Fastening assemblies for beam blockers in ion processing.

Abstract

A fastening assembly for fastening a beam blocker to an extraction plate, the fastening assembly including: a mounting pin having a shaft portion, a base portion at a first end of the shaft portion, and a head portion at a second end of the shaft portion; a centering sleeve radially surrounding the shaft portion and axially abutting the base portion, the centering sleeve being radially compressible between the shaft portion and the extraction plate and between the shaft portion and the beam blocker; an annular spacer surrounding the centering sleeve and axially abutting the beam blocker, the centering sleeve extending partially into the spacer; and a latching cap surrounding the shaft portion and axially abutting the spacer, the shaft portion extending through a through hole in the latching cap, the through hole being smaller than the head portion in a direction perpendicular to an axis of the mounting pin.

Description

[Technical Field]

[0001] Related Applications

[0001] This application claims priority to U.S. Non-Provisional Patent Application No. 17 / 556,390, entitled "FASTENING ASSEMBLY FOR BEAM BLOCKER IN ION PROCESSING APPARATUS," filed December 20, 2021, the entire contents of which are incorporated herein by reference.

[0002]

[0002] The present disclosure relates generally to semiconductor device processing equipment, and more particularly to a fastening assembly for attaching a beam blocker to an ion processing system. [Background technology]

[0003]

[0003] Plasmas are sometimes used to process semiconductor substrates, such as those used in electronic devices, for applications such as substrate etching, layer deposition, ion implantation, and other processes. Some processing equipment employs a plasma chamber to generate the plasma, which serves as an ion source for substrate processing. An ion beam is extracted through an extraction assembly and directed toward a substrate in an adjacent chamber. In some cases, the ion beam may be split around a so-called "beam blocker" positioned adjacent to the extraction aperture of the extraction assembly to form a pair of symmetrically angled ion beamlets directed toward the substrate. The beam blocker may be fastened to the extraction plate on opposite sides of the extraction aperture by a pair of fastening assemblies formed of cooperating mounting pins, spacers, and latches.

[0004] A drawback associated with the above-described types of fasteners is their tendency to cause misalignment of the beam blocker relative to the extraction aperture, resulting in a lack of symmetry between the beamlets directed toward the target substrate. For example, the entire beam blocker may sag, causing the gap above the beam blocker to be larger than the gap below the beam blocker. In another example, one side of the beam blocker may sag relative to the opposite side of the beam blocker, resulting in the extraction of "twisted" ion beamlets. Such misalignment may be due to variations in the size of the components of the fastener assembly due to manufacturing tolerances and / or sagging of the beam blocker due to gravity.

[0005]

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

[0006]

[0006] This Summary is provided to introduce a selection of concepts in a simplified form. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0007]

[0007] An embodiment of a fastening assembly for fastening a beam blocker to an extraction plate of an ion processing system according to the present disclosure may include a mounting pin having a cylindrical shaft portion, a base portion at a first end of the shaft portion, and a head portion at an opposite second end of the shaft portion; a tubular centering sleeve radially surrounding the shaft portion and abutting the base portion axially, the centering sleeve adapted to be radially compressed between the shaft portion and the extraction plate and between the shaft portion and the beam blocker; an annular spacer radially surrounding the centering sleeve and the shaft portion of the mounting pin and abutting the beam blocker axially, the centering sleeve extending partially into the spacer but not completely through the spacer; and a latching cap radially surrounding the shaft portion and abutting the spacer axially, the shaft portion extending through a through hole in the latching cap, the through hole being smaller than the head portion in a direction perpendicular to the axis of the mounting pin.

[0008] An ion processing system according to the present disclosure may include a plasma chamber, a process chamber adjacent to the plasma chamber, and an extraction assembly disposed between the plasma chamber and the process chamber. The extraction assembly may include an extraction plate disposed along a side of the plasma chamber and defining an extraction aperture, and a beam blocker disposed adjacent the extraction aperture and fastened to the extraction plate by a fastening assembly. The fastening assembly can include a mounting pin having a cylindrical shaft portion extending through the mounting aperture in the extractor plate and extending through the mounting aperture in the beam blocker, a base portion at a first end of the shaft portion and a head portion at an opposite second end of the shaft portion; a tubular centering sleeve radially surrounding the shaft portion within the mounting aperture in the extractor plate and within the mounting aperture in the beam blocker and axially abutting the base portion, the centering sleeve being held in radial compression between the shaft portion and the extractor plate and between the shaft portion and the beam blocker; an annular spacer radially surrounding the centering sleeve and the shaft portion of the mounting pin and axially abutting the beam blocker, the centering sleeve extending partially into the spacer but not completely through the spacer; and a latching cap radially surrounding the shaft portion and axially abutting the spacer, the shaft portion extending through an aperture in the latching cap that is smaller than the head portion in a direction perpendicular to the axis of the mounting pin.

[0009] A method of fastening a beam blocker according to the present disclosure to an extractor plate of an ion processing system includes inserting a mounting pin into a mounting aperture in the extractor plate from a front of the extractor plate, the mounting pin having a cylindrical shaft portion, a base portion at a first end of the shaft portion, and a head portion at an opposite second end of the shaft portion; and centering a mounting pin so as to axially abut the base portion of the mounting pin radially intermediate the shaft portion of the mounting pin and the extractor plate. inserting a first radial half of the centering sleeve into the mounting aperture of the extractor plate; inserting a second radial half of the centering sleeve into the mounting aperture of the extractor plate so that the first radial half of the centering sleeve axially abuts the base portion of the mounting pin radially intermediate the shaft portion of the mounting pin and the extractor plate, and the second radial half of the centering sleeve mates with the first radial half of the centering sleeve to define a tubular body held in radial compression between the shaft portion of the mounting pin and the extractor plate; the beam blocker extends through the mounting aperture in the beam blocker, the beam blocker is positioned flat against the rear of the extraction plate, and the tubular body of the centering sleeve is held in radial compression between the shaft portion of the mounting pin and the beam blocker; mating first and second radial halves of the spacer onto one another on the centering sleeve to define an annular body that axially abuts the beam blocker, with the centering sleeve extending partially into the through hole in the spacer; placing an annular latching cap over the head portion of the mounting pin such that the head portion is aligned with and inserted through a correspondingly shaped through hole in the latching cap, the latching cap being positioned over the shaft portion of the mounting pin and over the spacer in radially surrounding relationship therewith; and rotating the latching cap relative to the mounting pin to move the through hole in the latching cap out of alignment with the head portion of the mounting pin to prevent the latching cap from sliding axially off the mounting pin. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side cross-sectional view of an ion processing system consistent with an embodiment of the present disclosure. [Figure 2] 2 is a rear perspective view of the extraction assembly of the ion processing system shown in FIG. 1. [Figure 3] 2 is an exploded rear perspective view of an extraction assembly of the ion processing system shown in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view of the fastening assembly of the extraction assembly shown in FIGS. 2 and 3. [Figure 5] 5 is a perspective view of the mounting pin and centering sleeve of the fastener assembly shown in FIG. 4. [Figure 6] FIG. 5 is a rear perspective view of the fastener assembly shown in FIG. 4. [Figure 7] FIG. 10 is a flow diagram illustrating an exemplary method of using the fastening assembly of the present disclosure to fasten a beam blocker to an extraction plate of an ion processing system. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0017] The present embodiments will now be described more fully with reference to the accompanying drawings, which illustrate several embodiments. The subject matter of this disclosure may be embodied 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 numbers refer to like elements throughout.

[0012]

[0018] As used herein, elements or steps described in the singular and preceded by the word "a" or "an" should be understood to also include a plurality of elements or steps. Furthermore, references to "embodiments" of the present disclosure should not be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0013]

[0019]

[0006] The embodiments described herein provide apparatus and methods for mounting and centering a beam blocker in an ion processing system in a manner that mitigates beam blocker misalignment that may result from tolerance stackup in beam blocker components and / or beam blocker sag due to gravity. Improved beam blocker alignment may improve the symmetry of ion beamlets projected around the beam blocker, which in turn may improve processing (etching, implantation, etc.) of the target substrate.

[0014]

[0020] Reference is made to FIG. 1 , which is a schematic cross-sectional view of an ion processing system (hereinafter, “system 100”) consistent with embodiments of the present disclosure. The system 100 may include a plasma chamber 102, a process chamber 104, and an extractor assembly 106, which will be described in more detail below. The processing system 100 may further include a voltage supply 107 electrically coupled to generate a bias voltage between the plasma chamber 102 and a substrate 108 to be processed (or a platen 110 supporting the substrate 108). In this manner, the processing system 100 functions as an ion beam processing system that generates an ion beam for processing the substrate 108 disposed proximate the extractor assembly 106. The plasma chamber 102 may function as a plasma source that generates a plasma 112 by any suitable approach. For example, the plasma chamber 102 may be referenced to ground potential through a conductive back wall 114. Ionizable (ion) species of interest may be generated in the plasma 112 by inductively coupling RF power generated by an RF power source (not separately shown) from an RF antenna 116 through a dielectric window 118 to a working gas in the plasma chamber 102. Other known means of generating the plasma are also possible.

[0015]

[0021] The extraction assembly 106 may further include an extraction plate 120 disposed along a side of the plasma chamber 102. The extraction plate 120 may define an elongated extraction aperture 122 along the X-axis of the Cartesian coordinate system shown in FIG. 1 (note that the X-axis extends perpendicular to the plane of the page). The extraction aperture 122 allows ions from the plasma chamber 102 to pass to the substrate 108, as described further below. Refer to FIG. 2, which is a rear perspective view of the extraction assembly 106 in isolation. As best shown in this figure, the extraction aperture 122 may be formed in a recess 124 in an inner surface 126 of the extraction plate 120 (i.e., the surface of the extraction plate 120 facing the interior of the plasma chamber 102 shown in FIG. 1). The extraction assembly 106 may further include a beam blocker assembly 128 disposed adjacent to the extraction aperture 122 (see also FIG. 1). The beam blocker assembly 128 may include a beam blocker 130 that is elongated along the X-axis of the illustrated Cartesian coordinate system and has a height measured along the Y-axis of the Cartesian coordinate system equal to or approximately equal to the height of the extraction aperture 122. The beam blocker 130 may be fastened to the inner surface 126 of the extraction plate 120 on opposite longitudinal sides of the recess 124 by first and second fastening assemblies 134 a, 134 b (described in more detail below).

[0016]

[0022] 1 , when a negative voltage is applied to the substrate 108 (or platen 110) relative to the plasma chamber 102 in the presence of plasma 112, a plasma meniscus forms at slits (subapertures) 136 a, 136 b between the beam blocker 130 and the extraction plate 120 (i.e., above and below the beam blocker 130). The beam blocker 130 may be vertically centered (i.e., centered along the Y-axis of a Cartesian coordinate system) with respect to the extraction aperture 122 to facilitate the formation and extraction of two symmetrically angled ion beamlets 138 a, 138 b directed toward the substrate 108. Ion beam processing of the substrate 108 is performed by scanning the substrate 108 along the Y-axis of the Cartesian coordinate system and may also include rotating the substrate about the Z-axis of the Cartesian coordinate system.

[0017]

[0023] 3 and 4, which respectively illustrate an exploded rear perspective view of the extractor assembly 106 and a detailed cross-sectional view of the extractor plate 120 and the first fastener assembly 134ba. These figures will be referred to in parallel in the following description. The first and second fastener assemblies 134a, 134b are generally identical, and therefore the illustration of the first fastener assembly 134ba provided in FIG. 4, and the accompanying description provided below, shall be understood to also represent the second fastener assembly 134b.

[0018]

[0024] As briefly described above, the first and second fastening assemblies 134a, 134b are adapted to fasten the beam blocker 130 to the extraction plate 120 in a manner that ensures or improves vertical centering and alignment of the beam blocker 130 relative to the extraction aperture 122. The first and second fastening assemblies 134a, 134b may include respective mounting pins 140a, 140b, centering sleeves 142a, 142b, spacers 144a, 144b, O-rings 146a, 146b, and latching caps 148a, 148b. 4, mounting pin 140a may include a cylindrical base portion 150, a cylindrical shaft portion 152 extending from base portion 150 and having a smaller diameter than base portion 150, and an oval head portion 154 having a height measured along the Y-axis of a Cartesian coordinate system that is greater than the diameter of shaft portion 152 (see FIGS. 5 and 6 for illustrations of the oval shape of head portion 154). In various alternative embodiments, base portion 150 may have a shape other than cylindrical that is larger along the Y-axis and / or X-axis of the Cartesian coordinate system than shaft portion 152. Similarly, in various alternative embodiments, head portion 154 may have a shape other than oval that is larger along the Y-axis and / or X-axis of the Cartesian coordinate system than shaft portion 152.

[0019]

[0025] The mounting pin 140a may extend through a mounting aperture 156 in the extraction plate 120, with the base portion 150 of the mounting pin 140a positioned in a close clearance relationship with a counterbore 158 of the mounting aperture 156 formed in the front face (i.e., the right-most face in the orientation in FIG. 4 ) of the extraction plate 120. The mounting aperture 156 may have a diameter larger than the diameter of the shaft portion 152. In various non-limiting examples, the diameter of the mounting aperture 156 may be 12.34 millimeters ±0.08 millimeters larger than the diameter of the shaft portion 152. The forward-facing surface of the base portion 150 may be generally coplanar with the front face of the extraction plate 120.

[0020]

[0026] The shaft portion 152 of the mounting pin 140a may extend through a mounting aperture 160 in the beam blocker 130. The diameter of the mounting aperture 160 may be equal to or similar to the diameter of the mounting aperture 156 in the extraction plate 120. In various non-limiting examples, the diameter of the mounting aperture 160 may be 12.14 millimeters ±0.08 millimeters. The centering sleeve 142a may be a generally tubular member formed of a resilient material. The centering sleeve 142a may surround the shaft portion 152 of the mounting pin 140a and may extend through the mounting apertures 156, 160 in the extraction plate 120 and the beam blocker 130, with the forward-most end of the centering sleeve 142a abutting the base portion 150 of the mounting pin 140a. The centering sleeve 142a may have an uncompressed outer diameter that is slightly larger than the diameter of the mounting apertures 156, 160 in the extraction plate 120 and the beam blocker 130. In various non-limiting examples, the uncompressed outer diameter of the centering sleeve 142a may be 12.83 millimeters ±0.05 millimeters larger than the diameter of the mounting apertures 156, 160 in the extraction plate 120 and the beam blocker 130. As shown in FIG. 4 , when the centering sleeve 142a is operably installed in the first fastener assembly 134a, the centering sleeve 142a may be held in radial compression between the shaft portion 152 of the mounting pin 140a and the beam blocker 130 and extraction plate 120 (e.g., via an interference / friction fit). Thus, regardless of variations or inconsistencies in the diameter of the mounting pin 140a or the diameters of the mounting apertures 156, 160 (which may be the result of manufacturing tolerances, etc.), the centering sleeve 142a can prevent or mitigate radial movement or "play" of the beam blocker 130 relative to the mounting pin 140a and extraction plate 120, and can establish and maintain vertical centering / alignment of the beam blocker 130 relative to the extraction aperture 122.

[0021]

[0027] In various embodiments, centering sleeve 142a may be formed from polytetrafluoroethylene (PTFE) or other similarly resilient, plasma-resistant material. The present disclosure is not limited in this respect. With reference to FIG. 5 , centering sleeve 142a may include a plurality of axially elongated, radially extending fins 162. Fins 162 may be flexible and may facilitate or enhance the radial resilience and / or elasticity of centering sleeve 142a. Because centering sleeve 142a may have a smaller inner diameter than head portion 154 of mounting pin 140a, and thus cannot slide axially over shaft portion 152 of mounting pin 140a, centering sleeve 142a may be formed from separate first and second radial halves 142a1, 142a2 (see FIG. 3 ) that mate together over shaft portion 152 to define tubular centering sleeve 142a.

[0022]

[0028] 3 and 4, the spacer 144a of the first fastener assembly 134a may be an annular, washer-like member disposed on (i.e., radially surrounding) the centering sleeve 142a and abutting the beam blocker 130. In various embodiments, the centering sleeve 142a may extend partially into, but not completely through, the spacer 144a, as shown in FIG. 4. The disclosure is not limited in this respect. The spacer 144a may define a through-hole 164 having a diameter larger than the outer diameter of the centering sleeve 142a (although a tight radial engagement between the spacer 144a and the centering sleeve 142a is not required). In various non-limiting embodiments, the spacer 144a may include a radially inward-extending flange 166 that projects from the rear side of the through-hole 164. The flange 166 may define a second through-hole 168 having a smaller diameter than the through-hole 164 and may serve to protect the centering sleeve 142a from ion bombardment during operation of the system 100 (see FIG. 1 ) to prevent or mitigate etching of the centering sleeve 142a. Alternative embodiments of the present disclosure are also contemplated in which the flange 166 may be omitted. The spacer 144a may be formed of a plasma-resistant dielectric material, such as ceramic alumina. The disclosure is not limited in this respect. Similar to the centering sleeve 142a, the spacer 144a may be formed from separate first and second radial halves 144a1, 144a2 (see FIG. 3 ) fitted together on the shaft portion 152 and the centering sleeve 142a to define the annular spacer 144a.

[0023]

[0029] The latching cap 148a of the first fastener assembly 134a may be a generally annular, cap-shaped member that is disposed over (i.e., radially surrounding) the mounting pin 140a and the shaft portion 152 of the spacer 144a and axially abuts the rear of the spacer 144a. The latching cap 148a may define a throughbore 170 having an oval shape similar to but slightly larger than the shape of the head portion 154 of the mounting pin 140a (best shown in FIG. 6 ). Thus, during installation of the latching cap 148a, the throughbore 170 may be aligned with the head portion 154, and with the head portion 154 passing through the throughbore 170, the latching cap 148a may be slid axially over the mounting pin 140a and axially engaged with the spacer 144a. The O-rings 146a of the first fastener assembly 134a may be formed of a resilient material and may be disposed in circumferentially spaced cavities 172 in each of the rear surfaces of the spacers 144a. The O-rings 146a may protrude slightly from the cavities 172 when in an uncompressed state. Axial engagement of the latching cap 148a with the rear surface of the spacer 144a may compress the O-rings 146a. While the latching cap 148a is held in this position and the O-rings 146a are held under compression, the latching cap 148a may be rotated 90 degrees (or within a range around 90 degrees, e.g., 60 to 120 degrees) about its axis, thereby rotating the through-hole 170 out of alignment with the head portion 154 of the mounting pin 140a (as shown in FIG. 6 ). With the latching cap 148a so installed, the head portion 154 can prevent the spacer 144a from moving rearward along the X-axis of the Cartesian coordinate system, and the spring force of the compressed O-ring 146a can exert an axially directed force on the latching cap 148a and spacer 144a to hold the head portion 154, latching cap 148a, spacer 144a, beam blocker 130, and extraction plate 120 in tight axial engagement with one another.

[0024]

[0030] Reference is now made to FIG. 7, which is a flow diagram illustrating an exemplary method for installing the beam blocker 130 of the extractor assembly 106 using the first and second fastener assemblies 134a, 134b described above. While the installation of the first fastener assembly 134a will be described in detail, it should be understood that because the first and second fastener assemblies 134a, 134b are generally identical, the following description also describes a method for installing the second fastener assembly 134b. This method will now be described in conjunction with the illustrative extractor assembly 106 and the first and second fastener assemblies 134a, 134b shown in FIGS. 1-6.

[0025]

[0031] In block 200 of the exemplary method, the mounting pin 140 a can be inserted into the mounting aperture 156 from the front of the extraction plate 120, and the base portion 150 of the mounting pin 140 a can be seated within the counterbore 158 of the mounting aperture 156. When so seated, the forward-facing surface of the base portion 150 can be generally flush with the front surface of the extraction plate 120.

[0026]

[0032] At block 210 of the exemplary method, a first radial half 142a1 of the centering sleeve 142a can be inserted into the mounting aperture 156 through the rear of the extractor plate 120 and seated therein for axial abutment with the base portion 150 of the mounting pin 140a, radially intermediate the shaft portion 152 of the mounting pin 140a and the extractor plate 120. At block 220 of the method, a second radial half 142a2 of the centering sleeve 142a can be inserted into the mounting aperture 156 through the rear of the extractor plate 120 and seated therein for axial abutment with the base portion 150 of the mounting pin 140a, radially intermediate the shaft portion 152 of the mounting pin 140a and the extractor plate 120. The first and second radial halves 142a1, 142a2 may be mated together to define a tubular centering sleeve 142a. The centering sleeve 142a, thus seated within the mounting aperture 156, may be held in radial compression between the shaft portion 152 of the mounting pin 140a and the extraction plate 120 (e.g., via an interference / friction fit).

[0027]

[0033] At block 230 of the exemplary method, beam blocker 130 can be positioned over mounting pin 140a and centering sleeve 142a, with shaft portion 152 of mounting pin 140a and centering sleeve 142a extending through mounting aperture 160 in beam blocker 130, and beam blocker 130 positioned flush against the rear of extraction plate 120. With centering sleeve 142a thus positioned within mounting aperture 160, it can be held in radial compression between shaft portion 152 of mounting pin 140a and beam blocker 130 (e.g., via an interference / friction fit).

[0028]

[0034] At block 240 of the exemplary method, an O-ring 146a can be seated within the cavity 172 of each of the first and second radial halves 144a1, 144a2 of the spacer 144a. The O-ring 146a can protrude slightly from the cavity 172 when in an uncompressed state. At block 250 of the method, the first and second radial halves 144a1, 144a2 can be mated together over the shaft portion 152 and the centering sleeve 142a to define an annular spacer 144a that axially abuts the rear of the beam blocker 130, with the centering sleeve 142a extending partially into but not completely through the through-hole 164 of the spacer 144a. In various non-limiting embodiments, the spacer 144a can include a radially inward-extending flange 166 that juts radially from the rear side of the through-hole 164. The flange 166 can define a second through hole 168 having a smaller diameter than the through hole 164 and can serve to protect the centering sleeve 142a from ion bombardment during operation of the system 100, preventing or mitigating etching of the centering sleeve 142a.

[0029]

[0035] At block 260 of the exemplary method, the latching cap 148a can be placed over the head portion 154 of the mounting pin 140a, with the oblong head portion 154 aligned with and inserted through a corresponding oblong through-hole 170 in the latching cap 148a. The latching cap can be disposed over the shaft portion 152 of the mounting pin 140a and over the spacer 144a in a radially surrounding relationship therewith. The latching cap 148a can be pressed into axial abutment against the rear of the spacer 144a, compressing the O-ring 146a into its respective cavity 172. While latching cap 148a is held in this position and O-ring 146a is held under compression, in block 270 of the exemplary method, latching cap 148a is rotated about its axis 90 degrees (or within a range of about 90 degrees, e.g., 60 to 120 degrees) such that through-hole 170 is rotated out of alignment with head portion 154 of mounting pin 140a. With latching cap 148a so installed, head portion 154 can prevent spacer 144a from moving rearward, and the spring force of compressed O-ring 146a can exert an axially directed force on latching cap 148a and spacer 144a to hold head portion 154, latching cap 148a, spacer 144a, beam blocker 130, and extraction plate 120 in tight axial engagement with one another.

[0030]

[0036] In block 280 of the exemplary method, the operations performed in blocks 200-270 described above with respect to the first fastening assembly 134a can be repeated with the second fastening assembly 134b to fasten the opposite longitudinal end of the beam blocker 130 to the extraction plate 120.

[0031]

[0037] In view of the above, the present disclosure provides at least the following advantages. First, the fastening assembly of the present disclosure operates to prevent or mitigate beam blocker misalignment relative to the extraction aperture of the ion processing system, thus ensuring or enhancing symmetry of ion beamlets projected around the beam blocker toward the target substrate. Second, the fastening assembly of the present disclosure is quick and easy to install. Third, the fastening assembly of the present disclosure is self-protective against undesired ion etching of internal components (i.e., centering sleeves 142a, 142b).

[0032]

[0038] While specific embodiments of the present disclosure have been described herein, the present disclosure is not limited thereto but is to the broadest possible scope within the skill of the art, and the specification can be read accordingly. Therefore, the above description should not be construed as limiting. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

1. 1. A fastening assembly for fastening a beam blocker to an extraction plate of an ion processing system, comprising: a mounting pin having a cylindrical shaft portion, a base portion at a first end of said shaft portion, and a head portion at an opposite second end of said shaft portion; a tubular centering sleeve radially surrounding the shaft portion and axially abutting the base portion, the centering sleeve adapted to be radially compressed between the shaft portion and the extraction plate and between the shaft portion and the beam blocker; an annular spacer radially surrounding the centering sleeve and the shaft portion of the mounting pin and axially abutting the beam blocker, the centering sleeve extending partially within but not completely through the spacer; a latching cap radially surrounding the shaft portion and axially abutting the spacer, the shaft portion extending through a through hole in the latching cap, the through hole being smaller than the head portion in a direction perpendicular to the axis of the mounting pin; A fastening assembly comprising:

2. The fastener assembly of claim 1 , further comprising a plurality of O-rings disposed in corresponding cavities formed in the spacer and facing the latching cap.

3. The fastener assembly of claim 1 , wherein the head portion of the mounting pin has an oval shape.

4. 2. The fastener assembly of claim 1, wherein the shaft portion of the mounting pin extends through a through hole in the spacer, the spacer having a radially inwardly extending flange that projects radially from a rear side of the through hole in the spacer and covers an end of the centering sleeve to protect the centering sleeve from ion bombardment.

5. The fastener assembly of claim 1 , wherein the centering sleeve is formed from separate first and second radial halves adapted to be mated together.

6. The fastener assembly of claim 1 , wherein the spacer is formed from separate first and second radial halves adapted to mate with one another.

7. The fastener assembly of claim 1 , wherein the base portion of the mounting pin is larger than the shaft portion of the mounting pin in a direction perpendicular to the axis of the mounting pin.

8. The fastener assembly of claim 1 , wherein the centering sleeve is formed from polytetrafluoroethylene (PTFE).

9. 1. An ion processing system comprising: a plasma chamber; a process chamber disposed adjacent to the plasma chamber; 1. An extraction assembly comprising: an extraction plate disposed along a side of the plasma chamber and defining an extraction aperture; a beam blocker disposed adjacent the extraction aperture and fastened to the extraction plate by a fastening assembly; an extractor assembly, and wherein the fastening assembly comprises: a mounting pin having a cylindrical shaft portion extending through a mounting aperture in the extraction plate and extending through a mounting aperture in the beam blocker, a base portion at a first end of the shaft portion, and a head portion at an opposite second end of the shaft portion; a tubular centering sleeve radially surrounding the shaft portion within the mounting apertures of the extraction plate and the beam blocker and axially abutting the base portion, the centering sleeve being held in radial compression between the shaft portion and the extraction plate and between the shaft portion and the beam blocker; an annular spacer radially surrounding the centering sleeve and the shaft portion of the mounting pin and axially abutting the beam blocker, the centering sleeve extending partially within but not completely through the spacer; a latching cap radially surrounding the shaft portion and axially abutting the spacer, the shaft portion extending through a through hole in the latching cap, the through hole being smaller than the head portion in a direction perpendicular to the axis of the mounting pin; 1. An ion processing system comprising:

10. 10. The ion processing system of claim 9, further comprising a plurality of O-rings disposed in corresponding cavities formed in the spacer, the O-rings being held in compression between the latching cap and the spacer.

11. The ion processing system of claim 9 , wherein the head portion of the mounting pin has an oval shape.

12. 10. The ion processing system of claim 9, wherein the shaft portion of the mounting pin extends through a through hole in the spacer, the spacer having a radially inward extending flange that projects radially from a rear side of the through hole in the spacer and covers an end of the centering sleeve to protect the centering sleeve from ion bombardment.

13. 10. The ion processing system of claim 9, wherein the centering sleeve is formed from separate first and second radial halves adapted to mate with one another over the shaft portion of the mounting pin.

14. 10. The ion processing system of claim 9, wherein the spacer is formed from separate first and second radial halves adapted to mate with one another on the centering sleeve.

15. The ion processing system of claim 9 , wherein the base portion of the mounting pin is larger than the shaft portion of the mounting pin in a direction perpendicular to the axis of the mounting pin.

16. 1. A method of fastening a beam blocker to an extraction plate of an ion processing system, comprising: inserting a mounting pin into a mounting aperture in the extractor plate from a front portion of the extractor plate, the mounting pin having a cylindrical shaft portion, a base portion at a first end of the shaft portion, and a head portion at an opposite second end of the shaft portion; inserting a first radial half of a centering sleeve into the mounting aperture of the extraction plate so as to axially abut the base portion of the mounting pin radially intermediate the shaft portion of the mounting pin and the extraction plate; inserting the second radial half of the centering sleeve into the mounting aperture of the extractor plate such that the second radial half abuts the base portion of the mounting pin radially intermediate the shaft portion of the mounting pin and the extractor plate, and the second radial half of the centering sleeve mates with the first radial half of the centering sleeve to define a tubular body held in radial compression between the shaft portion of the mounting pin and the extractor plate; placing the beam blocker over the mounting pin and the centering sleeve such that the shaft portion of the mounting pin and the centering sleeve extend through a mounting aperture in the beam blocker, the beam blocker is positioned flush against the rear of the extraction plate, and the tubular body of the centering sleeve is held in radial compression between the shaft portion of the mounting pin and the beam blocker; defining an annular body axially abutting the beam blocker, and first and second radial halves of the spacer fitting together over the centering sleeve such that the centering sleeve extends partially into the through hole of the spacer; disposing an annular latching cap between the head portion of the mounting pin and the spacer such that the head portion is aligned with and inserted through a correspondingly shaped through hole in the latching cap, and the latching cap is disposed over the shaft portion of the mounting pin and over the spacer in radially surrounding relationship therewith; rotating the latching cap relative to the mounting pin to move the through hole of the latching cap out of alignment with the head portion of the mounting pin to prevent the latching cap from sliding axially off the mounting pin; A method comprising:

17. 17. The method of claim 16, wherein the spacer has a radially inward extending flange that projects radially from a rear side of the through hole in the spacer and covers an end of the centering sleeve to protect the centering sleeve from ion bombardment.

18. The method of claim 16, further comprising disposing a plurality of O-rings in corresponding cavities formed in the spacer.

19. The method of claim 18, wherein positioning the latching cap between the head portion of the mounting pin and the spacer includes compressing the plurality of O-rings into corresponding cavities.

20. 17. The method of claim 16, wherein inserting the mounting pin into the mounting aperture of the extraction plate includes disposing the base portion of the mounting pin in a counterbore of the mounting aperture of the extraction plate.

Images