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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[[image:ALD2.jpg|450x450px|right|thumb|ALD 2 (PEALD). Positioned in cleanroom F-2.]] | [[image:ALD2.jpg|450x450px|right|thumb|ALD 2 (PEALD). Positioned in cleanroom F-2.]] | ||
The ALD 2 (PEALD) is used to deposit very thin and uniform layers of different materials, by use of thermal ALD (Atomic Layer Deposition) or PEALD (Plasma Enhanced ALD). | The ALD 2 (PEALD) is used to deposit very thin and uniform layers of different materials, by use of thermal ALD (Atomic Layer Deposition) or PEALD (Plasma Enhanced ALD). Layers can be up to 100 nm thick, see the table below. | ||
The ALD deposition takes place in an ALD reactor chamber. In order to ensure that the temperature inside this reactor is the same everywhere, it has a dual chamber structure. The inner chamber is the reactor chamber, and the outer chamber is isolating the reactor chamber from room air. Both the inner and the outer chamber are under vacuum. The space between the two chambers is called an intermediate space (IMS), and the IMS is constantly purged with nitrogen. | The ALD deposition takes place in an ALD reactor chamber. In order to ensure that the temperature inside this reactor is the same everywhere, it has a dual chamber structure. The inner chamber is the reactor chamber, and the outer chamber is isolating the reactor chamber from room air. Both the inner and the outer chamber are under vacuum. The space between the two chambers is called an intermediate space (IMS), and the IMS is constantly purged with nitrogen. | ||
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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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[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=365 ALD 2 (PEALD) info page in LabManager] | [http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=365 ALD 2 (PEALD) info page in LabManager] | ||
== Process information == | == Process information == | ||
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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)''']] | ||
*[[/TiN deposition using ALD2| TiN deposition using '''ALD 2 (PEALD)''']] | *[[/TiN deposition using ALD2| TiN deposition using '''ALD 2 (PEALD)''']] | ||
*[[/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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*Al<sub>2</sub>O<sub>3</sub> - Thermal Al<sub>2</sub>O<sub>3</sub> (mainly backup for ALD1) and Al<sub>2</sub>O<sub>3</sub> using plasma | *Al<sub>2</sub>O<sub>3</sub> - Thermal Al<sub>2</sub>O<sub>3</sub> (mainly backup for ALD1) and Al<sub>2</sub>O<sub>3</sub> using plasma | ||
*TiO<sub>2</sub> (amorphous or anatase) - Thermal TiO<sub>2</sub> (mainly backup for ALD1) and TiO<sub>2</sub> using plasma | *TiO<sub>2</sub> (amorphous or anatase) - Thermal TiO<sub>2</sub> (mainly backup for ALD1) and TiO<sub>2</sub> using plasma | ||
*HfO<sub>2</sub> - Thermal HfO<sub>2</sub> (mainly backup for ALD1) | *HfO<sub>2</sub> - Thermal HfO<sub>2</sub> (mainly backup for ALD1) | ||
*AlN - AlN using plasma | *AlN - AlN using plasma | ||
*TiN - Thermal TiN and TiN using plamsa | *TiN - Thermal TiN and TiN using plamsa | ||
Is is not possible to deposit oxides and nitrides at the same time | *ZnO | ||
*AZO | |||
All precursors might not be available at the same time. | |||
Is is not possible to deposit oxides and nitrides at the same time. | |||
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!style="background:silver; color:black" align="center" valign="center" rowspan="2"|Performance | !style="background:silver; color:black" align="center" valign="center" rowspan="2"|Performance | ||
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|style="background:LightGrey; color:black"|Thickness | |style="background:LightGrey; color:black"|Thickness | ||
|style="background:WhiteSmoke; color:black"| | |style="background:WhiteSmoke; color:black"| | ||
*Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, HfO<sub>2</sub>: | *Oxides: Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, HfO<sub>2</sub>, ZnO, AZO: 0-100 nm | ||
* | *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> | |||
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!style="background:silver; color:black" align="center" valign="center" rowspan="3"|Process parameter | !style="background:silver; color:black" align="center" valign="center" rowspan="3"|Process parameter | ||