System for controlling the sublimation of reactants

• US 20030232138A1
• Filed: 06/16/2003
• Published: 12/18/2003
• Est. Priority Date: 06/17/2002
• Status: Active Grant

• Current Assignee: Eric Shero, Marko Tuominen, Mohith Verghese
• Original Assignee: ASM International NV
• Inventors: Verghese, Mohith, Tuominen, Marko, Shero, Eric
• Granted Patent: US 7,601,225 B2
• Time in Patent Office: Days
• US Class Current: 427/248.1
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/4481 by evaporation using carrier gas in contact with the source material C23C16/4486 takes precedence
• CPC Class Codes: C23C 16/4483 using a porous body
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]

Abstract

An apparatus and method improves heating of a solid precursor inside a sublimation vessel. In one embodiment, inert, thermally conductive elements are interspersed among units of solid precursor. For example the thermally conductive elements can comprise a powder, beads, rods, fibers, etc. In one arrangement, microwave energy can directly heat the thermally conductive elements.

Claims

1. A method of producing a vapor from a solid precursor for processing a substrate, comprising:

placing solid units of precursor into a vessel;

interspersing a thermally conductive material with the units of precursor;

forming a vapor through applying heat energy to both the thermally conductive material and the solid units of precursor; and

routing the vapor from the vessel to a reaction chamber.

2. The method of claim 1, further comprising reacting the vapor to deposit a layer on a substrate.

3. The method of claim 1, wherein interspersing the thermally conductive material with the solid units of precursor comprises forming a solid mixture having about 10% to 80% by volume of thermally conductive material in the mixture.

4. The method of claim 1, wherein the interspersing the thermally conductive material with the solid units of precursor comprises forming a solid mixture having about 30-60% by volume of thermally conductive material in the mixture.

5. A substrate processing system for forming a vapor from a solid precursor by distributing heat to the precursor, comprising:

a vessel configured to hold units of solid precursor;

a plurality of thermally conductive elements interspersed with the units of solid precursor; and

a heater being configured to transmit heat energy to both the thermally conductive elements and the precursor.

6. The system of claim 5, wherein the vessel is a heat conducting vessel.

7. The system of claim 5, further including a reaction chamber fluidly coupled to the vessel, the chamber being configured to provide a suitable environment for the reaction of a vapor, originating from the vessel, to deposit a layer on a substrate.

8. The system of claim 7, wherein the reaction chamber is a chemical vapor deposition chamber (CVD).

9. The system of claim 7, wherein the reaction chamber is an atomic layer deposition chamber (ALD).

10. The system of claim 5, wherein the units of solid precursor are in powder form.

11. The system of claim 5, wherein the thermally conductive elements are formed from a substance which is substantially inert to reactions within the vessel.

12. The system of claim 5, wherein the thermally conductive elements have a coating which is substantially inert to reactions within the vessel.

13. The system of claim 5, further including a vacuum chamber surrounding the vessel.

14. The system of claim 5, wherein the heater is a microwave generator configured to transmit microwave energy to the thermally conductive elements.

15. The system of claim 5, wherein the thermally conductive elements are rods configured to be inserted within the vessel.

16. The system of claim 15, wherein the rods are attached to a base plate configured to be inserted into the vessel.

17. The system of claim 15, wherein the rods are attached to a vessel base.

18. The system of claim 15, wherein the rods are each configured to be inserted independently of one another.

19. The system of claim 5, wherein the thermally conductive elements are fibers configured interspersed with the units of solid precursor contained within the vessel.

20. The system of claim 5, wherein the thermally conductive elements are in powder form.

21. The system of claim 5, wherein the thermally conductive elements comprise carbon.

22. The system of claim 21, wherein the thermally conductive elements comprise metal carbide.

23. The system of claim 21, wherein the thermally conductive elements comprise transition metal carbide.

24. The system of claim 21, wherein the thermally conductive elements comprise boron carbide.

25. The system of claim 21, wherein the thermally conductive elements comprise silicon carbide (SiC).

26. The system of claim 5, wherein the thermally conductive elements comprise a combination of rods and powder.

27. The system of claim 5, wherein the thermally conductive elements comprise a combination of rods and fibers.

28. The system of claim 5, wherein the thermally conductive elements have a thermal conductivity of at least about 50 W/m*K at room temperature.

29. The system of claim 5, wherein the thermally conductive elements have a thermal conductivity of at least about 80 W/m*K at room temperature.

30. A substrate processing system for forming a vapor from a solid precursor comprising:

a vessel configured to hold units of solid precursor; and

a microwave generator adjacent to the vessel, the generator being configured to transmit heat energy in the form of microwave energy to effectuate the heating of the precursor.

31. The system of claim 30, further comprising a plurality of thermally conductive elements interspersed with the units of solid precursor, the thermally conductive elements readily absorbing the microwave energy.

32. The system of claim 30, wherein the units of solid precursor are formulated to be directly heated by the microwave energy transmitted from the microwave generator.

33. The system of claim 30, wherein the vessel is formulated to be directly heated by the microwave energy transmitted from the microwave generator.

34. A mixture for producing a vapor used in substrate processing comprising:

a batch of precursor for producing a substrate processing vapor; and

a plurality of heat transmitting solid forms interspersed through the batch of precursor, the plurality of heat transmitting solid forms collectively increasing the thermal conductivity of the batch of precursor.

35. The mixture of claim 34, wherein the shape of the plurality of heat transmitting solid forms is selected from a group consisting of powder, spheres, irregularly shaped pieces, and machined pieces.

36. The mixture of claim 34, wherein the shape of the plurality of heat transmitting solid forms is selected from a group consisting of rods, screens, sieves, coils, and plates.

37. The mixture of claim 34, wherein, the plurality of heat transmitting solid forms are formed from a material selected from a group consisting of metal carbide, transition metal carbide, boron carbide, and silicon carbide.

38. The mixture of claim 34, wherein the plurality of heat transmitting solid forms are substantially inert with respect to desired reactions employed in the substrate processing.

39. The mixture of claim 34, wherein the plurality of heat transmitting solid forms are coated with a substantially inert material with respect to desired reactions employed in the substrate processing.

40. The mixture of claim 34, wherein the plurality of heat transmitting solid forms are configured to conduct heat from the precursor proximate to edges of the precursor batch to precursor substantially centrally located within the precursor batch.

41. The mixture of claim 34, wherein the plurality of heat transmitting solid forms absorb microwave energy originating from a microwave generator and release heat to the solid precursor.