Fixture device, substrate processing system and ion implantation system

Abstract

The present invention provides a clamp device, which may include: a clamp for clamping a substrate, wherein the clamp is arranged to be opposite to the back side of the substrate; and an irradiation system, which is configured to emit radiation to the substrate when the substrate is arranged on the clamp, wherein the radiation contains radiation energy, and the radiation energy is equal to or higher than the threshold energy for generating mobile charges in the substrate, wherein the irradiation system is configured to emit radiation to the front side of the substrate opposite to the back side of the substrate. The present invention also provides a substrate processing system and an ion implantation system.

Description

Technical Field

[0001] The present invention relates to substrate processing and, more particularly, to electrostatic chucks for holding substrates. Background Art

[0002] Substrate holders such as electrostatic clamps (also known as electrostatic chucks) are widely used in many manufacturing processes, including semiconductor manufacturing, solar cell manufacturing, and other component processing. Electrostatic clamping utilizes the principle of electrostatic induction in which the charge of electrons is redistributed in an object due to the direct influence of nearby charges. For example, a positively charged object near an electrically neutral substrate will induce a negative charge on the surface of the substrate. This charge creates an attractive force between the object and the substrate. For clamping of conductive substrates and semiconductor substrates with relatively low bulk resistivity, the redistribution of charge is easily achieved by applying a voltage to electrodes embedded in an insulator adjacent to the conductive substrate. Therefore, electrostatic clamps have been widely used to hold semiconductor substrates, such as silicon wafers with relatively low bulk resistivity.

[0003] One type of electrostatic chuck applies an alternating voltage to produce clamping, thereby enabling rapid clamping and unclamping of conductive substrates or low resistivity semiconductor substrates. However, known direct current or AC electrostatic chucks are ineffective in clamping high resistivity semiconductor substrates or electrically insulating substrates.

[0004] Additionally, substrate charging issues may adversely affect substrate processing (especially processing of high resistance substrates), such as when performing ion implantation. In addition to electrostatic chucks, non-electrostatic chucks (e.g., mechanical chucks) may contain conductive lift pins, ground pins, where the operation of such pins may be impaired when the substrate being chucked has a high resistance. Additionally, in ion implantation apparatus, charge accumulation on the substrate during implantation may require the use of charge compensation (e.g., a flood gun) to counteract the charging of the substrate.

[0005] It is with respect to these and other considerations that the present disclosure is provided. Summary of the invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be an aid in determining the scope of the claimed subject matter.

[0007] In one embodiment, an apparatus may include: a fixture for holding a substrate, wherein the fixture is arranged opposite to a back side of the substrate; and an irradiation system configured to emit radiation to the substrate when the substrate is disposed on the fixture. In this way, the radiation may be characterized by radiation energy that is equal to or higher than a threshold energy for generating mobile charges in the substrate, and the irradiation system is configured to emit radiation to a front side of the substrate opposite to the back side of the substrate.

[0008] In another embodiment, a substrate processing system may include: a process chamber; an electrostatic chuck disposed in the process chamber, the electrostatic chuck for clamping a substrate, wherein the electrostatic chuck is arranged opposite to a back side of the substrate. The substrate processing system may include an irradiation system, the irradiation system being configured to emit radiation to a front side of the substrate opposite to the back side of the substrate when the substrate is disposed on the electrostatic chuck, wherein the radiation contains radiation energy equal to or higher than 2.5 eV.

[0009] In yet another embodiment, an ion implantation system may include: a set of beamline components for generating an ion beam and projecting the ion beam to a substrate; and an electrostatic chuck for clamping the substrate, wherein the electrostatic chuck is arranged opposite to a back side of the substrate. The ion implantation system may include an irradiation system, wherein the irradiation system is arranged to project radiation to a front side of the substrate opposite to the back side of the substrate when the substrate is disposed on the electrostatic chuck, wherein the radiation contains radiation energy, and the radiation energy is equal to 2.5 eV. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A An electrostatic chuck device according to an embodiment of the present disclosure is shown.

[0011] Figure 1B A clamp device according to other embodiments of the present disclosure is shown.

[0012] Figure 1C An example of electrostatic clamping is shown.

[0013] Figure 2 A side view of an electrostatic chuck apparatus according to various embodiments of the present disclosure is shown.

[0014] Figure 3 A side view of another electrostatic chuck apparatus according to various embodiments of the present disclosure is shown.

[0015] Figure 4 A side view of yet another electrostatic chuck device according to various embodiments of the present disclosure is shown.

[0016] Figure 5A side view of yet another electrostatic chuck device according to various embodiments of the present disclosure is shown.

[0017] Figure 6 A side view of an additional electrostatic chuck arrangement is shown according to various embodiments of the present disclosure.

[0018] Fig. 7A A side view of another electrostatic chuck apparatus according to various embodiments of the present disclosure is shown.

[0019] Figure 7B and Figure 7C The geometry of a scanned radiation beam according to two different embodiments is shown.

[0020] Figure 8 A side view of yet another electrostatic chuck device according to various embodiments of the present disclosure is shown.

[0021] Fig. 9 A side view of an additional electrostatic chuck arrangement is shown according to various embodiments of the present disclosure.

[0022] Fig.10 A side view of another electrostatic chuck apparatus according to various embodiments of the present disclosure is shown.

[0023] Fig.11 A side view of another electrostatic chuck apparatus according to various embodiments of the present disclosure is shown.

[0024] Fig.12 A side view of yet another electrostatic chuck device according to various embodiments of the present disclosure is shown.

[0025] Fig.13 A side view of a processing system according to various embodiments of the present disclosure is shown.

[0026] Fig.14 Shows the relationship between radiation wavelength and energy.

[0027] Fig.15 An exemplary control system for electrostatic clamping is shown in accordance with some embodiments.

[0028] Fig.16 The relationship between charging time and resistivity for different substrate types is shown.

[0029] Fig.17 An exemplary irradiance graph of a radiation source suitable for use in the electrostatic chuck apparatus of the present embodiment is shown.

[0030] Fig.18 The generation of photocurrent is shown as a function of the irradiation energy of SiO2.

[0031] Fig.19Another exemplary irradiance graph of a radiation source suitable for use in the electrostatic chuck apparatus of the present embodiment is shown.

[0032] Fig. 20 An exemplary process flow is shown.

[0033] Fig.21 Another exemplary process flow is shown.

[0034] Fig. 22 Yet another exemplary process flow is shown.

[0035] Fig.23 Additional exemplary process flows are shown.

[0036] Fig.24 Another exemplary process flow is shown.

[0037] Fig.25 An embodiment of a processing system is shown. DETAILED DESCRIPTION

[0038] The present embodiments provide apparatus and techniques for increasing substrate clamping capabilities. In various embodiments, clamping apparatus and processing systems suitable for clamping various substrates, including high resistivity substrates, are disclosed. Various embodiments employ radiation sources capable of producing visible light as well as shorter wavelength radiation, including wavelengths in the ultraviolet (UV) range and vacuum ultraviolet (VUV) range (<200nm). Thus, various embodiments provide what may be referred to as an apparatus for light-assisted electronic clamping and release of various substrates, including irradiating the substrate with radiation before, during, and after clamping.

[0039] Figure 1A An electrostatic clamp system 100 is shown in accordance with an embodiment of the present disclosure. The electrostatic clamp system 100 may be deployed in any suitable environment in which a substrate is clamped for any suitable purpose. In various embodiments, the electrostatic clamp system 100 may be arranged in a substrate chamber 102 to accommodate a substrate 112. In various non-limiting embodiments, the substrate chamber 102 may represent a loading chamber in which a substrate 112 is loaded into the system, a transfer chamber in which a substrate 112 is transferred between locations, or a process chamber in which the substrate 112 is to be subjected to at least one process. Suitable process chambers include chambers for layer deposition on the substrate 112, for etching of the substrate 112, for heating of the substrate 112, for ion implantation into the substrate 112, or for other suitable processes.

[0040] like Figure 1AAs shown in FIG. 1 , the electrostatic clamp system 100 may include a clamp device 104, which includes an electrostatic clamp assembly 114. The electrostatic clamp assembly 114 may include known components of a known electrostatic clamp, including a cooling block, a heater, a gas channel, an electrode, wiring, etc. For clarity, only general components of the electrostatic clamp assembly 114 are shown. Figure 1A As shown in , the electrostatic clamp assembly 114 may include an insulator portion 108 directly supporting the substrate 112 and an electrode assembly 110 for applying a voltage to the insulator portion 108. In various embodiments, the electrode assembly 110 may include at least one electrode and may be operable to apply a DC voltage or an AC voltage. In some embodiments, the electrostatic clamp system 100 may be used as a known electrostatic clamp for clamping a low resistivity substrate.

[0041] like Figure 1A As further shown in FIG. 1 , the clamping device 104 may also include an irradiation system 106 configured to emit radiation (shown as radiation 120) to the substrate 112. According to various embodiments, the radiation 120 may be characterized by a radiation energy equal to or above a threshold energy for generating mobile charges in the substrate 112. In this manner, the irradiation system 106 may generate the radiation 120 while applying a clamping voltage to the electrostatic clamp assembly 114. Thus, in operation and with reference to FIG. Figure 1C When the substrate 112 is clamped by the electrostatic clamp assembly 114, the charges present in the substrate 112 can move to the electrodes of the electrode assembly 110 with opposite polarity to generate a high electric field and produce a large clamping force.

[0042] It should be noted that the time required for such charge movement depends on the resistivity of the substrate 112, such as Fig.16 As shown in Fig.16 1 and 2 show a range of resistivities for different types of commonly used substrates and the response time of the charge. The response time is shown for a substrate clamped using a clamping voltage without applying the illumination system 106. The substrate referred to as a "conventional Si wafer" represents a range of resistivities for relatively low resistance silicon wafers (showing resistivities ranging from approximately 1 Ohm-cm to 1000 Ohm-cm). In this example, the response time is approximately 1 μs to 100 μs. Fig.16 The rise time and clamping period of the AC clamp are also shown in FIG. As shown in the figure, this rise time is consistent with the response time of a conventional silicon wafer. Fig.16Also shown are the response times of the charges in a high bulk resistivity silicon wafer (HBR Si wafer), an HBR silicon carbide wafer (HBR SiC), and a glass substrate. Note that in the case of a glass substrate, the bulk resistivity of these other substrates extends beyond 10 seconds to 2 seconds to 108 seconds. These longer response times mean that the charges cannot move within these substrates within a time period consistent with the application of an AC voltage. Additionally, even with the application of a DC voltage, the response times are still too slow for practical processing purposes, especially for HBR SiC and glass.

[0043] When the resistivity of the substrate 112 is too high, the charge cannot move fast enough to establish a clamping force when a clamping voltage is applied by the electrostatic clamp assembly 114. The charging time is effectively infinite for insulating substrates such as glass wafers, which can be on the order of seconds to minutes in duration, compared to the time scale associated with clamping and processing the substrate 112. As such, without the use of the illumination system 106, substantially no substrate charge is generated in response to the applied clamping voltage, resulting in a clamping force that is nearly zero.

[0044] Thus, when the clamping device 104 is used, substrates including HBR semiconductor wafers and glass can be clamped. In addition to solving the clamping problem of high resistivity substrates, the clamping device 104 helps solve another problem, namely the generation of unwanted charges on high resistivity substrates, where removing such charges can be very difficult, for example due to triboelectricity. By generating mobile charges on the substrate 112, the clamping device 104 also facilitates the unclamping of the substrate. The high resistivity of insulating materials stems from different factors. First, these materials generally have very large electronic band gaps. For example, for silicon oxide (such as SiO2), the band gap is approximately 8 eV. Unlike dopants in semiconductors, impurities in insulators also have much higher ionization energies. Therefore, the mobile charge concentration in such substrates is very low. Secondly, many common insulating materials are amorphous (such as silica glass). The lack of a periodic crystal structure results in relatively low charge mobility. According to embodiments of the present disclosure, the conductivity of a high resistivity substrate (e.g., glass) can be significantly enhanced by transferring sufficient energy to the electrons of the high resistivity material such that the electrons enter a so-called extended state in the conduction band, upon application of radiation 120. For narrow bandgap semiconductors including Si, low energy photons (e.g., photons in infrared radiation) provide sufficient energy to overcome the bandgap. For wide bandgap semiconductor materials such as SiC, long wave UV radiation (315 nm to 400 nm) can provide sufficient energy to overcome the bandgap and generate charge carriers. For such wavelength ranges, in various non-limiting embodiments, the illumination system 106 can be implemented as a light source, including a laser diode, a light emitting diode (LED), an arc lamp, or other source.

[0045] According to additional embodiments, for substrates generally referred to as insulating substrates (e.g., glass substrates), other types of radiation sources may be used for the illumination system 106, as further described in detail below. Generally, the illumination system 106 will be arranged to provide radiation 120 with sufficient energy to generate mobile charges for the type of substrate used as the substrate 112. However, in various non-limiting embodiments, the illumination system 106 may be configured to clamp at least the following substrate types: 1) conventional silicon wafers: resistivity <1000 ohm-cm; 2) high resistivity silicon / or silicon-on-insulator (SOI) wafers: resistivity of 1000 ohm-cm to 100,000 ohm-cm; 3) silicon carbide wafers: available resistivity up to 1E9 ohm-cm; and 4) glass: resistivity >1E12 ohm-cm; 5) silicon on glass.

[0046] According to various embodiments of the present disclosure, the illumination system 106 is arranged to provide illumination to a major surface of the substrate 112 (including the front surface 112A on the front side or the back surface 112B on the back side). According to different embodiments, the radiation 120 can be provided directly in a line of sight manner, the radiation 120 can be provided by reflection, the radiation 120 can be provided by blanket illumination of the substrate, by scanning the substrate, by scanning the illumination source, or a combination of the methods. Ideally, high-intensity uniform light illumination over the entire substrate is useful. Due to limitations on the configuration of the light source and the electrostatic clamping device, certain embodiments provide novel configurations to maximize the efficiency of light generation in the substrate. In the following Figures 2 to 8 In the illustrated embodiment, a different electrostatic clamp system is shown, wherein a substrate stage 202 is shown, which may include the substrate stage as described above with respect to Figure 1A Electrostatic chuck for general description.

[0047] Go to Figure 1B , a clamping device 150 is shown according to an additional embodiment of the present disclosure. In this case, the clamping device 150 includes a mechanical clamp 154 ​​(including a support 156 as needed) to hold the substrate 112 using any suitable mechanical components. The clamping device 150 includes the above-mentioned irradiation system 106. In operation, while the substrate 112 is held by the mechanical clamp 154, radiation 120 can be emitted to the substrate 112 to increase mobile charge in the substrate 112 and assist in processing of the substrate, such as providing better conductivity between the substrate 112 and a lift pin or ground pin (not separately shown) or by reducing surface charging of the substrate 112.

[0048] Figure 2A side view of an electrostatic clamp system 200 according to various embodiments of the present disclosure is shown. In this embodiment, the irradiation system 201 is positioned to emit radiation 208 to the front surface of the substrate 112. Although in some embodiments, the substrate stage 202 may be fixed, in other embodiments the substrate stage 202 may include a scanning assembly (e.g., a known scanning assembly (not shown)) to scan the substrate 112 along at least one direction. Likewise, in some embodiments, the radiation 208 may be provided as a fixed beam that is arranged to cover the entire substrate. In some embodiments where the substrate stage 202 is arranged to scan the substrate, for example along the Y-axis of the Cartesian coordinate system shown, the radiation 208 may be provided in a manner that covers the entire scanning range of the substrate 112, such as Figure 2 . For example, the illumination system 201 may include a component referred to as an illumination source 204, including a component that generates radiation 208 at a suitable energy to generate photocarriers in the substrate 112, wherein examples of different illumination sources are described in detail below. The illumination source 204 may generate radiation as a beam having a specific size. In some embodiments, the beam emitted by the illumination source 204 may be large enough or expandable to become large enough to cover the substrate 112.

[0049] In other embodiments, the illumination system 201 may further include an optical system 206 disposed between the illumination source 204 and the substrate 112 to expand the radiation beam received from the illumination source 204 and to expand the radiation beam used to generate the radiation 208 to cover the entire substrate 112. An example of an optical system suitable for the optical system 206 is a set of refractive optical devices, such as optical lenses. In this embodiment and the following embodiments, the "optical system" will provide the ability to handle radiation in the UV range, which means that the refractive optical device will mean an optical device for refracting UV radiation, and the mirror optical device will be suitable for reflecting UV radiation.

[0050] Figure 3 A side view of an electrostatic clamp system 220 according to various embodiments of the present disclosure is shown. In this embodiment, the irradiation system 211 is positioned in a different manner to emit radiation 212 to the front surface of the substrate 112. Although in some embodiments, the substrate stage 202 may be fixed, in other embodiments, the substrate stage 202 may include a scanning component (such as a known scanning component (not shown)) to scan the substrate 112 along at least one direction. Likewise, in some embodiments, the radiation 212 may be provided as a fixed beam that is arranged to cover the entire substrate. In some embodiments where the substrate stage 202 is arranged to scan the substrate, for example along the Y-axis of the Cartesian coordinate system shown, the radiation 212 may be provided in a manner that covers the entire scanning range of the substrate 112, such as Figure 3 For example, the illumination system 211 may include the above Figure 2The illumination source 204 discussed. The illumination source 204 may generate radiation as a beam having a specific size. In such a configuration, the illumination source 204 may emit radiation as a beam that is not emitted toward the substrate 112 at the beginning. The illumination system 211 may also include an optical system 210, which is arranged to reflect the beam generated by the illumination source 204 and emit the reflected beam as radiation 212 to the substrate 112. The optical system 210 may include an optical mirror, and in some embodiments, the optical mirror may be arranged as an expansion mirror to expand the radiation beam received from the illumination source 204, reflect and expand the radiation beam used to generate the radiation 212 to cover the entire substrate 112. In additional embodiments, the illumination system may include a combination of refractive optics and mirror optics. The selection of optics for illumination can be guided by considering the spacing and placement of elements and the efficiency of generating illumination covering the substrate 112.

[0051] Figure 4 2 shows a side view of another electrostatic clamping system 250 according to various embodiments of the present disclosure. In this example, the electrostatic clamping system 250 may include the substrate stage 202 and the illumination source 204 generally described above. The electrostatic clamping system 250 may further include an illumination system 251 having an optical system 252, which includes components that provide scanning capabilities for the radiation beam received from the illumination source 204. Figure 2 The illustrated embodiment is different. The scanning capability may be provided by, for example, a motorized assembly. According to various embodiments, the radiation may be provided as a radiation beam 254A expanded from an initial beam size.

[0052] According to various embodiments of the present disclosure, the optical system 252 provides beam scanning of the radiation beam 254A. In some embodiments, in a configuration where the substrate 112 is scanned, the optical system 252 may also scan the radiation to follow the scan of the substrate 112. For example, the illumination source 204 and the optical system 252 may include refractive optics that generate the radiation beam 254A as a beam having a width that covers the substrate 112.

[0053] The optical system 252 may be further configured with a lens drive mechanism that is arranged to move the optical lens by rotation, translation, or rotation and translation. For example, the optical system 252 may be further configured with a scanning assembly, wherein when the substrate 112 is scanned along the Y axis at a rate of 10 cm per minute, the radiation beam 254A is scanned in the same direction at the same rate so that the radiation beam 254A covers the substrate 112 in any case. In this way, even when the substrate 112 is scanned, the width of the radiation beam 254A emitted to the substrate 112 does not need to be significantly larger than the width of the substrate, thereby protecting other components in the rest of the chamber that accommodates the substrate 112.

[0054] In other embodiments, the radiation beam 254A may be provided as a relatively narrow beam (e.g., a laser beam or a highly collimated incoherent beam) compared to the width of the substrate 112. This embodiment is represented by the radiation beam 254A, which is shown as having a much smaller width relative to the width of the substrate 112, at least along the Y direction. In this embodiment, the optical system 252 may be provided with components that rapidly scan the radiation beam 254A, for example, along the Y direction, in a manner that provides an average uniform irradiation to cover the entire substrate 112. In embodiments where the substrate 112 remains stationary, the optical system 252 may therefore simply scan the radiation beam 254A in a rapid manner to produce a radiation umbrella that covers the stationary substrate.

[0055] Figure 5 2 shows a side view of another electrostatic clamp system 260 according to various embodiments of the present disclosure. In this example, the electrostatic clamp system 260 may include the substrate stage 202 and the illumination source 204 generally described above. The electrostatic clamp system 260 may further include an illumination system 261 having an optical system 262, which includes components that provide scanning capabilities for the radiation beam received from the illumination source 204. Figure 3 The illustrated embodiment is different. The scanning capability may be provided by, for example, a motorized assembly. According to various embodiments, the radiation 264 may be provided as a beam expanded from an initial beam size.

[0056] According to various embodiments of the present disclosure, the optical system 262 provides beam scanning of the radiation 264. In some embodiments, in a configuration where the substrate 112 is scanned, the optical system 262 may also scan the radiation to follow the scanning of the substrate 112. For example, the illumination source 204 and the optical system 262 may include a reflective optical device (e.g., a UV mirror) that produces the radiation 264 as a beam having a width that covers the substrate 112. The optical system 262 may be further configured with a scanning component, wherein when the substrate 112 is scanned at a given rate along the Y axis, the radiation 264 is scanned in the same direction at the same rate so that the radiation 264 covers the substrate 112 in any case. In this way, even when the substrate 112 is scanned, the width of the radiation 264 emitted to the substrate 112 does not need to be significantly larger than the substrate width, thereby protecting other components in the rest of the chamber containing the substrate 112.

[0057] In other embodiments, the radiation from the illumination beam may be provided as a relatively narrow beam compared to the width of the substrate 112 (eg, a laser beam or a highly collimated incoherent beam). Figure 6112. The electrostatic clamping system 270 shown in is represented. The substrate stage 202 can be configured as generally in the previous embodiments. In this embodiment, the illumination system 271 includes an illumination source 272 that produces a narrow beam, which is shown as having a much smaller width relative to the width of the substrate 112 at least along the Y direction. The illumination source 272 can be a laser source or a collimated incoherent light source. In this embodiment, an optical system 274 can be provided with a refractive component to receive and transmit the beam emitted from the illumination source 272 as a narrow beam shown as a radiation beam 276 and scan the radiation beam 276 along, for example, the Y direction in a manner to provide an average uniform irradiation to cover the entire substrate 112.

[0058] In embodiments where the substrate 112 remains stationary, the optical system 274 may therefore only scan the radiation beam 276 in a rapid manner to produce a radiation umbrella 278 that covers the stationary substrate. In other embodiments where the substrate 112 is also scanned along the Y-axis, for example, the optical system 274 may include components that both rapidly scan the radiation beam 276 across the substrate 112 and slowly shift the average position of the radiation beam 276 in synchronization with the movement of the substrate. In this manner, the radiation beam 276 produces a radiation umbrella 278 whose dimensions along the Y-axis closely correspond or match the dimensions of the substrate along the Y-axis, and whose position is arranged so that the radiation umbrella 278 overlies the entire substrate 112 or a desired portion of the substrate 112 while not extending beyond the substrate 112. More generally, the electrostatic clamping system 270 may include a synchronization component to synchronize the movement of the optical lens with the movement of the substrate stage scanner (shown by the double arrows) so that the radiation beam remains aligned with the front side of the substrate 112 during scanning of the substrate 112. In Fig. 7A Another embodiment in which the radiation beam is provided as a scanned narrow beam is shown in FIG. This embodiment is represented by an electrostatic clamping system 280, in which the substrate stage 202 may be configured as in the previous embodiments. In this embodiment, the illumination system 281 may include an illumination source 272 that produces a narrow beam, as described above for Figure 6 In this embodiment, the optical system 284 may be provided with components that reflect the beam emitted from the illumination source 272 as a narrow beam (shown as radiation beam 286) and scan the radiation beam 286 along, for example, the Y direction to cover the entire substrate 112 in a manner that provides an average uniform irradiation.

[0059] In embodiments where the substrate 112 remains stationary, the optical system 284 may therefore only scan the radiation beam 286 in a rapid manner (e.g., by causing a mirror to move or rotate rapidly) to produce a radiation umbrella 288 that covers the stationary substrate. In other embodiments where the substrate 112 is also scanned, for example, along the Y-axis, the optical system 284 may include components that both rapidly scan the radiation beam 286 across the substrate 112 and slowly shift the average position of the radiation beam 286 in sync with the movement of the substrate. In this manner, the radiation beam 286 produces a radiation umbrella 288 whose dimensions along the Y-axis closely correspond or match the dimensions of the substrate along the Y-axis, and whose position is arranged so that the radiation umbrella 288 overlies the entire substrate 112 or a desired portion of the substrate 112 while not extending beyond the substrate 112.

[0060] In various embodiments in which the optical system provides radiation to the substrate 112 as a scanned narrow radiation beam, the scanned radiation beam may be provided as a spot beam or a ribbon beam within the plane of the substrate 112 (this means within the XY plane, as shown). Figure 7B An embodiment is shown in which radiation beam 276 or radiation beam 286 is provided as a ribbon beam elongated along the X-axis. The ribbon beam may have a length dimension comparable to the length of substrate 112 along the X-axis, and thus may not be scanned along the X-axis, but only along the Y-axis to produce radiation umbrella 278 or radiation umbrella 288. Figure 7C An embodiment is shown in which radiation beam 276 or radiation beam 286 is provided as a spot beam having a relatively small size compared to the width of substrate 112 along the X-axis, and can therefore be scanned along both the X-axis and the Y-axis to produce radiation umbrella 278 or radiation umbrella 288.

[0061] In additional embodiments, the electrostatic chuck system may include optics that combine a mirror assembly with a refractive assembly to direct the radiation beam toward the substrate.

[0062] Figure 8 2 shows a side view of another electrostatic clamping device according to various embodiments of the present disclosure. In this embodiment, an electrostatic clamping system 290 including the substrate stage described above is shown. Different from the embodiments described above, the electrostatic clamping system 290 includes an irradiation system 291 including a plurality of irradiation sources. Figure 8 The illustrated embodiment includes two different illumination sources (illustrated as illumination source 204A and illumination source 204B), each of which may be configured similarly to illumination source 204 described above. However, in other embodiments, more than two illumination sources may be employed. Figure 8In the illustrated configuration, illumination system 291 includes an optical system 292 arranged to project two radiation beams toward substrate 112 using a mirror configuration of mirror system 292A and mirror system 292B to reflect radiation generated by illumination source 204A and illumination source 204B and shown as radiation 294A and radiation 294B, respectively. In various variations, optical system 292 may be used in conjunction with, for example, Figure 3 , Figure 5 or Fig. 7A The previously described embodiments shown operate similarly, where a wide beam may be reflected onto the substrate 112, a narrower beam is reflected onto the substrate, and either a slow scan or a fast scan of the radiation beam is provided as described above. Figure 8 The illustrated configuration provides the advantage of being able to more uniformly illuminate the substrate 112 than using a single radiation beam. In other embodiments, multiple illumination sources may be coupled to corresponding multiple refractive optical systems (with Figure 2 , Figure 4 and Figure 6 The configuration shown is similar to that shown in the figure) to emit multiple radiation beams to the substrate 112, or multiple illumination sources can be coupled to a combination of at least one refractive optical system and at least one mirror optical system. Such an embodiment can be useful for placing an optical system within a given processing apparatus where the configuration of other components, such as a substrate table, and processing components may place restrictions on the location of other components.

[0063] One disadvantage of directing the illumination to the front surface of the substrate is that photocarriers tend to be generated near the front surface while clamping occurs on the back surface of the substrate. For high mobility materials, the generation of photogenerated charge carriers near the front surface is not a problem for clamping the substrate because the carriers can traverse the substrate quickly, but for low mobility materials (such as glass), the charge carriers may take too long to reach the back side of the wafer. In further embodiments of the present disclosure, the illumination system may be arranged to direct the illumination to the back side of the substrate.

[0064] Fig. 9A side view of an additional electrostatic clamping device according to various embodiments of the present disclosure is shown. In this embodiment, the electrostatic clamping system 300 is arranged with an illumination system 301, wherein at least a portion of the illumination system 301 is embedded in a substrate stage 302. It should be noted that the substrate stage 302 can be configured similarly to the previous embodiment of the substrate stage 202, and can include an electrostatic clamp and a scanning assembly for scanning the substrate stage 302. The illumination system 301 can include a plurality of illumination sources (illustrated as illumination source 304, illumination source 306, and illumination source 308) distributed in various positions in the XY plane. In general, the different illumination sources can be distributed across the substrate stage 302 in a one-dimensional array or a two-dimensional array, wherein the substrate stage includes an opening facing the substrate 112 to transmit radiation directly to the back side including the back surface 112B of the substrate 112 without obstruction. In other words, the gap between the substrate stage 302 and the substrate 112 can be used as a hollow light guide so that radiation such as UV light is beyond the entry point.

[0065] although Fig. 9 The illustrated embodiment shows an illumination system having multiple illumination sources, however in other embodiments a single illumination source may be employed. Fig.10 A side view of another electrostatic clamping device according to various embodiments of the present disclosure is shown. In this embodiment, the electrostatic clamping system 310 is arranged with an illumination system 311, wherein a portion of the illumination system 311 is embedded in the substrate stage 312 and a portion is located outside the substrate stage 312. It should be noted that the substrate stage 312 can be configured similarly to the previous embodiment of the substrate stage 202 and can include an electrostatic clamp and a scanning component for scanning the substrate stage 312. The illumination system 311 includes an illumination source 314, which may represent only one illumination source. The illumination source 314 is coupled to a plurality of light guides (optical light guides) extending through the substrate stage 312 so that radiation can be provided directly to the back surface 112B of the substrate 112. In general, different light guides can be distributed across the substrate stage 312 in a one-dimensional array or a two-dimensional array, wherein the substrate stage includes a plurality of openings 319 facing the substrate 112 to transmit radiation directly to the back surface 112B of the substrate 112 without obstruction. For simplicity, these light guides are shown as light guide 320, light guide 316, and light guide 318. As shown, the plurality of light guides are connected to the illumination source 314 at distal ends and have proximal ends extending through the plurality of openings 319, respectively.

[0066] Fig. 9 and Fig.10 The aforementioned embodiments shown thus provide an efficient way of coupling high energy radiation (eg UV radiation) directly to a substrate in a uniform manner.

[0067] Fig.111 shows a side view of another electrostatic clamping device according to various embodiments of the present disclosure. In this embodiment, the electrostatic clamping system 350 includes a substrate stage 352 having an illumination system 351 embedded in the substrate stage 352. It should be noted that the substrate stage 352 can be configured similarly to the aforementioned embodiment of the substrate stage 202 and can include an electrostatic clamp and a scanning component for scanning the substrate stage 352. The illumination system 351 includes an illumination source 354 embedded in the substrate stage 352 and a set of coupling optical devices (shown as coupling optical devices 356) to receive radiation from the illumination source 354 and output radiation 358 in a direction to couple the radiation 358 to the back surface 112B of the substrate 112. As shown in FIG. Fig.11 As shown in , the gap between the substrate stage 352 and the substrate 112 can act as a hollow light guide.

[0068] although Figures 2 to 11 The above embodiments are described with respect to an electrostatic clamp, however, in other embodiments, a mechanical clamp may be used to implement Figures 2 to 11 The irradiation system shown.

[0069] Fig.12 A side view of yet another electrostatic clamping device according to various embodiments of the present disclosure is shown. In this embodiment, the electrostatic clamping system 360 includes an irradiation system 361 formed by an irradiation source and an electrode assembly 368 disposed within a substrate stage 362, the irradiation system 361 being configured to emit radiation 366 toward the back side of the substrate 112 (see back surface 112B). It should be noted that the substrate stage 362 can be configured to include an electrostatic clamp and a scanning assembly for scanning the substrate stage 362. Unlike known electrostatic clamps, the substrate stage assembly including the electrostatic clamp assembly can be formed of a material that is transparent to the radiation 366. For example, the dielectric material used for the stage assembly and the electrostatic clamp (including the transparent stage body) and the cooling gas emitted into the substrate stage 362 can be made of a material that is transparent to the UV light used to form the radiation 366.

[0070] like Fig.12 , the radiation 366 may form a wide radiation beam that covers a majority of the substrate 112 or the entire substrate 112. In this embodiment, the electrostatic clamp portion (not separately shown) of the substrate stage 362 includes an electrode assembly 368 that is arranged as one or more electrodes in the form of a metal grid or metal mesh, wherein the transparency of the metal grid is high. In this way, the metal mesh can act as a uniform electrode system for electrostatic clamping while providing high transparency for UV radiation or other high energy radiation emitted by the illumination source 364.

[0071] In an additional embodiment of the present disclosure, an electrostatic clamping system (including Figures 1A to 12The disclosed embodiments) or variations thereof can be deployed in a substrate processing system to process a substrate. In some embodiments, an electrostatic clamping system is provided in a substrate processing chamber so that a substrate can be held while being processed. Fig.13 A side view of one such processing system is shown in accordance with various embodiments of the present disclosure. As shown, processing system 380 includes process chamber 382, ​​which can house various components of an electrostatic clamping system, including substrate stage 385 and illumination system 391. In the configuration shown, illumination system 391 includes reflective optics for front-side illumination, while in other embodiments, the illumination system can be based on refractive optics for front-side illumination or can be based on back-side illumination, wherein these various configurations have been described with reference to FIG. Figures 1A to 12 In this example, the illumination source 388 is disposed outside the substrate stage 385. In different embodiments, the illumination source 388 may be disposed within the process chamber 382, ​​partially disposed within the process chamber 382, ​​or disposed outside the process chamber 382. Fig.13 In the example shown, the illumination source 388 emits a beam to the UV mirror 392, which reflects the beam to emit radiation 396 to the substrate 112. The geometric configuration of the illumination source 388, the UV mirror 392, and the substrate 112 is arranged to ensure that the source UV beam generated by the illumination source 388 is appropriately expanded to cover the substrate. Similar to some of the aforementioned embodiments, a mirror drive mechanism may be incorporated and arranged to move an optical mirror, such as the UV mirror 392, by rotation, translation, or both. Fig.13 , the scanning motor 390 is mechanically coupled to the UV mirror 392 to scan the UV mirror 392 in accordance with the movement or scanning of the substrate 112 described above. In some implementations, a control system 398 coupled to the UV mirror 392 and the substrate stage 394 is used to control the scanning of the UV mirror 392 and the substrate stage 394 so that the expanded beam (radiation 396) follows the movement of the substrate in a manner that most or all of the radiation 396 is intercepted by the substrate 112. Thus, the control system 398 can generate scanning control and position sensing signals for controlling the substrate stage 394 and optical beam scanning control and position sensing signals for controlling the scanning motor 390 and the UV mirror 392.

[0072] The UV photons of radiation 396 are provided to generate sufficient mobile charges so that the substrate can be adequately clamped by an electrostatic clamp (not separately shown) within the substrate stage 394 even though it has a high band gap above 2.5 eV.

[0073] The processing system 380 also includes a beam generation assembly 384 to emit an ion beam 386 into the process chamber 382. The ion beam 386 can implant ions into the substrate 112 while the substrate 112 is held in place by the action of an electrostatic chuck system including an irradiation system 391 and an electrostatic chuck located within a substrate stage 394. Unlike known ion implantation systems, the processing system 380 can conveniently implant into highly resistive or insulating substrates where the substrate remains electrostatically clamped to the substrate stage.

[0074] Despite Fig.13 In the embodiment shown in , the beam generation assembly 384 may represent a series of beam line components for transmitting the ion beam to the substrate, however in other embodiments, the process system of the aforementioned embodiment including the electrostatic clamping system can be used to process the substrate for any suitable process (including film deposition, etching, heating, etc.).

[0075] In various embodiments of the present disclosure, the control system 398 or a similar control system may be used to enhance the ability of a UV irradiation system or a high energy irradiation system to assist in electrostatic clamping of a high resistivity substrate. It should be noted that, depending on the configuration of the process chamber and the capabilities of the irradiation source, the irradiation of the substrate may need to be synchronized with the scanning of the substrate and the electronic clamping of the substrate to improve the effectiveness of the irradiation. As previously described, when a scanning UV beam is used to irradiate the substrate, the control system 398 may synchronize the scanning of the UV beam with the scanning of the substrate stage. Fig.15 An exemplary control system arrangement 400 for electrostatic clamping according to some embodiments is shown. In this example, a controller 398A is coupled to various components of the electrostatic clamping system. For simplicity, an irradiation system 402 is shown that emits radiation 404 to the front side of the substrate 112 without using any optical components. It should be noted that the irradiation system 402 may include the components for scanning the radiation 404 described above. An electrostatic clamp 406 is disposed in a substrate stage 408 and includes an AC electrode system 410. A motor 412 is coupled to the substrate stage to scan the substrate stage 408. In addition, an AC voltage source 414 is coupled to the AC electrode system 410 to supply a voltage signal (including an AC voltage) to the electrodes of the AC electrode system 410. The controller 398A can be coupled to the irradiation system 402, the motor 412, and the AC voltage source 414 to synchronize the actions of these components. For example, the timing of irradiating the substrate 112 can be synchronized with the electronic excitation of the substrate using the controller 398A. In some embodiments, the controller 398A can be used to output the AC voltage source 414 to provide a given voltage waveform whose amplitude, AC frequency, and rise time are arranged to ensure that sufficient photocarriers can be generated within the same half cycle of the AC voltage. The details of the given voltage waveform can be based on the available UV intensity generated by the illumination system 402.

[0076] In certain embodiments, the controller 398A may monitor the current clamping signal of the electrostatic chuck 406 to determine the charging condition of the substrate 112. In some embodiments, the clamping current signal may also be used to sense the wafer type before initiating substrate clamping.

[0077] Examples

[0078] Irradiation source

[0079] According to some embodiments, illumination system 106 or any of the other aforementioned illumination sources may be a visible light source. These embodiments of visible light sources will be particularly suitable for use with low bandgap semiconductor substrates (e.g., silicon, III-V compound semiconductors, II-VI compound semiconductors) where the bandgap may be below approximately 2.5 eV.

[0080] According to other embodiments, the illumination system 106 or any of the other aforementioned illumination sources may be a long wavelength UV source, producing a wavelength range between 120 nm and 240 nm (which means an energy range of approximately 3 eV to 4 eV, such as Fig.14 These embodiments of the UV radiation source will be particularly suitable for use with wide bandgap semiconductor substrates such as silicon carbide (SiC).

[0081] According to further embodiments, the illumination system 106 or any of the other aforementioned illumination sources may be a VUV source, thereby generating radiation in a wavelength range of 120 nm to 240 nm or below (which means an energy range of approximately 5 eV to 10 eV or above 10 eV). These embodiments of VUV radiation sources will be particularly suitable for use with insulator substrates such as glass.

[0082] In some examples, any of the aforementioned illumination sources may be a multi-wavelength source, where a wide wavelength range may be obtained from a single illumination source or from multiple different illumination sources. The same electrostatic chuck system may thus employ light sources with multiple wavelengths, where the shortest wavelength source is selected for substrates with the highest energy band gap, while sources with longer wavelengths and higher radiant flux may be selected for substrates that require less photon energy to bridge the band gap to achieve higher conductivity.

[0083] While in some instances lasers may be employed to produce single wavelength radiation, in other instances incoherent light sources may be used to produce radiation characterized by a continuous wavelength spectrum or a discrete wavelength spectrum where the power is highly concentrated around a small number of resonant spectral lines (frequencies).

[0084] In certain examples, filters can be used to further tailor the output wavelength spectrum from the illumination source. For example, for some substrate processing applications, a silicon wafer is bonded to a glass substrate using a UV-sensitive adhesive. If the radiation emitted from the illumination source is filtered out using a filter disposed between the illumination source and the substrate to remove longer wavelengths that are transparent to the glass, then the shorter wavelength portion of the radiation can be used to generate photocarriers within the glass without completely penetrating through the glass and damaging the adhesive.

[0085] Non-limiting examples of suitable laser sources include diode lasers producing wavelengths as low as 191 nm, other solid-state lasers, excimer lasers (eg, ArF, KrF, F2), continuous wave lasers, pulsed lasers, and the like.

[0086] Examples of suitable incoherent sources include deuterium lamps, electrodeless lamps (including line sources or continuous wavelength sources). An example of a deuterium lamp source output spectrum is given in Fig.19 Some details are omitted for clarity. The output of such a source may be suitable for generating charge carriers in insulators having a band gap above about 6 eV. Some examples of commercially available resonant line sources are shown in Table I, including the type of radiation source and the wavelength of radiation. Some examples of commercially available continuum sources are shown in Table II.

[0087] (nm) hydrogen 121.6 krypton 116.5 123.6 xenon 129.6 147.0 mercury 184.9 253.7 iodine several

[0088] Table I

[0089] (nm) Argon 110-140 krypton 127-160 xenon 150-190

[0090] Table II

[0091] In one example, a VUV argon continuum source is used as the illumination source to aid in electrostatic clamping of glass or fused silica substrates. Fused silica has a bandgap of approximately 8 eV, which requires a light source with a wavelength < 150 nm to generate photocarriers. Fig.18 The photocurrent generated by the glass substrate varies with the photon energy. As shown in the figure, no photocurrent is generated below 8 eV, the photon energy gradually increases until it reaches 9 eV, above which the photocurrent increases rapidly, and the photocurrent reaches saturation at 10 eV or above. The reference dotted line at 9.5 eV is shown. In one embodiment, an ArCM-LHP high-power argon continuum source can be used to generate Fig.17The output spectrum is idealized, omitting certain minor details while illustrating the general characteristics of the argon emission spectrum. As shown, the peak wavelength is in the range between 116 nm and 140 nm, with most of the integrated intensity of the broad emission spectrum located at wavelengths below approximately 133 nm (indicated by the dashed line), corresponding to energies at or above 9.5 eV. This energy range matches the energy range in which photocurrent generation in glass is significant, such as Fig.18 Such sources are commercially available in a relatively compact footprint to fit easily into a common processing chamber.

[0092] UV Mirror

[0093] In one example, an aluminum mirror with a MgF2 coating can be used as a UV mirror to produce high reflectivity in the UV range and VUV range. Commercially available mirrors based on such materials can produce reflectivity greater than about 75% in the wavelength range from at least 300 nm down to 120 nm, providing efficient reflectivity of the initial UV beam. Such high reflectivity will facilitate beam expansion and steering using well-known methods for visible light mirror systems.

[0094] AC clamping of glass substrates using an argon arc lamp to achieve electrostatic clamping:

[0095] As described above, in the absence of photocarriers such as those generated according to the foregoing embodiments, when attempting to chuck an insulating substrate (dielectric substrate), the chuck electrodes of the electrostatic chuck (electronic chuck) establish an electric field throughout the dielectric.

[0096] Using the front-side illumination disclosed above, charge carriers are generated at the top of the insulating substrate. Under the influence of the applied electric field, the carriers are directed toward the back surface of the substrate (see Figure 1C ) moves. As a result of this process, the electric field in the gap between the substrate and the electron holder is strengthened. In the absence of charge carrier generation, the electric field in the gap is approximately V / w, where V is the voltage difference between the electrodes and w is the spacing between the electrodes. If the surface charge layer is as Figure 1C , the electric field in the gap is approximately V / d, where d is the gap between the substrate and the electrode and the dielectric thickness of the dielectric material. This thickness is typically much smaller than the electrode spacing. Electric field intensifications of 10 to 100 times can be easily achieved, corresponding to intensifications of 100 to 10,000 times in the clamping force. Therefore, a useful goal is to establish a high enough surface charge density in a short enough time to realize the potential benefits of increased clamping force. For example, to achieve effective AC clamping, the time for charge accumulation needs to be much shorter than the period of the applied AC voltage.

[0097] In the subsequent calculations, it is assumed that the known ArCM-LHP lamp is used as the one producing Fig.18 The radiation spectrum of the illumination source is shown in FIG. 6 , where the lamp can deliver electrons with energies above the SiO2 band gap of about 8 eV. 16 Photons / second / steradian and fixed angle The corresponding output angle 2θ=45°. The calculations can be adjusted quantitatively for different output angles and photon fluxes, as will be appreciated by those skilled in the art. UV mirrors can also be used to introduce reflection losses into the beam output by the lamp. In addition, it can be assumed that the expanded beam area is slightly larger than the substrate area, which also reduces the utilization of the beam flux. It is assumed that the mirror losses together with the substrate external beam losses result in a 50% loss of the available beam flux. This assumption indicates that 1.45×10 16 Photon flux of photons / second or Φ of a 300mm wafer = 2×10 13 Photons / second / cm 2 . The transport of photocarriers in silicon dioxide has been extensively studied previously, both experimentally and numerically. Photoconduction is a complex process. The conduction current is affected by factors such as light absorption, quantum yield, lifetime of mobile carriers (which depends on recombination and trapping rates and can be very different for electrons and holes), electron and hole mobilities (which can differ by many orders of magnitude), space charge accumulation in the insulator, and charge transfer across the interface between the substrate and the electron fixture. Therefore, estimating the current based on basic material properties is not appropriately reliable, and instead, the current calculations in this paper are based on experimentally measured photocurrents. In one specific example, the electron fixture was designed so that an electric field strength of 5 kV / mm was achieved in a glass substrate. The results of known studies have shown that at the above electric field values, at 5×10 11 Photons / second / cm 2 A flux of 7.6×10 -9 A / cm 2 In this example, a higher lamp intensity (2×10 13 Photons / second / cm 2 ), the current density is estimated to be J = 3 × 10 -7 A / cm 2 Under the experimental condition of a target clamping pressure of 50 torr, the charge density required to generate this clamping force is given by the following formula:

[0098]

[0099] Therefore, the characteristic charging time in this example is given by:

[0100]

[0101] This time is fast enough for low frequency AC excitation, for example with a frequency of 1 Hz to 2 Hz or a period of 500 ms to 1 s. It should be noted that this estimate of the characteristic charging time is an estimate of the order of magnitude of the response time using a practical electronic fixture electronic design and a commercially available VUV source. The estimate shows the feasibility of achieving practical AC clamping of insulating glass wafers using the above method. In other examples, the charging time can be shortened to less than 0.1 seconds by increasing the VUV intensity using multiple light sources and optimizing the electronic fixture electronic design and increasing the electric field.

[0102] Clamping of high resistivity Si wafers and SiC wafers

[0103] As mentioned above, commercially available HBR silicon wafers can show resistivities in the 100 kOhm-cm range. For SiC substrates, resistivities of 10 9 Ohm-cm. However, a practical system for generating photocarriers in a commonly used HBR semiconductor substrate may employ a UV light source, where the primary energy output is at a slightly longer wavelength (>250 nm) than the energy output of a SiO2 substrate, since the band gaps in Si and SiC are much smaller than those in SiO2. In addition, crystalline semiconductors such as Si and SiC have high electron and hole mobility and fewer defects that create traps compared to glass, and the structure also helps to reduce the transit time of photocarriers under an electric field. Therefore, assuming that the above experimentally based results indicate that the charging time of SiO2 is about 0.1 seconds, charging times significantly less than this time may be achieved for HBR Si substrates and HBR SiC substrates, which may be achieved using the exemplary irradiation source and fixture apparatus disclosed herein.

[0104] Although the foregoing embodiments focus on the use of high energy irradiation to achieve clamping enhancement of high resistivity substrates, de-clamping may also be enhanced according to additional embodiments. In other words, when an electrostatic clamp is used to clamp a semiconductor substrate or an insulating substrate, the clamping voltage may be removed in the event that the substrate is to be de-clamped. According to the embodiments disclosed above, to enhance the de-clamping of the substrate, photocarriers may be generated by exposure to an irradiation source. In this way, the decay rate of the previously established electric field and the removal of certain charges (e.g., to neutralize residual static charges) may be accelerated. Such enhancement may be applied to "conventional" semiconductor substrates with relatively low band gaps (e.g., in the visible range) as well as HBR semiconductor substrates and insulator substrates.

[0105] Fig. 20An exemplary process flow 500 is shown. At block 502, a substrate is provided on an electrostatic clamp assembly. In some embodiments, the substrate may be a HBR semiconductor substrate or an insulating substrate. At block 504, a clamping voltage (e.g., a DC voltage or an AC voltage) is applied to the electrostatic clamp assembly. At block 506, radiation is emitted to the substrate while the substrate is disposed on the electrostatic clamp assembly. The radiation may be characterized by an energy greater than a band gap of the HBR semiconductor substrate or the insulating substrate. The radiation may be emitted to a front surface of the substrate or to both back surfaces of the substrate. In this manner, the radiation may have sufficient energy and sufficient intensity to generate charge carriers within the substrate such that a target clamping force is generated when the clamping voltage is applied.

[0106] Fig.21 Another process flow 550 is shown according to an additional embodiment. At block 552, a high bandgap substrate is provided on an electrostatic clamp assembly. At block 554, high energy radiation is emitted to the substrate while the substrate is disposed on the electrostatic clamp assembly. The high energy radiation may have an energy above the bandgap of the substrate, wherein the energy may be sufficiently above the bandgap to generate charge carriers in the substrate. Non-limiting examples of high energy radiation include UV radiation or VUV radiation. At block 556, an AC clamping voltage waveform is applied to the electrostatic clamp assembly, wherein the AC clamping voltage waveform is characterized by an amplitude, a frequency, and a rise time. In this way, the AC clamping voltage waveform combined with the high energy radiation can be configured to generate sufficient photocarriers to establish a target clamping pressure during half a cycle of the AC clamping voltage waveform.

[0107] Fig. 22 Another exemplary process flow 600 is shown. At block 602, a high bandgap substrate is provided on an electrostatic chuck assembly. At block 604, a clamping current signal is detected to determine the substrate type of the high bandgap substrate. At method 606, high energy radiation is emitted to the substrate while the substrate is disposed on the electrostatic chuck assembly. At block 608, an AC clamping voltage waveform is applied to the electrostatic chuck assembly from an AC power source. In this way, the AC clamping voltage waveform can be characterized by a narrow high voltage pulse portion and a long duration low voltage portion, wherein the maximum charge transferred by the high voltage pulse portion is limited to be below a predetermined threshold.

[0108] Fig.23Another exemplary process flow 650 is shown. At block 652, a substrate is clamped to a substrate stage by an electrostatic clamp assembly. The substrate may be a silicon substrate, a silicon carbide substrate, a glass substrate, or other substrate. The substrate may be a low bandgap substrate or a high bandgap substrate. At block 654, the substrate is processed while it is on the substrate stage. The processing may be any suitable process. At block 656, at the end of the processing, high energy radiation is emitted to the substrate to remove static charge. The high energy radiation may be an energy above the bandgap of the substrate. The high energy substrate may be applied while removing the clamping voltage generated by the electrostatic clamp assembly.

[0109] Fig.24 Another exemplary process flow 700 is shown. At block 702, a substrate is clamped to a substrate table using an electrostatic clamp in combination with high energy radiation. The high energy radiation may have an energy above the band gap of the substrate and an intensity sufficient to produce charge carrier motion in the substrate sufficient to produce a target clamping pressure. At block 704, the substrate is scanned while using the substrate table during a processing interval. At block 706, the scanning of the substrate by the substrate is synchronized with the scanning of the radiation beam. In some variations, the radiation beam may be a wide beam that covers most of the substrate, wherein the scanning of the radiation beam involves scanning the wide beam at the same rate as the scanning of the substrate to ensure that most or all of the radiation beam is intercepted by the substrate. In some variations, the radiation beam may be a narrow beam that covers a narrow portion of the substrate, wherein the scanning of the radiation beam involves rapidly scanning the narrow beam back and forth to cover the target portion of the substrate, thereby producing a beam umbrella or beam envelope, while superimposing a slower scan rate at the same rate as the scanning of the substrate to ensure that most or all of the beam envelope is intercepted by the substrate as the substrate moves.

[0110] Although the foregoing embodiments focus on applications related to substrate clamping, in further embodiments, devices and techniques may be applied to reduce substrate charging in various processing environments. In various processing devices, including plasma devices, ion beam devices, and other devices, charged particles, including ions (ionic species) or electrons, may be used as process species to process substrates, where charging may occur in the substrate during processing. This situation is particularly acute for new substrates, such as SiC substrates, silicon-on-insulator (SOI) substrates, and glass substrates, where such substrates may generate charge during processing that is not removed due to the low mobility of charge carriers in such substrates.

[0111] According to an embodiment of the present disclosure, an illumination system (e.g., for Figures 1A to 13 and Fig.15 ion systems disclosed herein) to facilitate charge removal during substrate processing. Fig.25An embodiment of a processing system 800 for processing a substrate 112 is shown. According to various non-limiting embodiments, the processing system 800 may include a source 806 to emit a processing substance such as an ion beam, an electron beam, or a plasma to the substrate 112. For illustration purposes only, Fig.25 The illustrated example shows a treatment beam 807 being emitted to a substrate 112. The substrate 112 may be supported by a substrate holder 810. In a general embodiment, the substrate is scanned along a direction 808 to expose the entire front surface 112A of the substrate 112, for example when the treatment beam 807 does not cover the entire substrate 112. As generally described above, an illumination system 106 may be provided to emit illumination to a major surface of the substrate 112. According to some embodiments, the substrate 112 may be an electrical insulator, a high bandgap semiconductor, or other substrate with a relatively low charge mobility. For example, during processing by the treatment beam 807, the substrate 112 may tend to accumulate charge on the front surface 112A. The illumination system 106 may be activated to emit radiation 120 to the substrate 112 to reduce or eliminate charge accumulation on the substrate 112 and thereby improve substrate processing.

[0112] In some embodiments, the following process may be followed. A substrate 112 is provided in a process chamber 802. While the substrate is disposed in the process chamber 802, radiation 120 is emitted from the irradiation system 106 to the substrate 112. While the substrate is disposed in the process chamber 802, the substrate 112 is treated to provide a treatment substance to the substrate 112 in a treatment beam 807 separately from the radiation 120 provided by the irradiation system 106. According to a specific embodiment, at least a portion of the radiation energy of the radiation 120 is equal to or greater than 2.5 eV to produce an energy above the band gap of a given substrate. Although the radiation 120 and the treatment beam 807 are emitted to the substrate simultaneously with each other, the duration of the radiation 120 and the treatment beam 807 need not be the same, and the radiation 120 may be initiated before or after the treatment beam 807 is initiated, and the radiation 120 may be terminated before or after the treatment beam 807 is terminated.

[0113] The present embodiment provides at least the following advantages. First, practical methods have been developed to achieve electrostatic clamping of high resistivity substrates, where known electrostatic clamping is not suitable. Another advantage is that in a configuration where the illumination source is mounted on a substrate stage, illumination of the substrate is not affected by substrate movement (e.g., substrate scanning). Another advantage is that the application of novel voltage waveforms can further enhance the electrostatic clamping process. Yet another advantage is that the use of light illumination to enhance electrostatic clamping can also be used to enhance de-clamping. Additionally, as another advantage, illumination can be used to increase and control substrate temperature.

[0114] The scope of the present disclosure is not limited by the specific embodiments described herein. In fact, through the above description and the accompanying drawings, it will be apparent to those of ordinary skill in the art that, in addition to the embodiments and modifications described herein, various other embodiments of the present disclosure and various modifications to the present disclosure will also be apparent. Therefore, these other embodiments and modifications are intended to fall within the scope of the present disclosure. In addition, although the present disclosure has been described herein in the context of a specific embodiment in a specific environment for a specific purpose, it will be appreciated by those of ordinary skill in the art that the utility of the present disclosure is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Therefore, the claims described above should be understood in light of the full scope and spirit of the present disclosure described herein.

Claims

1. A clamp device, comprising: a clamp for clamping a substrate, wherein the clamp is arranged opposite to a rear side of the substrate; as well as an irradiation system configured to emit radiation to the substrate when the substrate is disposed on the fixture, wherein the radiation contains radiation energy that is equal to or higher than a threshold energy for generating mobile charges in the substrate, wherein the substrate is clamped or unclamped by emitting the radiation to the substrate, the illumination system being arranged to emit the radiation onto a front side of the substrate opposite the back side of the substrate, The clamp includes an electrode assembly, and the substrate is clamped by the clamp via the radiation emitted by the irradiation system and a clamping voltage from the electrode assembly.

2. The clamping device according to claim 1, Also included is an optical lens disposed between the illumination system and the front side of the substrate, the optical lens being arranged to receive the radiation from the illumination system as a first beam and to refract the radiation to produce a second beam wider than the first beam, wherein the second beam illuminates the entire front side of the substrate.

3. The clamping device according to claim 1, Also included is an optical mirror configured to receive the radiation from the illumination system as a first beam and reflect the radiation to produce a second beam that is wider than the first beam, wherein the second beam illuminates the entire front side of the substrate.

4. The fixture device of claim 3, wherein the illumination system is not arranged in a line of sight with the front side of the substrate.

5. The clamping device according to claim 2, further comprising: a substrate stage scanner arranged to scan the substrate along a scan direction; a lens drive mechanism arranged to move the optical lens by rotation, translation, or rotation and translation; as well as A controller is coupled to the substrate stage scanner and the lens drive mechanism and includes a synchronization component to synchronize movement of the optical lens with movement of the substrate stage scanner, wherein the second beam remains aligned with the front side of the substrate during scanning of the substrate.

6. The clamp device according to claim 3, further comprising: a substrate stage scanner arranged to scan the substrate along a scan direction; a mirror drive mechanism arranged to move the optical mirror by rotation, translation, or rotation and translation; as well as A controller is coupled to the substrate stage scanner and the mirror drive mechanism and includes a synchronization component to synchronize movement of the optical mirror with movement of the substrate stage scanner, wherein the second beam remains aligned with the front side of the substrate during scanning of the substrate.

7. The clamp device according to claim 1, further comprising: an optical lens disposed between the illumination system and the front side of the substrate, the optical lens being arranged to receive the radiation from the illumination system as a first beam and to refract the radiation to produce a second beam; as well as A lens drive mechanism is arranged to move the optical lens to scan the second beam over the front side of the substrate.

8. The clamp device according to claim 7, further comprising: a substrate stage scanner arranged to scan the substrate along a scan direction; as well as A controller is coupled to the substrate stage scanner and the lens drive mechanism and includes a synchronization component to synchronize movement of the optical lens with movement of the substrate stage scanner, wherein the second beam is scanned in a manner to maintain alignment with the front side of the substrate during scanning of the substrate.

9. The clamp device according to claim 1, further comprising an optical mirror configured to receive the radiation from the illumination system as a first beam and reflect the radiation to produce a second beam, wherein the second beam is reflected to the front side of the substrate; and A mirror drive mechanism is arranged to move the optical mirror to scan the second beam over the front side of the substrate.

10. The clamp device according to claim 9, further comprising: a substrate stage scanner arranged to scan the substrate along a scan direction; and A controller is coupled to the substrate stage scanner and the mirror drive mechanism and includes a synchronization component to synchronize movement of the optical mirror with movement of the substrate stage scanner, wherein the second beam is scanned in a manner to maintain alignment with the front side of the substrate during scanning of the substrate.

11. The fixture device according to claim 1, wherein the illumination system comprises a first illumination system disposed toward a first end of the substrate and a second illumination system disposed toward a second end of the substrate, the device further comprising: a first optical lens disposed between the first illumination system and the front side of the substrate, the first optical lens being arranged to receive the radiation from the first illumination system as a first beam and to emit the radiation as a second beam to the front side of the substrate; as well as a second optical lens disposed between the second illumination system and the front side of the substrate, the second optical lens being arranged to receive the radiation from the second illumination system as a third beam and to emit the radiation as a fourth beam to the front side of the substrate, The second beam and the fourth beam overlap each other.

12. The clamp device according to claim 11, further comprising: a substrate stage scanner arranged to scan the substrate along a scan direction; a lens drive mechanism arranged to move the first optical lens and the second optical lens by rotation, translation, or rotation and translation; as well as A controller is coupled to the substrate stage scanner and the lens drive mechanism and includes a synchronization component to synchronize movement of the first optical lens, movement of the second optical lens and movement of the substrate stage scanner, wherein during scanning of the substrate, the second beam and the fourth beam remain aligned with the front side of the substrate.

13. The fixture device according to claim 1, wherein the illumination system comprises a first illumination source disposed toward a first end of the substrate and a second illumination source disposed toward a second end of the substrate, the fixture device further comprising: a first optical mirror configured to receive the radiation from the first illumination source as a first beam and emit the radiation as a second beam to a surface of the substrate; a second optical mirror arranged to receive the radiation from the second illumination source as a third beam and to emit the radiation as a fourth beam to the front side of the substrate, The second beam and the fourth beam overlap each other.

14. The clamp device according to claim 13, further comprising: a substrate stage scanner arranged to scan the substrate along a scan direction; a lens driving mechanism, arranged to move the first optical mirror and the second optical mirror by rotation, translation, or rotation and translation; as well as a controller coupled to the substrate stage scanner and the lens drive mechanism and comprising a synchronization component to synchronize movement of the first optical mirror, movement of the second optical mirror, and movement of the substrate stage scanner, wherein the second beam and the fourth beam remain aligned with the front side of the substrate during scanning of the substrate.

15. The fixture apparatus of claim 1, the illumination system comprising an illumination source that produces radiation energy above 2.5 eV.

16. The clamping device of claim 1, wherein the clamp comprises an electrostatic clamp.

17. A substrate processing system comprising: Craft Room; an electrostatic chuck disposed in the process chamber, the electrostatic chuck being used to chuck a substrate, wherein the electrostatic chuck is arranged opposite to a back side of the substrate; as well as an irradiation system configured to emit radiation to a front side of the substrate opposite to the back side of the substrate when the substrate is disposed on the electrostatic chuck, wherein the radiation comprises radiation energy equal to or higher than 2.5 eV, wherein the substrate is chucked or unclamped by emitting the radiation to the substrate, The electrostatic chuck includes an electrode assembly, and the substrate is clamped by the electrostatic chuck via the radiation emitted by the irradiation system and a clamping voltage from the electrode assembly.

18. The substrate processing system according to claim 17, Also included is an optical lens disposed between the illumination system and the front side of the substrate, the optical lens being arranged to receive the radiation from the illumination system as a first beam and to refract the radiation to produce a second beam wider than the first beam, wherein the second beam illuminates the entire front side of the substrate.

19. The substrate processing system according to claim 17, Also included is an optical mirror configured to receive the radiation from the illumination system as a first beam and reflect the radiation to produce a second beam that is wider than the first beam, wherein the second beam illuminates the entire front side of the substrate.

20. An ion implantation system comprising: a set of beamline components for generating an ion beam and projecting the ion beam onto a substrate; an electrostatic chuck for holding the substrate, wherein the electrostatic chuck is arranged opposite to a back side of the substrate; as well as an irradiation system configured to emit radiation to a front side of the substrate opposite to the back side of the substrate when the substrate is disposed on the electrostatic chuck, wherein the radiation comprises radiation energy, the radiation energy being equal to 2.5 eV, wherein the substrate is chucked or unclamped by emitting the radiation to the substrate, The electrostatic chuck includes an electrode assembly, and the substrate is clamped by the electrostatic chuck via the radiation emitted by the irradiation system and a clamping voltage from the electrode assembly.

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