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KR-102965310-B1 - BIASABLE FLUX OPTIMIZER/COLLIMATOR FOR PVD SPUTTER CHAMBER

KR102965310B1KR 102965310 B1KR102965310 B1KR 102965310B1KR-102965310-B1

Abstract

In some embodiments described herein, a biasable collimator is provided. The ability to bias the collimator enables control of the electric field through which sputter species pass. In some embodiments of the present disclosure, a collimator is provided having a high effective aspect ratio while maintaining a low aspect ratio along the periphery of the collimator in a hexagonal array. In some embodiments, a collimator is provided having a steep entry edge in the hexagonal array. It has been confirmed that the use of a steep entry edge in the collimator reduces clogging and deposition overhang of the cells in the hexagonal array. These various features lead to improved film uniformity and extended lifespan of the collimator and process kit.

Inventors

  • 리커, 마틴 리
  • 창, 푸홍
  • 인판테, 안토니
  • 왕, 청

Assignees

  • 어플라이드 머티어리얼스, 인코포레이티드

Dates

Publication Date
20260513
Application Date
20160927
Priority Date
20151027

Claims (20)

  1. As a collimator assembly, It includes a collimator and a shield coupled to the collimator, The above collimator is, It includes a honeycomb structure having walls that define and separate hexagonal apertures, and said hexagonal apertures, First plurality of hexagonal apertures in a central zone having a first aspect ratio; Second plurality of hexagonal apertures in a peripheral area having a second aspect ratio less than the first aspect ratio; and It includes a third plurality of hexagonal apertures of a transition zone positioned between the central zone and the surrounding zone; and The walls defining the third plurality of hexagonal apertures of the transition zone are cut at a predetermined angle to form a conical shape surrounding the central zone, and the conical shape is defined by a circular edge formed by the wall of the transition zone, and The upper part of the above walls includes an entrance angle portion, and The above shield is, Top ring; A support leg below the uppermost ring — the support leg extends radially outward —; and A cylindrical band extending downward from the support member to a height below the honeycomb structure; comprising Collimator assembly.
  2. In Article 1, The above cylindrical band is, The first substantial vertical part; and including a radially inwardly inclined portion extending downward from the above-mentioned first substantial vertical portion, Collimator assembly.
  3. In Article 2, A second substantially vertical portion extending downward from the above-mentioned radially inwardly inclined portion, further comprising Collimator assembly.
  4. In Article 2, The above radially inwardly inclined portion extends across the portions of the second plurality of hexagonal apertures of the surrounding area, Collimator assembly.
  5. In Article 1, The first plurality of hexagonal apertures, the second plurality of hexagonal apertures, and the third plurality of hexagonal apertures are textured, Collimator assembly.
  6. In Article 1, The above-mentioned inlet angle portion has a predetermined angle of 2° to 16°, Collimator assembly.
  7. In Article 6, The above-mentioned entrance angle portion has a predetermined angle of 2.5° and a length of 2.54 centimeters, Collimator assembly.
  8. In Article 1, The first aspect ratio of the first plurality of hexagonal apertures is 2.5:1 to 3:1, Collimator assembly.
  9. In Article 8, The second aspect ratio is 1:1 to 2:1, Collimator assembly.
  10. In Article 2, The above radially inwardly inclined portion has an angle of 40° to 50° with respect to the first substantially vertical portion, Collimator assembly.
  11. In Paragraph 3, The above-mentioned radially inwardly inclined portion and the above-mentioned second substantially vertical portion form a lower shield and a labyrinth gap, Collimator assembly.
  12. In Article 1, The above collimator is coupled to a DC power source, Collimator assembly.
  13. As a substrate-processing chamber, A chamber body defining an internal volume; A sputtering target placed in the upper part of the above internal volume; A substrate support disposed below the sputtering target; and A collimator assembly surrounding the sputtering target; comprising The above collimator assembly is, It includes a collimator and a shield coupled to the collimator, The above collimator is, It includes a honeycomb structure having walls that define and separate hexagonal apertures, and said hexagonal apertures, First plurality of hexagonal apertures in a central zone having a first aspect ratio; Second plurality of hexagonal apertures in a peripheral area having a second aspect ratio less than the first aspect ratio; and It includes a third plurality of hexagonal apertures of a transition zone positioned between the central zone and the surrounding zone; and The walls defining the third plurality of hexagonal apertures of the transition zone are cut at a predetermined angle to form a conical shape surrounding the central zone, and the conical shape is defined by a circular edge formed by the wall of the transition zone, and The upper part of the above walls includes an entrance angle portion, and The above shield is, Top ring; A support leg below the uppermost ring — the support leg extends radially outward —; and A cylindrical band extending downward from the support member to a height below the honeycomb structure; comprising Substrate-processing chamber.
  14. In Article 13, The above cylindrical band is, The first substantial vertical part; and A radially inwardly inclined portion extending downward from the first substantial vertical portion; comprising Substrate-processing chamber.
  15. In Article 14, A second substantially vertical portion extending downward from the above-mentioned radially inwardly inclined portion, further comprising Substrate-processing chamber.
  16. As a collimator, It includes a honeycomb structure having walls that define and separate hexagonal apertures, and The above hexagonal apertures are, First plurality of hexagonal apertures in a central zone having a first aspect ratio; Second plurality of hexagonal apertures in a peripheral area having a second aspect ratio less than the first aspect ratio; and It includes a third plurality of hexagonal apertures of a transition zone positioned between the central zone and the surrounding zone; and The walls defining the third plurality of hexagonal apertures of the above transition zone form a conical shape surrounding the central zone, and the upper portions of the walls include an entrance angle portion, Collimator.
  17. In Article 16, The above-mentioned inlet angle portion has a predetermined angle of 2° to 16°, Collimator.
  18. In Article 17, The above-mentioned entrance angle portion has a predetermined angle of 2.5° and a length of 2.54 centimeters, Collimator.
  19. In Article 17, The above-mentioned entrance angle portion has a predetermined angle of 15° and a length of 3.81 millimeters, Collimator.
  20. In Article 16, The first aspect ratio is 2.5:1 to 3:1, and The second aspect ratio is 1:1 to 2:1, Collimator.

Description

Biasable Flux Optimizer/Collimator for PVD Sputter Chamber [0001] Embodiments of the present disclosure generally relate to an apparatus and method for uniform sputter deposition of materials to the bottom and sidewalls of high aspect ratio features on a substrate. [0002] Reliably generating sub-half-micron and smaller features is one of the major technical challenges for next-generation very large-scale integration (VLSI) and ultra large-scale integration (ULSI) semiconductor devices. However, as circuit technology continues to miniaturize, the reduced dimensions of interconnects in VLSI and ULSI technologies have raised additional demands on processing performance. For example, as circuit densities for next-generation devices increase, the widths of interconnects, such as vias, trenches, contacts, gate structures, and other features, as well as the dielectric materials between them, are reduced, while the thickness of the dielectric layers remains substantially constant, resulting in increased aspect ratios of the features. [0003] Sputtering, also known as physical vapor deposition (PVD), is widely used to deposit metallic features in integrated circuits. Sputtering is used to deposit layers to be used as diffusion barriers, seed layers, primary conductors, anti-reflective coatings, and etch stops. A source material, such as a target, is bombarded by ions strongly accelerated by an electric field. The bombardment ejects material from the target, and subsequently, the material is deposited onto a substrate. During deposition, the ejected particles move in variable directions rather than in directions orthogonal to the substrate surface, which can result in overhanging structures formed on the corners of high aspect ratio features on the substrate. Overhangs can undesirably result in holes or voids formed within the deposited material, which can lead to reduced electrical conductivity of the formed features. Geometric structures with higher aspect ratios are more difficult to fill without voids. [0004] One technique developed to enable the use of sputtering to deposit thin films on the bottom of high aspect ratio features is collimator sputtering. A collimator is a filtering plate positioned between a sputtering source and a substrate. A collimator typically has a uniform thickness and includes a number of paths formed through that thickness. Sputtered material passes through the collimator along the path of the sputtered material from the sputtering source to the substrate. The collimator filters out or collects the material, otherwise the material would collide with the workpiece at acute angles exceeding the desired angle. [0005] The actual amount of material filtering achieved by a given collimator depends on the aspect ratio of the apertures through the collimator. Materials such as particles moving along a path nearly perpendicular to the substrate pass through the collimator and are deposited on the substrate. This enables improved coverage of the bottom of high aspect ratio features. However, there are specific problems with the use of conventional collimators, which typically have an overall hexagonal shape. Unfortunately, PVD chambers with conventional collimators often suffer from cell clogging and leave six-point deposition near the edges of the substrate due to shadowing of the corners of the hexagonal collimator. [0006] Therefore, there is a need for improvements in the uniformity of deposition source materials across the substrate by PVD techniques. [0007] Embodiments of the present disclosure generally relate to an apparatus and method for uniform sputter deposition of materials to the bottom and sidewalls of high aspect ratio features on a substrate. In one embodiment, a collimator is provided. The collimator comprises a body having a central region, a peripheral region, and a transitional region disposed between the central region and the peripheral region. The collimator has a first plurality of apertures in the central region having a first aspect ratio, a second plurality of apertures in the peripheral region having a second aspect ratio less than the first aspect ratio, and a third plurality of apertures in the transitional region. The third plurality of apertures are cut so that the transitional region forms a conical shape surrounding the central region. The upper portions of the first plurality of apertures, the second plurality of apertures, and the third plurality of apertures include an entrance angle portion. [0008] In another embodiment, a collimator is provided. The collimator comprises a honeycomb structure having walls that define and separate hexagonal apertures. The hexagonal apertures include a first plurality of hexagonal apertures in a central zone having a first aspect ratio, a second plurality of hexagonal apertures in a peripheral zone having a second aspect ratio less than the first aspect ratio, and a third plurality of hexagonal apertures in a transition zone posi