Semiconductor processing tool, a diffusion plate and methods of etch operation

Abstract

A diffusion plate, for use in an etch tool, may be configured to promote a uniform flow rate of a gas-based etchant across a semiconductor substrate in a etch operation. The diffusion plate may have a curved three-dimensional shape, such as a bowl shape, a dome shape, and / or another type of hollow shell shape. The upward curvature of the diffusion plate may equalize the gas flow rate of a gas-based etchant across a semiconductor substrate by restricting the flow of the gas-based etchant as the gas-based etchant flows toward the perimeter of the diffusion plate. Additionally and / or alternatively, the diffusion plate includes a plurality of holes through which the gas-based etchant flows. The holes may be arranged in regions of the diffusion plate having different sized holes to equalize the gas flow rate of the gas-based etchant across a semiconductor substrate.

Claims

1. An etching operation method comprising: receiving a semiconductor substrate in a chuck within a processing chamber of an etching tool; providing a gas-based etchant to the processing chamber such that the gas-based etchant flows through a diffusion plate on the semiconductor substrate within the processing chamber, wherein the diffusion plate has a body having a dome shape, and a distance between a periphery of the diffusion plate and the chuck is greater than a distance between a center of the diffusion plate and the chuck; and etching a layer on the semiconductor substrate using the gas-based etchant.

2. The etching operation method of claim 1, wherein the gas-based etchant flows through a first plurality of holes in a central region of the diffuser plate; and wherein the gas-based etchant flows through a second plurality of holes in an annular region of the diffuser plate surrounding the central region; and wherein a first width of a first hole among the first plurality of holes and a second width of a second hole among the second plurality of holes are different widths.

3. The etching operation method of claim 1, wherein the dome shape promotes uniformity between a first flow rate of the gas-based etchant at an edge of one of the semiconductor substrates and a second flow rate of the gas-based etchant at a center of one of the semiconductor substrates.

4. The etching operation method of claim 1, wherein the radius of curvature of the dome shape of the diffuser plate is included in the range of approximately 8 times to approximately 24 times the radius of the diffuser plate.

5. The etching operation method as described in claim 2, wherein the radial thickness of one of the annular regions and the radius of one of the central regions are different.

6. A diffuser plate comprising: a body curved from a center to a periphery of the body and having an arcuate cross-sectional profile; a first plurality of holes through a central region of the body; a second plurality of holes through a first annular region of the body surrounding the central region; and a third plurality of holes through a second annular region of the body surrounding the first annular region, wherein a first size of one of the first plurality of holes, a second size of one of the second plurality of holes, and a third size of one of the third plurality of holes are different sizes.

7. The diffuser plate of claim 6, wherein the second size of the second hole is larger than the first size of the first hole.

8. The diffuser plate of claim 6, wherein a first density of the first plurality of holes in the central region, a second density of the second plurality of holes in the first annular region, and a third density of the third plurality of holes in the second annular region are approximately the same density.

9. A semiconductor processing tool comprising: a processing chamber including a sidewall defining an interior region of the processing chamber, a top cover, and a chamber bottom plate; a chuck located in the interior region and adjacent to the chamber bottom plate; a vent port located in the chamber bottom plate below the chuck; and a diffuser plate located in the interior region, wherein the diffuser plate is located on the chuck and adjacent to the top cover, wherein the diffuser plate comprises: a body curved from a center to a periphery of the body and having an arcuate cross-sectional profile, wherein a central region of the body is located further away from the top cover than the periphery of the body; and a plurality of holes passing through the body; and a gas inlet located in the top cover of the diffuser plate.

10. The semiconductor processing tool of claim 9, wherein the diffusion plate further comprises: a plurality of support members attached to the body, wherein the plurality of support members secure the diffusion plate to the upper cover of the processing chamber, and wherein the length of the plurality of support members is greater than a distance between the periphery of the body of the diffusion plate and the upper cover of the processing chamber.

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