不同磁控溅射方式制备的C掺杂h-BN薄膜微观结构与导电性研究

采用中频双极脉冲(IFBP)和射频(RF)磁控溅射分别在(100)取向的单晶Si衬底上沉积C掺杂h-BN(h-BN∶C)薄膜,随后在95%Ar+5%H2混合气氛中进行700℃退火处理,对其结构、化学组成、元素的化学价态、表面形貌以及导电性进行了分析研究。结果表明:两种溅射方法均成功在Si基片上制备出致密连续的h-BN∶C薄膜,其电阻率可低至2.9×10^4~2.5×10^5Ω·cm。对比发现两种制备方法中IFBP磁控溅射具有较快沉积速率,制备出的h-BN∶C薄膜结构更稳定,结晶性更好;而RF磁控溅射制备的h-BN∶C薄膜经700℃退火处理后形成了层状结构。在溅射气氛中掺入一定量H2对提高h-BN∶C薄膜稳定性极为重要,而沉积后的低温退火处理更可提高其结晶性和稳定性。

Microstructure and Conductivity of the C Doped h-BN Thin Films Prepared by Different Magnetron Sputtering Methods

The C doped h-BN (h-BN∶C) films were deposited on (100) Silicon substrate through intermediate frequency bipolar pulsed (IFBP) and radio frequency (RF) magnetron sputtering methods at the ambient temperature,followed by annealing at 700 ℃ in a mixture of 95% argon and 5% hydrogen. The microstructure,elemental composition and chemical valence,surface morphology and conductivity of the h-BN∶ C films were studied. The results show that the h-BN∶ C films with compact and uniform grains are successfully prepared by both two methods,while their resistivity is decreased to about 2.9×10^4~2.5×10^5 Ω·cm. It is found that the IFBP magnetron sputtering has faster deposition rate compared to RF magnetron sputtering,and the h-BN∶ C films prepared by this method possess good crystallinity and stability. After annealing at 700 ℃ for about 45 min,the morphology of the h-BN∶ C film prepared by RF magnetron sputtering is changed to layered structure. What’s more,adding a certain amount of H2 in the sputtering gas media is very important for improving the stability of the h-BN∶ C films. The crystallinity and stability of the films could be improved by annealing treatment with low temperature.