Device and method for vaporizing temperature sensitive materials

1. A method for vaporizing solid organic materials onto a substrate surface to form a film, comprising:

a) providing a quantity of solid organic material into a vaporization apparatus;

b) actively maintaining by cooling the solid organic material in a first region in the vaporization apparatus to be below the vaporization temperature;

c) heating a second region of the vaporization apparatus above the vaporization temperature of the solid organic material so that there is a steep thermal gradient on the order of 200° C./mm across the thickness of the organic material between the first and second regions that protects all but the immediately vaporizing material from the temperature in the second region; and

d) metering, at a controlled rate, solid organic material from the first region into the second heating region so that a thin cross section of the solid organic material is heated at a desired rate-dependent vaporization temperature, whereby the thin cross section of solid organic material vaporizes and forms a film on the substrate surface.

2. The method according to claim 1 where the vaporized organic material passes through a permeable member located between the first and second regions.

3. The method according to claim 1 further including providing a deposition chamber and interrupting the vaporization and thereby reducing contamination of the deposition chamber walls and conserving the solid organic material when a substrate surface is not being coated.

4. The method according to claim 1 where a constant volume is maintained in the second region so as to establish and maintain a constant plume shape.

5. The method according to claim 1 wherein the first region is maintained at a constant temperature by cooling as the solid organic material is consumed.

6. The method according to claim 1 wherein the second region is maintained at a constant heater temperature as the solid organic material is consumed.

7. The method according to claim 1 further including providing a cooling base block surrounding the solid organic material in the first region and providing a liquid between the cooling base block and the solid organic material in the first region to provide thermal contact and a vapor-tight seal between the solid organic material and the cooling base block.

8. The method according to claim 1 wherein the solid organic material is metered on the surface of a rotatable drum into a second region at a controlled rate that varies linearly with vaporization rate.

9. A method for vaporizing solid organic materials onto a substrate surface to form a film, comprising:

a) providing a quantity of solid organic material having at least two organic components into a vaporization apparatus;

b) actively maintaining by cooling the solid organic material in a first region in the vaporization apparatus to be below the vaporization temperature of each of the organic components;

c) heating a second region of the vaporization apparatus above the vaporization temperature of the solid material so that there is a steep thermal gradient on the order of 200° C./mm across the thickness of the organic material between the first and second regions of the vaporization apparatus that protects all but the immediately vaporizing material from the temperature in the second region; and

d) metering, at a controlled rate, solid organic material from the first region into the second region so that a thin cross section of the solid organic material is heated at a desired rate-dependent vaporization temperature of each of the organic components, whereby each of the solid organic material components simultaneously vaporizes and forms a film on the substrate surface.

10. The method according to claim 9 where the vaporized organic material passes through a permeable member.

11. The method according to claim 9 further including providing a deposition chamber and interrupting the vaporization rate and thereby minimizing contamination of the deposition chamber walls and conserving the solid organic materials when a substrate surface is not being coated.

12. The method according to claim 9 where a constant volume is maintained in the second region so as to establish and maintain a constant plume shape.

13. The method according to claim 9 wherein the first region is maintained at a constant temperature by cooling as the solid organic material is consumed.

14. The method according to claim 9 further including providing a cooling base block surrounding the solid organic material in the first region and providing a liquid between the cooling base block and the solid organic material in the first region to provide thermal contact and a vapor-tight seal between the solid organic material and the cooling base block.