Development Of Modulated Pulsed Power Magnetron Sputtering System And Preparation Of Alcrn Films

Modulated pulsed power magnetron sputtering is a new kind of magnetronsputtering technique. MPP can easily deliver adjustable voltage waveform, it canachieve multi-level pulse configuration. This new sputtering technique is capable ofproducing a high ionization fraction of sputter target species and while at the sametime achieving a high deposition rate. The obtained films are featured by fine grainsize, compact structure, low internal stress, Due to the high deposition rate thickfilms in the order of~100um in thickness.An MPP power has been developed in the article, the average power is5kWwith the pulse current of100A,the voltage of1000V,the maximum power is100kW,the total of pulse width is500-300μs.Through dual microprocessor control,simplified the control circuit, improved the stability of the power supply. By usingthe man-machine interface of OP320-A,it is easier to operate. Multi-waveform suchas one stage waveform, former low two-stage waveform, former high two-stagewaveform, low to high and then high to low three-stage waveform. high to low andthen low to high three-stage waveform has been conducted, MPP power runsstability.MPP‘s grow discharge in the vacuum chamber showed a nonlinearphenomenon. After study on the starter case, we found that the pulse edge extendedfrom left to right as the charging voltage increased, the pulse edge receded from leftto right as the gas pressure reduced. By adding a first stage of high-voltage pulsecan increase the stability of the power supply starter.After study on the discharge characteristics of AlCr target, we found that thepower density of MPP is lower than DC, the pulse current is low. Reducing thepressure and frequency, it will increase the difficulty of the pulse starter, but whichhas little relationship with pulse current, it indicates that self-sputtering processtake high percentage of high-power plasma discharge. Bias can increase the amountof ions reach to the base. Increase the proportion of nitrogen in gas can increase thepulse current obviously. when discharge on the target, it glows bright blue.During the process of depositing AlCrN film, we also found that MPPdeposition rate is lower than that of DC power supply, accounting for94%of the DC. Increasing the frequency can get the fastest deposition rate comparing withincreasing the voltage and pulse width. The AlCrN film made by MPP has finergrain size, lower surface roughness, which also get high plastic toughness. Inaddition, As the supply of power increase, the diffraction peak strength, it becomegentle near CrN(200). With the increase in the proportion of N2, diffraction peakincreases, their nano-hardness and elastic modulus increases with increasingproportion of N2/Ar. On the whole, film structure and performance can be improvedby using MPP.