Consiglio Nazionale delle Ricerche-Istituto per la Microelettronica e Microsistemi (CNR-IMM) Strada VIII n. 5, Zona Industriale, I-95121, Catania, Italy.
Nanotechnology. 2016 Aug 5;27(31):315701. doi: 10.1088/0957-4484/27/31/315701. Epub 2016 Jun 21.
In this paper, nanoscale resolution scanning capacitance microscopy (SCM) and local capacitance-voltage measurements were used to probe the interfacial donor concentration in SiO2/4H-SiC systems annealed in N2O. Such nitrogen-based annealings are commonly employed to passivate SiO2/SiC interface traps, and result both in the incorporation of N-related donors in SiC and in the increase of the mobility in the inversion layer in 4H-SiC MOS-devices. From our SCM measurements, a spatially inhomogeneous donor distribution was observed in the SiO2/4H-SiC system subjected to N2O annealing. Hence, the effect of a phosphorus implantation before the oxide deposition and N2O annealing was also evaluated. In this case, besides an increased average donor concentration, an improvement of the lateral homogeneity of the active doping was also detected. The possible implications of such a pre-implantation doping of the near-interface region on 4H-SiC MOS-devices are discussed.
在本文中，使用纳米级分辨率扫描电容显微镜（SCM）和局部电容-电压测量来探测在 N2O 中退火的 SiO2/4H-SiC 系统中的界面施主浓度。这种基于氮的退火通常用于钝化 SiO2/SiC 界面陷阱，导致在 SiC 中掺入 N 相关施主，并增加 4H-SiC MOS 器件中反型层的迁移率。从我们的 SCM 测量中，观察到在经历 N2O 退火的 SiO2/4H-SiC 系统中存在空间不均匀的施主分布。因此，还评估了在氧化层沉积和 N2O 退火之前进行磷注入的影响。在这种情况下，除了平均施主浓度增加之外，还检测到活性掺杂的横向均匀性得到改善。讨论了这种近界面区域的预植入掺杂对 4H-SiC MOS 器件的可能影响。
