An inverted gapped-target sputter magnetron for the deposition of thin ferromagnetic films

An Inverted Magnetron Operating in HiPIMS Mode

“…The ion flux during the HiPIMS pulse dramatically increased to a peak of Γi,peak ∼ 10 21 m −2 s −1 . It was two orders of magnitude higher than the ion flux of ∼10 19 m −2 s −1 during the DC mode [9]. Figure 4 shows the peak ion flux Γi,peak determined near the pulse terminal (t ∼ 250-300 µs) as a function of the peak of the discharge current Id,peak.…”

“…The discharge current jumped from~0.3 A in DC mode to~13 A in HiPIMS mode. The density of the plasma in DC mode has been reported to be approximately 0.6 × 10 16 m −3 [9]. Therefore, a plasma density during the HiPIMS pulses in the order of 3 × 10 16 m −3 could be expected.…”

“…The plasma sheath is a layer of electric field formed owing to the potential difference between the plasma potential and the probe potential [13]. Using a Langmuir probe, a plasma potential of larger than 120 V has been estimated in the DC mode [9], causing electron suppression to the grounded probe. Therefore, the electron flux to the probe can be negligible compared to the ion fluxes.…”

“…The structure of the inverted magnetron has been provided in detail elsewhere [9]. However, a schematic diagram showing the arrangement of the magnetron used in the present work is shown in Figure 1a.…”

“…Recently, the inverted gapped-target magnetron was developed as a device for ferromagnetic film deposition, providing a means to produce good quality, crack-free nickel films [9]. This is mainly due to the ion bombardment with energy of about 200 eV during the film growth.…”