热原子层沉积技术制备TiAlCN薄膜的特性

Properties of TiAlCN Thin Films Grown by Thermal Atomic Layer Deposition Technique

在Si和SiO_2基底上,采用热原子层沉积技术,以四(二甲基氨基)钛(Ti(N(CH_3)_2)_4)和三甲基铝(Al(CH_3)_3)为前驱体,制备TiAlCN薄膜。测试结果表明,随着基底温度的升高,膜层的沉积速率升高,电阻率降低,光学带隙由3.45 eV降低到2.00 e V,并在基底温度为300和350℃时出现了双吸收边;基底温度为350℃时,Al(CH_3)_3分解,使Al进入膜层与TiN和TiC形成TiAl N和TiAlC;膜层中TiN和TiC的形成,可以有效抑制膜层的自然氧化;基底温度为250和300℃时,薄膜为无定型结构,当基底温度为350℃时,有TiN晶体产生;膜层的表面粗糙度随着基底温度的升高先降低后升高,表面粗糙度的升高可能是因为在基底温度为350℃时前驱体材料的分解,使C—H键进入膜层所导致的。

The TiAl CN thin films were deposited on Si and SiO2 substrates by thermal atomic layer deposition technique using Ti（N（CH3）2）4 and Al（CH3）3 as the precursors.The testing results show that the deposition rate of thin films increases but the resistivity decreases with the increase of the substrate temperature.Optical band gap value decreases from 3.45 eV to 2.00 eV,and two absorption edges appear in the spectrum when the substrate temperature are 300 ℃ and 350 ℃.Al from decomposed Al（CH3）3 is doped into TiN and TiC and forms TiAlN and TiAl C at the substrate temperature of350 ℃.The formation of TiN and TiC in the film layer can suppress the autoxidation of thin films effectively.The films are amorphous at the substrate temperature of 250 ℃ and 300 ℃,and the TiN crystal forms at the substrate temperature of 350 ℃.The surface roughness decreases firstly and then increases with the increase of the substrate temperature.The increase of surface roughness may be due to the incorporation of C—H bond from the decomposition of precursor materials into the film layer at the substrate temperature of 350 ℃.