DUAL CHANNEL SHOWERHEAD ASSEMBLY

Abstract

Dual channel showerhead assemblies are described. In some embodiments, the dual channel showerhead assemblies, which include a showerhead upper plate and a showerhead lower plate, enable delivery of mutually incompatible precursors along separate channels that mix in the process zone above a wafer. The dual channel showerhead assemblies provide at least two separate gas paths. In some embodiments, the hole design and hole distribution are configured for minimal jetting effect and plenum volumes for fast purging. The dual channel showerhead assemblies described herein may have a reduced purge out time compared to single channel showerheads, spiral dual channel showerheads, and bonded dual channel showerheads.

Description

Claims

1. A dual channel showerhead assembly comprising: a thermal base having a back surface and a front surface defining a thickness of the thermal base, at least one first gas channel extending through the thickness of the thermal base to the front surface and at least one second gas channel extending through the thickness of the thermal base to the front surface;a showerhead upper plate having a back surface and a front surface defining a thickness of the showerhead upper plate, a portion of the back surface of the showerhead upper plate spaced a distance from a portion of the front surface of the thermal base to form an upper plenum, the at least one first gas channel of the thermal base having an aperture in the front surface of the thermal base at the portion forming the upper plenum, an outer peripheral region of the back surface of the showerhead upper plate in contact with an outer peripheral region of the front surface of the thermal base, the at least one second gas channel of the thermal base having an aperture aligned with at least one second gas channel passing through the thickness of the showerhead upper plate to an aperture formed in the front surface of the showerhead upper plate, the front surface of the showerhead upper plate having a plurality of spaced gas bosses extending from the front surface of showerhead upper plate, each of the gas bosses having a gas boss outer perimeter wall and a gas boss front surface, the showerhead upper plate having a plurality of first gas channels extending from the back surface to apertures in the gas boss front surface; anda showerhead lower plate having a back surface and a front surface defining a thickness of the showerhead lower plate, a portion of the back surface of the showerhead lower plate spaced a distance from a portion of the front surface of the showerhead upper plate to form a lower plenum, an outer peripheral region of the back surface of the showerhead lower plate in contact with an outer peripheral region of the front surface of the showerhead upper plate, a plurality of lower openings extending through the thickness of the showerhead lower plate, the plurality of lower openings aligned with the plurality of spaced gas bosses of the showerhead upper plate, each of the plurality of lower openings having a lower opening wall sized to provide a gap between the gas boss outer perimeter wall and the lower opening wall to allow a flow of gas from the lower plenum to pass through the thickness of the showerhead lower plate.

2. The dual channel showerhead assembly of claim 1, wherein each of the showerhead upper plate and the showerhead lower plate are individually mounted to the thermal base.

3. The dual channel showerhead assembly of claim 1, wherein the distance forming one or more of the upper plenum or the lower plenum is less than or equal to 20 mm.

4. The dual channel showerhead assembly of claim 1, wherein one or more of the at least one first gas channel or the at least one second gas channel is angled at less than or equal to 45 degrees.

5. The dual channel showerhead assembly of claim 1, wherein the showerhead lower plate has angled openings extending outwardly from the front surface of the showerhead lower plate to the back surface of the showerhead lower plate.

6. The dual channel showerhead assembly of claim 1, further comprising an outer ring around the thermal base having an inner diameter surface and a lower surface, the inner diameter surface spaced a distance from an outer diameter surface of the thermal base to form an exhaust plenum.

7. The dual channel showerhead assembly of claim 6, wherein the outer peripheral region of the back surface of the showerhead lower plate is in contact with the lower surface of the outer ring.

8. The dual channel showerhead assembly of claim 1, wherein the showerhead upper plate has an upper extension boss with a second opening having an aperture in a back surface of the upper extension boss.

9. The dual channel showerhead assembly of claim 1, wherein the plurality of spaced gas bosses is staggered within the front surface of the showerhead upper plate.

10. The dual channel showerhead assembly of claim 1, wherein the plurality of spaced gas bosses is not bonded to either of the showerhead upper plate or the showerhead lower plate.

11. The dual channel showerhead assembly of claim 1, wherein the at least one first gas channel and the at least one second gas channel have an elliptical shape, eye shape, a tear-drop shape, or a round cross-section.

12. The dual channel showerhead assembly of claim 10, wherein at least one of the plurality of spaced gas bosses has an elliptical shape, an eye shape, a tear-drop shape, or a cylindrical shape.

13. The dual channel showerhead assembly of claim 10, wherein the plurality of spaced gas bosses has in a range of from 50 to 1000 bosses.

14. The dual channel showerhead assembly of claim 13, wherein each of the showerhead upper plate and the showerhead lower plate comprise a plurality of holes extending through the thickness of the showerhead upper plate and the thickness of the showerhead lower plate, and each of the plurality of spaced gas bosses align with the plurality of holes.

15. The dual channel showerhead assembly of claim 10, wherein at least one of the plurality of spaced gas bosses has a diameter in a range of from 2 mm to 8 mm.

16. The dual channel showerhead assembly of claim 1, wherein the dual channel showerhead assembly having the showerhead upper plate and the showerhead lower plate has a reduced purge out time compared to each of a single channel showerhead, a spiral dual channel showerhead, or a bonded dual channel showerhead.

17. The dual showerhead assembly of claim 1, wherein the gap between the gas boss outer perimeter wall and the lower opening wall is in a range of from 0.1 mm to 3 mm.

18. The dual showerhead assembly of claim 1, wherein the thermal base has a sloped front face and the distance forming the upper plenum increases toward a center of the thermal base.

19. The dual showerhead assembly of claim 1, wherein the showerhead upper plate comprises a plurality of spaced tabs extending outwardly from an outer peripheral face of the showerhead upper plate, and the showerhead lower plate comprises a plurality of recesses sized and shaped to complement the plurality of spaced tabs.

20. A dual channel showerhead assembly comprising: a thermal base having a back surface and a front surface defining a thickness of the thermal base, at least one first gas channel extending through the thickness of the thermal base to the front surface and at least one second gas channel extending through the thickness of the thermal base to the front surface;a showerhead upper plate having a back surface and a front surface defining a thickness of the showerhead upper plate, a portion of the back surface of the showerhead upper plate spaced a distance from a portion of the front surface of the thermal base to form an upper plenum, the at least one first gas channel of the thermal base having an aperture in the front surface of the thermal base at the portion forming the upper plenum, an outer peripheral region of the back surface of the showerhead upper plate in contact with an outer peripheral region of the front surface of the thermal base, the at least one second gas channel of the thermal base having an aperture aligned with at least one second gas channel passing through the thickness of the showerhead upper plate to an aperture formed in the front surface of the showerhead upper plate, the front surface of the showerhead upper plate having a plurality of spaced gas bosses extending from the front surface of showerhead upper plate, each of the gas bosses having a gas boss outer perimeter wall and a gas boss front surface, the showerhead upper plate having a plurality of first gas channels extending from the back surface to apertures in the gas boss front surface;a showerhead lower plate having a back surface and a front surface defining a thickness of the showerhead lower plate, a portion of the back surface of the showerhead lower plate spaced a distance from a portion of the front surface of the showerhead upper plate to form a lower plenum, an outer peripheral region of the back surface of the showerhead lower plate in contact with an outer peripheral region of the front surface of the showerhead upper plate, a plurality of lower openings extending through the thickness of the showerhead lower plate, the plurality of lower openings aligned with the plurality of spaced gas bosses of the showerhead upper plate, each of the plurality of lower openings having a lower opening wall sized to provide a gap between the gas boss outer perimeter wall and the lower opening wall to allow a flow of gas from the lower plenum to pass through the thickness of the showerhead lower plate; andan outer ring around the thermal base having an inner diameter surface and a lower surface, the inner diameter surface spaced a distance from an outer diameter surface of the thermal base to form an exhaust plenum.