CN102301451A - Wafer processing deposition shield - Google Patents

Abstract

Embodiments described herein generally relate to an apparatus and method for uniformly sputter-depositing material onto the bottom and sidewalls of features having a high aspect ratio on a substrate. In one embodiment, a collimator is provided that is positioned between a sputtering target and a substrate support and mechanically and electrically connected to a shielding member. The collimator includes a central region and a peripheral region, wherein the collimator has a plurality of apertures extending therethrough, wherein the apertures in the central region have a higher aspect ratio than the apertures in the peripheral region.

Description

Wafer Handling Deposition Shield Components

technical field

Embodiments of the invention generally relate to an apparatus and method for uniform sputter deposition of material onto the bottom and sidewalls of high aspect ratio features on a substrate.

Background technique

In the fabrication of integrated circuits, sputtering or physical vapor deposition (PVD) is a technique widely used to deposit thin metal layers on substrates. Layers that act as diffusion barrier, seed layer, primary conductor, antireflective coating, and etch stop layer are deposited using PVD. However, it is difficult to form a uniform thin film maintaining the shape of a substrate in which steps such as forming holes or grooves occur by PVD. In particular, the wide angular distribution of deposited sputtered atoms results in poor coverage in the bottom and sidewalls of features with high aspect ratios, such as holes and trenches.

Collimator sputtering techniques were developed to allow deposition of thin films in the bottom of features with high aspect ratios using PVD. A collimator is a filter plate positioned between the sputter source and the substrate. A collimator typically has a uniform thickness and includes channels formed through the thickness. The sputtered material must pass through a collimator on its way from the sputtering source to the substrate. The collimator filters out material that would strike the workpiece at an acute angle beyond the desired angle.

The actual amount filtered by a given collimator depends on the aspect ratio of the channel passing through that collimator. Thus, particles traveling along a path approximately perpendicular to the substrate pass through the collimator and deposit on the substrate. This can improve coverage in features with high aspect ratios at the bottom.

However, the use of small magnet magnetrons in conjunction with collimators has been known to present some problems. Using a small magnet magnetron will result in a high flux of ionized metal, which is good for filling high aspect ratio features. Unfortunately, PVD with known collimators incorporating small magnet magnetrons provides uneven deposition across the substrate. The source material may deposit a thicker layer in one area of the substrate than in other areas on the substrate. For example, depending on the radial positioning of the small magnets, thicker layers may be deposited in the center or edges of the substrate. This phenomenon not only results in non-uniform deposition across the substrate, but also in some regions of the substrate across the sidewalls of features with high aspect ratios. For example, small magnets positioned radially to provide optimal magnetic field uniformity in regions near the periphery of the substrate result in more source material being deposited on the feature sidewalls facing the center of the substrate than on the Larger on the sidewall of the feature facing the periphery of the substrate.

Accordingly, there exists a need to improve the uniformity of deposition of source material across a substrate by PVD techniques.

Contents of the invention

A deposition apparatus of one embodiment described herein comprises: an electrically grounded chamber; a sputter target supported by and electrically insulated from the chamber; a substrate support positioned on the sputter target and a substrate support surface substantially parallel to the sputtering surface of the sputtering target; a shield member supported by the chamber and electrically connected to the chamber; and a collimator mechanically and electrically connected to the chamber A shielding member is positioned between the sputtering target and the substrate support. In one embodiment, the collimator has a plurality of apertures extending therethrough. In one embodiment, the apertures located in the central region have a higher aspect ratio than the apertures located in the peripheral region.

In another embodiment, a deposition apparatus comprises: an electrically grounded chamber; a sputtering target supported by and electrically insulated from the chamber; a substrate support positioned below the sputtering target and having a substrate support surface substantially parallel to the sputtering surface of the sputtering target; a shield member supported by the chamber and electrically connected to the chamber; a collimator mechanically and electrically connected to the shield components and positioned between the sputtering target and the substrate support; a gas source; and a controller. In one embodiment, the sputter target is electrically connected to a DC power source. In one embodiment, the substrate support is electrically connected to an RF power source. In one embodiment, the controller is programmed to provide signals to control the gas source, the DC power source, and the RF power source. In one embodiment, the collimator has a plurality of apertures extending therethrough. In one embodiment, the apertures located in the central region have a higher aspect ratio than the apertures located in the peripheral region of the collimator. In one embodiment, the controller is programmed to provide a high bias voltage to the substrate support.

In yet another embodiment, a method for depositing a material onto a substrate comprises the step of: aligning the sputter target with a collimator positioned between the sputter target and the substrate support in a chamber having a collimator applying a DC bias to the material; providing a process gas in a region adjacent to the sputtering target within the chamber; applying a bias to the substrate support; and pulsing the substrate support between a high bias and a low bias seat bias. In one embodiment, the collimator has a plurality of apertures extending therethrough. In one embodiment, the apertures located in the central region have a higher aspect ratio than the apertures located in the peripheral region of the collimator.

In yet another embodiment, a collimator positioned between a sputter target and a substrate support for mechanical and electrical connection of a shielding member is provided. The collimator includes a central region and a peripheral region, wherein the collimator has a plurality of apertures extending therethrough, and wherein the apertures in the central region have a higher aspect ratio than the apertures in the peripheral region.

In yet another embodiment, a lower shield for surrounding a substrate support facing a target in a processing chamber is provided. The lower shield includes a cylindrical outer band having a first diameter sized to surround the sputtering surface and substrate support of the sputtering target, the outer cylindrical band including a sputtering surface surrounding the sputtering target An upper portion of the projecting surface; a middle portion; and a lower portion, which surrounds the substrate support seat; a support flange, which has a bearing surface and extends radially outward from the cylindrical outer band; a base plate, which extends from the cylindrical outer band a lower portion extending radially inwardly; and a cylindrical inner band connected to the base plate and partially surrounding the perimeter of the substrate support.

In yet another embodiment, an upper shield for surrounding a sputtering target facing a support pedestal in a substrate processing chamber is provided. The upper shield contains a shield portion and an integrated flow optimizer for directional sputtering.

Description of drawings

Therefore, the features of the invention briefly described above may be further understood and described by reference to a more particularly described embodiment of the invention, some of which are shown in the accompanying drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is a schematic cross-sectional view of a semiconductor processing system with one embodiment of the processing kit described herein.

2 is a top plan view of a collimator according to embodiments described herein.

3 is a schematic cross-sectional view of a collimator according to embodiments described herein.

4 is a schematic cross-sectional view of a collimator according to embodiments described herein.

5 is a schematic cross-sectional view of a collimator according to embodiments described herein.

6 is an enlarged partial cross-sectional view of a bracket for attaching a collimator to an upper shield of a PVD chamber, according to embodiments described herein.

7 is a partial cross-sectional view of a bracket used to attach a collimator to an upper shield of a PVD chamber, according to embodiments described herein.

8 is a schematic cross-sectional view of a semiconductor processing system having another processing kit according to the description herein.

9A is a partial cross-sectional view of a shield on a monolith according to embodiments described herein.

9B is a top plan view of the shield on a monolith of FIG. 9A according to embodiments described herein.

10A is a cross-sectional view of a lower shield according to embodiments described herein.

Figure 10B is a partial cross-sectional view of one embodiment of the lower shield of Figure 10A.

Figure 10C is a top view of one embodiment of the lower shield of Figure 10A.

Detailed ways

Embodiments described herein provide apparatus and methods for uniformly depositing sputtered material across high aspect ratio features of a substrate during the fabrication of integrated circuits on the substrate.

PVD处理腔室。应了解也可利用得自其它制造商的处理腔室来实行本文所述的实施例。FIG. 1 illustrates an example embodiment of a processing chamber 100 having one embodiment of a processing kit 140 that can process a substrate 154 . The processing kit 140 includes a one-piece lower shield 180 , a one-piece upper shield 186 and a collimator 110 . In the illustrated embodiment, the processing chamber 100 comprises a sputtering chamber, also known as It is a physical vapor deposition (PVD) chamber. Examples of suitable PVD chambers include the ALPS, both available from Applied Materials, Inc., Santa Clara, California. Plus and SIPENCORE

PVD processing chamber. It should be appreciated that processing chambers from other manufacturers may also be utilized to practice the embodiments described herein.

The chamber 100 includes a sputtering source, such as a target 142 having a sputtering surface 145, and a substrate support 152 having a peripheral edge 153 for receiving a semiconductor substrate 154 thereon. The substrate support can be located in the grounded chamber wall 150 .

In one embodiment, the chamber 100 includes a target 142 supported by a grounded conductive adapter 144 via a dielectric isolator 146 . Target 142 comprises material to be deposited onto the surface of substrate 154 during sputtering and includes copper deposited as a seed layer for high aspect ratio features formed within substrate 154 . In one embodiment, the target 142 may also include an adhesive composition of a metal surface layer of a sputterable material (eg, copper) and a back layer of a structural material (eg, aluminum).

In one embodiment, the pedestal 152 supports a substrate 154 to be sputter coated, wherein the substrate 154 has high aspect ratio features, the bottom of which is planar relative to the major surface of the target 142 . The substrate support 152 has a planar substrate receiving surface disposed generally parallel to the sputtering surface of the target 142 . The seat 152 is movable vertically through a bellow 158, which is connected to the bottom chamber wall 160 to allow substrates to be loaded via a load lock valve (not shown) in the lower portion of the chamber 100. Transport to seat 152. The seat 152 can then be raised to the deposition position as shown.

In one embodiment, process gas may be supplied into the lower portion of the chamber 100 from a gas source 162 via a mass flow controller 164 . In one embodiment, a negative voltage or bias may be applied to the target 142 using a controllable direct current (DC) power source 148 connected to the chamber 100 . A radio frequency (RF) power source 156 may be connected to mount 152 to induce a DC self-bias on substrate 154 . In one embodiment, socket 152 is grounded. In one embodiment, socket 152 is electrically floating.

In one embodiment, magnetron 170 is positioned above target 142 . Magnetron 170 may include a plurality of magnets 172 supported by a base plate 174 connected to an axis 176 that may be axially aligned with the central axis of chamber 100 and substrate 154 . In one embodiment, the magnets are arranged in a kidney-shaped pattern. The magnet 172 generates a magnetic field in the chamber 100 close to the front of the target 142 to generate a plasma, so that a large amount of ion flow hits the target 142, causing the target material to be sputtered out. The magnet 172 is rotatable about an axis 176 to increase the uniformity of the magnetic field across the surface of the target 142 . In one embodiment, the magnetron 170 is a small magnet magnetron. In one embodiment, the magnets 172 are mutually rotatable and movable in a linear direction substantially parallel to the target surface to generate a helical motion. In one embodiment, the magnet 172 is rotatable about a central axis and an independently controllable second axis to control its radial and angular position.

In one embodiment, the chamber 100 includes a grounded lower shield 180 having a support flange 182 supported by and connected to the chamber sidewall 150 . Upper shield 186 is supported by and connected to flange 184 of adapter 144 . The upper shield 186 and the lower shield 180 are connected in the same manner as the adapter 144 is electrically connected to the chamber wall 150 . In one embodiment, both the upper shield 186 and the lower shield 180 comprise stainless steel. In one embodiment, chamber 100 includes a middle shield (not shown) connected to upper shield 186 . In one embodiment, upper shield 186 and lower shield 180 are electrically floating within chamber 100 . In one embodiment, upper shield 186 and lower shield 180 may be connected to an electrical power source.

In one embodiment, the upper shield 186 has an upper portion that closely fits the annular side groove of the target 142 with a narrow gap 188 (between the upper shield 186 and the target 142), the narrow gap 188 being narrower. Enough to prevent plasma from penetrating and sputter coating the dielectric spacer 146 . The upper shield 186 may also include a downwardly projecting top 190 that covers the interface between the lower shield 180 and the upper shield 186, thereby preventing the shields from joining by sputter deposited material.

In one embodiment, the lower shield 180 extends down to a cylindrical outer band 196 that extends generally along the chamber wall 150 below the top surface of the seat 152 . The lower shield 180 may have a base plate 198 extending radially inward from a cylindrical outer band 196 . The base plate 198 may include a cylindrical inner band 103 extending upwardly around the periphery of the seat 152 . In one embodiment, when the seat 152 is in the lower loading position, the cover ring 102 is supported on the top of the cylindrical inner belt 103; when the seat is in the upper deposition position, the cover ring 102 is supported on the outer periphery of the seat 152 to protect the seat 152 from Will be subject to sputter deposition.

The lower shield 180 surrounds the sputtering surface 145 of the target 142 facing the support base 152 and surrounds the peripheral wall of the support base 152 . The lower shield 160 covers and shields the chamber wall 150 of the chamber 100 to reduce deposition of sputter deposits from the sputtering surface 145 of the sputtering target 142 onto components and surfaces behind the lower shield 180 . For example, the lower shield 180 can protect the surface of the support base 152 , portions of the substrate 154 , the chamber wall 150 , and the bottom wall 160 of the chamber 100 .

In one embodiment, directional sputtering can be achieved by positioning the collimator 110 between the target 142 and the substrate support 152 . The collimator 110 may be mechanically or electrically connected to the upper shield 186 . In one embodiment, the collimator 110 may be connected to an intermediate shield (not shown) positioned lower in the chamber 100 . In one embodiment, the collimator 110 is integrated into the upper shield 186 as shown in FIG. 8 . In one embodiment, the collimator 110 is soldered to the upper shield 186 . In one embodiment, the collimator 110 may be electrically floating within the chamber 100 . In one embodiment, the collimator 110 is connectable to an electrical power source. The collimator 110 includes a plurality of orifices (omitted in FIG. 1 ) for directing gas and/or material flow within the chamber.

FIG. 2 is a top plan view of one embodiment of the collimator 110 . The collimator 110 is generally a close-packed honeycomb structure with hexagonal walls 126 separating hexagonal apertures 128 . The aspect ratio of the hexagonal aperture 128 may be defined as the depth of the aperture 128 (equal to the thickness of the collimator) divided by the width 129 of the aperture 128 . In one embodiment, the thickness of the wall 126 is between about 0.06 inches and about 0.18 inches. In one embodiment, the thickness of the wall 126 is from about 0.12 inches to about 0.15 inches. In one embodiment, the collimator comprises a material selected from aluminum, copper, and stainless steel.

FIG. 3 is a schematic cross-sectional view of a collimator 310 according to one embodiment described herein. Collimator 310 includes a central region 320 that has a high aspect ratio, for example, from about 1.5:1 to about 3:1. In one embodiment, the central region 320 has an aspect ratio of about 2.5:1. The aspect ratio of the collimator 310 decreases along the radial direction from the central region 320 to the outer peripheral region 340 . In one embodiment, the aspect ratio of the collimator 310 decreases from about 2.5:1 to about 1:1 from the central region 320 to the peripheral region 340 . In another embodiment, the aspect ratio of the collimator 310 decreases from about 3:1 to about 1:1 from the central region 320 to the peripheral region 340 . In one embodiment, the aspect ratio of the collimator 310 decreases from about 1.5:1 to about 1:1 from the central region 320 to the peripheral region 340 .

In one embodiment, the reduction in the radial aperture of the collimator 310 is accomplished by changing the thickness of the collimator 310 . In one embodiment, the central region 320 of the collimator 310 has an increased thickness, for example, between about 3 inches and about 6 inches. In one embodiment, the thickness of the central region 320 of the collimator 310 is about 5 inches. In one embodiment, the thickness of the collimator 310 decreases radially from about 5 inches to about 2 inches in thickness from the central region 320 to the peripheral region 340 . In one embodiment, the thickness of the collimator 310 decreases radially from about 6 inches to about 2 inches in thickness from the central region 320 to the peripheral region 340 . In one embodiment, the thickness of the collimator 310 decreases radially from about 2.5 inches to about 2 inches in thickness from the central region 320 .

Although the aspect ratio variation of the embodiment of the collimator 310 in FIG. 3 shows a radially decreasing thickness, the aspect ratio can also be reduced by increasing the width of the collimator 310 aperture from the central region 320 to the peripheral region 340 . In another embodiment, the thickness of the collimator 310 decreases from the central region 320 to the peripheral region 340 and the width of the collimator 310 increases from the central region 320 to the peripheral region 340 .

In general, the embodiment in Figure 3 shows an aspect ratio that decreases radially in a linear fashion to obtain an inverse conical shape. Other embodiments of the invention may include non-linearly reduced aspect ratios.

FIG. 4 is a schematic cross-sectional view of a collimator 410 according to one embodiment of the present invention. The collimator 410 has a thickness that decreases in a non-linear manner from the central region 420 to the peripheral region 440 to obtain a convex shape.

FIG. 5 is a schematic cross-sectional view of a collimator 510 according to an embodiment of the present invention. The collimator 510 has a thickness that decreases in a non-linear manner from a central region 520 to a peripheral region 540 to obtain a concave shape.

In some embodiments, the central region 320 , 420 , 520 is approximately zero such that the central region 320 , 420 , 520 appears as a point at the bottom of the collimator 310 , 410 , 510 .

Referring back to FIG. 1 , regardless of the actual shape of the collimator 110 radially reduced aspect ratio, the operation of the PVD processing chamber 100 is similar to the function of the collimator 110 . The system controller 101 is disposed outside the chamber 100 and generally facilitates the control and automation of the overall system. System controller 101 may include a central processing unit (CPU) (not shown), memory (not shown), and support circuitry (not shown). The CPU can be any computer processor used in industrial equipment to control various system functions and chamber processes.

In one embodiment, system controller 101 provides signals to position substrate 154 on substrate support 152 and generate plasma in chamber 100 . The system controller 101 sends a signal to apply a voltage through a DC power source 148 to bias the target 142 and energize a process gas (eg, argon) into a plasma. The system controller 101 may further provide a signal to cause the RF power source 156 to DC self-bias the socket 152 . The DC self-bias helps to attract the positively charged ions generated in the plasma deep into the high aspect ratio holes and grooves on the substrate surface.

The collimator 110 functions as a filter to trap ions and neutral particles emitted from the target 142 at angles beyond a selected angle (nearly perpendicular to the substrate 154). The collimator 110 may be one of the collimators 310, 410, 510 shown in Figs. 3, 4, 5 respectively. The collimator 110 having the property of reducing the aspect ratio radially from the center allows a larger percentage of ions emitted from the peripheral region of the target 142 to pass through the collimator 110 . Therefore, the number of ions deposited on the peripheral region of the substrate 154 and the angle of arrival of the ions can be simultaneously increased. Thus, according to embodiments of the present invention, the deposited material may be sputtered more uniformly across the surface of the substrate 154 . In addition, material can be more uniformly deposited on the bottom and sidewalls of high aspect ratio features, especially high aspect ratio holes and grooves near the periphery of substrate 154 .

Additionally, in order to provide greater coverage of sputter-deposited material on the bottom and sidewalls of features having high aspect ratios, the material sputter-deposited on the field and bottom regions of the feature may be sputter etched. In one embodiment, system controller 101 applies a high bias to seat 152 so that target 142 ion-etches a film that has been deposited on substrate 154 . Thus, the field deposition rate onto the substrate 154 is reduced, and the sputtered material redeposits to the sidewalls or bottoms of features having high aspect ratios. In one embodiment, the system controller 101 applies a high bias voltage and a low bias voltage to the seat 152 in a pulsed or alternating manner such that the process becomes a pulsed deposition/etch process. In one embodiment, a collimator 110 unit located specifically below the magnet 172 directs the mass of deposited material toward the substrate 154 . Thus, at any given time, material may be deposited in one area of substrate 154 while material already deposited in another area of substrate 154 may be etched.

In one embodiment, to provide greater coverage of sputter-deposited material on the sidewalls of features with high aspect ratios, a secondary plasma such as an argon plasma (generated in the chamber close to the substrate) can be used. region of material 154) to sputter etch the material that was sputter deposited on the bottom of the feature. In one embodiment, the chamber 100 includes an RF coil 141 attached to a lower shield 180 by a plurality of coil spacers 143 that electrically insulate the coil 141 from the lower shield 180 . The system controller 101 sends a signal to apply RF power to the coil 141 through the shield 180 through a feedthrough standoff (not shown). In one embodiment, an RF coil inductively couples RF energy to the interior of the chamber 100 to ionize a precursor gas (eg, argon) to maintain a secondary plasma near the substrate 154 . The secondary plasma resputters the deposited layer from the bottom of the high aspect ratio feature and redeposits material onto the sidewalls of the feature.

Still referring to FIG. 1 , the collimator 110 may be attached to the upper shield 186 by a plurality of radial brackets 111 .

6 is an enlarged cross-sectional view of bracket 611 used to attach collimator 110 to upper shield 186 in accordance with an embodiment of the present invention. The bracket 611 includes an internally threaded tube 613 welded to the collimator 110 and extending radially outward from the collimator 110 . A fastening member 615, such as a bolt, can be inserted into an aperture of the upper shield 186 and threaded into the tube 613 to attach the collimator 110 to the upper shield 186 while allowing Materials are kept to a minimum.

7 is an enlarged cross-sectional view of a bracket 711 for attaching the collimator 110 to the upper shield 186 according to another embodiment of the present invention. The bracket 711 includes a stud 713 that is welded to the collimator 110 and extends radially outward from the collimator 110 . Internally threaded fastening member 715 may be inserted through an aperture in upper shield 186 and threaded onto stud 713 to attach collimator 110 to upper shield 186 while making possible deposition on stud 713 or fastening The material of the threaded portion of member 715 is minimized.

8 is a schematic cross-sectional view of a semiconductor processing system 800 having another embodiment of a processing kit 840 described herein. Similar to treatment kit 140 , treatment kit 840 includes a single-piece lower shield 180 . However, unlike processing kit 140, which includes a separate collimator 110 connected to upper shield 186 through radial brackets 111, processing kit 840 includes a monolithic upper shield 886 that includes shield portion 892 and an integrated through-shield. Quantity optimizer section 810. The unibody construction of the shield 886 on a unibody allows for maximum cooling efficiency. The integrated flux optimizer portion 810 includes a plurality of orifices (omitted in FIG. 8 ) that direct gas and/or material flux within the chamber as described above.

FIG. 9A is a partial cross-sectional view of a monolithic upper shield 886 according to embodiments described herein. FIG. 9B is a top plan view of the monolithic upper shield 886 of FIG. 9A according to embodiments described herein. Shield 886 on the monolith is sized to surround sputtering surface 145 of sputtering target 142 facing support 152 . Monolithic upper shield 886 shields adapter 144 of chamber 100 to reduce deposits sputter-deposited from sputtering surface 145 of sputtering target 142 .

As shown in FIGS. 8 , 9A and 9B , monolithic upper shield 886 is a single structure and includes shield portion 892 and integrated flux optimizer portion 810 . For example, shield portion 892 and integrated flux optimizer portion 810 may be fabricated from a single mass of material. Shield portion 892 includes cylindrical strip 902 . Cylindrical strip 902 includes a top wall 904 and a bottom wall 906 . A support flange 908 extends radially outward from the top wall 904 of the cylindrical band 902 . The support flange 908 includes a support surface 910 for supporting the adapter 144 of the chamber 800 . In one embodiment, the support surface 910 and the bottom wall 906 intersect to form a 90 degree angle. In one embodiment, the support flange 908 has a plurality of slots shaped to receive pins that align the upper shield 892 to the adapter 144 . In one embodiment, the support flange 908 has one or more notches 940 positioned periodically around the cylindrical band 902 .

As shown in FIG. 9A , top wall 904 further includes a top surface 925 , an inner perimeter 926 , and an outer perimeter 928 . The outer perimeter of top wall 904 and support flange 908 meet to form stepped portion 932 .

In one embodiment, as shown in FIG. 8 , the bottom wall 906 of the cylindrical band 902 has an outer diameter (shown by arrow "A") sized to fit and support the lower shield 180 in the adapter 144 The stepped portion 1032 (shown in FIG. 10B ). In one embodiment, the outer diameter "A" of the bottom wall 906 is between about 18 inches (45.7 cm) and about 18.5 inches (47 cm). In another embodiment, the outer diameter "A" of the bottom wall 906 is between about 18.1 inches (46 cm) and about 18.2 inches (46.2 cm). In one embodiment, cylindrical band 902 has an inner diameter shown by arrow "B". In one embodiment, the inner diameter "B" of the cylindrical band 902 is between about 17.2 inches (43.7 cm) and about 17.9 inches (45.5 cm). In another embodiment, the inner diameter "B" of the cylindrical band 902 is between about 17.5 inches (44.5 cm) and about 17.7 inches (45 cm). In one embodiment, top wall 904 has an outer diameter shown by arrow "C". In one embodiment, top wall 904 and bottom wall 906 have the same inner diameter "B".

In one embodiment, the outer diameter "C" of the top wall 904 is between about 18 inches (45.7 cm) and about 18.5 inches (47 cm). In another embodiment, the outer diameter "C" of the top wall 904 is between about 18.3 inches (46.5 cm) and about 18.4 inches (46.7 cm). In one embodiment, the outer diameter "C" of the top wall 904 is greater than the outer diameter "A" of the bottom wall 906 .

The integrated flux optimizer part 810 may be designed similarly to one of the collimators 310, 410 or 510 shown in Figs. 3, 4 and 5 respectively. As shown in FIG. 9B , integrated flux optimizer section 810 is generally a honeycomb structure in a close-packed configuration with hexagonal walls 942 separating hexagonal orifices 944 . The aspect ratio of the hexagonal aperture 944 may be defined as the depth of the aperture 944 (equal to the thickness of the integrated flux optimizer portion 810 ) divided by the width 946 of the aperture. In one embodiment, the hexagonal wall 942 adjacent the shield portion 892 has a chamfer 950 and a radius.

In one embodiment, the monolithic upper shield 886 may be machine formed from a single piece of aluminum. Monolithic upper shield 886 may optionally be coated or anodized. Alternatively, the monolithic upper shield 886 may be made of other materials compatible with the processing environment, and may also contain one or more segments. Alternatively, the shield portion 892 of the upper shield and the integrated flux optimizer portion 810 may be formed in separate pieces and connected together using suitable attachment means, such as welding.

10A and 10B are partial cross-sectional views of a lower shield according to embodiments described herein. Figure 10C is a top view of one embodiment of the lower shield of Figure 10A. As shown in FIGS. 1 and 10A-10C , lower shield 180 is a single structure and includes cylindrical outer band 196 , base plate 198 and inner cylindrical band 103 . Cylindrical outer band 196 has a diameter sized to surround sputtering surface 145 of sputtering target 142 and peripheral edge 153 of seat 152 . The cylindrical outer band 196 includes an upper portion 1012 , a middle portion 1014 , and a lower portion 1016 . Upper portion 1012 is sized to surround sputtering surface 145 of sputtering target 142 . A support flange 182 extends radially outward from an upper portion 1012 of the cylindrical outer band 196 . The support flange 182 includes a bearing surface 1024 for supporting the chamber wall 150 of the chamber 100 . The support surface 1024 may have a plurality of slots shaped to receive pins that align the lower shield 180 to the chamber wall 150 or any adapter positioned between the chamber wall 150 and the lower shield 180 . In one embodiment, support surface 1024 has a surface roughness of about 10 to about 80 microinches, even about 16 to about 63 microinches, or in one embodiment, about 32 microinches.

As shown in FIG. 10B , upper portion 1012 includes a top surface 1025 , an inner perimeter 1026 , and an outer perimeter 1028 . Outer perimeter 1028 extends upwardly above top surface 1025 to form annular lip 1030 . The annular lip 1030 forms a stepped portion 1032 having a top surface 1025 . In one embodiment, annular lip 1030 is positioned perpendicular to the top surface 1025 to form stepped portion 1032 . The stepped portion 1032 provides a bearing surface to engage the upper shield 186 .

In one embodiment, annular lip 1030 has an outer diameter shown by arrow "D". In one embodiment, the outer diameter "D" of the annular lip 1030 is between about 18.4 inches (46.7 cm) and about 18.7 inches (47.5 cm). In another embodiment, the outer diameter "D" of the annular lip 1030 is between about 18.5 inches (47 cm) and about 18.6 inches (47.2 cm). In one embodiment, annular lip 1030 has an inner diameter shown by arrow "E". In one embodiment, the inner diameter "E" of the annular lip 1030 is between about 18.2 inches (46.2 cm) and about 18.5 inches (47 cm). In another embodiment, the inner diameter "E" of the annular lip 1030 is between about 18.3 inches (46.5 cm) and about 18.4 inches (46.7 cm).

In one embodiment, the outer diameter of the top surface 1025 is the same as the inner diameter “E” of the annular lip 1030 . In one embodiment, the top surface has an inner diameter shown by arrow "F". In one embodiment, the inner diameter "F" of the top surface 1025 is between about 17.2 inches (43.7 cm) and about 18 inches (45.7 cm). In another embodiment, the inner diameter "F" of the top surface 1025 is between about 17.5 inches (44.5 cm) and about 17.6 inches (44.7 cm).

In one embodiment, the outer diameter of the top surface 1025 is the same as the inner diameter “E” of the annular lip 1030 . In one embodiment, the top surface has an inner diameter indicated by arrow "F". In one embodiment, the inner diameter "F" of the top surface 1025 is between about 17.2 inches (43.7 cm) and about 18 inches (45.7 cm). In another embodiment, the inner diameter "F" of the top surface 1025 is between about 17.5 inches (44.5 cm) and about 17.6 inches (44.7 cm).

In one embodiment, the inner perimeter 1026 of the upper portion 1012 is angled radially outward from vertical at an angle α. In one embodiment, the angle α is from about 2° to about 10° from the vertical. In one embodiment, angle α is about 4° from vertical.

Lower portion 1016 is sized to surround seat 152 . Base plate 198 extends radially inward from lower portion 1016 of cylindrical outer band 196 . The cylindrical inner band 103 is connected to the base plate 198 and is sized to surround the seat 152 . The cylindrical inner band 103, base plate 198, and cylindrical outer band 196 form a U-shaped channel. The cylindrical inner band 103 comprises a height which is lower than the height of the cylindrical outer band 196 . In one embodiment, the height of the inner cylindrical band 103 is about one-fifth the height of the outer cylindrical band 196 . In one embodiment, the middle portion 1014 has a notch 1040 . In one embodiment, cylindrical outer band 196 has a plurality of gas holes 1042 .

In one embodiment, base plate 198 has an outer diameter indicated by arrow "G". In one embodiment, the outer diameter "G" of the base plate 198 is between about 17 inches (43.2 cm) and about 17.4 inches (44.2 cm). In another embodiment, the outer diameter "G" of the base plate 198 is between about 17.1 inches (43.4 cm) and about 17.2 inches (43.7 cm). In one embodiment, base plate 198 has an inner diameter indicated by arrow "I". In one embodiment, the inner diameter "I" of the base plate 198 is between about 13.9 inches (35.3 cm) and about 14.4 inches (36.6 cm). In another embodiment, the inner diameter "I" of the base plate 198 is between about 14 inches (35.6 cm) and about 14.1 inches (35.8 cm).

In one embodiment, the inner cylindrical band 103 has an outer diameter indicated by an arrow "H". In one embodiment, the outer diameter "H" of the inner cylindrical band is between about 14.0 inches (35.6 cm) and about 14.3 inches (36.3 cm). In another embodiment, the inner cylindrical band 103 has an outer diameter indicated by an arrow "H". In one embodiment, the outer diameter "H" of the inner cylindrical band 103 is between about 14.2 inches (36.1 cm) and about 14.3 inches (36.3 cm).

In one embodiment, cylindrical outer band 196, base plate 198, and inner cylindrical band 103 comprise a unitary structure. The single lower shield 180 is superior to known shields that include multiple parts, typically in two or three individual pieces to assemble the entire lower shield. For example, a single segment shields more parts shielding more thermally evenly during heating and cooling processes. For example, the single-segment lower shield 180 has only one thermal contact surface with the chamber wall 150 so that the heat exchange between the shield 180 and the chamber wall 150 is more controlled. Shield 180 having multiple shield parts makes it more difficult and laborious to remove the shield for cleaning. The single segment shield 180 has a continuous surface exposed to sputter deposition without hard to clean joints or corners. The single segment shield 180 is also effective in shielding the chamber wall 150 from sputter deposition during processing cycles.

In one embodiment, the upper shield 186, 886 and/or the lower shield 180 can be made of 300 series stainless steel, or in other embodiments, can be made of aluminum. In one embodiment, the exposed surfaces of the upper shield 186, 886 and/or the lower shield 180 are treated with CLEANCOATTW, which is available from Applied Materials, Inc. of Santa Clara, CA. CLEANCOATTW is a twin-wire aluminum arc spray coating applied to substrate processing chamber components (e.g., upper barriers 186, 886 and/or lower barrier 180) to reduce particle shedding and deposition on the shield, thereby preventing contamination of the substrate in the chamber. In one embodiment, the twin core aluminum arc spray coating on the upper screen walls 186, 886 and/or the lower screen wall 180 has a surface roughness of from about 600 to about 2300 microinches.

The upper screen 186 , 886 and/or the lower screen 180 have exposed surfaces facing the interior space in the chamber 100 , 800 . In one embodiment, the exposed surface is bead blasted to have a surface roughness of 175±75 microinches. The textured bead blasting surface serves to reduce particle shedding and prevent contamination within the chamber 100,800. The mean value of the surface roughness is the mean of the absolute values of the displacements from the mean line from the peak to the valley of the roughness characteristic of the exposed surface. Roughness average, skewness, or other properties can be determined by a profilometer that moves a needle over an exposed surface and produces a highly perturbed trace of roughness on the surface, or by scanning electron microscopy using a beam of electrons reflected from the surface to produce an image of the surface.

While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the essential scope of the invention, which is defined by the following claims.

Claims (15)

1. A lower shield for surrounding a substrate support seat, wherein the substrate support seat faces a sputtering target in a substrate processing chamber, the lower shield comprising: a cylindrical outer band having a first diameter sized to surround the sputtering surface of the sputtering target and the substrate support, the outer cylindrical band comprising: an upper portion surrounding the sputtering surface of the sputtering target; middle part; and a lower portion surrounding the substrate support; a support flange having a bearing surface and extending radially outward from the cylindrical outer band; a base plate extending radially inwardly from said lower portion of said cylindrical outer band; and A cylindrical inner band is attached to the base plate and partially surrounds the peripheral edge of the substrate support. 2. The lower shield of claim 1, wherein the upper portion comprises: top surface; inner perimeter; and an outer perimeter, wherein the outer perimeter extends upwardly above the top surface to form an annular lip, the annular lip and the top surface forming a stepped portion for engaging the upper shield. 3. The lower shield according to claim 2, wherein the angle between the inner periphery of the upper portion and the vertical direction is about 2[deg.] to 10[deg.]. 4. The lower shield of claim 1, wherein said cylindrical inner strip, said base plate, said cylindrical outer strip form a U-shaped channel. 5. The lower shield of claim 4, wherein the cylindrical inner band comprises a height that is lower than the height of the cylindrical outer band. 6. The lower shield of claim 5, wherein the height of the cylindrical inner band is about one-fifth the height of the cylindrical outer band. 7. The lower shield of claim 1, wherein the cylindrical outer band, the support flange, the base plate, and the cylindrical inner band comprise a unitary structure. 8. An upper shield for surrounding a sputter target, wherein the sputter target faces a support seat in a substrate processing chamber, the upper shield comprising: the shielding part; and Integrated flux optimizer for directional sputtering. 9. The upper shield of claim 8, wherein the integrated flux optimizer comprises: Central District; and A peripheral region, wherein the integrated flux optimizer has a plurality of apertures extending therethrough, and wherein apertures located in the central region have a higher aspect ratio than apertures located in the peripheral region. 10. The upper shield of claim 9, wherein the integrated flux optimizer is thicker in the central region than in the peripheral region. 11. The upper shield of claim 9, wherein an aspect ratio of the aperture decreases continuously from the central region to the peripheral region. 12. The upper shield of claim 11, wherein a thickness of the integrated flux optimizer decreases continuously from the central region to the peripheral region. 13. The upper shield of claim 9, wherein the aspect ratio of the aperture decreases linearly from the central region to the peripheral region, the thickness of the integrated flux optimizer decreases from the central region decreases linearly to the peripheral region. 14. The upper shield of claim 9, wherein an aspect ratio of said aperture decreases non-linearly from said central region to said peripheral region, a thickness of said integrated flux optimizer increases from said central region to said peripheral region. area decreases non-linearly to the surrounding area. 15. The upper shield of claim 9, wherein the shield portion and the integrated flux optimizer are machined from a single piece of aluminum.

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