, the length of the electrical lead 95 is from about 10 mm to about 50 mm, and the width of the electrical lead 95 is from about 2 mm to about 10 mm. Preferably, the electrical contact 100 is connected to the voltage supply terminal 10.
5 is a disk with an exposed area sized to directly contact and electrically engage 5, with a preferred area of about 50 to about 400 mm ² .

Each of the fuses 50 is automatically controlled, and when a current exceeding the amperage rating of the fuse flows through the fuse 50 adjacent to the electrode 25, at least one of the electrodes 25 is electrically disconnected from the output terminal of the power bus. Have the ability to Fuse 50
A current-sensitive that has the ability to automatically electrically disconnect the electrode 25 from the output terminal 45 during large current surges resulting from plasma discharge when the insulator 30 destroys the electrode 25 and exposes it to the process environment. Element. Fuse 5 adjacent to electrode 25
Discharging the plasma through zero switches the fuse off, for example, by melting or burning. Usually, each fuse comprises a conductor surrounded by an insulator and having a reduced cross section. The amperage rating of fuse 50 is the current that the fuse can conduct without blowing, melting, or exceeding certain temperature rise limits. Fuse 50
Is the maximum short-circuit current that the fuse can safely break. An instantaneous rise in current usually switches the fuse off in less than a quarter cycle. Preferably, each fuse 50 connects electrode 25 from output terminal 45 when a current of at least about 300 microamps, more usually at least about 500 microamps, and most usually at least about 1 milliamp flows through fuse 50. Ability to electrically disconnect. Preferably, the fuse will be made to burn rapidly in at least less than about 100 milliseconds, and more preferably, less than 10 milliseconds.

In a preferred configuration, each fuse 50 comprises a resistive wire or layer between the electrode and the power bus, which provides a resistance of at least about 100Ω, more preferably, about 100-3000Ω, most preferably about 300Ω. Have. The resistor comprises a thin lead or layer of resistive material connecting the electrode 25 to the output terminal 45 of the power bus 40. The resistance of a conductor is given by the equation R = ρx (l / A), where ρ is the resistance per unit length, l is the length, and A is the area, It should be understood that the body can be made of a conductive or resistive material. Thus, even with highly conductive materials, if the length of the material is appropriately long, or its area is small enough,
Can operate as a resistor. For example, the resistor may be made of a conductive material, such as copper or aluminum, formed as a very thin lead or layer connecting the electrode 25 to the output terminal 45. Alternatively, the resistor can be made from conventional resistive materials, including carbon, nickel, phosphorus, chromium, tin, and mixtures thereof. Preferably, the resistor material is made of nickel-phosphorous, nickel-chromium, chromium, or tin, which are highly current sensitive materials.

The shape and size of the fuse 50, ie, the length, width, diameter, or thickness of the fuse, depends on the material of the fuse and the amperage of the current flowing through the fuse. For example, a resistor fuse 50 made of a resistive material such as nickel-phosphorous, nickel-chromium, chromium, or tin and having an amperage rating of about 50 mA has a suitable thickness of about 0.005 to about 0.005. 1 μm, more preferably about 0.0
1 to about 0.2 μm. In a preferred configuration, the fuse comprises a thin lead of resistive material connecting the electrode 25 to an output terminal 45 on the power bus 40. If the amperage rating of the current flowing through the resistive lead exceeds the maximum current that the fuse can conduct without blowing or melting, as described above, the thin lead will burn or melt. Further, for fuses having a thickness of about 0.01 to about 0.2 μm, a preferred width is about 0.1 to about 1 mm, more preferably,
0.1 to 0.3 mm (0.005 to 0.012 inches); and a preferred length is about 0.1 to 5 mm, more preferably 0.5 to 2.5 mm (0.0
2 to 0.1 inches). The resistive fuse element 50 can be embedded in the insulator 30 surrounding the electrode 25, or can be made as a separate, insulated fuse assembly, as described in more detail below.

The power bus 40 may include a conductive wire or layer embedded in an insulator and spaced from the electrode 25. The power bus 40 has an output terminal 45 for supplying a voltage to the electrode 25 or a junction. The output terminals 45 of the power bus 40 can be located below the electrodes 25, as shown in FIG. 5, or can be located flush with the electrodes and between the electrodes, as shown in FIG. Alternatively, as shown in FIG.
5 and power bus 40 can be located on different structures or remote from chuck 20.

The electrode 25 of the chuck, the power bus 40, the fuse 50, and the hollow cavity 5
The manufacturing method of No. 5 will be described below. Preferably, the chuck is formed as a stack of insulators 30, having electrodes 25, power buses 40, and fuses 50 embedded therein. In one of the fabrication methods schematically illustrated in FIGS. 9a to 9g,
A composite layer (i) selecting a first insulator support layer 30a; (ii) depositing a resistor layer 200 on the first insulator support layer 30a to form a fuse; (Iii) depositing a patterned conductor layer 205 on the resistor layer 200 to form the electrode 25 and the power bus 40. The support layer 30a is available from DuPont de Nemours, Wilmington, Delaware.
KAPTON, a polyimide film manufactured by Co., Ltd .; APIQUEO manufactured by Kanegafuchi Chemical Indust., Japan
"UPILEX" manufactured by Ube Indus. Ltd., Japan;
Commercially available, such as "NITOMID" manufactured by Nitto Electric Indus. Co. Ltd., Japan; or "SUPERIOR FILM" manufactured by Mitsubishi Plastics Indus. Ltd., Japan It can include a polymer film.

Preferably, the resistor layer 200 includes a first insulator layer 30 a, as shown in FIG.
It can be formed by depositing a thin layer of a conductive or resistive material, preferably nickel-phosphorus, nickel-chromium, chromium, or tin. The thickness of the resistor layer is from about 0.005 to about 1 μm. As shown in FIG. 9b, a first patterned resist layer 215 is formed on the resistor layer 200, and the resist layer 215 is patterned for the electrode 25 and power bus 40 configuration. The resist may comprise a hard mask or a photoresist material, such as "RISTON" manufactured by DuPont de Nemours Co., Wilmington, Delaware. Silicon Processing for the VLSI Era, Volume 1: Process Technology , Stanley Wolf and Richard N. Tauber, Lattice Press, California, incorporated herein by reference.
Conventional photolithographic techniques, such as those described in Chapters 12, 13, and 14 of (1986), can be used to pattern resist layer 215 to correspond to the shape of electrode 25 and power bus 40. Thereafter, electroplating is used to deposit a conductive layer 205 between the portions coated with the resist, forming electrodes 25, power bus 40, and electrical connector 90. The conductor layer 205 has a thickness of 2 μm to 10 μm.
It is deposited to a thickness of 0 μm, more preferably about 5 μm. The conductor layer 205 can also be deposited by sputtering a layer of copper on the insulator film, with a chromium oxide bonding layer in between. Vapor deposition is advantageous by allowing the deposition of thin electrode layers having a thickness of less than about 500 nm, more preferably less than 250 nm. After the deposition of the conductive layer 205, the residual photoresist is removed from the composite layer using a conventional acid or oxygen plasma removal process to obtain the structure shown in FIG. 9c.

Thereafter, as shown in FIG. 9d, a second patterned resist layer 220 is formed on the resistor layer 200 and the patterned resist shape corresponds to the desired fuse 50 configuration. As shown in FIG. 9e, the exposed portion of the resistor layer 200
Next, the electrode 25 is etched using a normal etching method to connect the electrode 25 to the power bus 4.
A resistive fuse 50 connecting to zero is formed. Conventional wet or dry chemical etching methods can be used to etch resistor layer 200. Suitable wet chemical etching methods include iron chloride, sodium persulfate, or an acid or base.
Dipping the composite film into an etchant until the film is etched. Suitable dry etch process, supra, are described in Chapter 16 of Silicon processi ng, it is embedded reference herein.

As shown in FIG. 9f, a cover layer 30 b is formed with hollow cavities 55 a, 55 b sized and configured to be placed over fuse 50. The cover layer 30b can include one or more layers of adhesion and / or insulation. The hollow cavity in the cover layer 30b can be machined, stamped, cast, or formed by a photolithography and etching process similar to that described above to form the fuse 50.

The electrical connector 90 of the electrostatic chuck 20 is typically a
By embossing, punching, or pressing out 0, it is formed as an integral extension of the electrode 25. Preferably, the electrical connector 90 is cut out such that the electrical leads 95 and contacts 100 are located within one of the grooves 145. After the electrical connector 90 has been cut, the insulator 30 on the electrical contact is removed, exposing the underlying conductor layer 205, which forms the electrical contact 100. The electrical leads 95 and the electrical contacts 100 are inserted through holes in the base 80, thereby placing the electrical contacts 100 under the base 80, as shown in FIG. The chuck stack is adhered to the base 80 of the chuck 20 using a conventional pressure or temperature sensitive adhesive, such as polyimide. A top view of the resulting chuck 20 is shown in FIGS. 10a and 10b.

Instead of fabricating a composite laminate, a commercially available composite comprising (i) a first insulator layer 30 having a resistor layer 200 and (ii) a conductor layer 205 thereon. Multilayer films can also be used. A suitable multilayer film is "R /," manufactured by Rogers Corporation, Chandler, Arizona, comprising a 125 micron thick polyimide insulator layer 30a; a 0.1 micron resistor layer 200; and a 25 micron conductive copper layer 205. Flex
Includes 1100 "film. Another suitable multilayer film is IBM Corporation, Endico
"81G3365" film manufactured by tt, New York. As described above, the resistor layer 200 is etched or cut to form the resistive fuse 50, the copper layer is etched or cut, and the electrodes 25, the integral electrical connector 90,
And a power bus 40. Thereafter, the second insulator layer 30b is bonded to the etched laminated structure to form the chuck 20.

The electrostatic chuck 20 with features of the present invention has several advantages. First,
The chuck is resistant to damage resulting from erosion or destruction of insulator 30 on electrode 25. The current flowing through the fuse 50 as a result of the electrostatic discharge through the exposed electrode 25 causes the exposed electrode 25 to be electrically disconnected in a relatively short time. This involves manipulating the remaining insulated electrode 25 (or electrode site) and the substrate 3
5 can be held electrostatically. Thus, the assembly of each fuse 50 and electrode 25 of the present invention functions as a micro chuck that operates independently. In this way, the electrostatic chuck 20 of the present invention withstands catastrophic failure even when the insulator 30 covering the electrode 25 is broken or eroded. In addition, the sealed cavity 55 surrounding the fuse may be used to remove burned or melted residue from the fuse.
The possibility of forming a conductive path or connection between the power supply and the output terminal of the power bus.

In another aspect of the invention, a current detector 175 and an optional counter 1 are electrically connected in series to the power bus 40 to detect current flow through the fuse 50.
The use of 80 provides a system for early detection and optional counting of the number of electrode 25 breaks. Monitoring current surge through the current detector 175 provides an indication of the number of electrodes 25 exposed to the process environment or the number of disconnected electrodes 25. In this way, current detector 175 and counter 180 can be used to provide an early warning of the failure of one or more electrodes 25, allowing the chuck to be replaced before catastrophic failure of the chuck during the process. To

[0053]

【Example】

The following comparative examples illustrate the advantages of the breakage resistant electrostatic chuck 20 of the present invention,
Then, the fuse 50 was confined by the hollow cavity 55 in the insulator 30. In both examples, the fuse 50 was made from 0.2 μm thick nickel-phosphorous and the fuse length was varied from about 0.3 to about 3 mm (= 0.01 to 0.1 inch). . Copper electrode 25 and power bus 40 structures were fabricated by a reduced etching process from an 18 μm layer of copper deposited on a 50 μm thick supporting dielectric layer. To test the fuse 50 structure, the power bus 40 is connected to one of the terminals of the DC power supply, while the copper electrode 25 is connected through the supporting dielectric layer 30a and to the other terminal of the power supply. Electrical contact with the needle probe.

The first example demonstrates the effect of the fuse 50 continuing to apply a DC voltage on a fuse structure that is not confined in the hollow cavity 55. In this example,
The electrode and fuse patterns were covered with a single solid polyimide layer about 50 μm thick. 1000 and 200 (to reproduce the plasma discharge in the plasma process)
When a potential of 0 volts DC was applied between the power bus 40 and the copper electrode 25, a large current flowed through the fuse 50. The large current load caused the fuse 50 to blow. However, it has been found that, despite the fuse being blown, a sporadic arc that continues beyond the fuse gap along the oxidized residue of the blown fuse 50 continues.

In the second embodiment, the electrostatic chuck 20 was manufactured according to FIGS. 3a and 3c. The fuse 50 element, electrode 25, and polyimide dielectric were identical to those of the previous example, with the following exceptions. The cover layer is composed of two 25 μm thick polyimide layers 30.
The polyimide layer made closer to the fuse was formed by bc, and had a hole having a diameter substantially the same size as the length of the fuse. Thus, the hollow cavity has an outer diameter of about 1.5 mm (= 60 mils) (approximately equal to the length of the fuse 50) and about 25 μm (= 1 mils) (about half the combined thickness of the cover layer). ) Was formed on the insulator in the shape of a cylinder having a height. Fuses 50 of various lengths,
When tested under the same conditions as in the previous example, these fuses were found to blow and switch off with the first application of DC voltage, and in any case, continued application of DC potential caused the fuse gap to Beyond did not lead to further arcs.

In the third embodiment, the fuse 50 is made of nickel-phosphorus and has a thickness of about 0.2 μm.
(= 0.01 mils) and a length of about 1 mm (= 40 mils). The shape and size of the fuse were selected to electrically disconnect the electrode from the output terminal of the power bus when a current of at least about 10 mA flows through the fuse.
Support layer 30a having a thickness of about 5 to about 500 μm (= 0.2 to 20 mil)
The structure of copper electrodes 25 and power bus 40 from a thin sheet of multilayer foil 195 having a thickness of about 1.8 to about 185 μm (= 0.07 to 7.1 mil) bonded to Made a body. Multi-layer foil 195 is approximately 0
. A resistor layer 200 having a thickness of 025 to 2.5 μm (= 0.001 to 0.1 mil)
And about 1.8 to about 180 μm (0.07 to 7 mil) thick conductor layer 205
With. Preferably, the resistor layer 200 and the conductor layer 205 are, for example,
Available from ga Technologies, Culver City, California and having a thickness of about 17 μm (0.7 mils) plated on one side of a NiP layer having a thickness of about 0.3 μm (= 0.01 mils) It is made from a thin sheet 195 of a multilayer foil, such as a 1/2 ounce weight A100 Ohmega ^™ foil, with a layer of copper. To test the fuse 50 structure, the power bus 40 is connected to one of the terminals of the DC power supply, while the copper electrode 25 is connected through the supporting dielectric layer 30a to the other terminal of the power supply. Electrical contact was made to the connected needle probe.

As shown in FIG. 13, the chuck 20 includes a plurality of insulating layers 30a-c and adhesive layers 220a and 220b. This can be done without the need for an extra step of applying a liquid adhesive to the layers and without requiring excessively high temperatures to laminate the layers together.
By making the bonding of c possible, the chuck 20 can be easily manufactured. Insulator 3
0 comprises a support layer 30 a supporting the electrodes 25, the power bus 40 and the fuse 50. The cover layer 30b having the plurality of hollow cavities 55 is provided with an adhesive layer 220a.
Are coupled on the electrode 25, the power bus 40, the output terminal 45, and the fuse 50. Second adhesive layer 220b couples third insulating layer 30c to cover layer 30b.

A method for manufacturing the chuck 20 of FIG. 13 will be described below. Referring to the flowchart of FIG. 14, in a first step 230, a stack is formed from the support layer 30a, the conductor layer 205, and the resistor layer 200. 15a, the step of selecting the support layer 30a; the step of disposing the multilayer foil 195 composed of the resistor layer 200 and the conductor layer 205 on the support layer 30a; the step of selecting the support layer 30a; And applying pressure and heat to bond to the support layer 30a. Preferably, the pressure is in an autoclave, platen press, or
It is added using a pressure forming device such as an equalizing press. More preferably, about 700
To about 2000 kPa and a temperature of about 100 to about 400 ° C. are applied to the layers to be assembled for about 60 minutes. The support layer 30a may comprise a commercially available polymer film as described above.

In a second step 235, a resist layer 215 is deposited on the foil 195 and patterned to correspond to the configuration of the electrodes 25 and the power bus 40, as shown in FIG. 15b. Next, in a first etching step 240, a wet etching process is used to partially remove the conductor layer 205 between the resist coated portions,
The electrodes 25 and the power bus 40 are formed. The resistor layer 200 is partially removed in a second etching step 245. Thereafter, the remaining resist is removed in a removal step 250, and the exposed surfaces of the conductor layer 205 and the support layer 30a are washed as shown in FIG. 15c. The exposed surface of the conductor layer 205 is then subjected to an oxide formation step 255
To form a brown oxide layer 275. Brown oxide layer 275 is desirable to enhance the adhesion of the layer overlying conductor layer 205.

The cover layer 30 b with the cavity 55 formed therein is joined in a second lamination step 260 to the support layer 30 a using the adhesive layer 220 a and the lamination process described above. Hollow cavities in cover layer 30b can be formed by machining, embossing, casting, photolithography, or etching processes. As shown in FIG. 15e, the underlying foil 195 exposed by the cavity 55 is then etched in a wet etching step 265 to have the desired size and shape, connecting the electrode 25 to the power bus 40. A resistive fuse 50 is formed. Thereafter, the surfaces of the exposed portions of the cover layer 30b, the fuse 50, and the support layer 30a are cleaned; in the final laminating step 270, as shown in FIG.
Is bonded to the cover layer 30b.

Although the invention has been described in considerable detail with reference to certain preferred versions, many other versions will be apparent to those skilled in the art. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional schematic side view of an embodiment of an electrostatic chuck according to the present invention.

FIG. 2 is a partial cross-sectional schematic side view of a process chamber illustrating operation of a monopolar electrostatic chuck according to the present invention.

FIG. 3a is a schematic plan view, partially in section, of a hollow cavity in an insulator of the chuck of the present invention.

FIG. 3b is a partial cross-sectional schematic side view of an electrostatic chuck of the present invention showing the plurality of layers forming the insulator and the hemispherical hollow cavities in the insulator.

FIG. 3c is a partial cross-sectional schematic side view of the electrostatic chuck of the present invention, showing a plurality of layers forming an insulator, and a cylindrical hollow cavity in the insulator.

FIG. 4 is a partial cross-sectional schematic side view of a process chamber illustrating the operation of a bipolar electrostatic chuck according to the present invention.

FIG. 5 is a schematic cross-sectional side view of another embodiment of the electrostatic chuck according to the present invention.

FIG. 6 is a schematic cross-sectional side view of another embodiment of an electrostatic chuck according to the present invention, showing the power bus under the electrodes.

FIG. 7 is a schematic cross-sectional side view of another embodiment of an electrostatic chuck according to the present invention, showing a first insulator having a plurality of electrodes and a second insulator covering the fuse.

FIG. 8 is a schematic cross-sectional side view of another embodiment of the electrostatic chuck according to the present invention.

FIG. 9a is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 9b is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 9c is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 9d is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 9e is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 9f is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 9g is a schematic cross-sectional side view showing successive steps in the manufacture of an electrostatic chuck according to the present invention.

FIG. 10a is a schematic plan view of an electrode, power bus, and fuse assembly of an electrostatic chuck manufactured using the process illustrated in FIGS. 9a-9g.

FIG. 10b is an enlarged schematic view of the insertion box 10b of FIG. 10a showing details of the electrode, power bus and fuse assembly.

FIG. 11 is a schematic plan view of a bipolar electrostatic chuck according to the present invention having two semicircular groups of electrodes.

FIG. 12 is a schematic plan view of another bipolar electrostatic chuck according to the present invention having a double ring electrode configuration.

FIG. 13 is a partial cross-sectional schematic side view of another version of the electrostatic chuck of the present invention, showing a plurality of adhesive and polymer layers forming a cylindrical hollow cavity in the insulator and insulator layer.

FIG. 14 is a flowchart illustrating the steps of forming one version of the electrostatic chuck of the present invention.

FIG. 15a shows the continuing steps in the production of a version of the electrostatic chuck according to the invention;
It is a cross-section schematic side view.

FIG. 15b shows the continuing steps in the production of a version of the electrostatic chuck according to the invention;
It is a cross-section schematic side view.

FIG. 15c shows the continuing steps in the production of a version of the electrostatic chuck according to the invention;
It is a cross-section schematic side view.

15a to 15d show successive steps in the production of a version of the electrostatic chuck according to the invention;
It is a cross-section schematic side view.

15a to 15e show successive steps in the production of a version of the electrostatic chuck according to the invention;
It is a cross-section schematic side view.

15a to 15f show successive steps in the production of a version of the electrostatic chuck according to the invention;
It is a cross-section schematic side view.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventors Clinton, John, Tee. Paine Avenue 3200 Number 406 (72) San Jose, California, United States of America Inventor Bedy, Salinder, S.E. United States, California, Fremont, Decker Terrace 5438 (72) Inventor Shamowilian, Shamowill United States of America, California, San Jose, Little Falls Drive 6536 (72) Inventor Kumar, Ananda, H. Norvie Drive, Milpitas, California, United States of America 1296 (72) Inventor Contreras, Mark, S.S. Hill Bright Place, San Jose, California, USA 525 F term (reference) 5F031 CA02 HA02 HA03 HA17 HA19 JA01 JA21 MA28 MA29 MA31 PA06 PA08 PA10

Claims (25)

[Claims] 1. An electrostatic chuck comprising an insulator having a surface thereon for receiving a substrate, said insulator being embedded therein: (a) upon application of a voltage to an electrode, An electrode for electrostatically holding the substrate; (b) a power bus having an output terminal for transmitting the voltage to the electrode; and (c) a fuse for connecting the electrode in series from the power bus to the output terminal. And the fuse disposed in a hollow cavity confined in the insulator. 2. The method of claim 2, wherein the hollow cavity in the insulator is free from a burn-out of the fuse without forming a conductive path between the electrode and the output terminal of the power bus. The electrostatic chuck according to claim 1, wherein the electrostatic chuck has a surface area that is set to be large enough to receive the fragments of the electrostatic chuck. 3. The hollow cavity in the insulator has the following characteristics: (a) about 0.25 to about 5 times the length of the fuse; and (b) about 0.001 to about 100 mm. ^2. The electrostatic chuck of claim 1, comprising: at least one of: a surface area of about ² ; and (c) a circular shape having a diameter of about 1 to about 5 mm. 4. The electrostatic capacitor of claim 1, wherein the insulator comprises a first layer supporting the fuse, and a second layer having the hollow cavity aligned over the fuse. Chuck. 5. The first insulating layer supporting the fuse, the second adhesive layer having a hollow cavity aligned on the fuse, and a third insulating layer covering the adhesive layer. The electrostatic chuck according to claim 1, comprising: 6. The electrostatic chuck is operated in a plasma process environment and the fuse is sufficiently severable to electrically disconnect the electrode from the output terminal as a plasma current discharge flows through the fuse. With a low amperage rating,
The electrostatic chuck according to claim 1. 7. The fuse according to claim 1, wherein: (1) the fuse electrically disconnects the electrode from the output terminal of the power bus when a current of at least about 10 mA flows through the fuse; (2) whether the fuse has a property of burning out in less than about 10 milliseconds; (3) whether the fuse has a resistor having a resistance of at least about 100Ω; (4) the fuse has a carbon, nickel, , Phosphorus, nickel-phosphorus, nickel-
(5) The fuse has the following dimensions: (i) a thickness of about 0.02 μm to about 25 μm; (ii) a width of about 10 to about 500 μm. (Iii) about 500 to 20
2. The electrostatic chuck according to claim 1, further comprising at least one of a resistor having at least one of a length of 00 μm. 8. The electrode comprises first and second electrodes sized and configured to operate as bipolar electrodes, each electrode being connected via a fuse to an output terminal of the power bus. The electrostatic chuck according to claim 1, wherein 9. A plasma processing chamber comprising the electrostatic chuck according to claim 1. 10. A puncture-resistant electrostatic chuck for holding a substrate in a process environment, the electrostatic chuck comprising an insulator having a surface thereon for receiving the substrate, wherein the insulator comprises: Embedded therein: (a) the plurality of electrodes for electrostatically holding the substrate when applying a voltage to the electrodes; and (b) power having a plurality of output terminals for conducting the voltage to the electrodes. And (c) a plurality of fuses, each fuse connecting at least one electrode in series to an output terminal from the power bus, each fuse being disposed within a hollow cavity in the insulator. An electrostatic chuck having a plurality of fuses; 11. Each hollow cavity in the insulator receives debris from a blown fuse without forming a conductive path between the electrode and the output terminal of the power bus. The electrostatic chuck according to claim 10, comprising a surface area set to be large enough to: 12. Each of the hollow cavities in the insulator has the following characteristics: (a) about 0.25 to about 5 times the length of the fuse; and (b) about 0.001 to about 100 mm. 11. The electrostatic chuck of claim 10, comprising at least one of: a surface area of about ² ; and (c) a circular shape having a diameter of about 1 to about 5 mm. 13. The insulator comprises a first layer supporting the fuse, and a second layer having the hollow cavity aligned over the fuse.
The electrostatic chuck according to claim 10. 14. A plasma processing chamber comprising the electrostatic chuck according to claim 10. 15. The method according to claim 10, further comprising applying a voltage to the electrode in the electrostatic chuck to electrostatically hold the substrate in a plasma processing chamber that processes the substrate in a plasma. How to use the electrostatic chuck. 16. A damage-resistant electrostatic chuck for holding a substrate in a process environment, comprising: (a) (i) a plurality of electrostatic chucks for electrostatically holding the substrate when applying a voltage to the electrode; (Ii) a power bus having a plurality of output terminals for conducting the voltage to the electrodes; and (iii) a plurality of fuses wherein each fuse connects at least one electrode to the output terminal of the power bus in series. (B) an upper surface of the cover layer includes an insulator that insulates the electrode, and a lower surface of the cover layer has a hollow cavity disposed around the fuse on the support layer. And a cover layer on the support layer. 17. Each of the hollow cavities in the cover layer receives debris from a blow of the fuse without forming a conductive path between the electrode and the output terminal of the power bus. The electrostatic chuck according to claim 16, wherein the electrostatic chuck has a surface area set to be large enough to perform the operation. 18. The hollow cavity in the insulator may have the following characteristics: (a) about 0.25 to about 5 times the length of the fuse; and (b) about 0.001 to about 100 mm. 17. The electrostatic chuck of claim 16, comprising: at least one of: a surface area of about ² ; and (c) a circular shape having a diameter of about 1 to about 5 mm. 19. The electrostatic chuck is operated in a plasma processing environment.
If the insulator breaks down the electrode and exposes it to the process environment, so that a current discharge from the plasma flows through the fuse,
17. The electrostatic chuck of claim 16, comprising an amperage rating low enough to electrically disconnect the electrode from the output terminal. 20. A plasma processing chamber comprising the electrostatic chuck according to claim 16. 21. A method for forming an electrostatic chuck having a plurality of electrodes connected via fuses to output terminals of a power bus, comprising: (a) a power bus having a plurality of electrodes and an output terminal; Forming a fuse on the insulating support layer; (b) forming a hollow cavity in the insulating cover layer; and (c) insulating the insulating cover layer so that each hollow cavity is aligned on the fuse. Bonding to a support layer. 22. The method of claim 21, wherein said cover layer comprises one or more adhesive and insulating layers. 23. Step (a) comprises: (i) depositing a layer of conductor and resistor material on said insulating support layer; and (ii) said conductor or resistor to form a plurality of electrodes. Etching the layer, wherein each electrode is connected to an output terminal from a power bus via a fuse. 24. The hollow cavity in the cover layer receives debris from a blown fuse without forming a conductive path between the electrode and the output terminal of the power bus. 22. The method of claim 21, comprising a surface area set to be large enough to: 25. The hollow cavity in the cover layer has the following characteristics: (a) about 0.25 to about 5 times the length of the fuse; and (b) about 0.001 to about 100 mm. 22. The method of claim 21, comprising: at least one of: a surface area of about ² ; and (c) a circular shape having a diameter of about 1 to about 5 mm.