UV LIGHT IRRADIATING APPARATUS WITH LIQUID FILTER

• US 20080230721A1
• Filed: 03/23/2007
• Published: 09/25/2008
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: MATSUSHITA, Kiyohiro, KAGAMI, Kenichi
• Granted Patent: US 7,763,869 B2
• Time in Patent Office: Days
• US Class Current: 250/492.2
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/6715 Apparatus for applying a liquid, a resin, an ink or the like H01L21/67126 takes precedence

Abstract

A UV light irradiating apparatus for irradiating a semiconductor substrate with UV light includes: a reactor in which a substrate-supporting table is provided; a UV light irradiation unit connected to the reactor for irradiating a semiconductor substrate placed on the substrate-supporting table with UV light through a light transmission window; and a liquid layer forming channel disposed between the light transmission window and at least one UV lamp for forming a liquid layer through which the UV light is transmitted. The liquid layer is formed by a liquid flowing through the liquid layer forming channel.

Claims

1. A UV light irradiating apparatus for irradiating a semiconductor substrate with UV light, comprising:

a reactor in which a substrate-supporting table is provided, said reactor being provided with a light transmission window;

a UV light irradiation unit connected to the reactor for irradiating a semiconductor substrate placed on the substrate-supporting table with UV light through the light transmission window, said UV light irradiation unit including at least one UV lamp; and

a liquid layer forming channel disposed between the light transmission window and the UV lamp for forming a liquid layer through which the UV light is transmitted, said liquid layer being formed by a liquid flowing through the liquid layer forming channel.

2. The UV light irradiating apparatus according to claim 1, wherein the liquid layer is formed by the flowing liquid which has substantially or nearly no absorption of UV light having a wavelength of 250 nm or lower.

3. The UV light irradiating apparatus according to claim 2, wherein the liquid constituting the liquid layer is water.

4. The UV light irradiating apparatus according to claim 1, wherein the liquid layer forming channel is formed with a glass capable of transmitting UV light having a wavelength of 250 nm or lower.

5. The UV light irradiating apparatus according to claim 1, wherein the liquid layer forming channel is formed by two transparent walls for passing the liquid therebetween.

6. The UV light irradiating apparatus according to claim 5, wherein a distance between the two walls is about 5 mm to 15 mm.

7. The UV light irradiating apparatus according to claim 5, wherein the liquid layer forming channel is formed by a double walled enclosure comprising an inner wall and an outer wall for passing the liquid between the walls, said enclosure enclosing the UV lamp.

8. The UV light irradiating apparatus according to claim 7, wherein the UV lamp has an elongated shape.

9. The UV light irradiating apparatus according to claim 7, wherein the double walled enclosure has a liquid inlet port for introducing the liquid between the inner and outer walls and a liquid outlet port for discharging the liquid from between the inner and outer walls.

10. The UV light irradiating apparatus according to claim 7, where the double walled enclosure has an inert gas inlet port for introducing inert gas into an interior enclosed by the inner wall and an inert gas outlet port for discharging the inert gas from the interior.

11. The UV light irradiation apparatus according to claim 1, wherein the liquid layer forming channel is disposed in parallel to and closer to the UV light transmission window than to the UV lamp.

12. The UV light irradiating apparatus according to claim 1, wherein the UV light transmission window constitutes the liquid layer forming channel.

13. The UV light irradiating apparatus according to claim 1, wherein the UV irradiation unit is provided with a reflection plate disposed along an inner wall of the UV irradiation unit, said reflection plate being angled to reflect UV light from the UV lamp toward the UV light transmission window.

14. The UV light irradiating apparatus according to claim 1, wherein the liquid layer forming channel has a liquid inlet port for introducing the liquid into the channel and a liquid outlet port for discharging the liquid from the channel and is provided with a temperature sensor disposed at the liquid outlet port for detecting a temperature of the liquid at the liquid outlet port.

15. The UV light irradiating apparatus according to claim 14, wherein the liquid layer forming channel is provided with a flow controller disposed upstream of the liquid inlet port for controlling the liquid flow according to the temperature detected by the temperature sensor.

16. A method for irradiating a semiconductor substrate with UV light, comprising:

placing a semiconductor substrate on a substrate-supporting table in a reactor;

forming a liquid layer by passing a liquid through a liquid layer forming channel disposed between a UV lamp provided in a UV light irradiation unit and a light transmission window provided between the reactor and the UV light irradiation unit; and

irradiating the semiconductor substrate with UV light emitted from the UV lamp through the liquid layer and the light transmission window.

17. The method according to claim 16, wherein the liquid layer is formed by passing the liquid which has substantially or nearly no absorption of UV light having a wavelength of 250 nm or lower.

18. The method according to claim 17, wherein the liquid constituting the liquid layer is water.

19. The method according to claim 16, wherein the substrate has a low-k film subjected to the UV light irradiation.

20. The method according to claim 16, wherein the liquid layer forming channel is formed by a double walled enclosure which encloses the UV lamp and comprises an inner wall and an outer wall, wherein the liquid layer forming step comprises passing the liquid between the inner and outer walls.

21. The method according to claim 20, where the liquid layer forming step further comprises introducing inert gas into an interior enclosed by the inner wall and discharging the inert gas from the interior.

22. The method according to claim 16, wherein the liquid layer is formed in parallel to and closer to the UV light transmission window than to the UV lamp.

23. The method according to claim 16, wherein the UV light transmission window serves as the liquid layer forming channel, and the liquid layer is formed in the UV light transmission window.

24. The method according to claim 16, wherein the UV irradiation unit is provided with a reflection plate disposed along an inner wall of the UV irradiation unit, wherein the irradiation step further comprises reflecting UV light from the UV lamp using the reflection plate toward the UV light transmission window.

25. The method according to claim 16, wherein the liquid layer forming step comprises introducing the liquid into the channel, discharging the liquid from the channel, detecting a temperature of the liquid discharging from the channel, and controlling the flow of the liquid introduced into the channel according to the detected temperature.

26. The method according to claim 25, wherein the liquid flow is controlled to control the temperature of the liquid discharging from the channel at 40°

C. or lower.