Specific Process Knowledge/Thin film deposition/Deposition of Silver/Deposition of Silver

Thermal deposition of Silver

Note: This text is under construction

Silver can be thermally evaporated in Wordentec. The deposition rate is highly sensitive to the process parameters (at least for a requested deposition rate of 5 Å/s).

Therefore, different settings have been tested, to find a situation with rather stabel depositon rate.

These settings were fond to give a fairly stabel deposition rate:

Max power 6.6 %

Soak power 1 : 4 %

Soak power 2 : 6.6 %

Soak time 2: 1 min (can be set to for example 2 min, if a higher stability of the deposition rate is requested).

Deposition rate: (requested) 2.5 Å/s

Density : 10.5 (thermal evap. of Al, 2.7) Z-ratio : 0.529 (thermal evap. of Al 1.08)

Master Tooling should be set to: 120% (to get the requested layer thickness on the wafer). (Master tooling for Al = 167%).

Actual value of deposition rate flucturate, staring at about 1 Å/s, going up to maximum 3 Å/s, and flucturating between 2-3 Å/s after a while.

15 pellets (1/8" diameter x 1/8" long) were placed in the boat before the evaporation processes were started. More than 8500 Å could be deposited from that amount, without any problem with covered contacts or smilar things.