Specific Process Knowledge/Thermal Process/Resist Pyrolysis furnace: Difference between revisions
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All process gases (except purge nitrogen) are heated, before they are introduced into the furnace at the door side. | All process gases (except purge nitrogen) are heated, before they are introduced into the furnace at the door side. | ||
The furnace tube is heated by use of 12 long heaters situated along the furnace tube and combined in three groups (top, bottom left and bottom right) and two flat heaters situated in the ends of the furnace tube. The this way the temperature will be very uniform everywhere in the furnace tube. The heating can be done very fast, up to 30 <sup>o</sup>C/min. The maximum allowed processing time and temperature is 3 hours at 1050 <sup>o</sup>C. | The furnace tube is heated by use of 12 long heaters situated along the furnace tube and combined in three groups (top, bottom left and bottom right) and two flat heaters situated in the ends of the furnace tube. The this way the temperature will be very uniform everywhere in the furnace tube. However, the front heater is unfortunately broken at the moment. The heating can be done very fast, up to 30 <sup>o</sup>C/min. The maximum allowed processing time and temperature is 3 hours at 1050 <sup>o</sup>C. | ||
The furnace body surrounding the furnace tube consists of a top and bottom half-shell. To cool down the furnace (when the temperature is below 800 <sup>o</sup>C), the top half shelf can be lifted up, and cooling fans will then flow air from the surroundings around the furnace tube to cool it down | The furnace body surrounding the furnace tube consists of a top and bottom half-shell. To cool down the furnace (when the temperature is below 800 <sup>o</sup>C), the top half shelf can be lifted up, and cooling fans will then flow air from the surroundings around the furnace tube to cool it down. | ||
It is not possible to open the furnace when the temperature is above 300 <sup>o</sup>C. | It is not possible to open the furnace, when the temperature is above 300 <sup>o</sup>C. | ||
For resist pyrolysis, samples with different resist layers are heated up to maximum | For resist pyrolysis, samples with different resist layers are heated up to maximum 1050 <sup>o</sup>C in a nitrogen atmosphere. At high temperatures carbon is formed by pyrolysis of the resist. In this way conductive structures can be made from a resist patterned sample. If oxygen from the air or from outgassing of the resist is present in the furnace, the resist layer will be removed, thus it is important to evacuate the furnace and flush it with nitrogen, before a high temperature for resist pyrolysis is obtained. Pyrolysis of a large amount of resist may also be a problem due to resist outgassing. | ||