Bubbler for constant vapor delivery of a solid chemical

1. A bubbler for providing a vaporized compound in a chemical vapor deposition process comprising: (a) a bubbler chamber assembly having an inlet and an outlet; (b) a means for providing an inert carrier gas to said compound connected to said inlet; (c) a means for removing said vaporized compound and carrier gas from said chamber assembly and conveying said compound to said chemical vapor deposition process connected to said outlet; and (d) temperature control means in which said bubbler chamber assembly is placed that causes said compound to vaporize into said carrier gas; said bubbler chamber assembly comprising two or more chambers connected in series with the flow of said vaporized compound and carrier gas alternating between up flow and down flow between adjoining chambers in said series, all chambers being in substantially vertical orientation, in which chambers contain a solid source of said compound, the ratio between the length of said combined length of chambers connected in series with respect to the direction of flow of said carrier gas through said chambers and the average diameter equivalent of the cross section of said chambers with respect to the direction of flow of said carrier gas through said chamber or chambers is not less than about 6:1.

2. The bubbler of claim 1 wherein the total length of said chambers is sufficient for said carrier gas to be saturated or near saturated with said compound at said outlet of said bubbler chamber assembly until most of said compound is depleted.

3. The bubbler of claim 1 wherein the chambers in said bubbler chamber assembly are positioned at least about 45° from the horizontal.

4. The bubbler of claim 1 wherein the chambers comprising said bubbler assembly have average internal diameters of from about 1.3 cm to about 7.6 cm.

5. The bubbler of claim 1 wherein the chambers comprising said bubbler assembly have the same or different average internal diameters throughout their length.

6. The bubbler of claim 1 wherein said bubbler assembly comprises two or more of said chambers in series with connectors between chambers in adjoining sequence comprising tubes connected at each end with said chambers in adjoining sequence, the connection between said chambers of adjoining sequence and chambers of said connectors being mitered fittings.

7. The bubbler of claim 1 wherein said bubbler assembly comprises two or more of said chambers in series with connectors between chambers in adjoining sequence comprising tubes connected at each end with said chambers in adjoining sequence, the connection between said chambers of adjoining sequence and chambers of said connectors being rounded fittings.

8. The bubbler of claim 1 wherein said bubbler chamber assembly comprises two or more chambers connected in series with at least one of said chambers comprising the annular space of concentric chambers.

9. The bubbler of claim 1 wherein said compound comprises an organometallic compound.

10. The bubbler of claim 9 wherein said organometallic compound is selected from the group consisting of trimethylaluminum (TMAL), trimethylgallium (TMG), triethylgallium (TEG), trimethylantimony (TMSb), dimethyl hydrazine (DMHy), trimethylindium (TMI), and cyclopetadienylmagnesium (Cp 2 Mg).

11. The bubbler of claim 10 wherein said organometallic compound comprises trimethylindium and/or cyclopentadienylmagnesium.

12. The bubbler of claim 1 wherein said compound comprises carbon tetrabromide and/or Hafnium tetrachloride.

13. The bubbler of claim 1 wherein said carrier gas is selected from the group consisting of hydrogen, nitrogen and the inert gases.

14. The bubbler of claim 13 wherein said carrier gas comprises hydrogen.

15. The bubbler of claim 1 wherein the inside walls of said chamber or chambers are corrugated or contain baffles with the corrugations or baffles substantially aligned perpendicular to the direction of flow of said carrier gas.

16. The bubbler of claim 1 wherein said compound comprises particles of a solid mixed with packing.

17. The bubbler of claim 16 wherein said packing comprises substantially spherical particles or other shapes inert to said compound and carrier gas.

18. The bubbler of claim 17 wherein said spherical particles or other shapes comprise stainless steel and/or glass.

19. The bubbler of claim 1 wherein the ratio between the length of said combined length of chambers connected in series with respect to the direction of flow of said carrier gas through said chambers and the average diameter equivalent of the cross section of said chambers with respect to the direction of flow of said carrier gas through said chamber or chambers is not less than 6:1.

20. The bubbler of claim 1 wherein the ratio between the length of said combined length of chambers connected in series with respect to the direction of flow of said carrier gas through said chambers and the average diameter equivalent of the cross section of said chambers with respect to the direction of flow of said carrier gas through said chamber or chambers is about 6:1.

21. A bubbler for providing a vaporized compound in a chemical vapor deposition process comprising: (a) a bubbler chamber assembly having an inlet and an outlet; (b) a means for providing an inert carrier gas to said compound connected to said inlet; (c) a means for removing said vaporized compound and carrier gas from said chamber assembly and conveying said compound to said chemical vapor deposition process connected to said outlet; and (d) temperature control means in which said bubbler chamber assembly is placed that causes said compound to vaporize into said carrier gas; said bubbler chamber assembly comprising two or more chambers connected in series with the flow of said vaporized compound and carrier gas alternating between up flow and down flow between adjoining chambers in said series, all chambers being in substantially vertical orientation, in which chambers contain a solid source of said compound.

22. The bubbler of claim 21 wherein the ratio between the length of said combined length of chambers connected in series with respect to the direction of flow of said carrier gas through said chambers and the average diameter equivalent of the cross section of said chambers with respect to the direction of flow of said carrier gas through said chamber or chambers is not less than about 6:1.

23. The bubbler of claim 21 wherein the ratio between the length of said combined length of chambers connected in series with respect to the direction of flow of said carrier gas through said chambers and the average diameter equivalent of the cross section of said chambers with respect to the direction of flow of said carrier gas through said chamber or chambers is not less than 6:1.