BCN Composited BCN/carbon fibers prepared by RF magnetron sputtering deposition

(1. New Energy Source Institute, Shenyang Institute of Engineering, Shenyang 110136, China;2. School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China)



BCN Composited BCN/carbon fibers prepared by RF magnetron sputtering deposition

(1. New Energy Source Institute, Shenyang Institute of Engineering, Shenyang 110136, China;2. School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China)

In nature, the diamond is the hardest materials, but it is easy to be oxidated in the high temperature, so it can’t be used to make cutting tools under the nature conditions. Cubic boron nitride has many excellent properties, but its internal stress is large, which largely affects its development in the industrial production. People expect to create a new ternary compound boron carbon and nitrogen material, and hope that the compound has the advantages of two substances original without their shortcomings. Boron carbon nitride films were deposited onto silicon substrates by medium frequency magnetron sputtering from graphite and boron targets with Ar and N2as feedstock. By changing sputtering power of graphite target amorphous B-C-N thin films were synthesized on silicon substrate. The chemical bonding states, structure and morphology of B-C-N films were investigated by FTIR, AFM, and XRD analysis.

B-C-N film; magnetron sputtering; substrate; targets

0 Introduction

Since the early eighties, Matsumoto and otherchemists successful synthesis diamond films by vapor deposition (CVD) techniques at low temperature and pressure conditions. The researchers have made great progress on synthetic diamond films in various countries by magnetron sputtering technology. However, due to poor thermal stability of diamond, it will be oxidized when it is heated in air to 600 ℃, and easily reacts with the iron group metals[1]. Thus Diamond role is extremely limited in the processing of the steel material, it is essential that synthetic the new diamond superhard materials close to or above diamond hardness.

Cubic boron nitride (c-BN) molecular structure, physical properties and synthesis methods are all very similar to diamond, its hardness second only to diamond, and its thermal stability and chemical stability are better than diamond, suitable for processing iron group metals. Thus recent c-BN film development is very rapid. Ternary BCN compounds have similar hexagonal and cubic BN structure. Hexagonal BCN (h-BCN) nature is between graphite and hexagonal BN (h-BN), a semiconductor or a semi-metal, and by changing the atomic composition band gap and semiconductor properties can also be adjusted; cubic BCN properties is similar to diamond and cubic BN, but it has better high temperature, oxidation, and chemical inertness than diamond; higher hardness and wear resistance than c-BN, is a new type of super-hard materials[2].

Special electrical, optical, thermal and mechanical properties of BCN material may be used as new high-temperature semiconductors, laser diodes, laser detectors, catalysts, electrode materials, molecular sieves, high-quality cutting tools, wear-resistant materials, corrosion protection layer materials widely. Therefore, the synthesis and characterization of BCN new materials has become one of most active research areasin the world. The researchers choose different materials and used a variety of synthetic methods for preparing BCN compounds of various components and structures.

Magnetron sputtering is one of the physical vapor depositions. Magnetron sputtering introduce magnetic field in the target cathode surface and make use of the magnetic field of a charged particle constraints to enhance plasma density in order to increase the sputtering rate.

1 Experiments

Fig.1 JEPG450 R.f. magnetron sputtering equipment

This experiment equipment is adopted in the experiment by thechinese academy of sciences Shenyang scientific instrument development center Co.,LTD. Production of JEPG450 type high vacuum rf magnetron sputtering. The experiment equipment is mainly composed of vacuum system (sputtering chamber), the cooling system (circulating water), power supply and control system. As can be seen from the Fig.1.

The experiment studiedBCN film structural changes by changing graphite target power. Graphite target power adjustment as shown in Table 1.

Table 1 range of key experimental parameters

2 Results and discussions

Fig.2 XRD spectra of silicon substrate and B-C-N thin films

As can be seen from the Fig.2. The pattern displayed no peaks in addition to the base peak in the range of 2θ(20°～80°), indicating that these BCN films are amorphous, which almost identical results with Xiangyang Chen[3]and all researchers. Some people think that the main reason is low thermally driven energy of atomic nucleation and isolated[4].

2.2 Fourier transform infrared spectroscopy (FTIR) analysis results

Fig.3 IR spectra of B-C-N films synthesized by changing the sputtering powers of graphite targets

IR spectra of B-C-N films synthesized by changing the sputtering powers of graphite targets are shown in Fig.3. When boron target power is 130 W, the graphite target power is 50 W,100 W,150 W respectively. From the FTIR spectra of the samples, there are two obvious absorption peaks at 2 200 cm-1and 1 600 cm-1position. The absorption peaks at around 1 100 cm-1,1 300 cm-1,1 400 cm-1and 1 600 cm-1are attributed to the B-C[5], C-N[6], B-N,C=C and C= N[7], respectively. The broad absorption peaks at 2 200 cm-1can be classified as carbon and nitrogen triple bond. And we can observe that the absorption peak intensity at 2 200 cm-1and 1 600 cm-1position will enhance with increasing graphite target sputtering power. With increasing power of graphite target, it is conducive to the formation of chemical bonds in the film. And three kinds of atoms achieve atomic scale compound.

2.3 Analysis results atomic force microscopy (AFM) analysis results

The AFM images of those samples are shown in Fig.3. In order to further analyze the surface morphology and surface roughness of the sample, we tested films by AFM. Shown in Fig.4, at room temperature graphite sputtering power is 50 W,100 W,150 W, respectively; the scanning area is 2 m×2 m. We can see that with increasing power of graphite target, the surface morphology of the films become more compact and smaller roughness, root mean square (RMS) roughness was 2.89 nm, 2.56 nm, 1.65 nm.

(1)—50 W; (2)—100 W; (3)—150 W respectively.

Fig.5 The surface RMS roughness of films with different graphite sputtering power

The surface RMS roughness of films with different graphite sputtering power are shown in Fig.5. With the increase of sputtering power graphite, carbon atoms energy also increases accordingly, which means carbon atoms have higher kinetic energy. When they get to the substrate, they have a higher surface mobility, which could help increase the membrane surface roughness.

2.4 Steps instrument analysis results

Fig.6 Deposition rate of the B-C-N thin films synthesized by changing the sputtering powers of graphite targets

We take average, each sample tested three times, respectively is 518 nm,632 nm,831 nm. Common sputtering 2 h, so the growth rate is 4.32 nm/min,5.27 nm/min,6.93 nm/min respectively. Deposition rate of the B-C-N thin films synthesized by changing the sputtering powers of graphite targets are shown in Fig.6. With the change of graphite target power, film thickness and deposition rate increase. This is due that with the increase of graphite target power per unit time out of the sputtering target material yield also increased, so the film thickness and deposition rate is increasing trend.

许多客观问题是不可避免的，学生之间存在个体差异这是每位教育工作者都会面临的问题，学生之间的能力差距往往也是培养学生解决问题能力的难点。面对这种情况，教师应该懂得从不同的角度去开导学生，利用层次化教学，实现因材施教。落实到实际教学中，教师应该针对具体知识点从不同角度进行提问，根据学生的实际情况，让学生解决符合自身能力水平的问题，激发学生数学学习的自信，享受解决问题的成就感。如果学生接触不适合自身水平的问题，就可能产生迷茫的心理，不知道接下来所要努力的方向，这对学生的发展是极其不利的。

3 Conclusions

FTIR spectra reveal that all these synthesized B-C-N films are atomic-level hybrids composed of B, C and N atoms, when we use the graphite target as a carbon source. With increasing power of graphite target, it is conducive to the formation of chemical bonds in the film; the surface morphology of the films becomes more compact and smaller roughness.

4 Acknowledgments

This work was supported bythe ministry of education key laboratory under Grant LABKF1406, “Research on properties regulation of InN films grown on free-standing diamond substrates with low temperature ECR-PEMOCVD” and by education department of Liaoning province “Research on properties of InN films grown on free-standing diamond substrates with low temperature ECR-PEMOCVD”.

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1673-5862(2015)03-0333-04

WANGJian1,ZHANGDong1,2,WANGXiaowen1,ZHAOYan1,LIYucai1,WANGGang1,WANGBaoshi1,GUORui1,SONGShiwei1,DINGYanbo1,LIULiying1,WANGHan1

射频磁控溅射沉积系统制备BCN薄膜的研究

王 健1, 张 东1,2, 王晓文1, 赵 琰1, 李昱材1, 王 刚1,王宝石1, 郭 瑞1, 宋世巍1, 丁艳波1, 刘莉莹1, 王 晗1

(1. 沈阳工程学院 新能源学院, 沈阳 110136; 2. 大连理工大学 物理与光电工程学院, 辽宁 大连 116024)

在自然界中,金刚石是最硬的一种材料,但把金刚石高温暴露在空气中时变得容易被氧化,所以在该条件下它不能用来做成切割工具。立方氮化硼有许多优异的特性,但它的内应力比较大,很大程度上影响了它在工业生产上的发展。人们期望能够合成出一种新的三元化合物硼碳氮材料,并且希望这种化合物既具有金刚石和c-BN的优点而且还能克服2种物质原有的缺点。采用射频磁控溅射方法,以石墨靶材和甲烷气体作为碳源,通过调控石墨靶功率在硅基片上沉积非晶B-C-N薄膜。……