新型高k栅介质HfSiON薄膜的制备及性能研究

Fabrication and Properties of the Novel HfSiON High-k Gate Dielectrics Films

为了替代传统的SiO2栅介质,利用射频反应溅射法在Si衬底上制备了新型HfSiON薄膜。研究了HfSiON薄膜的成分、结构和介电性能。由XRD图谱可知,HfSiON薄膜经900℃高温退火处理后仍为非晶态,显示出良好的热稳定性。MOS电容的高频C-V曲线测量显示,HfSiON薄膜具有较好的介电特性,其介电常数可达到18.9,电容等效氧化层厚度为4.5nm。I-V测量结果表明,HfSiON薄膜的漏电流密度很低,在外加偏压(Vg)为±1.5V处的漏电流密度分别为3.5×10-7A/cm2(+1.5V)和1.5×10-6A/cm2(–1.5V)。研究表明,HfSiON薄膜将会是一种很有希望取代SiO2的新型高k栅介质材料。

HfSiON thin films were prepared on p-type Si substrates by using reactive radio-frequency sputtering deposition. Composition, structure and dielectric properties of the new high-k gate dielectric HfSiON films were investigated. XRD analyses show that the films are amorphous even after annealed at 900 ℃. The capacitance-voltage （C-V） curves of MOS capacitor present that the dielectric constant k of the films is about 18.9 and the capacitance equivalent oxide thickness is 4.5 nm. I-V characteristic exhibits that the low leakage current of 2.5× 10^-7 A/cm^2 and 4.9×10^-7 A/cm^2 at Vg=＋1.5 V and -1.5 V, respectively. The analyses results show that HfSiON films will be a promising candidate for SiO2 gate dielectric .