SrHfON高k栅介质薄膜的漏电特性研究

Growth and Current Leakage Characteristics of SrHfON High-k Gate Dielectric Films

采用射频反应磁控溅射法在p-Si(100)衬底上成功制备出SrHfON高k栅介质薄膜,并研究了Au/SrHfON/Si MOS电容的漏电流机制及应力感应漏电流(SILC)效应。结果表明,MOS电容的漏电流密度随N2流量的增加而减小。在正栅压下,漏电流主要由Schottky发射机制引起;在负栅压下,漏电流机制在低、中、高栅电场区时分别为Schottky发射、F-P发射和F-N隧穿机制。同时,Au/SrHfON/SiMOS电容表现出明显的SILC效应,经恒压应力后薄膜在正栅压下的漏电流由Schottky发射和F-P发射机制共同作用,且后者占主导地位。

The SrHfON high-k gate dielectric films,deposited by RF reactive magnetron sputtering on p-type Si（100）substrates,were used to fabricate the Au/SrHfON/Si MOS capacitor.The impacts of the growth conditions on the leakage current density were evaluated with X-ray photoelectron spectroscopy and conventional proves.The leakage current conduction mechanisms and the stress induced leakage current（SILC）effect of the MOS capacitor were studied.The leakage current density of the MOS capacitor was found to decrease with an increase of N2 flow rate.At a positive bias of the metal gate,the leakage current mainly originated from Schottky emission,but at a negative bias,the leakage current in the low-,medium-and high-gate voltage ranges resulted from Schottky emission,Poole-Franel（F-P）emission and Fowler-Nordheim（F-N） tunneling,respectively.In addition,the SILC effect was found to dominate the Au/SrHfON/Si MOS capacitor;but after being stressed by a constant voltage,Schottky emission outperforms F-P emission in generating the leakage current.