Center Director: Kohei M. Itoh (Professor, Faculty of Science and Technology)
Primary location: Shin-Kawasaki Town Campus (K2)
Center Overview
TCAD (Technology Computer Aided Design) is a research field that contributes to the elucidation of physical phenomena in semiconductors and the development of the semiconductor industry by predicting semiconductor device performance through process and device simulations based on physical and chemical models. Researchers from Keio University have significantly contributed to its development. To lead its further advancement as a fundamental academic discipline and its application in industry, the TCAD Research and Development Center is established as a contract research base jointly funded by multiple private companies. This center serves as a hub for TCAD researchers within Keio and fulfills its mission as the core of a TCAD collaboration network, promoting cooperation with TCAD researchers from participating companies. To promote TCAD research and development in the fields of semiconductor physics and semiconductor engineering, the center brings together researchers in a collaborative framework between academia and industry. In particular, to advance TCAD technology, we will create an environment where TCAD researchers from participating companies and researchers within Keio can interact closely.
Furthermore, the center will engage in activities to connect researchers from public research institutions like AIST and domestic universities with participating companies, building a framework for R&D using TCAD through industry-academia collaboration. It will also expand the TCAD user base by extending its application to fields other than semiconductors (e.g., nuclear engineering, space engineering, biochemistry, pharmacology, and medical sciences), and will provide educational opportunities in semiconductor physics for students by using TCAD as a practical teaching tool in universities. Ultimately, these research outcomes will be provided to participating companies as TCAD systems, contributing to the development of domestic industries.
Keywords and Main Research Themes
TCAD, physics, chemistry, applied physics, electrical engineering, mechanical engineering
Fiscal Year 2018 Business Plan
■Regarding activities continuing from the previous fiscal year: background, rationale, and goals for continuation
As an applied development of our fundamental technologies, we plan to apply domain decomposition calculations to structures similar to actual commercial devices.
Specifically, with the goal of further scaling up, we will increase the number of devices and incorporate the structure of peripheral circuits to improve convergence and reduce calculation time using domain decomposition techniques.
To this end, we will investigate a matrix solver compatible with GPU (Graphics Processing Unit) computing technology. We also aim to achieve practical levels of speedup in GPU-compatible Monte Carlo ion implantation simulation technology.
Meanwhile, for physical models of SiC, we will investigate physical models within SiC substrates. Specifically, we are considering the introduction of SiC defect models and the investigation of impurity diffusion models in SiC.
■New activity goals, content, and implementation background for fiscal year 2018
To improve the simulation accuracy of SiC power devices, we will introduce physical models that account for external influences such as stress, thermal, and electromagnetic fields on the power devices. For this purpose, we will develop co-simulation technology using the API functionality of a multiphysics-compatible simulator and a TCAD simulator.
Furthermore, to speed up large-scale analysis, we will consider introducing parallel and distributed processing technology in addition to refining the domain decomposition technique. We also aim to expand the functionality of the TCAD simulator to accommodate applications to other power devices.
Fiscal Year 2018 Business Report
■Implementation details for the fiscal year's business plan, research results, and degree of achievement
We conducted research and development on large-scale, large-domain, and ultra-high-speed simulations. We also developed functionalities not available in commercial TCAD simulators. Specific results are shown below.
Large-scale, large-domain, ultra-high-speed domain decomposition technology: A test case of a vertical MOS 36 (6x6) cell array with peripheral structures can now be calculated collectively using the domain decomposition method. Hybrid mesh generation technology: By introducing a composite mesh of cubes and cuboids instead of the conventional orthogonal mesh, we reduced the number of mesh points to 1/8, calculation time to 1/13, and memory usage to 1/6, enabling large-scale, large-domain calculations. Monte Carlo ion implantation simulation using GPU (Graphics Processing Unit): Using GPU technology, we achieved a 100-fold speedup in the calculation time for ion implantation simulation on a Si substrate compared to a single CPU. The prediction accuracy of the impurity concentration distribution was almost identical to that of conventional calculations, thus achieving a significant speedup.
API (Application Programming Interface) functionality: The introduction of API functionality has made it easier to incorporate physical models and computer science technologies that are difficult to handle with commercial simulators. We enhanced the semiconductor physical models, including physical models for SiC, small-signal analysis, piezoresistance models, thermal conductivity models, and specific heat models. We also improved calculation control functions, such as the convergence judgment function, control of Newton's method, and calculation time control.
Improved accuracy of diffusion models: Added implanted impurity species (F, C, N, Al). Added physical information to the diffusion model. Improved accuracy by increasing the number of variables for impurity diffusion calculations (from 8 to 30).
Documentation improvement: Improved usability by creating maintenance procedure manuals and program explanation documents.
TCAD Academic Council activities: For 50 domestic universities and public research institutions, we provided licenses for a new TCAD simulator with API functionality and held training sessions for users. This facilitated the expansion and introduction of new physical models, thereby expanding the user base and creating opportunities for student education.
■Number of published papers (count and major journal names), number of conference presentations (domestic/international), and achievements in social contribution such as events (date, location)
Number of conference presentations: 9 (domestic)
June 6, 2018: Held a user council and research meeting (TCAD Academic Council) for the TCAD simulator at the Shin-Kawasaki Town Campus (K2), attended by 50 domestic universities and public research institutions.
■Notable achievements through the center's activities
As a result of contract research, released TCAD systems (6 times) to partners within Keio and contract research companies: HyENEXSS V8.0K–HyENEXSS V8.5K.
Announced the release of the TCAD simulator with new features to members of the TCAD Academic Council, which led to the further expansion of TCAD software use (increase in users) at domestic research institutions and in different fields beyond semiconductor physics (particle physics, space engineering, catalytic chemistry, computer science).
As a result of joint research, we were able to add functionalities that could not be handled by commercial TCAD.
Project Members
Principal Investigator
Kohei M. Itoh
ProfessorFaculty of Science and Technology, Department of Applied Physics and Physico-InformaticsHideharu Amano
ProfessorFaculty of Science and Technology, Department of Information and Computer Science