Showerhead for a Gas Supply Apparatus

Abstract

A showerhead for a gas supply apparatus. This showerhead includes a body having a distribution plate on one side and at least one gas chamber contained within the body. A plurality of holes extend normally from an outer surface of the distribution plate to the chamber. Furthermore, at least a portion of at least one hole is frustoconical or frustopyramidal in shape along the normal axis with the base of the frustoconical or frustopyramidal hole positioned adjacent the outer surface of the distribution plate.

Description

BRIEF DESCRIPTION OF THE DRAWING

A better understanding of the present invention will be had upon reference to the following detailed description when read in conjunction with the accompanying drawings, wherein like reference characters refer to like parts throughout the several views, and in which:

FIG. 1 is a side diagrammatic view illustrating a preferred embodiment of the showerhead of the present invention in a gas reaction device;

FIG. 2 is a fragmentary sectional view taken along circle 2-2 in FIG. 1 and enlarged for clarity;

FIG. 3 is a fragmentary plan view taken along line 3-3 in FIG. 2;

FIG. 4 is a view similar to FIG. 2, but illustrating a modification thereof

FIG. 5 is a view similar to FIG. 2, but illustrating a further modification thereof; and

FIG. 6 is a fragmentary plan view taken along line 6-6 in FIG. 5.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION

With reference first to FIG. 1, a reaction device of the type used for semiconductor processing is illustrated diagrammatically. The device 10 includes a reaction chamber 12 in which a semiconductor wafer 14 is supported. A showerhead 16 is also positioned within the reaction chamber 12 and includes a distribution plate 18 positioned away from but generally parallel to the wafer 14.

At least one, and oftentimes two or more, reaction gas supplies 20 are fluidly connected to manifolds contained within the showerhead 16. These manifolds in turn form gas chambers for the reaction gas 20.

With reference now particularly to FIGS. 2 and 3, the showerhead 16 includes a body 24 having a lower distribution plate with the outer lower surface 18. The gas chamber 22 is formed within the body 24 and clearly connected by conventional means to one or more reaction gas sources 20.

A plurality of spaced holes 28 is formed normally along a normal axis 30 through the distribution plate 26 from the outer surface 18 and to the gas chamber 22. At least one, and preferably all, of the holes 28 are frustoconical in shape along the normal axis 30 with the base of each hole 28 positioned adjacent the outer surface 18 of the distribution plate 26. Optionally, the holes 28″ may be frustopyramidal in shape as shown in FIGS. 5 and 6 to minimize the surface area of the outer surface of the plate 18.

As best shown in FIG. 2, each hole 28 is illustrated as having its base 32 aligned with the outer surface 18 of the distribution plate 26 and its apex open to the reaction gas chamber 22. However, other configurations are alternatively possible.

For example, as shown in FIG. 4, each hole 28′ includes a frustoconical central portion 34 with a cylindrical section 36 connecting the frustoconical portion 34 with the reaction gas chamber 22 and a further cylindrical portion 38 fluidly connecting the frustoconical portion 34 with the outer surface 18 of the distribution plate 26. Consequently, it is only necessary that a portion of the hole 28′ be frustoconical in shape.

In practice, the frustoconical or frustopyramidal shape of the holes 28 in the showerhead distribution plate 26 ensures intermixing of the gases with the gas flow from adjacent holes even in high-pressure applications. As such, direct impingement of the gases from any single showerhead hole 28 is avoided, thus minimizing gas recirculation within the reaction chamber 12.

Such intermixing of the gases from each hole 28 with the gases from the adjacent hole prior to impingement on the wafer 14 is also accomplished in low-pressure applications. Consequently, the showerhead 16 of the present invention may be utilized in a variety of different applications and processing modes without the previously known undesirable direct impingement of the gases from any individual holes onto the wafer 14 and the resulting undesirable recirculation of gases within the reaction chamber 12.

From the foregoing, it can be seen that the present invention provides a showerhead gas distribution manifold for use in semiconductor processing which overcomes the disadvantages of the previously known showerhead gas distribution manifolds. Having described my invention, however, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.

Claims

1. A showerhead for a gas supply apparatus comprising: a body having a distribution plate on one side,at least one chamber contained within said body,a plurality of holes extending normally from an outer surface of said distribution plate to said at least one chamber,wherein at least a portion of at least one of said holes is frustoconical in shape along said normal axis with a base of the frustoconical hole positioned adjacent said outer surface of said distribution plate.

2. The invention as defined in claim 1 wherein said at least one hole comprises a plurality of said holes.

3. The invention as defined in claim 1 wherein said base of the frustoconical hole is aligned with said outer surface of said distribution plate.

4. A showerhead for a gas supply apparatus comprising: a body having a distribution plate on one side,at least one chamber contained within said body,a plurality of holes extending normally from an outer surface of said distribution plate to said at least one chamber,wherein at least a portion of at least one of said holes is frustopyramidal in shape along said normal axis with a base of the frustopyramidal hole positioned adjacent said outer surface of said distribution plate.

5. The invention as defined in claim 4 wherein said at least one hole comprises a plurality of said holes.

6. The invention as defined in claim 4 wherein said base of the frustopyramidal hole is aligned with said outer surface of said distribution plate.