1. Sputtering Threshold
The minimum energy value of the incident ions needed to sputter target atoms out is not related to the type of incident ions but related to the target. After the energy amount exceeds the sputtering threshold, the sputtering yield is proportional to the square of the ion energy before 150 ev as the ion energy increases, and the sputtering yield is proportional to the ion energy in the range of 150 ev to 1 kev. In the range of 1kev~10kev, the sputtering yield changes slightly. When the energy was increased again, the sputtering yield showed a downward trend. The following are the sputtering thresholds of several metals bombarded with different incident ions.
|Metal||Ion Sputtering threshod/eV||Sublimation Heat/eV|
2. Sputtering Yield
Sputtering yield refers to the average number of atoms per positive ion that can be emitted from the target when incident ions bombard the target. The influencing factors mainly include the following aspects:
◆ The sputtering yield shows a certain periodicity with the change of the atomic number of the target. With the increase of the electron filling degree of the d shell of the target atom, the sputtering yield increases (roughly changing trend).
◆ Effect of incident ion species on sputtering yield
The sputtering yield increases periodically with increasing atomic number of incidents.
The sputtering yield of silver, copper, and tantalum that corresponding to a variety of incident ions of 45Kev.
◆ Effect of ion incidence angle on sputtering yield
For the same target and incident ions, the sputtering yield increases as the incident angle of the ion increases. When the angle increases to 70° ~ 80°, the sputtering yield is the largest. Continue to increase the angle of incidence, the sputtering yield is sharply reduced, and the sputtering yield is 0 at 900° .
◆ Effect of target temperature on sputtering yield
In general, in a temperature range where sputtering yield can be considered closely related to sublimation energy, the sputtering yield hardly changes with temperature. If the temperature exceeds this range, the sputtering yield tends to increase rapidly.