Specific Process Knowledge/Thin film deposition/Deposition of Tantalum/Sputtering of Ta

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Sputtering of Tantalum

Ta can be DC sputtered in the Sputter-System (Lesker) as well as in the cluster sputter system. You will find information on the pressure, max power and expected deposition rate for the Sputter-System Lesker (commonly called the "old" Lesker)here in LabAdviser. To see all the deposition parameters used in that machine by others, search the Sputter-System Lesker Process Log in LabManager. Ta has also been deposited in the newer cluster sputter system in the chamber called PC 3 from room temperature to 500 °C. You can search the PC 3 Process Log for further information on deposition parameters.

Below you will find information on the surface roughness of sputtered Ta films from the old Sputter-System (Lesker).

Surface roughness optimization

By Bjarke Thomas Dalslet @Nanotech.dtu.dk

The Lesker CMS 18 sputter system provides thin films of varying surface roughness. This roughness was verified to be dependent on the sputtered material, sputter mode (DC or RF) and the substrate bias strength. Other probable factors include sputter power and pressure. Here you find the results for Ta. Similar studies were carried out for SiO₂ and Si.

The "Ta" study was done on clean Si substrates. The sputter pressure was 3 mTorr using DC sputtering of a Ta target. Some O₂ was added to wafer 25 and 26 to make Ta$_{2}$O$_{5}$. In order to get fully oxidized films, up to 30-45% O₂ should be added. Consult the thesis of Carsten Christensen for details on Ta$_{2}$O$_{5}$.

Ta

Wafer nr	RF bias (W)	Reactive O2 (%)	Power(W)	Rq (RMS) (nm)	Thickness (nm)
blank1	0	0	180	0.209
16	10	0	180	0.36	56
24	20	0	180	0.357
25	20	9	180	0.202	110
26	20	5	180	0.194	95
27	15	0	180	0.413
28	25	0	180	0.164
31	30	0	180	0.3