Effects of W Content on Structural and Mechanical Properties of TaWN Films
Round 1
Reviewer 1 Report
The introduced manuscript under the title of “Effects of W content on Structural and mechanical properties of TaWNx films” shows the Effects of W content on Structural and Mechanical Properties of TaWNx films. The films were co-sputtered on Si substrates as a protective hard coating. Structural, mechanical, and tribological properties of deposited TaWNx films are discussed.
Publication of this paper may be suitable because of the importance of TaWNx coating for industrial need. Mechanical testing and structural investigation well covered the manuscript.
The following suggestions to the authors may be proposed to improve the paper:
- The vertical lines in Figure 4 should be adjusted at the peak centers.
- The detected peaks in Figure 4 should be enlarged, especially in the vertical direction to be easily noticed.
Comments for author File: 
Comments.pdf
Author Response
1. The vertical lines in Figure 4 should be adjusted at the peak centers.
A: “The vertical lines in Figure 4 indicate the standard positions of reflections for TaN and W2N phases.” was added in lines 208–209. These vertical lines indicated the peak shifts for these TaWN films. Similar illustration was shown in the figure caption (Lines 229 and 230).
2. The detected peaks in Figure 4 should be enlarged, especially in the vertical direction to be easily noticed.
A: The reflections with low intensity were visible in this version. Figure 5 illustrates the lattice constants of the TaWN films determined using reflections shown in Figure 4.
Reviewer 2 Report
The paper presents new results for deposition of TaWNx films. The following points should be considered prior to publication.
Why are the films assigned as TaWNx. According to results, the Ta/W ratio differs from 1. Hence, some suffix should be attached to either Ta or W or both, e.g., TaxWyNz. or as in line 133
Line 78: After “pumping” the chamber
line 100/102: lattice constants a0 respectively a. What is a0 and what is a?
line 117: why SiO2? how long is the etching time?
Line 168: “d-spacing” ?
Line 232: how large is the employed doublet splitting. What kind of peak shapes (Gaussian, Lorentzian) have been employed?
Table 2: I expect to find here the extracted nitrogen-to-metal ratio.
Author Response
Why are the films assigned as TaWNx. According to results, the Ta/W ratio differs from 1. Hence, some suffix should be attached to either Ta or W or both, e.g., TaxWyNz. or as in line 133
A: Thanks for the comment. “TaWNx” was revised as “TaWN”. The specific samples were labelled as TayWzN(100-y-z).
Line 78: After “pumping” the chamber
A: This was corrected in line 81.
line 100/102: lattice constants a0 respectively a. What is a0 and what is a?
A: Thanks for the reminding. “where É‘ is the lattice constant for the distinct reflection, …” was revised in line 108.
line 117: why SiO2? how long is the etching time?
A: The sentences were revised as “An Ar+ ion beam of 3 keV was used to sputter the coatings for depth profiling, which sputter etching rate was 8.3 nm/min for SiO2. XPS analyses were conducted at depths of 16.6, 24.9, 33.2, 41.5, and 49.8 nm after the samples were etched for 2, 3, 4, 5, and 6 min, respectively.” in lines 126–130.
Line 168: “d-spacing” ?
A: “d-spacings” was correct in line 181.
Line 232: how large is the employed doublet splitting. What kind of peak shapes (Gaussian, Lorentzian) have been employed?
A: New sentences “ The splitting energies were 1.91 and 2.18 eV for Ta 4f and W 4f doublets [37], respectively. The peaks were fitted with a mixed Gaussian–Lorentzain function.” were added in lines 125 and 126.
Table 2: I expect to find here the extracted nitrogen-to-metal ratio.
A: The N/M ratios of TaWN films were added in Table 1.
Reviewer 3 Report
Dear authors,
the paper is very interesting and fits well Coatings subject areas.
Let me propose some suggestions that can improve it.
1) Line 77: Please describe what was the purpose of the coated samples on Si
2) Line 77: Please add table with composition and hardness of the SUS420 substrate.
3) Line 110: Please add information about X-ray source: characteristic line, its energy, monochromatic or not, half-width measured on Au 4f line.
4) Line 117: Please add physical conditions of the sputtering process: kind of ions, pressure, accelerating voltage, beam current.
5) Line 121: "radius of which was 200 nm in diameter". Please correct this sentence: I suppose that you mean the rounding radius of the indenter.
6) Line 123: "an indentation of 70 nm" Was it really a constant penetration depth not a constant load in your experiments?
7) Please add method and device for roughness measurements to Methods section.
8) Please explain in the text meaning of Pt on Figs. 2a and 3a.
9) Line 252: It would be very good to add corresponding binding energies for pure Ta and W to Table 2 and mark these binding energies on spectra Fig. 6.
Author Response
1) Line 77: Please describe what was the purpose of the coated samples on Si
A: The sentences in lines 82–84 was revised as “The samples prepared on SUS420 plates were used for the wear test, whereas the samples on Si substrates were used for all the other tests.”
2) Line 77: Please add table with composition and hardness of the SUS420 substrate.
A: New sentences “The chemical composition of the SUS420 plates is Fe-13% Cr-0.33% C-1% Si-1% Mn in wt.% [33]. The hardness of tempered SUS420 was HRC 50.” were added in lines 79–81.
3) Line 110: Please add information about X-ray source: characteristic line, its energy, monochromatic or not, half-width measured on Au 4f line.
A: The sentence was revised as “… with a monochromatic Al Kα X-ray beam (energy = 1486.6 eV and power = 44.5 W) operated at 15 kV.” in lines 118–119.
4) Line 117: Please add physical conditions of the sputtering process: kind of ions, pressure, accelerating voltage, beam current.
A: The sentence was revised as “An Ar+ ion beam of 3 keV was used to sputter the coatings for depth profiling, which sputter etching rate was 8.3 nm/min for SiO2.” in lines 126–128.
5) Line 121: "radius of which was 200 nm in diameter". Please correct this sentence: I suppose that you mean the rounding radius of the indenter.
A: Thanks for the suggestion. This sentence was revised as “ …, the rounding radius of the indenter was 200 nm in diameter.” in line 133.
6) Line 123: "an indentation of 70 nm" Was it really a constant penetration depth not a constant load in your experiments?
A: Yes, this sentence was revised as “ …, their mechanical properties were evaluated in a constant penetration depth mode with an indentation of 70 nm.” in lines 135 and 136.
7) Please add method and device for roughness measurements to Methods section.
A: New sentences “The Ra values were determined by using an atomic force microscope (AFM, Dimension 3100 SPM, Nanoscope IIIa, Veeco, Santa Barbara, CA, USA). The scanning area of each image was 5 × 5 μm2 with a scanning rate of 1.0 Hz.” were added in lines 85–88.
8) Please explain in the text meaning of Pt on Figs. 2a and 3a.
A: The sentence in lines 102–104 was revised as “The TEM samples with a protective Pt layer were prepared using a focused ion beam system (NX2000, Hitachi, Tokyo, Japan).”
9) Line 252: It would be very good to add corresponding binding energies for pure Ta and W to Table 2 and mark these binding energies on spectra Fig. 6.
A: “The splitting energies were 1.91 and 2.18 eV for Ta 4f and W 4f doublets [37], respectively.” was added in lines 125 and 126.
“The 4f7/2 levels for pure Ta and W were 21.9 and 31.4 eV [37], respectively, and the standard values for 4f doublets were marked in Figure 6 for comparison.” was added in line 246–248.
