Specific Process Knowledge/Thin film deposition/ALD2 (PEALD): Difference between revisions
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The precursor pulse time is controlled by special ALD valves that allow very short precursor pulses to be introduced into the ALD reactor chamber and at the same time allow a constant nitrogen or argon flow. Thus, nitrogen and argon are always flowing through the ALD valves into the chamber, independent on whether a precursor pulse is introduced or not. | The precursor pulse time is controlled by special ALD valves that allow very short precursor pulses to be introduced into the ALD reactor chamber and at the same time allow a constant nitrogen or argon flow. Thus, nitrogen and argon are always flowing through the ALD valves into the chamber, independent on whether a precursor pulse is introduced or not. | ||
At the moment it is possible to deposit Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, HfO | At the moment it is possible to deposit Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, HfO<sub>2</sub>, AlN and TiN in the ALD. In order to deposit good quality nitride layers with low sheet resistance, the amount of oxygen has to be very low. Thus, the ALD reactor chamber has to be passivated for about three days, before nitride depositions can be done, and oxides and nitrides cannot be deposited at same time. | ||
Samples are loaded through a load lock. 6" and 8" wafers can be loaded directly in the load lock, while 4" wafers and smaller samples have to be placed on a 6" carrier plate or a 6" silicon dummy wafer with an etched recess. It is only possible to load one wafer or carrier plate at a time by use of the load lock. | Samples are loaded through a load lock. 6" and 8" wafers can be loaded directly in the load lock, while 4" wafers and smaller samples have to be placed on a 6" carrier plate or a 6" silicon dummy wafer with an etched recess. It is only possible to load one wafer or carrier plate at a time by use of the load lock. | ||