Ion beam processing system and method of manufacturing a shutter and plasma panel assembly therefor

Abstract

The present invention provides an ion beam processing system and a manufacturing method of a blocker and a plasma plate assembly thereof. The ion beam processing system includes a plasma chamber, a plasma plate disposed beside the plasma chamber, the plasma plate defining a first extraction aperture, a beam blocker disposed within the plasma chamber and facing the extraction aperture, a blocker electrode disposed on a surface of the beam blocker outside the plasma chamber, and an extraction electrode disposed on a surface of the plasma plate outside the plasma chamber.

Description

Technical Field

[0001] The present embodiment relates to an ion beam processing system and a method of manufacturing a blanker and plasma plate assembly thereof, and more particularly, to an angled ion beam extracted from a plasma source using a novel ion extraction assembly. Background Art

[0002] Ion-assisted plasma processes are often used to manufacture complex 3D semiconductor structures. Many of these processes use ion beams with zero or small angles of incidence relative to the normal to the substrate plane. There are processes such as controlled etching of trench sidewalls, in which an ion beam with an ion angular distribution (IAD) characterized by a high average angle (>50°) relative to the normal is required. Such a high angle of incidence can be achieved by extracting the beam at zero degrees (relative to the wafer normal when the wafer is oriented at a preset "horizontal" orientation) and tilting the wafer at the required angle. For example, an ion beam with a cross-section smaller than the area of ​​the substrate to be processed can be directed to impact generally along the normal to the horizontal plane, while the tilted substrate is scanned in the horizontal direction (relative to the horizontal plane) to expose the entire substrate to the ion beam in a sequential manner. A disadvantage of this approach is that the process is not uniform across the wafer surface: given the inherent beam divergence, the ion beam dose will vary as the wafer (substrate) is scanned in front of the beam.

[0003] It is with respect to these and other considerations that the present disclosure is provided. Summary of the Invention

[0004] 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 used as an aid in determining the scope of the claimed subject matter.

[0005] An ion beam processing system according to a non-limiting embodiment of the present disclosure may include: a plasma chamber; a plasma plate disposed adjacent to the plasma chamber, the plasma plate defining a first extraction aperture; a beam blanker disposed within the plasma chamber and facing the extraction aperture; a blanker electrode disposed on a surface of the beam blanker outside the plasma chamber; and an extraction electrode disposed on a surface of the plasma plate outside the plasma chamber.

[0006] An ion beam processing system according to another non-limiting embodiment of the present disclosure may include: a plasma chamber; a plasma plate formed of an electrically insulating material and disposed adjacent to the plasma chamber, the plasma plate defining a first extraction aperture; a beam blanker formed of an electrically insulating material and disposed within the plasma chamber and facing the extraction aperture; a blanker electrode formed of an electrically conductive material and covered by a first dielectric coating, disposed on a surface of the beam blanker outside the plasma chamber, wherein the blanker electrode is planar and has a thickness measured in a direction perpendicular to a front surface of the beam blanker, wherein the thickness of the blanker electrode is less than 1 mm; an extractor electrode formed of an electrically conductive material and covered by a second dielectric coating, disposed on a surface of the plasma plate outside the plasma chamber, wherein the extractor electrode is planar and has a thickness measured in a direction perpendicular to the front surface of the plasma plate, wherein the thickness of the extractor electrode is less than 1 mm; and a pulsed voltage power supply electrically coupled to the plasma chamber and the extractor electrode to generate a bias voltage between the extractor electrode and the plasma chamber.

[0007] A method of manufacturing a plasma panel assembly for an ion beam processing system according to a non-limiting embodiment of the present disclosure may include: providing a plasma panel formed of an electrically insulating material, the plasma panel defining an elongated extraction aperture; applying an electrically conductive material to a front surface of the plasma panel surrounding the extraction aperture to form an extraction electrode, the extraction electrode being planar and having a thickness measured perpendicular to the front surface of the plasma panel of less than 1 mm; and applying a dielectric coating to the plasma panel and the extraction electrode, the dielectric coating covering the front surface of the plasma panel and the extraction electrode.

[0008] A method of manufacturing a blanker assembly for an ion beam processing system according to a non-limiting embodiment of the present disclosure may include: providing a beam blanker formed of an electrically insulating material; applying an electrically conductive material to a front surface of the beam blanker to form a blanker electrode, the blanker electrode being planar and having a thickness measured in a direction perpendicular to the front surface of the beam blanker of less than 1 mm; and applying a dielectric coating to the beam blanker and the blanker electrode, the dielectric coating covering the front surface of the beam blanker and the blanker electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A vertical cross-section of a processing apparatus consistent with an embodiment of the present disclosure is presented.

[0010] Figures 2A to 2D Collectively depicted are the evolution of electron and ion distributions as a function of time according to embodiments of the present disclosure.

[0011] Figures 3A to 3C Description based on Figure 1 The operating scenario of the arranged processing equipment, and shows the beamlets, shape and electrostatic potential distribution in the extraction area.

[0012] Figures 4A to 4C Describe the appearance Figures 3A to 3C Curves of the ion angular distribution for the scenario depicted in .

[0013] Figure 5 A vertical cross-section of a processing apparatus consistent with another embodiment of the present disclosure is presented.

[0014] Figures 6A to 6F Description based on Figure 5 The operating scenario of the arranged processing equipment, and shows the beamlets, shape and electrostatic potential distribution in the extraction area.

[0015] Figures 7A to 7F Describe the appearance Figures 6A to 6F Curves of the ion angular distribution for the scenario depicted in .

[0016] Figure 8A and Figure 8B 1 and 2 illustrate perspective and exploded views of a plasma chamber and extraction assembly of a processing apparatus consistent with embodiments of the present disclosure.

[0017] Figures 9A to 9C A series of perspective views illustrating a method of manufacturing a plasma panel, an extraction electrode, and a first dielectric coating of a processing apparatus consistent with an embodiment of the present disclosure.

[0018] Figure 10 To show Figures 9A to 9C Flowchart of the method described in .

[0019] Figures 11A to 11C A series of perspective views illustrating a method of fabricating a beam blanker, a blanker electrode, and a second dielectric coating for a processing apparatus consistent with embodiments of the present disclosure.

[0020] Figure 12 To show Figures 11A to 11C Flowchart of the method described in . DETAILED DESCRIPTION

[0021] The present embodiments will now be described more fully below with reference to the accompanying drawings, some of which are shown. The subject matter of the present disclosure can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the subject matter to those skilled in the art. In the drawings, like reference numerals refer to like elements throughout.

[0022] The embodiments described herein provide systems and methods for controlling the angular distribution of ions directed to a substrate using hidden deflection electrodes. In some embodiments, an apparatus is disclosed that facilitates the generation of ion beams with large incident angles on a wafer in a compact ion beam source. In addition to extracting ion beams with high incident angles, the present embodiments can also be used in chemically reactive plasmas (feedstock gas: C x F y 、C x H y F z The present invention can be used with the use of ions (e.g., SF6, H2, O2, Cl2, I2, Br2, and / or mixtures thereof) to generate ionic radicals and highly reactive radicals. Specifically, ion beams ranging from several hundred electron volts to several kiloelectron volts and beam currents of tens of milliamperes can be extracted with high on-wafer angles of incidence (e.g., up to 45°). As an example of device processing, the use of symmetrical ribbon beamlet extraction provided by the present embodiment allows for simultaneous processing of vertical trench walls in complex semiconductor structures while scanning the substrate parallel to the extraction assembly.

[0023] In the following embodiments, an ion beam processing system may include a plasma chamber and an extraction assembly. The extraction assembly may include a plasma plate disposed along a side of the plasma chamber, wherein the plasma plate includes an extraction aperture. According to various embodiments of the present disclosure, the plasma plate may be formed of an electrically insulating material. The extraction assembly may include a beam blanker, also formed of an electrically insulating material, disposed within the plasma chamber while facing the extraction aperture. Thus, the beam blanker can be used to divide the extraction aperture into two separate sub-apertures. The extraction assembly may include a blocker electrode, the blocker electrode including a conductive film disposed on a surface of the beam blanker outside the plasma chamber, and an extraction electrode, the extraction electrode including a conductive film disposed on a surface of the plasma plate outside the plasma chamber. In specific embodiments, the blocker electrode may be covered by a first dielectric coating covering surfaces of the blocker electrode and the beam blanker, and the extraction electrode may be covered by a second dielectric coating covering surfaces of the extraction electrode and the plasma plate. As described in the following embodiments, this arrangement facilitates the generation of high-angle ion beams through the sub-apertures, wherein the high-angle ion beams define large angles of incidence relative to a plane normal to the plasma panel, such as 30 degrees or more.

[0024] The extraction aperture of the plasma panel can have an elongated shape to facilitate extraction of a pair of ribbon ion beams or ribbon ion beamlets and directing the ribbon ion beamlets at a wide angle toward a substrate, for example, aligned parallel to the plane of the plasma panel. As used herein, the term "wide angle toward the substrate" can be greater than 30 degrees relative to a normal (perpendicular) to the plane of the substrate.

[0025] Now go to Figure 1, shows a vertical cross-section of a processing system consistent with embodiments of the present disclosure. The processing system 100 includes a plasma chamber 102, a processing chamber 103, and an extraction assembly 130, described in greater detail below. The processing system 100 further includes a pulsed voltage power supply 124 electrically coupled to generate a bias voltage between an extraction electrode 114 and the plasma chamber 102. Thus, the processing system 100 functions as an ion beam processing system to generate an ion beam for processing a substrate 122, which is disposed proximate to the extraction electrode 114. The plasma chamber 102 can function as a plasma source to generate a plasma 132 within the plasma chamber 102 by any suitable method. For example, the plasma chamber 102 can be referenced to a ground potential via a conductive wall 134. Ionic species of interest may be generated in plasma 132 by inductively coupling rf power generated by an rf power source (not separately shown) from rf antenna 136 to the working gas through dielectric window 104. Other known methods of generating plasma are possible.

[0026] like Figure 1 As shown in FIG, the extraction assembly 130 may include a plasma plate 106 disposed along a side of the plasma chamber 102. The plasma plate 106 may be formed from an electrical insulator, such as Al2O3 (aluminum oxide), quartz, AlN, or other suitable electrically insulating materials. The plasma plate 106 may define an extraction aperture 138 extending along the X-axis of the illustrated Cartesian coordinate system (note that the X-axis extends generally perpendicularly into the plane of the page). Thus, the extraction aperture 138 may define a space through which ions from the plasma chamber 102 may be transmitted. The extraction assembly 130 may further include an extraction electrode 114 formed from a thin film (e.g., up to 1 mm thick) of conductive material disposed on the face of the plasma plate 106 outside the plasma chamber 102. The extraction electrode 114 may be covered by a first dielectric coating 115 forming a layer of chemically inert dielectric material, thereby covering the extraction electrode 114 and the face of the plasma plate 106. Collectively, the plasma panel 106 , the extractor electrode 114 , and the first dielectric coating 115 may be referred to as a “plasma panel assembly.”

[0027] The extraction assembly 130 may also include a beam blanker 108 formed of, for example, an insulating material. Figure 1In an arrangement, when a negative voltage is applied to the substrate 122 (or substrate plate 120) relative to the plasma chamber 102 in the presence of plasma 132, a plasma meniscus forms in a gap (sub-aperture) formed between the extraction aperture 138 and the beam blanker 108. In various embodiments, the beam blanker 108 can be symmetrically arranged above the extraction aperture 138 to allow for the formation and extraction of two symmetrical ion beamlets 112. Ion beam processing of the substrate 122 is performed by scanning the substrate 122 in the y-direction and can also include rotating the substrate about the z-axis. In various non-limiting embodiments, depending on the conductivity of the substrate 122 (thick or thin oxide), the ion beamlets 112 can be extracted as a pulsed ion beam, wherein the pulse frequency and duty cycle can be adjusted to target values ​​within the range of 10 kHz to 50 kHz and 10% to 100%, respectively, so that the substrate is not charged. Advantageously, the extraction electrode 114 and beam blanker 108 use dielectric materials to facilitate use in highly reactive plasmas for generating ionic and radical species.

[0028] The extraction assembly 130 may also include a biasable blocker electrode 110. Figure 1 As shown in , the blocker electrode 110 is formed of a thin film (e.g., up to 1 mm thick) of conductive material disposed on the face of the beam blanker 108 outside the plasma chamber 102. The blocker electrode 110 may be covered by a second dielectric coating 117 that forms a layer of chemically inert dielectric material, thereby covering the blocker electrode 110 and the face of the beam blanker 108. Collectively, the beam blanker 108, the blocker electrode 110, and the second dielectric coating 117 may be referred to as a "blocker assembly." Figure 1 , the beam blanker 108 and the plasma plate 106 (although non-coplanar) can be considered to define a boundary on the underside between the interior of the plasma chamber 102 and the exterior of the plasma chamber 102. Thus, the blanker electrode 110, whether disposed above the plasma plate 106 or not, can be considered to be placed on the exterior of the plasma chamber 102.

[0029] In some non-limiting embodiments, the height of the extraction aperture 138 along the y-direction can vary. In various embodiments of the present disclosure, the plasma panel 106, the extraction electrode 114, and the substrate 122 can be parallel to each other and can be positioned parallel to the XY plane. Therefore, the plane of the plasma panel 106 can be considered to be a plane parallel to the XY plane and substantially parallel to the scanning direction (y-direction) of the substrate 122.

[0030] The extraction aperture 138 can be aligned symmetrically with respect to the blanker electrode 110 and the beam blanker 108, thereby establishing symmetry in the two ion beamlets 112 extracted from the gap between the beam blanker 108 and the plasma panel 106. In some embodiments, the beam blanker 108, the blanker electrode 110, and the extraction aperture 138 can be elongated to extend 350 mm to 400 mm in the x-direction, thereby extracting a uniform ribbon beamlet 300 mm wide (in the x-direction).

[0031] According to various non-limiting embodiments, the biasable elements of the extraction assembly 130, such as the blocker electrode 110 and the extraction electrode 114, can be disposed at the same electrical potential as the substrate 122. This configuration means that the substrate 122 is advantageously not part of the extraction assembly 130. Specifically, because the substrate 122 is at the same electrical potential as the blocker electrode 110 and the extraction electrode 114, there is no potential difference, and therefore no electric field, between the substrate 122 and the extraction electrode 114 or the blocker electrode 110.

[0032] Thus, the relative position of the substrate 122 relative to the extraction assembly 130 (e.g., the extraction electrode 114 and the plasma plate 106) does not affect the ion angular distribution of the ion beam extracted via the extraction assembly 130. Under this condition, the substrate position can be varied from 5 mm to greater than 20 mm along the Z-axis, thereby significantly reducing contamination of the plasma chamber by material sputtered and / or chemically etched from the substrate. In other words, when desired, the substrate can be positioned at a greater separation from the extraction assembly along the Z-axis to reduce contamination, as contamination decreases with increasing solid angle, so the extraction aperture "sees" less of the wafer as separation increases.

[0033] In order to be electrically biasable, as described above, the blocker electrode 110 and the extraction electrode 114 can be composed of a thin film (e.g., up to 1 mm thick in the z direction) of a conductive material (e.g., a metal, such as aluminum, titanium, copper, molybdenum, tungsten, and in some non-limiting embodiments, doped silicon can be used for these components). Because these parts are not exposed to ion beam bombardment, as described in detail below, metal contamination is reduced. According to some embodiments, in order to more comprehensively prevent contamination, the electrically biasable part can be coated with a thin dielectric film surrounding the inner body or part formed by the conductive material. In one non-limiting embodiment, a suitable dielectric coating is made of a mixture of yttrium, aluminum and zirconium oxide and has a thickness of 100 microns. Such dielectric materials are known to provide etching resistance. In other embodiments, Al2O3, AlFO, yttrium oxide (Y2O3) or zirconium oxide (ZrO2) or a combination thereof can be used as a dielectric coating.

[0034] As is known, the shape and position of the plasma meniscus and the mechanism of ion beam extraction depend on the relative values ​​of the plasma density in the plasma (e.g., plasma 132), and further on the extraction electric field. When non-conductive materials (e.g., dielectrics) are used to make the components of the ion extraction assembly, the physics of ion beam extraction changes considerably. This change occurs because the plasma sheath, which is the interface between the plasma 132 and the walls of the ion extraction assembly (in this embodiment, the beam blanker 108 and the plasma plate 106), is a function of the nature of the walls: insulating or conductive. For pulsed plasmas, where the pulse frequency (f) is higher than the plasma frequency (f), the plasma meniscus is located at the plasma 132 and the plasma plate 106. pi )

[0035]

[0036] where n, ε0 and m i For the plasma density, elementary charge, dielectric constant of vacuum and ion mass, we have a so-called matrix sheath, where ions are immobile and electrons are pushed away from the walls. In this case, the sheath thickness is given by:

[0037]

[0038] Among them, V0, k B and T e Represent the voltage drop across the sheath, the Boltzmann constant, and the electron temperature, respectively. D The indicated quantity is the Debye length given by

[0039]

[0040] Depending on the value of the voltage on the wall, the sheath thickness can be in the range of tens to one hundredth of the Debye length in the case of a matrix sheath. 9 Cubic centimeters and 5×10 11 Typical plasma densities are between 100 and 250 MHz, with plasma frequencies much higher than the extraction voltage pulse frequency (10 to 50 kHz). In this case, the ions have enough time to be accelerated by the electric field in the sheath and, assuming collision-free motion, the sheath thickness is given by Child's law:

[0041]

[0042] Assuming an electron temperature of 3.5 electron volts, the sheath thickness increases with voltage and with the inversion of plasma density and varies from a fraction of a millimeter to approximately 20 millimeters for the range of interest.

[0043] According to various embodiments, as described above, the ion beam of the present embodiment can be extracted as a pulsed ion beam. The extraction voltage system can, for example, include a pulsing component, such as circuitry that switches extraction voltage pulses on and off according to a desired pulse duration and duty cycle. At relatively low ion beam currents, the pulse duty cycle can be 100%, i.e., continuous ion extraction. Specifically, the pulse duration and duty cycle can be configured to facilitate extraction of angled ion beams, as discussed below. Because the beam blanker 108 and plasma plate 106 components can be formed from dielectric materials, the pulsing of the ion beam can be configured to account for the time-dependent evolution of the plasma sheath.

[0044] Steering Figures 2A to 2D , according to an embodiment of the present disclosure, illustrates the evolution of electron and ion distributions in ZY space as a function of time. In the simulation shown, the voltage on the substrate (where the position is represented by the vertical line at z = 2.5 cm) was pulsed at -1 kilovolt with a 20 kHz pulse frequency and a 50% duty cycle. The beam blanker and plasma panel assembly are schematically shown as bright vertically elongated rectangles. The beam blanker and plasma panel are modeled as being made of a dielectric material (quartz) that allows electrostatic charging. Figure 2A and Figure 2B The electron and ion distributions are shown, respectively, 1 microsecond after the start of the applied negative voltage pulse. Because quartz allows the transmission of electric field lines, a high voltage drop occurs across the sheath at the start of the pulse (1 microsecond), resulting in a considerable sheath thickness (~6 mm). The electric field near the extraction gap is oriented perpendicular to the plasma plate and beam blanker (along the z direction), and therefore few, if any, ions are extracted (see Figure 2B ion distribution in ).

[0045] Now go to Figure 2C and Figure 2D As the plasma sheath evolves over time, ions continue to reach the inner walls of the plasma panels and plasma blocker. Without a path to ground, the ions create an imbalance in the plasma density, a condition that leads to the formation of a bipolar electric field. In this case, equal fluxes of electrons and ions are directed toward the inner walls.

[0046]

[0047] in is the gradient of plasma density in the direction perpendicular to the face plate and the blocker wall (z direction), and Da is the two-stage diffusion coefficient.

[0048]

[0049] where μ e,i and D e,iare the mobility and diffusion coefficients of electrons and ions, respectively. Due to the two-stage diffusion, the sheath thickness decreases (contracts) until the point where the plasma meniscus forms in the extraction gap and the extraction of the ion beamlets begins. This reduction in sheath thickness can be seen in Figure 2C and Figure 2D , which shows the zy phase space of electrons and ions at 4 microseconds after the start of the negative voltage pulse. In this example, Figure 2D As shown in , ion beamlets are easily formed, extracted, and directed to the substrate location.

[0050] Thus, according to various embodiments, the duty cycle and frequency of the voltage pulses can be set to provide a given pulse duration that exceeds the time required for the plasma sheath to retract (the plasma sheath retraction period) and the start of ion beam extraction. In the above example, assuming a minimum plasma sheath retraction period of 4 microseconds, a pulse duration of 10 microseconds or greater may be suitable to ensure proper extraction of the ion beam. At a 50% duty cycle, this pulse duration is equivalent to a pulse period of 20 microseconds or greater, meaning that the voltage pulse frequency can be set to 50 kHz or less to achieve the desired extraction time. Figures 2A to 2D Efficiently extract ions in a variety of situations.

[0051] Figures 3A to 3C Describe the above and Figure 1 , and shows the beamlets, shapes, and electrostatic potential distribution in the extraction region (i.e., the region between the blocker electrode 110 and the substrate 122). More specifically, Figures 3A to 3C The depiction shows the results of OPERA modeling of the conductive wall 134, plasma plate 106, extractor electrode 114, beam blanker 108, blanker electrode 110, and substrate 122 of the plasma chamber 102. In the series of views shown, the plasma density and bias voltage remain the same (600 watts rf power and -1.5 kilovolts), and the distance between the extractor electrode 114 and the substrate 122 in the z direction is increased from Figure 3A 6 mm increased to Figure 3B 10 mm to Figure 3C As can be seen, the dielectric structure of the extraction assembly 130 is transparent to the electrostatic field potential 140, whereas the metal structure is not. Figure 3B As shown in FIG, the electrostatic potential line 140 extends through the outermost portion of the beam blanker 108 that is not covered by the blanker electrode 110 (hereinafter “uncovered portion 142”), and this uncovered portion 142 has a height (Hh) / 2 in the y direction. Similarly, as Figure 3BAs shown in FIG, the electrostatic potential line 140 extends through a portion of the plasma panel 106 that is not covered by the extraction electrode 114 (hereinafter referred to as "uncovered portion 144"), such uncovered portion 144 having a height r in the y direction. Figure 3B ) will diverge at a natural angle (given by the geometry of the extraction assembly 130) in a manner generally dictated by the ratio of the height of the uncovered portion 142, the uncovered portion 144, the bias voltage, and to a lesser extent the ion beam current. Therefore, and also due to the geometric symmetry of the extraction assembly, the ion beamlet 112 will have a normal to the plane of the substrate 122 (i.e., to the Z-axis) characterized as + / -Θ (see Figure 3C ) angle of the ion angular distribution.

[0052] Figures 3A to 3C The ion angular distributions of the arrangement depicted in Figures 4A to 4C As shown in the curves shown in . When the blocker electrode 110, the extraction electrode 114, and the substrate 122 are maintained at the same electrostatic potential, the electric field between the ion source and the substrate 122 is almost entirely concentrated in the extraction gap region (see the distribution of equipotential lines). Therefore, due to the small space charge effect, the ion angular distribution of the extracted ion beamlet 112 is unaffected by the z-gap length and its characteristics are quasi-uniform, with the same average angle (40°) and slightly increasing angular spread (10°, 11°, and 12°) as the distance in the z-direction between the extraction electrode 114 and the substrate 122 increases from 6 mm to 10 mm and from 10 mm to 15 mm. Therefore, the substrate 122 can be moved away from the extraction assembly as needed to minimize contamination of the plasma chamber 102 by material etched from the substrate 122 while maintaining the average angle of the ion beamlet 112 relative to the substrate 122.

[0053] Reference Figure 5 , shows an alternative embodiment of the processing system 100 in which a second pulsed voltage power supply 150 is implemented (i.e., in addition to the pulsed voltage power supply 124 described above, hereinafter referred to as the "first pulsed voltage power supply 124"). The second pulsed voltage power supply 150 can be coupled to the blocker electrode 110 for differentially biasing the blocker electrode 110 relative to the extraction electrode 114. The second pulsed voltage power supply 150 can be bipolar to facilitate negative or positive biasing relative to the extraction electrode 114. A phase controller 152 can be connected between the first pulsed voltage power supply 124 and the second pulsed voltage power supply 150 to ensure that a sufficient phase is maintained therebetween.

[0054] Figures 6A to 6F depiction Figure 5, and illustrates the beamlets, shape, and electrostatic potential distribution in the extraction region. More specifically, Figures 6A to 6F The depiction shows the results of OPERA modeling of the conductive wall 134, plasma plate 106, extractor electrode 114, beam blanker 108, blanker electrode 110, and substrate 122 of the plasma chamber 102. In the illustrated series of views, the plasma density, the bias voltage applied by the first pulsed voltage power supply 124, and the distance in the z-direction between the extractor electrode 114 and the substrate 122 are all kept the same (600 W rf power, 1.5 kV, and 15 mm, respectively), while the bias voltage applied by the second pulsed voltage power supply 150 to the blanker electrode 110 is reduced in increments of 300 V from Figure 6A 1.8 kV is reduced to Figure 6D As can be seen, as the relative voltage bias increases, the distribution of the electrostatic potential lines 140 in the extraction gap region becomes less dense and more parallel to the substrate (ie, closer to parallel). Consequently, the angular spread and on-substrate coverage of the beamlet 112 decrease.

[0055] Figures 6A to 6F The ion angular distributions of the arrangement depicted in Figures 7A to 7F As shown in the curve shown in FIG. Due to the differential bias applied to the blocker electrode 110, the average angle of the ion beamlet 112 relative to the normal on the plane of the substrate 122 (ie relative to the Z axis) can be changed from Figure 7A 52° is reduced to Figure 7E 8° in the figure, then the average angle can be obtained by the normal to Figure 7F Thus, the disclosed arrangement facilitates a tunability range of almost 60°. Additionally, the angular spread of the beamlets 112 can be increased from 15° at ΔV = -300 volts to 15° at -300 volts. Figure 6A and Figure 7A ) is reduced to 2.8°( Figure 6F and Figure 7F ).

[0056] Figure 8A and Figure 8BPortions of a processing system 100 are shown, including perspective and exploded views, respectively, of the plasma chamber 102 and extraction assembly 130 described above. The extraction assembly 130 can include a plasma panel 106 and a beam blanker 108, wherein the beam blanker 108 can extend across a rear portion of the extraction aperture 138 and can be fastened to a rear surface of the plasma panel 106, such as by mechanical fasteners (not shown) extending through respective mounting holes 160a, 160b and 162a, 162b formed in the beam blanker 108 and the plasma panel 106. The plasma plate 106 can cover the open front of the plasma chamber 102 and can be fastened to the front surface of the plasma chamber 102, for example, by mechanical fasteners (not shown) extending through corresponding mounting holes 164a, 164b and 166a, 166b formed in the plasma plate 106 and the plasma chamber 102. The extraction electrode 114 disposed on the front surface of the plasma plate 106 and surrounding the extraction hole 138 can be covered by the first dielectric coating 115 and thus Figure 8B The blocker electrode 110 disposed on the front surface of the beam blanker 108 is covered by the second dielectric coating 117 and is thus Figure 8B Indicated by the dotted outline in .

[0057] Figures 9A to 9C is a series of perspective views illustrating a method of manufacturing the plasma panel assembly of the extraction assembly 130. Figure 10 is a flow chart showing the same method. Figure 9A And to Figure 10 At block 200 in the accompanying drawings, the plasma panel 106 can be fabricated and provided. In various examples, the plasma panel 106 can be machined from a sheet of electrically insulating material, such as Al2O3 (aluminum oxide), quartz, AlN, or other suitable electrical insulators. The present disclosure is not limited in this respect. The plasma panel 106 can define an extraction aperture 138 extending along the X-axis of the illustrated Cartesian coordinate system. Optionally, a recess or depression 170 can be formed (e.g., machined) in the front surface of the plasma panel 106, the recess 170 having a size and shape suitable for accommodating the extraction electrode 114, described further below. In a non-limiting example, the recess 170 can have a depth, as measured along the Z-axis, in the range of 0.2 mm to 0.3 mm.

[0058] refer to Figure 9B And to Figure 10At block 210 in FIG. 1 , the extraction electrode 114 may be formed or disposed on the front surface of the plasma panel 106 surrounding the extraction aperture 138. In various examples, the extraction electrode 114 may be formed of a conductive material (e.g., aluminum, nickel, titanium, copper, molybdenum, tungsten, or doped silicon) and may be printed, sprayed, or adhered to the front surface of the plasma panel 106. In a non-limiting example, the extraction electrode 114 may have a thickness in the range of 0.2 mm to 0.3 mm as measured along the Z axis. If the recess 170 is formed in the front surface of the plasma panel 106 as described above (see FIG. 1 ), the extraction electrode 114 may be formed of a conductive material (e.g., aluminum, nickel, titanium, copper, molybdenum, tungsten, or doped silicon) and may be printed, sprayed, or adhered to the front surface of the plasma panel 106. Figure 9A ), the recess 170 may be filled with a conductive material, such as by spraying the material into the recess 170 to form the extraction electrode 114 .

[0059] refer to Figure 9C And to Figure 10 At block 220, a first dielectric coating 115 may be applied to the plasma panel 106 and the extractor electrode 114. The first dielectric coating 115 may cover the front surface of the plasma panel 106 and the extractor electrode 114. In various embodiments, the first dielectric coating 115 may be formed from a chemically inert dielectric material (e.g., Al2O3, Y2O3, ZrO2, or a combination thereof) and may be applied using a plasma spray process. The present disclosure is not limited in this regard. A small portion of the extractor electrode 114 may be masked during application of the first dielectric coating 115 to provide an exposed connector area 172 not covered by the first dielectric coating 115, for example, to facilitate electrical connection of the extractor electrode 114 to the first pulsed voltage power supply 124 described above.

[0060] Figures 11A to 11C 1 is a series of perspective views illustrating a method of manufacturing the blocker assembly of the extraction assembly 130 . Figure 12 is a flow chart showing the same method. Figure 11A And to Figure 12 At block 300 in the accompanying drawings, the beam blank 108 can be fabricated and provided. In various examples, the beam blank 108 can be machined from a plate of an electrically insulating material, such as Al2O3 (aluminum oxide), quartz, AlN, or other suitable electrical insulators. The present disclosure is not limited in this respect. The beam blank 108 can be elongated along the X-axis of the illustrated Cartesian coordinate system.

[0061] refer to Figure 11B And to Figure 10 At block 310 in FIG. 1 , a blocker electrode 110 may be formed or disposed on the front surface of the beam blanker 108. In various examples, the blocker electrode 110 may be formed of a conductive material, such as aluminum, nickel, titanium, copper, molybdenum, tungsten, or doped silicon, and may be printed, sprayed, or adhered to the front surface of the beam blanker 108. In a non-limiting example, the blocker electrode 110 may have a thickness in a range of 0.2 mm to 0.3 mm as measured along the Z-axis.

[0062] refer to Figure 11C And to Figure 12 In block 320 of the embodiment of the present invention, a second dielectric coating 117 may be applied to the beam blanker 108 and the blocker electrode 110. The second dielectric coating 117 may cover the front surface of the beam blanker 108 and the blocker electrode 110. In various embodiments, the second dielectric coating 117 may be formed of a chemically inert dielectric material (e.g., Al2O3, Y2O3, ZrO2, or a combination thereof) and may be applied using a plasma spray process. The present disclosure is not limited in this respect. A small portion of the blocker electrode 110 may be masked during application of the second dielectric coating 117 to provide an exposed connector area 174 not covered by the second dielectric coating 117, for example, to facilitate electrical connection of the blocker electrode 110 to the pulsed voltage power supply 124 (or the second pulsed voltage power supply 150) described above.

[0063] The present embodiment provides a number of advantages in the art. A first advantage is found in an extraction assembly having a novel combination of low profile conductive electrodes completely covered by dielectric material, thereby facilitating the extraction of ion beamlets having high on-wafer angles of incidence (>30° average angle) while mitigating metal contamination. Another advantage is the ability to instantly control the ion angular distribution. Another advantage is the ability to reduce contamination of the plasma chamber from material sputtered and / or chemically etched from the substrate by allowing the substrate to move away from the plasma chamber while maintaining the on-wafer angle of incidence of the ion beamlets. In addition, for small ion beam systems, the substrate is removed from the extraction assembly configuration while maintaining a simple diode electrostatic extraction process. Another advantage is the use of the same power supply to bias both the substrate and the biasable electrode, thereby simplifying cost and design complexity. Another example of the advantages of the present embodiment is the ability to use a simple low voltage power supply floating on a high voltage power supply to provide a differential bias to the blocker electrode relative to the extraction electrode and the substrate.

[0064] The scope of the present disclosure is not limited by the specific embodiments described herein. In fact, in addition to those embodiments and modifications described herein, it will be apparent to those skilled in the art that various other embodiments of the present disclosure and modifications to the present disclosure will be apparent based on the above description and accompanying drawings. Therefore, such other embodiments and modifications tend to fall within the scope of the present disclosure. In addition, although the present disclosure has been described in the context of specific embodiments under specific circumstances for specific purposes, those skilled in the art will recognize that its usefulness is not limited thereto, and that the present disclosure can be advantageously implemented in any number of environments for any number of purposes. Therefore, the claims set forth above should be interpreted in light of the full scope and spirit of the present disclosure as described herein.

Claims

1. An ion beam processing system comprising: plasma chamber; a plasma plate disposed adjacent to the plasma chamber, the plasma plate defining an extraction aperture; a beam blanker disposed in the plasma chamber and facing the extraction hole; a blanker electrode disposed on a surface of the beam blanker outside the plasma chamber; as well as an extraction electrode disposed on the surface of the plasma panel outside the plasma chamber, The outermost edge of the extraction electrode is recessed relative to an edge of the plasma panel that bounds the extraction hole in a direction parallel to the front surface of the plasma panel.

2. The ion beam processing system of claim 1, wherein the plasma plate is formed of an electrically insulating material and the beam blanker is formed of an electrically insulating material.

3. The ion beam processing system of claim 1, wherein the blocker electrode is formed of a conductive material and is covered by a first dielectric coating, and wherein the extractor electrode is formed of a conductive material and is covered by a second dielectric coating.

4. The ion beam processing system of claim 3, wherein a portion of the blocker electrode is not covered by the first dielectric coating to facilitate electrical connection of the blocker electrode to a pulsed voltage power supply.

5. The ion beam processing system of claim 3, wherein a portion of the extractor electrode is not covered by the second dielectric coating to facilitate electrical connection of the extractor electrode to a pulsed voltage power supply.

6. The ion beam processing system of claim 1, wherein the blanker electrode is planar and has a thickness measured in a direction perpendicular to the front surface of the beam blanker, wherein the thickness is less than 1 mm.

7. The ion beam processing system of claim 1, wherein the extractor electrode is planar and has a thickness measured in a direction perpendicular to the front surface of the plasma panel, wherein the thickness is less than 1 mm.

8. The ion beam processing system of claim 1, wherein an outermost edge of the blanker electrode is recessed relative to an outermost edge of the beam blanker in a direction parallel to a front surface of the beam blanker.

9. The ion beam processing system of claim 1 , further comprising: A pulsed voltage power supply is electrically coupled to the plasma chamber and the extraction electrode to generate a bias voltage between the extraction electrode and the plasma chamber.

10. The ion beam processing system of claim 9, the pulsed voltage power supply having a pulse component to generate a pulsed bias voltage between the extraction electrode and the plasma chamber.

11. The ion beam processing system of claim 9 further comprising a processing chamber housing a substrate, the pulsed voltage power supply being electrically coupled to the plasma chamber on a first side and to the extractor electrode, the blocker electrode, and the substrate on a second side.

12. An ion beam processing system according to claim 9, wherein the pulsed voltage power supply is a first pulsed voltage power supply, and the ion beam processing system also includes a second pulsed voltage power supply, which is electrically coupled to the blocker electrode for differentially biasing the blocker electrode relative to the extraction electrode.

13. An ion beam processing system comprising: plasma chamber; a plasma panel formed of an electrically insulating material and positioned adjacent to the plasma chamber, the plasma panel defining an extraction aperture; a beam blanker formed of an electrically insulating material, disposed in the plasma chamber and facing the extraction aperture; a blanker electrode formed of a conductive material and covered by a first dielectric coating, disposed on a surface of the beam blanker outside the plasma chamber, wherein the blanker electrode is planar and has a thickness measured in a direction perpendicular to a front surface of the beam blanker, wherein the thickness of the blanker electrode is less than 1 mm; an extractor electrode formed of a conductive material and covered by a second dielectric coating, disposed on a surface of the plasma panel outside the plasma chamber, wherein the extractor electrode is planar and has a thickness measured in a direction perpendicular to a front surface of the plasma panel, wherein the thickness of the extractor electrode is less than 1 mm; and a pulsed voltage power supply electrically coupled to the plasma chamber and the extraction electrode to generate a bias voltage between the extraction electrode and the plasma chamber, wherein an outermost edge of the extraction electrode is recessed relative to an edge of the plasma panel that bounds the extraction hole in the direction parallel to the front surface of the plasma panel.

14. A method of manufacturing a plasma panel assembly for an ion beam processing system, the method comprising: providing a plasma plate formed of an electrically insulating material, the plasma plate defining an elongated extraction aperture; applying a conductive material to a front surface of the plasma panel surrounding the extraction aperture to form an extraction electrode, the extraction electrode being planar and having a thickness less than 1 mm measured in a direction perpendicular to the front surface of the plasma panel; and applying a dielectric coating to the plasma panel and the extractor electrode, the dielectric coating covering the front surface of the plasma panel and the extractor electrode, wherein an outermost edge of the extraction electrode is recessed relative to an edge of the plasma panel that bounds the extraction hole in the direction parallel to the front surface of the plasma panel.

15. The method of claim 14 , wherein applying the dielectric coating to the plasma panel and the extractor electrode comprises masking portions of the extractor electrode to provide exposed connector areas not covered by the dielectric coating for facilitating electrical connection of the extractor electrode to a pulsed voltage power supply.

16. The method of claim 14, further comprising forming a recess in the front surface of the plasma panel for accommodating the extractor electrode before applying the conductive material to the front surface of the plasma panel.

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