Papers by Keyword: SSRM

Paper TitlePage

Authors: Craig A. Fisher, Romain Esteve, Stefan Doering, Michael Roesner, Martin de Biasio, Martin Kraft, Werner Schustereder, Roland Rupp
Abstract: In this paper, an investigation into the crystal structure of Al-and N-implanted 4H-SiC is presented, encompassing a range of physical and electrical analysis techniques, with the aim of better understanding the material properties after high-dose implantation and activation annealing. Scanning spreading resistance microscopy showed that the use of high temperature implantation yields more uniform resistivity profiles in the implanted layer; this correlates with KOH defect decoration and TEM observations, which show that the crystal damage is much more severe in room temperature implanted samples, regardless of anneal temperature. Finally, stress determination by means of μRaman spectroscopy showed that the high temperature implantation results in lower tensile stress in the implanted layers with respect to the room temperature implantation samples.
411
Authors: John Österman, Srinivasan Anand, Margareta K. Linnarsson, Anders Hallén
663
Authors: Katerina Tsagaraki, Maher Nafouti, Herve Peyre, Konstantinos Vamvoukakis, Nikolaos Makris, Maria Kayambaki, Antonis Stavrinidis, George Konstantinidis, Marianthi Panagopoulou, Daniel Alquier, Konstantinos Zekentes
Abstract: Different methods for cross-section characterization of SiC Trenched-singly-implanted vertical junction field effect transistors (TSI-VJFETs) are presented with the purpose to determine the epitaxial structure in terms of doping topography.
653
Authors: Ryoji Kosugi, Yuuki Sakuma, Kazutoshi Kojima, Sachiko Itoh, Akiyo Nagata, Tsutomu Yatsuo, Yasunori Tanaka, Hajime Okumura
Abstract: We have tried to fabricate a super junction (SJ) structure in SiC semiconductors by the trench-filling technique. After the deep trench formation by dry etching, epitaxial layer is grown over the trench surface. Doping profile of the embedded p-type epitaxial region between the trenches is evaluated by a scanning spreading resistance microscopy (SSRM). The SSRM result reveals that the doping profile is not uniform and there exists a low concentration region along the trench side-wall. Based on the SSRM result, two-dimensional device simulations are performed using pn-type test structures with the non-uniform SJ drift layer. The simulation result shows that blocking voltage of the test structure can be optimized and becomes comparable to that of the ideal one by adjusting the concentration design of the embedded layer to balance the total charge in SJ structure.
785
Authors: Lukas K. Swanson, Patrick Fiorenza, Filippo Giannazzo, Fabrizio Roccaforte
Abstract: This work reports on the morphological, structural and electrical effects of a nitrous oxide (N2O) ambient post-oxidation annealing (POA) of the SiO2/4H-SiC interface. In particular, a conventional electrical characterization of MOS capacitors showed that nitrous oxide POA reduces the presence of both fixed oxide charge and the density of interface states. A local atomically flat interface was observed by transmission electron microscopy with only a moderate step bunching observed at a macroscopic scale. A novel nanoscale characterization approach via scanning spreading resistance microscopy resolved local electrical changes induced at the SiC surface exposed to N2O POA. This result subsequently revealed additional insight into the mechanism for the improved device performance subjected to N2O POA treatment.
719
Authors: Lukas K. Swanson, Patrick Fiorenza, Filippo Giannazzo, S. Alessandrino, S. Lorenti, Fabrizio Roccaforte
Abstract: This work reports on the morphological, structural and electrical effects of a nitrous oxide (N2O) ambient post-oxidation annealing (POA) of the SiO2/4H-SiC interface. In particular, a conventional electrical characterization of MOS capacitors showed that nitrous oxide POA reduces the presence of both fixed oxide charge and the density of interface states. A local atomically flat interface was observed by transmission electron microscopy with only a moderate step bunching observed at a macroscopic scale. A novel nanoscale characterization approach via scanning spreading resistance microscopy resolved local electrical changes induced at the SiC surface exposed to N2O POA. This result subsequently revealed additional insight into the mechanism for the improved device performance subjected to N2O POA treatment.
715
Authors: Rudolf Elpelt, Bernd Zippelius, Stefan Doering, Uwe Winkler
Abstract: Computer-Aided-Design for the prediction of the technology process and the physical device properties (TCAD) is a key tool for the development and improvement of new device concepts as well as for the analysis and understanding of device properties and device behavior under application conditions. Apart from physical device models and parameters the precise process simulation of implanted doping profiles is mandatory for a sufficient prediction quality of the subsequent device simulations. In order to verify and improve the accuracy of process simulation, we employ the – for silicon carbide – relatively new method of Scanning Spreading Resistance Microscopy (SSRM) for the characterization of doping profiles.
295
Authors: K. Kojima, A. Nagata, S. Ito, Y. Sakuma, R. Kosugi, Yasunori Tanaka
Abstract: We performed deep trench filling by using epitaxial SiC growth. It was found that the trench filling condition depend on trench width. A high growth temperature was needed to fill a narrow trench and a low growth temperature was needed to fill a wide trench structure. We optimized the filling condition and successfully filled 7μ m deep and 2 μm wide trench without void formation. We also investigated the 2D doping distribution of the filled area by SSRM. As a result, it is found that the existence of a sub-trench was related to the generation of a doping distribution in the filled area. The trench filling mechanism and doping distribution are discussed.
793
Authors: Naohiro Sugiyama, Yuuichi Takeuchi, Mitsuhiro Kataoka, Adolf Schöner, Rajesh Kumar Malhan
Abstract: The migration enhanced embedded epitaxy (ME3) mechanism and 2D dopant distribution of the embedded trench region is investigated with the aim to realize the all-epitaxial, normally-off junction field effect transistor (JFET). We found that the embedded growth consists of two main components. First one is the direct supply without gas scattering and the other one is the surface migration supply via the trench opening edge, which dominate the ME3 process. An inhomogeneous 2D distribution of Aluminum (Al) concentration was revealed for the first time in the 4H-SiC embedded trench regions by the combined analysis of secondary ion mass spectrometry (SIMS) and scanning spreading resistance microscopy (SSRM) results. The maximum variation of Al concentration in the trench is estimated to be about 4-times, which suggests that the Al concentration is highest for the (0001) plane and lowest for the trench corner (1-10x) plane. Al concentration in the (1-100) plane, which determines the JFET p-gate doping level is 1.5-times lower than (0001) plane for trench region fabricated on Si-face wafers.
171
Showing 1 to 9 of 9 Paper Titles