Cathode 4 Q4 (a) What is the effect of magnetic field for magnetron sputtering? Explain it...

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Cathode 4 Q4 (a) What is the effect of magnetic field for magnetron sputtering? Explain it showing a path of charges particles close to target. (b) For polycrystalline coatings with grain size larger than 10 nm, X-ray diffraction can be used to identify the residual stress. Explain how. (c) The deposition chamber consists of 4 magnetrons (close- field arrangement, see Fig. Q4). The deposition of the coating consist of four steps: 1. The deposition of 300 nm of pure Cr layer (20 minutes) 2. A maximum power is applied to tungsten and carbon targets for 60 minutes (power to Cr target is zero). 3. The power of carbon targets is kept constant (maximum), and tungsten power linearly decreases from maximum to zero (120 minutes). 4. The sputtering continues for 120 minutes only with carbon targets. Sketch a coating cross-section and indicate expected chemical composition and structure as a function of coating thickness. C W Cathode 1 Cr Fig. Q4 Cathode 3 Cathode 7 Page 6 of 7 (d) Nanocomposite coatings, such as nc-TiN/SIN, are very hard. Explain why using terms grain boundary and discocation. Cathode 4 Q4 (a) What is the effect of magnetic field for magnetron sputtering? Explain it showing a path of charges particles close to target. (b) For polycrystalline coatings with grain size larger than 10 nm, X-ray diffraction can be used to identify the residual stress. Explain how. (c) The deposition chamber consists of 4 magnetrons (close- field arrangement, see Fig. Q4). The deposition of the coating consist of four steps: 1. The deposition of 300 nm of pure Cr layer (20 minutes) 2. A maximum power is applied to tungsten and carbon targets for 60 minutes (power to Cr target is zero). 3. The power of carbon targets is kept constant (maximum), and tungsten power linearly decreases from maximum to zero (120 minutes). 4. The sputtering continues for 120 minutes only with carbon targets. Sketch a coating cross-section and indicate expected chemical composition and structure as a function of coating thickness. C W Cathode 1 Cr Fig. Q4 Cathode 3 Cathode 7 Page 6 of 7 (d) Nanocomposite coatings, such as nc-TiN/SIN, are very hard. Explain why using terms grain boundary and discocation.