Method and device for thermal treatment of substrates
View Patent ↗The object of the invention is to measure temperature using pyrometers, in a simple and economic way, enabling precise temperature measurement, even for low temperatures. The invention presents a device and method for thermally treating substrates, wherein the substrate is exposed to at least a first and at least a second radiation; the predetermined wavelengths of the first radiation are absorbed between the first radiation source and the substrate; a radiation from the substrate is measured in the predetermined wavelength using a radiation detector arranged on the same side as a second radiation source; the second radiation from the second radiation source is modulated and determined.
1. An apparatus for thermally treating substrates, comprising:
at least one first radiation source for heating a substrate;
at least one transparent shield disposed between the first radiation source and the substrate, wherein such transparent shield reduces prescribed wavelengths of radiation of the first radiation source;
at least one second radiation source for heating said substrate, wherein said second radiation source irradiates said substrate at least with radiation that lies in said prescribed wavelengths of radiation;
at least one radiation detector, which is disposed on a side of said second radiation source and is directed toward said substrate, wherein said radiation detector measures a radiation intensity coming from said substrate at least partially within said prescribed wavelengths of radiation;
means for modulating at least the radiation emitted by said second radiation source; and,
means for determining a radiation intensity coming from said second radiation source.
2. An apparatus according to claim 1 , wherein said first and said second radiation sources are disposed on opposite sides of said substrate.
3. An apparatus according to claim 1 , wherein a device is provided for regulating said at least one first radiation source.
4. An apparatus according to claim 1 , wherein a device for controlling said at least one second radiation source is provided.
5. An apparatus according to claim 1 , wherein said radiation sources are heating lamps.
6. An apparatus according to claim 5 , wherein said at least one transparent shield is formed by bulbs of said heating lamps.
7. An apparatus according to claim 1 , wherein said at least one transparent shield is a process chamber wall that is disposed between said at least one first radiation source and said substrate.
8. An apparatus according to claim 1 , wherein said at least one transparent shield is provided with at least one filter layer for absorption of said prescribed wavelengths.
9. An apparatus according to claim 8 , wherein said at least one filter layer is spatially separated from a further transparent material.
10. An apparatus according to claim 1 , wherein said at least one transparent shield has an OH-enriched quartz glass.
11. An apparatus according to claim 1 , wherein said at least one transparent shield absorbs wavelengths between 2.7 μm and 2.8 μm.
12. An apparatus according to claim 1 , wherein a device is provided for cooling said at least one transparent shield.
13. An apparatus according to claim 12 , wherein said device for cooling is provided with a cooling gas or a cooling liquid.
14. An apparatus according to claim 1 , wherein said at least one radiation detector is a pyrometer.
15. An apparatus according to claim 1 , wherein said substrate is a coated semiconductor wafer.
16. An apparatus according to claim 15 , wherein said coating is a CO- and/or Ti-coating.
17. An apparatus according to claim 1 , wherein said substrate has a transmissivity of less than 0.15.
18. An apparatus according to claim 1 , wherein at least one second radiation detector is provided and is directed toward said substrate.
19. An apparatus according to claim 18 , wherein said at least one second radiation detector measures radiation beyond said prescribed wavelengths.
20. An apparatus according to claim 19 , wherein said at least one second radiation detector measures radiation below and above said prescribed wavelengths.
21. An apparatus according to claim 18 , wherein said at least one second radiation detector is directed toward that side of said substrate that is remote from said at least one second radiation source and measures radiation having said prescribed wavelengths.