NH_3等离子体处理钝化层致Ge MOS界面特性的改善  

Improved Interfacial Properties of Ge MOS Capacitor by Treating Passivation Layer with NH_3-Plasma

作　　者：罗权[1] 徐静平[1] 刘璐[1] 程智翔 黄勇[1] 刘晓宇[1] 

机构地区：[1]华中科技大学光学与电子信息学院,武汉430074

出　　处：《微电子学》2017年第3期429-432,共4页Microelectronics

基　　金：国家自然科学基金资助项目(61274112)

摘　　要：制备了以TaYON作为钝化层,以HfTiON作为高k栅介质的Ge MOS电容。研究了NH_3和N_2等离子体处理TaYON对界面特性的影响。结果表明,N_2和NH_3等离子体处理可以有效改善器件的界面及电性能,其中,NH_3等离子体处理的效果更好,可获得更高的k值(25.9)、更低的界面态密度(6.72×10^(11) eV-1·cm^(-2))和等效氧化物电荷密度(-9.43×10^(11) cm^(-2)),以及更小的栅极漏电流(5.18×10^(-5) A/cm^2@V_g=1V+V_(fb))。原因在于NH3等离子体分解产生的N原子或H原子以及NH基团能有效钝化界面附近的悬挂键和缺陷态,防止GeO_x低k界面层的形成,N原子的结合也增加了介质的热稳定性。Ge MOS capacitors with TaYON as passivation layer and HfTiON as high-k gate dielectric were fabricated, and the impacts of NH3-and N2-plasma treatment of the passivation layer on the TaYON/Ge interface were investigated. Experimental results showed that the NH3-and N2-plasma treatments could improve the interracial and electrical properties of devices, with the former better than the latter： a large k value （25.9）, a low interface-state density （6.72×10^11 eV-1·cm^-2 ）, an equivalent oxide-charge density （- 9.43×10^11 cm^-2 ）, and a low gate leakage current density （5.18 × 10^-5 A/cm2 @Vg = 1 V＋Vfb）. The involved mechanism lied in the fact that N or H atom and NH ridicals decomposed from the NH3 plasma could effectively play a role in passivating the interracial defects and dangling bonds, thus preventing the formation of low-k GeOx interlayer, and increasing the thermal stability of the dielectric due to N atom incorporation.

关 键 词：高K栅介质 等离子体处理 表面钝化 界面层 

分 类 号：TN386.1[电子电信—物理电子学]