高温退火处理下SiNx薄膜组成及键合结构变化

采用等离子增强化学气相沉积法, 以氨气和硅烷为反应气体, p型单晶硅为衬底, 低温下(200 ℃)制备了非化学计量比氮化硅(SiN_x)薄膜. 在N₂氛围中, 于500–1100 ℃范围内对薄膜进行热退火处理. 室温下分别使用Fourier变换红外吸收(FTIR)光谱技术和X射线光电子能谱(XPS)技术测量未退火以及退火处理后SiN_x薄膜的Si–N, Si–H, N–H键键合结构和Si 2p, N 1s电子结合能以及薄膜内N和Si原子含量比值R的变化. 详细讨论了不同温度退火处理下SiN_x薄膜的FTIR和XPS光谱演化同薄膜内Si, N, H原子间键合方式变化之间的关系. 通过分析FTIR和XPS光谱发现退火温度低于800 ℃时, SiN_x薄膜内Si–H和N–H键断裂后主要形成Si–N键; 当退火温度高于800 ℃时薄膜内Si–H和N–H键断裂利于N元素逸出和Si纳米粒子的形成; 当退火温度达到1100 ℃时N₂与SiN_x薄膜产生化学反应导致薄膜内N和Si原子含量比值R增加. 这些结果有助于控制高温下SiN_x薄膜可能产生的化学反应和优化SiN_x薄膜内的Si纳米粒子制备参数.关键词：x薄膜')" href="#">SiN_x薄膜Fourier变换红外吸收光谱X射线光电子能谱键合结构

The variations in composition and bonding configuration of SiNx film under high annealing temperature treatment

Non-stoichiometric silicon nitride（SiN_x） thin films are deposited on p-type crystalline silicon substrates at low temperature （200℃） using ammonia and silane mixtures by plasma enhanced chemical vapor deposition.The evolutions of Si—N,Si—H and N—H bonding configurations,the variations of Si 2p and N 1s electron binding energy and the ratio R of nitrogen to silicon atoms in SiN_x films annealed at temperature in a range of 500—1100℃are investigated at room temperature by Fourier transform infrared spectroscopy（FTIR） and X-ray photoelectron spectroscopy（XPS）,respectively.The relationship between the evolutions of FTIR and XPS spectroscopy of the samples at different annealing temperatures and the variations of bonding configurations of Si,N and H atoms is discussed in detail.According to the arguments about FTIR and XPS spectroscopy we conclude that when the annealing temperature is lower than 800℃,the breakings of Si—H and N—H bonds in the SiN_x films lead mainly to the formation of Si—N bonds;when the annealing temperature is higher than 800℃,the breakings of Si—H and N—H bonds are conducible to the effusion of N atoms and the formation of silicon nanoparticles;when the annealing temperature equals 1100℃,the N₂ react on the SiN_x films to cause the ratio R of nitrogen to silicon atoms to inerease.These results are useful for controlling the probable chemical reaction in SiN_x films under high annealing temperatures and optimizing the fabrication parameters of silicon nanoparticles embedded in SiN_x films.