Specific Process Knowledge/Thin film deposition/ALD2 (PEALD): Difference between revisions
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=ALD 2 (PEALD)= | =ALD 2 (PEALD)= | ||
[[Category: Equipment|Thin film]] | [[index.php?title=Category:Equipment|Thin film]] | ||
[[Category: Thin Film Deposition|ALD]] | [[index.php?title=Category:Thin Film Deposition|ALD]] | ||
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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. | ||
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*[[/HfO2 deposition using ALD2| HfO<sub>2</sub> deposition using '''ALD 2 (PEALD)''']] | *[[/HfO2 deposition using ALD2| HfO<sub>2</sub> deposition using '''ALD 2 (PEALD)''']] | ||
*[[/AlN deposition using ALD2| AlN deposition using '''ALD 2 (PEALD)''']] | *[[/AlN deposition using ALD2| AlN deposition using '''ALD 2 (PEALD)''']] | ||
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*[[/Al2O3 deposition using plasma ALD2 at room temperature| Al<sub>2</sub>O<sub>3</sub> deposition using '''ALD 2 (PEALD)''' at room temperature]] | *[[/Al2O3 deposition using plasma ALD2 at room temperature| Al<sub>2</sub>O<sub>3</sub> deposition using '''ALD 2 (PEALD)''' at room temperature]] | ||
'''Obsolete process:''' | |||
*[[/SiO2 deposition using ALD2| SiO<sub>2</sub> deposition using '''ALD 2 (PEALD)''']] | |||
==Equipment performance and process related parameters== | ==Equipment performance and process related parameters== | ||
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*Oxides: Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, HfO<sub>2</sub>, ZnO, AZO: 0-100 nm | *Oxides: Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, HfO<sub>2</sub>, ZnO, AZO: 0-100 nm | ||
*Nitrides: | *Nitrides: AlN, TiN: 0-100 nm | ||
<i>As the purpose of ALD 2 is to deposit very thin and uniform layers, the allowed deposition thickness is limited to 100 nm, and it is not allowed to do more depositions on the same sample(s) to deposit thicker layers than 100 nm. Deposition of thicker layers is not allowed, because this will occupy the machine for long time and thus make it available for less users. Long depositions also cause issues and with flakes and particles, which means that the chamber and the pump line will have to be cleaned or changed quite often. Furthermore, the delivery time on precursors is usually quite long. So when you make a sample design, you should avoid steps, where you need to deposit thicker layers than 100 nm with ALD, or you can consider, if the same material can be deposited using other machines in the cleanroom.</i> | <i>As the purpose of ALD 2 is to deposit very thin and uniform layers, the allowed deposition thickness is limited to 100 nm, and it is not allowed to do more depositions on the same sample(s) to deposit thicker layers than 100 nm. Deposition of thicker layers is not allowed, because this will occupy the machine for long time and thus make it available for less users. Long depositions also cause issues and with flakes and particles, which means that the chamber and the pump line will have to be cleaned or changed quite often. Furthermore, the delivery time on precursors is usually quite long. So when you make a sample design, you should avoid steps, where you need to deposit thicker layers than 100 nm with ALD, or you can consider, if the same material can be deposited using other machines in the cleanroom.</i> | ||
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