`Samsung Electronic's Exhibit 1031
`Exhibit 1031, Page 1
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`
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`KH. Nam et aL / Surface and Coatings Technology 131 (2000) 222-227
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`223
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`and scanning electron microscopy (SEM), and mechan-
`ical properties were evaluated by microhardness and
`adhesion tests.
`
`Table 1
`
`Conditions for CrNx coating process
`
`Deposition parameters
`
`Conditions
`
`2. Experimental details
`
`2.]. Film deposition
`
`CrNx films were deposited on A181 304 stainless
`steel and Si wafers by magnetron sputtering of a rect-
`angular Cr target with a moving magnet designed for
`high erosion efficiency,
`in our laboratory. The dis-
`charges of this magnetron, which are elliptically shaped
`with the longer axis perpendicular to the longer axis of
`the target, are generated by separated magnetic units
`placed behind the target. Non-sputtered regions inside
`the individual racetracks are eliminated by the simulta-
`neous sweeping of all magnetron discharges along the
`longer axis of the target, which is achieved by moving
`the magnetic means behind the target. All specimens
`were cleaned following conventional cleaning process
`prior to deposition. The deposition process was per-
`formed in the following steps: (1) radiation heating; (2)
`DC glow discharge cleaning in an Ar atmosphere for 10
`min; (3) sputter deposition of a 0.2 pm Cr interlayer
`film; (4) deposition of CrNx films at various conditions
`listed in Table 1.
`
`Base pressure
`Ar pressure
`Target power density
`Distance between target and
`substrate
`
`Temperature
`N2 flow rate
`Substrate bias (pulsed DC)
`Voltage (V)
`Duty cycle (%)
`Frequency (kHz)
`
`3 X 10—5 torr
`1.8 X 10_3 torr
`13 i 1 W/cm2 (DC)
`80 mm
`
`400 i 10°C
`0 ~ 45 sccm
`
`— 50, — 100, — 200
`50, 70, 100
`5, 10, 20
`
`tional morphologies were investigated and the deposi-
`tion rate of coated samples was calculated. Micro
`Knoop hardness was measured at a normal load of
`0.025 N. The adhesion strength was compared by
`observing the propensity for cracks and the degree of
`delamination near the indentation periphery using an
`optical microscope after Rockwell C indentation test.
`
`3. Results and discussion
`
`3.1. Influence of N2 flow rate
`
`2.2. Evaluation offilms
`
`For the evaluation of phase and texture formation
`for CrNx films XRD analyses were performed with an
`incident angle of 3°. By using SEM fracture cross-sec-
`
`Fig. 1 shows XRD patterns of CrNx fihns deposited
`on Si wafer with various N2 flow rates at a negative DC
`bias of — 100 V. At a N2 flow rate of 20 sccm, a mixed
`phase containing Cr(110), CrN(200) and Cr2N(111) was
`observed. As N2 flow rate is further increased upon
`
`CrN(200)
`
`Cr2N(002)
`\
`CrN(111)
`\: 3
`
`5.35‘
`
`C'(2.°°)9'2N‘3°°)
`
`
`””922?
`
` |ntensity(arb.
`unit)
`
`Cr(211)
`
`a)
`
`Cr(110)
`
`30
`
`40
`
`50
`
`60
`
`70
`
`80
`
`90
`
`2 theta
`
`Fig. 1. XRD patterns of CrNI fihns deposited on Si wafer with various N2 flow rates. (a) 0 seem, (b) 20 sccm, (c) 30 sccm, (d) 40 sccrn and (e) 45
`$0011].
`
`Ex. 1031, Page 2
`Ex. 1031, Page 2
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`224
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`K.H. Nam et aL / Sun‘ace and Coatings Technology 131 (2000) 222—227
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`
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`(a) Deposition rate I 236nm/min
`
`(b) Deposition rate I 204nm/min
`
`11’
`i
`
`,
`
`CV'VV‘
`r
`
`.. w. x.
`.
`
`,
`
`(‘
`
`9‘
`
`E-
`
`f 3.“ 13"»
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`
`(
`
`.
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`(c) Deposition rate I 206nm/min
`
`(d) Deposition rate I 165nm/min
`
`
`
`(e) Deposition rate I 181nm/min
`
`Fig. 2. Cross-sectional scanning electron micrographs of CrNJr films deposited on Si wafer with various N2 flow rates. (a) 0 seem, (b) 20 sccm, (c)
`30 sccm, (d) 40 seem and (e) 45 sccm.
`
`deposition, CrNx films tend to change from the hexago-
`nal Cr2N phase to the cubic CrN phase. The CrNx film
`deposited with N2 flow rate of 30 sccm was formed
`mostly with Cer mono-phase and then transformed to
`
`CrN mono-phase with a further increase of the N2 flow
`to 45 sccm.
`The SEM micrographs of fractured cross-sections of
`the films are illustrated in Fig. 2. It shows that the
`
`Ex. 1031, Page 3
`Ex. 1031, Page 3
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`2500
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`K.H. Nam et al. / Sun‘ace and Coatings Technology 131 (2000) 222—227
`
`225
`
`2000
`
`1500
`
`1000
`
`500
`
`I.
`
`Cr ----- Chi-CrNx
`
`Cer-m Cr2N+CrN
`
`CrN
`
`MicroKnoopHardness(kg/mm2)
`
`
`
`0
`
`20
`
`30
`
`40
`
`45
`
`in terms of the German short form of adhesion strength
`[13,14].
`
`3.2. Influence of substrate bias
`
`For the understanding of substrate bias effect influ-
`enced CrNx film properties CrNx films were deposited
`with various substrate bias voltage, duty cycle and
`frequency using pulsed DC power supply at constant
`N2 flow rate of 40 sccm. Table 2 illustrates sample
`name and summary of the substrate bias effect on the
`deposition rate, microhardness and adhesion strength
`of CrNx films. Moreover, the microstructure of each
`coated sample was identified in Fig. 4 by XRD analy-
`ses. The microstructure of CrN, film deposited with a
`negative DC bias voltage of —100 V (CrN-2) was
`defined to be Cr2N + CrN multi-phase. However, this
`multi-phase was changed to Cer mono-phase(CrN—1,
`3) when the substrate bias voltage was varied. Also, the
`variation of pulse frequency at a duty cycle of 70% led
`to the phase transformation from Cr2N mono-phase
`(CrN-5) to Cr2N+ CrN multi-phase (CrN-4, 6), and
`then Cr2N mono-phase (CrN-5) was changed to Cer
`+ CrN multi-phase (CrN-7) with the decrease of duty
`cycle at the same frequency. These phase transforma-
`tions with the change of substrate bias is due to nearly
`equal energy of formation between Cr2N (—122.88
`kJ/mol) and CrN (—123.98 kJ/mol) at 400°C with
`constant N2 partial pressure [10]. Two different phases,
`CrN and Cer, which have very closed value of free
`energy of formation have almost same probability to
`nucleate and grow. Thus, these two phases might inde-
`pendently nucleate depending on the adatom energy
`state which is strongly influenced by substrate bias
`when other deposition parameters such as power den-
`sity of target, substrate temperature and N2 flow rate
`were the same.
`
`At a negative bias voltage with sufficient duty cycle
`and frequency (CrN-5, 6), respectively, the deposition
`rate was increased. It is estimated that the ionization
`
`N2 flow rate
`
`Fig. 3. Microhardness changes of CrNx films measured at normal
`load of 0.025 N for various N2 flow rates.
`
`increasing of N2 flow rate leads to an increase of film
`density and the decrease of its deposition rate from 236
`to 165nm/min except for CrNx film deposited with a
`N2 flow rate of 45 sccm. This reduction of deposition
`rate is due to the formation of chromium nitride at the
`
`target surface, the so called ‘poisoning effect’ [4,5].
`Fig. 3 illustrates the microhardness of CrNx films
`deposited with various N2 flow rates. The maximum
`hardness value of 2250 kg/mm2 was obtained for CrN,
`film deposited with a N2 flow rate of 20 sccm while
`further increase of the N2 flow rate up to 45 sccm
`tended to reduce the hardness
`in the range of
`1800-2000 kg/mmz. These results are somewhat dif-
`ferent from other reports in which the maximum hard-
`ness value was obtained for CrZN mono-phase [10,11].
`It is estimated that the mixing effect [12] between Cr,
`Cr2N and CrN plays a role to improve hardness of
`CrNx film deposited with N2 flow rate of 20 sccm. And
`also the reason why the similar hardness value was
`obtained for Cr2N film deposited with N2 flow rate of
`30 sccm compared with CrN films is predicted that this
`film was consist of not only Cer phases but also CrN
`phases as shown in Fig. 1.
`After results of Rockwell C indentation adhesion
`
`tests, all CrNx films deposited with various N2 flow
`rates persisted in fairly good adhesion with a little
`crack and delamination corresponding to HF1 ~ HF3
`
`efficiency was increased by repetitive impact and stag-
`nation between adatoms caused by a negative pulsed
`DC bias [15]. The maximum deposition rate of 210
`
`Table 2
`
`Sample identification and summary of the substrate bias effect
`
`Sample
`
`CrN-1
`CrN-2
`CrN-3
`CrN-4
`CrN-5
`CrN-6
`CrN-7
`
`Duty
`cycle (%)
`
`Frequency
`(kHz)
`
`Bias
`voltage (V)
`
`100
`100
`100
`70
`70
`70
`50
`
`—
`—
`—
`5
`10
`20
`10
`
`— 50
`— 100
`— 200
`— 100
`— 100
`— 100
`— 100
`
`Deposition
`rate (nm/min)
`174
`165
`194
`162
`210
`180
`163
`
`Microhardness
`(kg/mmz)
`1631
`1930
`2099
`2044
`2037
`2063
`1599
`
`Adhesion
`strength
`HF3 ~ 4
`HF1 ~ 2
`HF1 ~ 2
`HF2 ~ 3
`HF1 ~ 2
`HF1 ~ 2
`HF3 ~ 4
`
`Ex. 1031, Page 4
`Ex. 1031, Page 4
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`226
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`K.H. Nam et aL / Sun‘ace and Coatings Technology 131 (2000) 222—227
`
`CHNU‘IK: ; CrN(200)
`Cr2N(002)
`
`Sfii
`
`CENPOO) eer:(113) CrZEN(302)
`
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`3
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`to
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`C(
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`:I:
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`mC(
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` 30
`
`Cr2N(‘l11)
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`c N(002)\- ./
`ES
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`
`(b)
`
`Si
`:
`5
`a
`
`Cr2N(30°)
`i
`5
`2
`
`Cr1N(302)
`1
`5
`i E
`
`
`
`
`40
`
`50
`
`60
`
`70
`
`80
`
`90
`
`2 theta
`
`Fig. 4. XRD patterns of CrNJr films deposited on Si wafer at N2 flow rate of 40 sccm with (a) various substrate bias voltages and (b) various
`substrate bias duty cycles and frequencies.
`
`nm/min was obtained for CrN-S, which is 89% com-
`pared with the deposition rate of pure Cr coating under
`the same conditions except for a negative-pulsed DC
`duty cycle.
`The microhardness of CrNx films were measured to
`be similar values independent of the microstructure
`except for CrN-l and CrN-7 which were deposited with
`low bias voltage or duty cycle. It has been reported
`[16,17] that the low bias voltage or duty cycle leads to a
`decrease of microhardness of films due to decreasing
`adatom mobility. After results of adhesion tests by
`Rockwell C indentation, CrN-1 and CrN-7 were proved
`
`to be HF?) ~ 4 while other films have a good adhesion
`strength corresponding to HF1 ~ 3. The low adhesion
`of CrN-l and CrN-7 is understood by the decrease of
`ion bombardment caused by low adatom mobility dur-
`ing processes.
`
`4. Summary
`
`The high rate deposition of CrNx films was carried
`out by magnetron sputtering with controlled micro-
`
`Ex. 1031, Page 5
`Ex. 1031, Page 5
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`K.H. Nam et al. / Sun‘ace and Coatings Technology 131 (2000) 222-227
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`227
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`structure. In this study, the following results have been
`obtained:
`
`the present study by the Ministry of Commerce, Indus-
`try and Energy of Korea.
`
`1. The maximum deposition rate for CrNx compound
`films was reached to 89% compared with that for
`pure Cr coating due to the increase of ionization
`efficwecy caused by a “game pulsed DC blas'
`2- The mICTOSthture 0f CrNx films 0011101 be success'
`fully controlled with by variation of the negative
`bias voltage, duty ratio and frequency as well as the
`N2 flow rate.
`3. Microhardness for CrNx fihns were measured to be
`more than two times of that for Cr coating and the
`-
`2
`malenum hardness value Of_ 2250. kg/m was
`obtained for CrNx film depos1ted w1th the N2 flow
`rate of 20 sccm at a negative DC bias of — 100 V.
`
`Aeknefledgements
`
`The authors are grateful for the financial support of
`
`References
`
`[1] B. Schultrich, P. Siemroth, Surf. Coat. Technol. 93 (1997) 64.
`[2] P. Siemroth, T. Witke, Surf. Coat. Technol. 68/69 (1994) 314.
`[3]
`J. Musil, A. Rajsky, J. Vac. Sci. Technol. A 14 (1996) 2187.
`[4] MS. Wong, W.J. Chia, Surf. Coat. Technol. 86/87 (1996) 381.
`[5] P. Yashar, J. Rechner, Surf. Coat. Technol. 94/95 (1997) 333.
`[6] C. Meunier, G. Bertrand, Surf. Coat. Technol. 107 (1998) 149.
`[7] C. Gautier, J. Machet, Surf. Coat. Technol. 86/87 (1996) 254.
`[8] SJ. Bull, D.S. Rickerby, Surf. Coat. Technol. 43/44 (1990) 732.
`[9]
`J.P. Terrat, A. Gaucher, Surf. Coat. Technol. 45 (1991) 59.
`[10] M. Pakala, R.Y. Lin, Surf. Coat. Technol. 81 (1996) 233.
`[11] P. Hones, R. Sanjines, Surf. Coat. Technol. 94/95 (1997) 398.
`[12]
`J. MuSil, J. Vlcek, Czech. J. Phys. 48 (1998) 10.
`[13] R. Bantle, A. Matthew, Surf. Coat. Technol. 74/75 (1995) 857.
`[14] W. Heinke, A. Matthew, Thin Solid Films 270 (1995) 431.
`[15] KT. Rie, F. Schnatbaum, Mater. Sci. Eng. A 160 (1991) 448.
`[16] o. Piot, J. Machet, Surf. Coat. Technol. 94/95 (1997) 409.
`[17] E. Lugscheider, O. Knotek, Surf. Coat. Technol. 76/77 (1995)
`705.
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`Ex. 1031, Page 6
`Ex. 1031, Page 6
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