CHEMICAL VAPOR DEPOSITION FLOW INLET ELEMENTS AND METHODS

• US 20100143588A1
• Filed: 12/04/2009
• Published: 06/10/2010
• Est. Priority Date: 12/04/2008
• Status: Active Grant

• Current Assignee: Veeco Instruments Incorporated
• Original Assignee: Veeco Instruments Incorporated
• Inventors: Mitrovic, Bojan, Moy, Keng, Belousov, Mikhail
• Granted Patent: US 8,303,713 B2
• Time in Patent Office: Days
• US Class Current: 427/255.280
• CPC Class Codes: C23C 16/45574 Nozzles for more than one gas
• CPC Class Codes: C23C 16/45578 Elongated nozzles, tubes with holes
• CPC Class Codes: C23C 16/4584 the substrate being rotated
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases

Abstract

A flow inlet element (22) for a chemical vapor deposition reactor (10) is formed from a plurality of elongated tubular elements (64, 65) extending side-by-side with one another in a plane transverse to the upstream to downstream direction of the reactor. The tubular elements have inlets for ejecting gas in the downstream direction. A wafer carrier (14) rotates around an upstream to downstream axis. The gas distribution elements may provide a pattern of gas distribution which is asymmetrical with respect to a medial plane (108) extending through the axis.

Claims

1. A chemical vapor deposition reactor comprising;

(a) a reaction chamber having upstream and downstream directions;

(b) a carrier support adapted to support a wafer carrier at a carrier location within the reaction chamber for rotation about an axis extending in the upstream and downstream directions;

(c) a flow inlet element mounted to the chamber upstream of the carrier location, the inlet element having a gas distribution surface extending in X and Y horizontal directions perpendicular to one another and perpendicular to the downstream direction, the flow inlet element having a plurality of elongated gas inlets for discharging gases into the chamber, the elongated gas inlets extending parallel to one another and across the gas distribution surface in the X horizontal direction and extending across a Y-direction medial plane of the reactor, the elongated gas inlets including a plurality of first gas inlets for discharging a first reactive gas and a plurality of second gas inlets for discharging a second reactive gas, the first gas inlets being spaced apart from one another in the Y horizontal direction, the second gas inlets being spaced apart from one another in the Y horizontal direction and interspersed with the first gas inlets.

2. A reactor as claimed in claim 1 wherein the elongated gas inlets are arranged in a pattern extending over a major portion of the gas distribution surface of the inlet element.

3. A reactor as claimed in claim 1 wherein the first and second gas inlets are arranged in a pattern which is not symmetrical about a medial plane of the reactor extending in the X horizontal direction.

4. A reactor as claimed in claim 3 wherein the first and second gas inlets are arranged in a pattern which is antisymmetrical about the medial plane extending in the X horizontal direction, such that for any first gas inlet disposed at a positive Y distance to one side of the X-direction medial plane, a second gas inlet is disposed at the corresponding negative Y distance to the opposite side of the X-direction medial plane.

5. A flow inlet element having a gas distribution surface facing in a downstream direction and extending in X and Y horizontal directions perpendicular to one another and perpendicular to the downstream direction, the flow inlet element having a plurality of elongated gas inlets for discharging gases into the chamber, the elongated gas inlets extending parallel to one another in the X horizontal direction, the elongated gas inlets being arranged in a pattern extending over a major portion of the gas distribution surface, the elongated gas inlets including a plurality of first gas inlets for discharging a first reactive gas and a plurality of second gas inlets for discharging a second reactive gas, the first gas inlets being spaced apart from one another in the Y horizontal direction, the second gas inlets being spaced apart from one another in the Y horizontal direction and interspersed with the first gas inlets.

6. A flow inlet element for a chemical vapor deposition reactor comprising a structure having a downstream side and defining a downstream direction away from the downstream side, the structure defining a plurality of elongated base gas inlets open in the downstream direction and extending parallel to one another in an X horizontal direction perpendicular to the downstream direction, the base gas inlets being spaced apart from one another in a Y horizontal direction perpendicular to the X horizontal direction, the structure further including a plurality of elongated diffusers projecting downstream from the base gas outlets extending parallel to one another in the X horizontal direction between the base gas inlets, the diffusers tapering so that the dimension of each diffuser in the Y horizontal direction diminishes in the downstream direction to an edge downstream from the base gas outlets, at least some of the diffusers having additional gas inlets with openings at the edges of the diffusers.

7. A flow inlet element as claimed in claim 6 wherein each diffuser includes at least one coolant passage extending in the X direction within such diffuser, and wherein the structure includes a gas distribution channel extending in the X direction associated with each diffuser, the gas distribution channels being disposed upstream from the coolant passages and communicating with the additional gas inlets.

8. A flow inlet element as claimed in claim 7 wherein each diffuser has two coolant passages spaced apart from one another in the Y direction, and one or more connecting passages extending from the gas distribution channel associated with the diffuser to the opening of the additional gas inlet of the diffuser, the connecting passages of each diffuser extending between the coolant passages of such diffuser.

9. A flow inlet element as claimed in claim 7 wherein the structure includes a tubular element associated with each of the diffusers, the tubular element associated with each diffuser defining the gas distribution channel associated with such diffuser and structurally supporting such diffuser, the tubular elements extending parallel to one another in the X direction.

10. A flow inlet element as claimed in claim 9 wherein the base gas inlets extend between adjacent ones of the tubular elements.

11. A flow inlet element as claimed in claim 8 wherein the structure defines an active region including the base gas inlets and additional gas inlets and one or more manifolds horizontally offset from the active region, at least some of the tubular elements extending to the one or more manifolds.

12. A flow inlet element for a chemical vapor deposition reactor comprising a plurality of elongated elements extending parallel to one another and mechanically attached to one another so that the elongated elements cooperatively define a plate having upstream and downstream sides, the plate having base inlet openings extending from the upstream side to the downstream side between adjacent ones of the elongated elements, the flow inlet element further comprising a structure defining one or more gas spaces upstream of the plate and communicating with the base inlet openings.

13. A flow inlet element as claimed in claim 12 wherein at least some of the elongated elements are tubular, each tubular element defining one or more gas distribution channels.

14. A flow inlet element as claimed in claim 12 further comprising additional gas inlets communicating with the gas distribution channels, the additional gas inlets being open to the downstream side of the plate.

15. A flow inlet element as claimed in claim 13 further comprising elongated diffusers extending along at least some of the tubular elements and projecting downstream from such tubular elements, at least some of the additional gas inlets extending through the diffusers.

16. A flow inlet element as claimed in claim 13 further comprising one or more manifolds connected to the tubular elements at ends of the tubular elements and communicating with the gas distribution channels.

17. A chemical vapor deposition reactor comprising;

(a) a reaction chamber having upstream and downstream directions;

(b) a carrier support adapted to support a wafer carrier at a carrier location within the reaction chamber for rotation about an axis extending in the upstream and downstream directions;

(c) a flow inlet element mounted to the chamber upstream of the carrier location, the inlet element having a gas distribution surface extending in horizontal directions perpendicular to the downstream direction, the flow inlet element having a plurality of elongated gas inlets for discharging gases into the chamber, the elongated gas inlets extending parallel to one another in a first one of the horizontal directions, the elongated gas inlets including a plurality of first gas inlets for discharging a first reactive gas, a plurality of second gas inlets for discharging a second reactive gas, and a plurality of third gas inlets for discharging a carrier gas substantially devoid of the first and second reactive gasses and substantially nonreactive with first and second reactive gasses, the gas inlets being spaced apart from one another in a second one of the horizontal directions perpendicular to the first horizontal direction and interspersed with one another so that at least some of the first and second gas inlets constitute pairs of adjacent inlets and at least some of the third gas inlets are disposed between the first and second gas inlets of at least some of the pairs.

18. A reactor as claimed in claim 17 wherein a third gas inlet is disposed between the first and second gas inlet of every one of the pairs of adjacent first and second gas inlets.

19. A reactor as claimed in claim 17 wherein the flow inlet element includes elongated diffusers extending in the first horizontal direction and projecting downstream from the third gas inlets, and wherein the first and second gas inlets are disposed on the diffusers.

20. A method of chemical vapor deposition comprising the steps of:

(a) maintaining a wafer carrier holding one or more wafers within a reaction chamber so that surfaces of the wafers face in an upstream direction;

(b) rotating the wafer carrier around an axis extending in the upstream and downstream directions; and

(c) discharging a plurality of gasses downstream toward the wafer carrier from a plurality of elongated gas inlets extending parallel to one another in a first horizontal direction transverse to the axis, the discharging step being performed so that streams of first and second reactive gases are discharged from separate ones of the elongated inlets and so that a carrier gas carrier gas substantially devoid of the first and second reactive gasses and substantially nonreactive with the first and second reactive gasses is discharged from other ones of the reactive inlets and so that at least some of the streams of carrier gasses are discharged between adjacent streams of first and second carrier gasses.

21. A method as claimed in claim 20 wherein the first reactive gas includes one or more sources of one or more Group III metals and the second reactive gas includes and one or more sources of one or more Group V elements.

22. A chemical vapor deposition reactor comprising;

(a) a reaction chamber having upstream and downstream directions;

(b) a carrier support adapted to support a wafer carrier at a carrier location within the reaction chamber for rotation about an axis extending in the upstream and downstream directions;

(c) a flow inlet element mounted to the chamber upstream of the carrier location, the inlet element having a gas distribution surface extending in horizontal directions perpendicular to the downstream direction, the flow inlet element having a plurality of first gas inlets for discharging a first reactive gas, a plurality of second gas inlets for discharging a second reactive gas, and a plurality of third gas inlets for discharging a carrier gas substantially devoid of the first and second reactive gasses and substantially nonreactive with first and second reactive gasses, the first, second and third gas inlets extending to first, second and third radial distances from the axis, respectively, the third radial distance being greater than at least one of the first and second radial distances.

23. A reactor as claimed in claim 22 wherein the first and second radial distances are substantially equal to one another.

24. A method of chemical vapor deposition comprising:

(a) rotating a disc-like holder carrying the substrates about an axis while maintaining surfaces of the substrates substantially perpendicular to the axis and facing in an upstream direction along the axis; and

, during the rotating step,

(b) discharging first and second gasses reactive with one another in a downstream direction parallel to the axis toward the substrates as first and second sets of gas streams extending to first and second radial distances from the axis, respectively, and simultaneously discharging a third gas substantially non-reactive with the first and second gases in the downstream direction as a third set of gas streams extending to a third radial distance from the axis greater than at least one of the first and second radial distances.