The main factors that affect the sputtering voltage of a magnetron target are: the magnetic field of the target surface, the target material, the gas pressure, the cathode-anode distance, and so on. This article analyzes the influence of these factors on the target sputtering voltage in detail.
· Some sputtering targets (such as manganese Mn, chromium Cr, etc.) have relatively high sputtering voltages, and generally require more than 700V to complete the normal magnetron sputtering process; while some targets (such as indium tin oxide ITO) sputtering The radio voltage is relatively low, and the normal magnetron sputtering deposition coating can be realized at a voltage of more than 200 volts.
· In the actual coating process, due to changes in the working gas pressure, or the distance between the cathode and the anode is too small (changes the impedance characteristics in the vacuum chamber), or the mechanical dimensions of the vacuum chamber and the magnetron target do not match, the output characteristics are selected at the same time For reasons such as softer target power supply, the sputtering voltage of the magnetron target (that is, the output voltage of the target power supply) is much lower than the normal sputtering value, and it may appear that the front memory of the target shows a very bright aperture, but it is not visible. When the target ion is flooded with the corresponding color, it can not be sputtered to form a film.
· The influence of working gas pressure on target sputtering voltage
The general rule is: when the environmental conditions of the vacuum equipment are determined and the control panel setting parameters of the target power supply remain unchanged, as the working gas (such as argon) pressure (0.1~10Pa) gradually increases, the density of the gas discharge plasma will also The synchronous increase causes the equivalent plasma impedance to decrease, the sputtering current of the magnetron target will gradually increase, and the sputtering operating voltage will also decrease synchronously.
· The influence of reactive gas pressure on target sputtering voltage
In the process of reactive magnetron sputtering coating, when the environmental conditions of the vacuum equipment are determined and the control panel setting parameters of the target power supply remain unchanged, as the pressure (or flow) of the reactive gas (such as nitrogen and oxygen) gradually increases (generally Be careful not to exceed the upper limit of the process setting value). As the magnetron target surface and the substrate (workpiece) surface are gradually covered by the insulating film, the equivalent impedance of the discharge between the cathode and the anode will also increase simultaneously. The sputtering current of the target will gradually decrease (until "cathode poisoning" and "anode disappear"), and the sputtering working voltage will also increase simultaneously.
· Twin target (or dual magnetron target) cathode-anode spacing symmetrical bipolar pulse intermediate frequency target power supply and sine wave intermediate frequency target power supply when operating with twin target or dual magnetron target, it is recommended that the two alternating cathode-anode minimum poles The spacing should not be less than 2 inches 2 inches;
· Single magnetron target cathode-anode spacing
When the target power supply is operated with a single magnetron target, this problem generally does not exist; however, it is easy to ignore this problem when the small vacuum chamber is equipped with a long rectangular planar magnetron single target. The magnetron target surface and the inner wall of the vacuum chamber metal shell The minimum distance between poles is generally recommended not to be less than 2 inches 2 inches.
Xinkang New Materials is a global supplier of various high-quality sputtering targets such as metals, alloys, oxides, and ceramic materials. All the sputtering targets mentioned above are provided by Xinkang. If you have any questions about the target materials, please consult us.