A.E. Anurov, A.A. Danilov, A.A. Zhukov
Currently, an actual problem is to develop low temperature methods of dielectric material fabrication in particular high quality thin films for different applications. Synthesis high temperatures of the said layers (films) lead to formation and development of structural defects and impurity redistribution in semiconductor material structures that inevitably reduce product yield. In this case, fabrication installations are widely-distributed that use low temperature PE CVD (plasma enhanced chemical vapor deposition) allowing dielectric nano-thick films to be obtained of rather high quality.
The aim of this work was to study and optimize the fabrication PE CVD method of silicon nitride in particular nano-thick films of high quality for different applications and to estimate the influence of the main characteristics of the fabrication method on the obtained films quality. Silicon nitride nano-thick films on a silicon substrate and silicon nitride cantilevers with different dimensions on polyimide layer served as objects of study. The obtained silicon nitride film quality is controlled by several methods: spectral ellipsometry to measure thickness and refraction, time measuring of liquid etching process to determine the film density, semiconductor device measurement techniques to control the disruption voltage and porosity, optical microscopy to control the internal stress. A method using enhanced plasma is presented of silicon nitride film processing allowing the following characteristics to be obtained: disruption voltage of 200 nm silicon nitride film is approximately 200 V, refraction 1,74 that is consistent with properties of films manufactured by high temperature methods. The obtained results allow to automate silicon nitride film forming process for functional purposes of required quality