HWP-CVD氮化硅薄膜的结构和光学特性

Microstructure and Optical Properties of Hydrogenated Amorphous Silicon Nitride Films Deposited by Helicon Wave Plasma Enhanced Chemical Vapor Deposition

采用傅立叶红外吸收谱和紫外-可见透射谱研究了螺旋波等离子体增强化学气相沉积法制备的氢化非晶氮化硅薄膜的原子间键合结构和光学特性。结果表明,在不同硅、氮活性气体配比冗下,薄膜表现出不同的Si/N比和H原子键合方式,富氮样品中H原子主要和N原子结合,而富硅样品中主要和Si原子结合。随着R的增加,薄膜的光学带隙Eg和E04逐渐减小,此结果关联于薄膜结构无序性程度的增加,而薄膜的(E04-Eg)和Tauc斜率B值之间存在着相互制约关系。

The atomic configurations and optical properties of hydrogenated amorphous silicon nitride (alpha-SiNx:H) films deposited by helicon wave plasma enhanced chemical vapor deposition (HWP-CVD) were analyzed by using Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-VIS) spectroscopy. The results reveal that the films show different Si/N ratio and hydrogen bonding mode at the various ratio between the silicon and nitrogen containing gases (R), For nitride-rich samples, hydrogen has a chemical preference to bind to nitride. On the other hand, for silicon-rich samples, hydrogen atoms bind preferentially to silicon. The optical band gap, E-g and E-04 of a-SiNx:H films decrease gradually with the increase of R, which is attributed to the increase of disorder degree of the a-SiNx:H film microstructure. Additionally, the correlation between (E-04-E-g) and the slop of Tauc plot, B for the a-SiNx:H films is established.