**2. Growth of thin films using DC reactive magnetron sputtering technique**

Most publication about nanocomposite films has shown that the DC reactive magnetron cosputtering technique is the most used to deposit these materials (see **Table 1**), and they have reported that the formation and microstructure of the films are determined by the deposition parameters, such as applied power at the target, working pressure, bias voltage, and deposition temperature (see **Table 2**).

In a sputtering process, the surface target is hitting with ions produced by an electric discharge, which form plasma. Normally, no reactive gas (Argon-Ar) is used to form the plasma. The interaction of these ions with the surface of the target causes the atoms on the surface to be ripped off through a moment exchange between ions and atoms of the target [4, 77, 79]. These sputtered atoms must transit from target to the substrate surface. During this displacement, the sputtered atoms experience many collisions with the particles that are in this region (sputtered atoms or Ar atoms or reactive atoms in the case of a reactive gas). These collisions change the velocity, direction, and the energy of the sputtered atoms. Therefore, the number of atoms that reach to the substrate surface will depend on the working pressure and the target-substrate distance. Moreover, the formation of the film is related with the condensing energy of the atoms (adatoms) on the surface of the substrate. Different works have found that amorphous films are formed when the adatoms have low energy of diffuse on the surface that does not allow that they may find low energy sites for the nucleation; while, a crystalline structure may be formed when the adatoms have a high surface mobility [8, 15, 80–88]. However, several works have found that when the growing films are exposed to bombardment


*RT and NM are used to room temperature and when the variable is not mentioned, respectively.*

*a Temperature.*

*b Gas type and flux.*

*c First target power.*

*d Second target power.*

*e Working pressure f*

*Direct current. g Radio frequency.*

#### **Table 2.**

*Deposition parameters for different nanocomposite films obtained by reactive magnetron sputtering.*

of high-energy particle, the structure and properties of deposited films can be improved. This can be achieved by applying a negative voltage called bias to the surface substrate [18, 81, 89]. These high-energy particles can improve the diffusion of the adatoms on the substrate surface. Another way to improve adatoms mobility is by increasing the temperature of the substrate [15, 83, 85]. Therefore, in the deposition of thin films, it is important to be able to find the deposition parameters to determine and understand their physical and chemical properties.

Finally, the composition of the target is another parameter that will affect the characteristics of the films. It has been shown that the addition of silicon to transition metal nitride can affect the structure and properties of the films; due to that the addition of the silicon atoms can block the surface mobility of the adatoms of the metal or the transition metal nitride [28, 51, 57, 63, 90]. Therefore, as the amount of silicon is increased, the structure of the film is changed from a polycrystalline, nanocrystalline to amorphous.

Zirconium nitride with silicon films was deposited via DC reactive magnetron sputtering technique. Only one zirconium target was used with silicon pellets on the target surface to tailor the Si content in the Zr▬Si▬N films. The deposition parameters used are shown in **Table 3**. This sputtering method has been used for depositing different nanocomposite films such as: Ti▬Si▬N [91], W▬Si▬N [72], Zr▬Si▬N [92], Al▬Si▬N [93], and Nb▬Si▬N [71].

**27**

for the ZrN + 2Si film.

**Table 3.**

*Effect of Silicon Content in Functional Properties of Thin Films*

**Deposition parameters Value** Target of sputter Zr (99.99%) Reactive gas Nitrogen Target diameter (cm) 5 Distance target-substrate (cm) 5 Base pressure (Pa) 4 × 10<sup>−</sup><sup>4</sup> Working pressure (Pa) 8 × 10<sup>−</sup><sup>1</sup> Temperature (°C) 200 Voltage of bias (V) 0 Applied power (W) 140 Number of Si pellets 0, 1, 2 Deposition time (s) 3600

The zirconium nitride and silicon nitride were obtained by adding of nitrogen as reactive gas to the deposition chamber. Three series of samples were deposited with different numbers of silicon pellets (X), ZrN + XSi, where X = 0, 1, and 2. Finally, thicknesses of the deposited film were obtained from the cross-sectional scanning electronic microscope images, which are not included in this chapter. These images showed that the thicknesses of the films were 823±2, 955 ±8, and 1060 ±6 nm for ZrN, ZrN + 1Si, and ZrN + 2Si, respectively. The results of the chemical and structural characterization and

the study of the functional properties are shown in the following subsections.

*Deposition parameters used to deposit ZrN*-*Si films via DC reactive magnetron sputtering.*

**3. Chemical characterization by means of spectroscopy of the X-ray dispersive (EDX) and spectroscopy of photoelectrons (XPS)**

In the sputtering technique, the elements of target are transferred to the substrate surface; this is verified with EDX analysis. **Figure 1a** shows the EDX spectrum

The EDX spectrum evidences the presence of zirconium, nitrogen, and silicon in the film. The elemental chemical composition of the deposited films is listed in **Table 4**. **Figure 1b** shows the variation of the zirconium content with the increase of the silicon content in the films. As silicon content increases, the Zr content decreases in the films due to the reduction of the effective sputtering area of the Zr target with the Si pellets. These results are similar to those published by other authors using the same sputtering configuration [59, 62, 92]. The EDX results also showed that with one Si

It has been found that when the solubility limit of Si in MeN lattice is exceeded, the Si atoms form a Si3N4 phase [94]. The formation of Si3N4 phase into MeN grain boundaries is typical for the Me▬Si▬N systems [17, 19, 25, 41, 71, 73]. Therefore, in our case, a chemical analysis for XPS of the ZrN▬Si deposited films with different Si contents was carried out to show the formation of the Si3N4 phase with the Si addition. **Figure 2** shows the high-resolution XPS spectrum for the MeN films. The XPS results of Zr 3d peaks (**Figure 2a**) showed the presence of Zr▬N bond with a binding energy of 179.6 eV [95], and the Si 2p peaks (**Figure 2b**) showed the presence of Si-N bond to 100.8 eV [24] on the film surface. Additionally, the results

pellet, the Si content was of 8 at.% and with two pellets was of 15 at.%.

*DOI: http://dx.doi.org/10.5772/intechopen.85435*

*The Ar/N2 flow ratio was optimized to obtain ZrN films.*



#### **Table 3.**

*Silicon Materials*

**Nanocomposite T<sup>a</sup>**

ZrSiN [17, 33, 39] RT

AlSiN [19, 47] 400

200 500 900

500

TiSiN [41] 200 Ti (1)

CrSiN [75] NM Cr (1)

TiAlSiCuN [65] RT TiAlSi alloy

CrZrSiN [37] 120 CrZrSi

CrTaSiN [36] NM Cr (1)

 **(C) Target Gasb**

Zr (1) Si (2) Zr + Si pellets

Si (2)

Al-Si alloy Al-Si

Si (2)

Cu (2)

segment

Ta (2) Si (3)

*RT and NM are used to room temperature and when the variable is not mentioned, respectively.*

**(sccm)**

Ar:19 N2:2 Ar + N2 Ar:8 N2:4

Ar + N2 Ti:

Ar + N2 TiAlSi:

WSiN [49, 72] 500 WSi2 alloy Ar + N2 NM 0 0.05–0.5 100 TaSiN [50] 500 TaSi2 alloy Ar + N2 NM 0 5 × 10<sup>−</sup><sup>1</sup> 50

> Ar: 12 N2: 8

**Powerc (W)**

Zr: 120–150f

300–500f

537.5

**Powerd (W)**

Si: 0–250g

Si: 50–150g

Ar + N2 75 0 1 NM

Ar + N2 Cr: 20 cm<sup>−</sup><sup>2</sup> NM NM 100

Ar + N2 0.7 kg 0 5 × 10<sup>−</sup><sup>1</sup> NM

Si: 150f

Cr: 150g Ta: 100f

Cu: 0–21.25 **W.P<sup>e</sup>**

4 × 10<sup>−</sup><sup>1</sup> 2.7 × 10<sup>−</sup><sup>1</sup>

 **(Pa) Bias (V)**

0.9–1.2 25

6 × 10<sup>−</sup><sup>1</sup> NM

4 × 10<sup>−</sup><sup>1</sup> NM

0–100

**26**

*a*

*b*

*c*

*d*

*e*

*f*

*g*

**Table 2.**

*Temperature.*

*Gas type and flux.*

*First target power.*

*Working pressure*

*Radio frequency.*

*Direct current.*

*Second target power.*

of high-energy particle, the structure and properties of deposited films can be improved. This can be achieved by applying a negative voltage called bias to the surface substrate [18, 81, 89]. These high-energy particles can improve the diffusion of the adatoms on the substrate surface. Another way to improve adatoms mobility is by increasing the temperature of the substrate [15, 83, 85]. Therefore, in the deposition of thin films, it is important to be able to find the deposition parameters

*Deposition parameters for different nanocomposite films obtained by reactive magnetron sputtering.*

Finally, the composition of the target is another parameter that will affect the characteristics of the films. It has been shown that the addition of silicon to transition metal nitride can affect the structure and properties of the films; due to that the addition of the silicon atoms can block the surface mobility of the adatoms of the metal or the transition metal nitride [28, 51, 57, 63, 90]. Therefore, as the amount of silicon is increased, the structure of the film is changed from a polycrys-

Zirconium nitride with silicon films was deposited via DC reactive magnetron sputtering technique. Only one zirconium target was used with silicon pellets on the target surface to tailor the Si content in the Zr▬Si▬N films. The deposition parameters used are shown in **Table 3**. This sputtering method has been used for depositing different nanocomposite films such as: Ti▬Si▬N [91], W▬Si▬N [72],

to determine and understand their physical and chemical properties.

talline, nanocrystalline to amorphous.

Zr▬Si▬N [92], Al▬Si▬N [93], and Nb▬Si▬N [71].

*Deposition parameters used to deposit ZrN*-*Si films via DC reactive magnetron sputtering.*

The zirconium nitride and silicon nitride were obtained by adding of nitrogen as reactive gas to the deposition chamber. Three series of samples were deposited with different numbers of silicon pellets (X), ZrN + XSi, where X = 0, 1, and 2. Finally, thicknesses of the deposited film were obtained from the cross-sectional scanning electronic microscope images, which are not included in this chapter. These images showed that the thicknesses of the films were 823±2, 955 ±8, and 1060 ±6 nm for ZrN, ZrN + 1Si, and ZrN + 2Si, respectively. The results of the chemical and structural characterization and the study of the functional properties are shown in the following subsections.
