RAPID THERMAL PROCESSING

Rapid Thermal Processing


Rapid Thermal Processing (dt: rapid thermal processing ) is an umbrella term for the processing of wafers in a high-temperature process in which a very rapid heating of the wafer with halogen lamps is achieved.

Principle 

Integrated into the wafer processing chamber by several halogen lamps (usually 150-250 pieces at 200 mm wafers) with a total capacity of 40 kW and more heated to a temperature of 1000 ° C.
Due to the high efficiency of the lamps are heating rates (engl. ramp-up ) above 100 degrees per second. After switching off the halogen lamps of the wafer cools down again very quickly (English ramp down , about 50 degrees per second). Most RTP processes take place under vacuum to an unwanted oxidation to avoid
Processes 

Rapid thermal annealing 


Rapid thermal annealing (RTA, dt: rapid thermal annealing ) is used for healing of the crystal structure of the wafer, for example, after implantation processes . By this method, are crystal lattice defects in the wafer treated reduced and thus improves the electrical properties. To achieve this, the wafer 10-20 seconds to temperatures around 1000 ° C is brought. May balance out any minor dislocations in the crystal and dopants include at interstitial places better in the crystal lattice. By the short process times, however, the further diffusion of the dopants is limited to a minimum.
Rapid thermal oxidation
Rapid thermal oxidation (RTO, dt: rapid thermal oxidation ) is used to produce very thin oxides (<20 angstroms), primarily silicon dioxide on silicon substrates, for example, the screen oxide than for implantation processes are used. The process builds upon the thermal oxidation of silicon dar. In contrast to thermal oxidation, in which a plurality of wafers are processed simultaneously in an oxidation furnace, it is at RTO system usually to single wafer processing equipment. RTO is in terms of oxide growth is not significantly faster than the oxidation in high oxidation furnaces, considering, but the entire process (loading, high heat, oxidation, and cooling) reduces the time effort from hours to a few minutes, but only for one instead of 50 wafers.
Other applications

Production of titanium silicide by coating a titanium layer of approximately 40 nm thickness and subsequent conversion into a silicide by RTP